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Pilot-Scale Nutsche Filter Testing for Successful Scale-Up

Posted on September 30, 2026

Perform Nutsche Piloting Studies Before Scaling Up Filtration

It Starts in the Laboratory

Pope Scientific 4L Benchtop Nutsche with Agitator

Pope Scientific 4L Benchtop Nutsche with Agitator

In fine chemical and pharmaceutical development labs, several process steps are typically combined to build a high-purity processing scheme. When the final product is a solid, a powder, for instance, the scheme usually includes a filtration and washing step, often right after a reaction that produces crystals, followed by drying. Common lab-scale equipment for this includes fritted glass funnels, membrane filter holders, Gooch crucibles, Hirsch funnels, and most commonly — Büchner funnels. Once a lab-scale process is working well, the next goal is scaling it up to production.

Use Caution in Moving From Lab to Production

Jumping straight from lab to production is rarely practical. What works at lab scale often doesn’t hold up at larger scale, a result of nonlinearity and other “factors of scale”: greater heat-exchange demands, different volume-to-surface-area ratios, longer mass-transfer distances, and more. For high-purity solid-liquid filtration at production scale, the standard equipment is a nutsche filter-dryer — most often an agitated nutsche filter-dryer (ANFD) — a fundamentally different design from a Büchner funnel. That gap in equipment design makes an intermediate step between lab and production even more necessary.

Why Pilot Work Matters

Production equipment like ANFDs requires major capital investment, so getting the specification right is critical. Pilot studies conducted before final equipment selection reduce that risk: they generate data for right-sizing the equipment and help identify any special nutsche functions or design features the production application may need. Because a pilot nutsche is compact, testing with small quantities of high-value product also saves significant cost compared to trials on full-size equipment — and it lets a team produce small batches for final product testing or customer samples. So which equipment is suited for pilot-scale nutsche work?

Benchtop Nutsche Filter-Dryers Bridge the Gap Between Lab and Production

A nutsche filter is a cylindrical stainless steel vessel fitted with a filter screen and support plate spanning nearly the full diameter of its bottom head. Pope Scientific’s Benchtop Nutsche Filter-Dryer (BNFD) is a miniature version of a production nutsche system, built with the same core features and design as its full-scale counterparts: 316L stainless steel construction as standard, ASME- and CE-certified pressure and vacuum ratings, jacketed heating and cooling, a raising/lowering agitator with a full-diameter angled blade, sight glasses, a spray nozzle, process valves, bottom drain, pressure/vacuum gauge, and a pressure relief device. Just as important, both share single-vessel product isolation — protecting operator safety with hazardous materials, preserving product purity, and minimizing handling.

None of this exists in simple lab apparatus like a Büchner funnel. A Büchner relies on vacuum alone to drive liquid through the solids, capping the available differential pressure at about 1 bar. A nutsche vessel, by contrast, can be pressurized — at 3 bar, for example, it provides three times the driving force, pushing liquid out faster. The pressurizing gas is typically dry, clean nitrogen, which keeps the system isolated for purity and eliminates oxygen exposure when product reactivity is a concern. A spray nozzle and agitator wash the cake far more efficiently, and with much less handling, than a glass spatula and squirt bottle. And because the vessel can heat and agitate under vacuum, the cake dries efficiently without the solids ever leaving the vessel.

This is what makes moving directly from lab apparatus to production equipment so difficult and risky — and why the data captured with these features is what makes accurate production-equipment sizing possible. The result is a powerful pre-production tool for filtration research, process development, and pilot plant work, one that also supports established operations: teams can trial a wide range of parameters on small quantities of material, without the cost and disruption of a full production run. A BNFD trial can be run on the equivalent of 50 grams or less of finished product, versus 50 kilograms or more for a production nutsche run. Some Pope customers have production runs worth $1 million in finished product — which puts into perspective the cost savings of experimenting on a BNFD instead of a full production run.

How Nutsches Function

Operation begins with charging the nutsche with a solid-liquid slurry, by gravity or pressure transfer — often directly from a reactor where high-purity crystals have just precipitated. The vessel is then pressurized (usually with nitrogen) to force the liquid filtrate through the screen and out the bottom drain, leaving a wet filter cake on top of the screen. The cake can be washed with fresh solvent from a top-mounted spray head, then re-pressurized with the agitator running, so residual impurities are carried out of the cake along with the wash solvent; this step can be repeated as needed. The washed cake is then dried in the same vessel under vacuum, heat, and agitation — the blade is slowly rotated, with periodic raising and lowering through the cake, to improve drying efficiency. Rotating in one direction digs up and churns the solids, breaking up lumps; rotating in the other smooths and levels the cake to prevent channeling and promote even drying. Once the solids are sufficiently dry, the nutsche is opened and the material harvested; if this is the final process step, the dried product is ready for packaging and inventory.

Pope 4L Benchtop Nutsche components open

4L Benchtop Nutsche, Disassembled

Operating Parameters Are Numerous — Test Them During Piloting

Given all of the above, a nutsche run can be operated across a wide range of parameters, including: the volume of the initial slurry charge (and any subsequent charges during the run); solids concentration in the slurry; the pressure used to drive out the liquid; agitator RPM and the frequency and speed of its raising and lowering; number of wash cycles; drying temperature; vacuum level; filter pore size; and others. Looking at some of these:

  • Pressure level. Increased pressure generally forces liquid filtrate out faster, but depending on the nature of the solids, a point may be reached where this becomes counterproductive — forcing particles together and packing them into the filter pores, much like a traffic jam, and blocking the liquid flow path. This is difficult to predict and requires experimentation. Vacuum can also be used to pull filtrate downward, depending on the application. Always stay within the pressure and temperature ratings of the nutsche vessel and its jacket.
  • Slurry volume. The nutsche should be charged with a slurry volume no greater than the nominal volume of the vessel, and no greater than the quantity that results in a cake depth exceeding the upper height of the agitator blade. Depending on solids concentration, more than one charge may be fed to the vessel, but the same cake-depth guidance still applies. (For more information, see the Pope Nutsche Cake Depth Chart, Rev. 7.)
  • Washing routine. Washing can be performed with or without cake agitation; agitation is normally more effective, though this too depends on the application. This, along with the number of wash cycles, is ideally determined during pilot experimentation.
  • Drying routine. Higher temperature generally speeds cake drying, but it should not exceed a level that risks thermal degradation of the product. A gradual temperature ramp helps avoid overheating solids near the jacketed vessel wall early in the drying cycle. During pilot trials, experimenting with different rotational speeds and with the periodicity and reversal of raising and lowering helps optimize operation. Drying often passes through a “sticky point,” where the solids form tough, rubbery clumps that require high torque to handle — another phenomenon best studied during piloting, before production scale-up. Piloting may also reveal that a small, controlled leak of nitrogen through the filter cake, particularly if preheated, assists drying.
  • Filter pore size. This is a critical parameter that often receives too little attention during process development and becomes “locked in” once production operations begin. Because of its importance, it’s treated separately below.

Establishing Filter Pore Size

Stainless Mesh Nutsche Filter Discs

Stainless Mesh Nutsche Filter Discs

Pope’s default BNFD filter pore size is 20 microns (20 µ), which performs well across a range of applications, though not all. Stainless steel filter screens are available from 1 to 200 µ, plus special membranes down to 0.1 µ or smaller. These BNFD screens are relatively inexpensive; however, customers often purchase only the default size, or perhaps just one other filter with the initial purchase, which limits their ability to test different pore sizes during piloting. In many cases, a pore size is chosen simply because it “worked okay” in early discovery-lab experimentation; in others, a pore size much smaller than the particle size is chosen to minimize yield loss, “just to be safe.” That choice can then carry straight through into production equipment and rarely gets revisited. Because production-scale screen assemblies are expensive to replace, and because SOP changes meet resistance, filter size often goes unexamined even after the nutsche becomes a significant throughput bottleneck — yet a different screen size can cut processing cycle time significantly and improve profitability. Some customers have cut their filtering time in half simply by switching to a different filter screen.

A related assumption involves particle size itself. Average particle size is often estimated rather than measured; a team member mentions a “likely” size in a meeting, and over time it becomes gospel. Analytical equipment is available that can measure particle size accurately — not just the average, but the range and tightness of the distribution. Getting these measurements, whether in-house or through an outside lab, is strongly recommended. Other factors also affect filtration performance, including particle hardness, changes in particle size during processing, surface tension, packing behavior, and angle of repose. With so many variables in play, filtration performance can be hard to predict from theory alone. A Pope Benchtop Nutsche Filter-Dryer equipped with a set of four, five, or more filter pore sizes can provide real-world, assumption-free data to guide the decision.

Pope Standard BNFDs Are Stocked, Custom Systems Also Offered

Pope 100L XP Nutsche with Agitator

Pope 100L XP Nutsche with Agitator, Rotatable

Pope keeps BNFDs in stock, in sizes from 1 to 5 liters, for delivery typically around three weeks. A rent-to-own program is also available as an alternative to outright purchase. Units can be ordered as a nutsche alone or as a turnkey system with matching cake agitator, jacket heating/cooling circulator, and vacuum pump. Larger nutsches for pilot or production use are stocked in 25-, 50-, and 100-liter sizes. Pope also specializes in custom production and pilot plant nutsche systems, designed to suit a wide range of customer requirements and preferences, including special instrumentation and automation, harvesting isolation, mounting styles such as vessel lifting and rotation, additional certifications, internal coatings, and alternate alloys such as Hastelloy.

Contact Pope About Your Filtering and Process Equipment Applications

Let’s discuss which Benchtop Nutsche or larger-scale configuration may be the right fit for your application. If your process calls for a custom Nutsche design, Pope can also work with you to develop a configuration tailored to your specific requirements.

For more information, see the Pope Nutsche Cake Depth Chart.

Pope also offers a range of process equipment for additional processing needs, including lab-, pilot-, and production-scale reactors and vessel systems, fractional column and wiped-film distillation and evaporation systems, and automated, multifunction, skid-mounted turnkey processing systems.

Everything You Need To Know about Nutsche Filter Dryers

Posted on July 31, 2026

Everything You Need To Know about Nutsche Filter Dryers

When you’re working with a pharmaceutical API that took months to synthesize, the yield is small and the material is irreplaceable. Moving it through filtration, washing, and drying without losing a single milligram to contamination or sloppy transfers is not guaranteed with standard lab equipment. This is exactly the situation agitated nutsche filter dryers were built for.

Most Agitated Nutsche filter dryer (ANFD) content online is written for industrial engineers managing throughput at commercial scale. This post is for the researcher or process chemist working at lab, kilo lab, or pilot scale, where every gram matters and purity is non-negotiable. Here’s how ANFDs work, what to look for in a design, and why choosing the right manufacturer makes all the difference.

 

 

How Do Agitated Nutsche Filter Dryers Work?

An Agitated Nutsche filter dryer is a closed, pressure- and vacuum-rated vessel that combines filtration, washing, re-slurrying, and drying into a single contained unit. The name comes from the German word “nutsche,” meaning suction filter. Modern agitated designs have evolved far beyond this initial concept. ANFD filtration follows a six-part basic process sequence:

  1. Slurry is introduced into the vessel.
  2. Pressure applied from above drives liquid rapidly through the filter cake.
  3. Spray assemblies deliver wash solvent evenly across the surface, cleaning the bed in place across multiple cycles.
  4. The cake is broken up and re-slurried with fresh solvent; this is an optional step for applications requiring higher purity.
  5. Drying occurs under vacuum, pulling residual solvent from the bed at reduced temperature and protecting thermally sensitive materials.
  6.  The agitator breaks up the cake and then smooths it, preventing cracks from forming and allowing for even drying throughout.

From slurry transfer to dry product, the vessel remains closed. Meaning no contamination risk, less cleaning validation, and minimal room for operator error.  

In some specialized applications, the liquid coming through is the product itself. The nutsche retains unwanted solids while the clarified liquid passes cleanly through, making the filter dryer equally useful for recovery and clarification workflows.

 

Agitated Nutsche Filter Dryers Benefits in Laboratory and Pilot Settings

Small-scale labwork presents a unique set of pressures. A 1-liter benchtop unit needs to perform every function a 200-liter pilot unit can handle, in less space, often operated by a single person, with no margin for error.

At lab and pilot scale, the material being processed is frequently extraordinary in terms of cost and scarcity. A few percent yield loss from poor cake washing or incomplete drying can translate to significant financial loss or months of setback. This is also where process development decisions get made. Whatever works at lab scale tends to define what the final commercial process looks like, which means getting it right here has downstream consequences.

Pope Scientific stocks a standard benchtop line designed specifically for high-purity applications:

  • 1L (4″ diameter) filters for early-stage development and small-batch synthesis.
  • 3L, 4L, and 5L (6″ diameter) filters for kilo lab and pilot applications requiring more throughput.

Common applications at this scale include pharmaceutical APIs and HPAPIs, biomaterials, electronics-grade intermediates, fine specialty chemicals, and catalyst recovery. All units over 3L are ASME stamped and arrive pre-fitted with valves, sight glasses, pressure relief, spray assemblies, and pressure/vacuum gauges, so setup time is minimal and the unit is ready to run. Rental options are also available for one-time projects or proof-of-concept work, removing capital commitment as a barrier to getting started.

 

Nutsche Filter Core Process Capabilities

A special 5 Liter Bench Top sized Nutsche Filter Dryer with side discharge valve for contained material handling

Pressure-assisted filtration is one of the ANFD’s key advantages. By pressurizing the vessel from above, liquid is driven through the filter cake faster than vacuum drainage alone can achieve. This matters enormously for compressible or slow-filtering slurries, and Pope units can be rated to 200 psi to handle demanding filtration profiles.

Vacuum drying at reduced temperature protects thermally sensitive materials that cannot withstand conventional drying conditions. Jacket heating or electric heating on smaller units, combined with deep vacuum, removes residual solvent without degrading the product. The in-place spray assembly allows even, multi-cycle cake washing without disturbing the bed or opening the vessel, which delivers a meaningful improvement in final purity. Gas blanketing with an inert atmosphere protects oxygen- or moisture-sensitive materials throughout the process.

The agitator is what separates an ANFD from a simple pressure filter. Raising and lowering the agitator breaks up clumps, exposes fresh surface area, shortens drying time, and can even enable controlled cake harvesting through a side discharge valve. Pope standard Nutsches utilize an open harvest design; however contained discharges can be designed into any unit.

 

 

How Pope Scientific Approaches Agitated Nutsche Filter Dryer Manufacturing

Many ANFD vendors take a catalog-first approach: here are the standard sizes, choose the one that fits closest to your process. Pope works in the opposite direction. The process comes first, and the unit is designed around it.

Pope’s deep history in laboratory and pilot-scale equipment means our engineering team has encountered process problems that off-the-shelf designs simply cannot solve. That experience has produced a range of design innovations worth knowing about:

  • Mid-body flanges allow the vessel to separate partway up, keeping the cake fully contained in the lower section during harvesting for cleaner, lower-loss discharge.
  • Removable basket designs let the entire cake be lifted out in a contained insert, which is especially valuable for fragile or adhesive products that would be damaged by conventional discharge.
  • Rotating and tilting vessel configurations address drying profiles and harvesting requirements that a fixed orientation cannot accommodate.
  • S-blade cake agitators dig into the cake, smooth the surface, and drive discharge through a side valve, combining the drying and harvesting steps into one continuous operation.
  • Custom containment systems, including flexible and rigid isolator options and glove box interfaces, provide the operator protection required for HPAPI and cytotoxic workflows.

Funnel heads, powder containment stands, custom alloys, and specialty coatings are all available as well. We will engage with the process problem before specifying a product.

The Nutsche Application Questionnaire is the best starting point for that conversation.

 

 

Agitated Nutsche Filter Dryer FAQ

  • What does “Nutsche” mean?
    • Nutsche comes from the German word for suction filter. The name reflects the ANFD’s origins as a simple vacuum-driven filtration vessel before agitation, pressure capability, and drying functions were incorporated into modern designs.
  • What solvents can be processed in an Agitated Nutsche filter dryer?
    • Most common process solvents can be handled, including alcohols, ketones, hydrocarbons, halogenated solvents, and aqueous systems. Material selection for seals, gaskets, and wetted surfaces is matched to the specific solvent to ensure compatibility.
  • How long does a typical Agitated Nutsche filter dryer cycle take?
    • Cycle time varies widely depending on slurry volume, cake thickness, solvent type, and drying requirements. A lab-scale cycle might run two to eight hours, while more demanding drying profiles or multi-stage washing can extend that significantly.
  • How do I know what size Nutsche filter dryer I need?
    • Batch volume and filter area requirements are the primary drivers. We can help narrow down the right configuration based on your slurry volume, filtration rate, cake depth, and desired cycle time. 
  • Can Nutsche filter dryers be used under GMP conditions?
    • Yes. ANFD units can be designed and documented to meet GMP requirements, including surface finish specifications, material traceability, and cleanability standards. 
  • What documentation and certifications come with a Pope Nutsche filter dryer?
    • Standard units include ASME pressure vessel certification. Additional documentation such as material certifications, weld records, surface finish reports, and factory acceptance test records can be provided based on project requirements.

 

Pope Scientific: The Industry’s Leading Custom Agitated Nutsche Filter Dryer Provider

For researchers and process chemists working with materials where yield, purity, and containment are paramount, an Agitated Nutsche filter dryer is the best tool for the task. Pope Scientific combines decades of lab-scale expertise with the engineering flexibility to build units that fit your process rather than the other way around.

Contact us to discuss your application and find the configuration that fits your work.

When To Switch from Glass Short-Path to Wiped-Film Distillation and How To Calculate the ROI

Posted on June 30, 2026

When To Switch from Glass Short-Path to Wiped-Film Distillation and How To Calculate the ROI

If your batch queue is backing up, your operators are running stills around the clock, and yield inconsistencies are starting to creep into your product, it’s time to make a change. The question most production managers face at this stage is whether to add another glass short-path unit or make the jump to wiped-film distillation. The answer almost always comes down to throughput, and there is a clear volume threshold where wiped film stops being a nice-to-have and becomes the only financially sound choice.

The Benefits and Drawbacks of Glass Short-Path Distillation

Short Path Diagram

Glass short-path distillation serves an important function in the lab. The upfront cost is low, the learning curve is manageable, and for R&D work or small-batch production it performs exactly as intended. It’s a reliable option for small-batch production.

The structural limitations, however, are baked into the format. Glass short-path runs in batch mode, which means every cycle requires manual setup, teardown, and cleaning before the next one can begin. Throughput tops out at roughly one to two liters per hour per unit. Operators need to be present and attentive throughout each run, and fragility becomes a growing concern as run hours accumulate. At a small scale, these are acceptable tradeoffs. As demand grows, they become the bottleneck.

How To Know When It’s Time To Switch to Wiped-Film Distillation

To determine whether you should switch to wiped-film distillation, look at your volume.

  • ~2–4 L/hr combined capacity: You’re likely running 2–3 glass short-path units in parallel. Labor costs are multiplying, not throughput.
    • Verdict: Not yet a hard switch, but start planning. You’re approaching the ceiling, and adding a fourth short-path unit is likely becoming uneconomical.
  • ~5 L/hr threshold: The logistical overhead of managing multiple batch stills (scheduling, cleaning, operator hours) begins to cost more than the equipment itself.
    • Verdict: This is the tipping point. At 5 L/hr, the economics of wiped film begin to outpace stacking more short-path units.
  • Beyond 5 L/hr: A single Pope pilot-scale wiped-film molecular still that’s operating in continuous mode can match or exceed the output of an entire short-path array, with less labor and more consistent purity.
    • Verdict: Switch. Continuing to scale short-path beyond this threshold is operationally unsustainable and leaves significant revenue on the table.

Pope’s wiped-film systems scale from 2-inch lab units through 4-inch and 6-inch pilot configurations to full production, so you can step up methodically as demand grows rather than committing to large leaps before you’re ready. The right unit size depends on your target throughput, and our team can helpyou map the path from where you are to where you need to be.

The Operational Advantages of Wiped-Film Distillation at Scale

Wiped Film Diagram

When production volume justifies the move to wiped-film distillation, the operational advantages are clear.

  • Continuous operation: feed in, distillate out; no batch cycles means no downtime between runs.
  • Consistent purity: the wiped-film mechanism creates a thin, uniform evaporation layer, reducing heat exposure to seconds and minimizing thermal degradation, which is critical for heat-sensitive compounds.
  • Reduced labor per liter: once dialed in, wiped-film systems require less hands-on operator time per unit of output.
  • Cleaner separations: lower operating pressures (high vacuum) enable separation of compounds that batch short-path cannot resolve.
  • Process reproducibility: critical for regulated industries (pharma, food-grade, cGMP) where batch-to-batch consistency is a compliance requirement.

For separations that push beyond what a standard wiped-film system can resolve, Pope also offers a hybrid still option that combines wiped-film evaporation with short-path distillation in a single unit, giving operators additional flexibility for the most demanding applications.

ROI Analysis: Calculating the Payback Period

The ROI framework for this decision is straightforward. On the short path side, add up the cost of the units you are running, your operator labor across a full year, consumables and breakage replacement, and the revenue you are leaving behind because throughput has hit its ceiling. On the wiped film side, pilot-scale Pope systems start at $100,000, with training and process integration included in the equipment cost. Installation fees apply for large-scale equipment, but not for standard configurations.

The payback formula is simple: take the capital cost and divide it by monthly savings in labor and consumables plus the revenue gain from higher throughput. For an operation running four liters per hour across three short path stills and switching to a single wiped film unit, payback typically falls in the range of twelve to twenty-four months depending on the value of the product per liter. Our toll processing service lets you validate those throughput economics before committing capital.

Are You Ready To Switch from Short Path to Wiped Film Distillation?

Wiped Film Diagram
If you are unsure whether your operation has crossed the threshold, this checklist can help you reach a decision.

  • Are you running more than two short path stills to keep up with demand?
  • Is your cost-per-liter increasing as you add units?
  • Are you losing batches to thermal degradation or inconsistency?
  • Do you need to meet cGMP or food-grade documentation standards?
  • Is your product valued high enough per liter that yield improvement pays quickly?

If two or more of these questions apply to your operation, the economics and the operational evidence are both pointing in the same direction, and it is time to talk to Pope about wiped-path distillation.

Upgrade to Wiped Film Distillation Equipment with a Trusted Provider

Glass short path distillation is the right starting point for many operations, but it is not built to carry production indefinitely as demand scales. The throughput ceiling, labor demands, and batch-mode limitations that are manageable at low volume become compounding costs as output requirements grow, and you will eventually reach a tipping point where adding more short path units stops solving the problem.

Pope Scientific offers the full range of support you need to make that transition with confidence, including lab testing services, toll processing, process development, and wiped film systems sized for every stage of growth across multiple applications. Whether you are approaching five liters per hour of production or already past it, the right system and the right expertise are available to move your operation forward.

Contact Pope Scientific to discuss your throughput goals and find out which wiped film solution fits where you are headed.

Beyond Recycling: How Pope Scientific Equipment Enables Next-Generation Battery Upcycling

Posted on May 14, 2026

Beyond Recycling: How Pope Scientific Equipment Enables Next-Generation Battery Upcycling

The Growing Demand for Lithium-Ion Battery Technology

Lithium-Ion Battery (LIB) technology has become increasingly important in recent years with the growth of electric vehicles and several other markets requiring LIB power. Many improvements are being made in technology, but rechargeability lifetimes for many batteries remain limited to typically 10-15 years.

Lithium-Ion Battery Recycling and Material Sourcing

The majority of these batteries utilize a cathode lattice layer consisting of Nickel, Manganese, and Cobalt (NMC), in addition to Lithium. With age, the composition and structure of NMC changes, resulting in lower energy apacity.  One reason for this is the gradual decline in Nickel (Ni) percentage in the cathode.  This lower-energy material is known as NMC111, and it is a major factor in LIB lifetime. 

However, these materials are expensive, subject to sourcing risk, and present pronounced health and environmental hazards for end-of-life disposal.  For these reasons, the technologies for effective, economic lithium battery recycling have become as important as those for original manufacturing.

Lithium Ion Battery Cross Section Diagram

Recycling schemes entailing crushing and completely separating each of the materials into their individual starting forms and using them for remaking batteries nearly “from scratch” have been found to be impractical. Most current approaches involve partial separations of used batteries and renewal of intermediate contents such that the subsequent and final steps of making new batteries from intermediates result in finished items equal or close to brand new products. This process is increasingly referred to as battery upcycling. 

Lithium Battery Diagram

Lithium Battery Diagram

One upcycling approach for this involves battery deconstruction, grinding of cathode material into very small particles and increasing the relative level of Ni via a precipitation reaction onto NMC particles while suspended in a turbulent chemical reactor. This renewed material is designated as NMC622. (After reaction processing, several steps are required, including re-fusing and annealing together of these particles at 800-1000°C, and forming renewed cathode films which are sandwiched together with other material layers and electrolyte in the fabrication of upcycled LIB’s).

Battery Particle Materials

Continuous Stirred Tank Reactors (CSTRs) for Battery Upcycling Processes

Pope Scientific equipment has a role to play in this process in the design and manufacturing of specialized reactors. Continuous stirred tank reactors (CSTR’s) are used, rather than batch reactors, as they are optimal for the process plus are scalable to large industrial production requirements.  R&D lab and pilot-scale systems have been made and utilized for various clients, including Argonne National Laboratory.

The process involves a slow, continuous feed into the stirred reactor of a solution NMC111  cathode particles suspended in solvent. Simultaneously, Sodium Hydroxide (NaOH) and Nickel Sulphate (NiSO4) solutions are also fed in at tightly controlled feed rates at stoichiometric ratios.  These two chemicals react and precipitate, forming a Nickel Hydroxide (Ni(OH)2) layer onto the surface of the cathode particles in motion. The reaction also causes the pH to change, thus to keep it constant, a buffer must also be added to the reactor.  Finished product slowly discharges from the reactor via an upper overflow port.  This continuous reaction may be run from several hours to several days. Later in the overall upcycling process during annealing, the Oxygen and Hydrogen are driven off from the deposited (Ni(OH)2), leaving behind elemental Nickel enriched in ratio, bringing the cathode material up to “like new” NMC622 specifications.

Critical Process Controls for CSTR Reactor Performance

The CSTR requires the following automation for proper, optimized operation:

  • Control of reactor temperature via vessel jacketing and a thermal fluid heating/cooling circulator with PID setpoint
  • Control of feed rates of cathode suspension, reactants, and buffer via pressurized vessels, flow control valves and flowrate sensors in individual PID control loops
  • Control of pH via pH probe, buffer pump and PID control loop
  • Control of agitator speed
  • Controls for vessel pressurization
  • A PLC control system for control of the above plus data logging

The photo shows an example of a twin reactor system with two 4-liter 316L stainless steel ASME vessels, automated raising top heads, custom agitators and baffling, thermal circulators, pressurized vessels, piping, and the control instrumentation described above. Pope Scientific routinely produces customized reactors such as this example to meet the wide range of specialized needs of researchers and production groups at companies and institutions worldwide.

Pope Twin Reactor System

Twin 4L Reactor System with PLC for battery materials R&D

Processing Equipment for Lithium-Ion Battery Manufacturing and Upcycling

Turnkey 12” Molecular Still with Degassing Stage System, Corner View

Turnkey 12” Molecular Still with Degassing Stage System, Corner View

Lithium-ion battery manufacturing and upcycling involve other processes where Pope Scientific equipment is utilized.  For example, there are many materials and formulations used in R&D and production of batteries that need to be concentrated or distilled.  Pope’s Wiped Film Evaporators (WFE) and Wiped Film Molecular Stills (WFMS) are particularly useful when materials are thermally sensitive and may partially decompose if processed with other, conventional, still equipment.  When high purity is paramount, Pope’s Fractional Column Distillation Systems are utilized in either batch or continuous mode designs.

 Electrolyte and Specialty Chemical Processing

For Lithium battery R&D and small lot runs, many organizations require a variety of different Lithium electrolyte solutions, many of which are custom formulations.  Manufacturing these materials is very difficult and dangerous and is thus usually best left to specialized vendors who are equipped and experienced in the practice.  This type of manufacturing requires reaction vessels equipped for accurate feed, dissolving, and blending for a variety of different liquid and solid ingredients, which change for each product run. 

Pope designs and manufactures such systems in a range of sizes, custom-engineered for safe, isolated handling of the corrosive and hazardous materials, incorporating complex instrumentation and control elements, piping, and automation.  Special “Safety PLC” systems with redundant SIL certification and componentry, multistep batching programmability, recipe storage, and other features are required for accurate and safe batch manufacturing.

Pope 350 Liter Nutsche

100L XP Nutsche Filter Dryer with Cake Agitator and Rotating Stand

100L XP Nutsche Filter Dryer with Cake Agitator and Rotating Stand

Solid-Liquid Separation in Battery Upcycling

Another application in battery and electronic materials manufacturing involves reactions where crystallization and precipitation occur near the end, creating slurries of solid particles suspended in solution. The crystals are often solids of high purity requiring post-reaction processing. 

Pope’s Nutsche Filter-Dryer systems are designed for this purpose.  Slurry is fed into a Nutsche, where filtrate liquid is efficiently passed through a large diameter bottom filter disc under vessel pressure.  The resulting solids filter cake is then washed with rinses of fresh solvent for increased purity and then dried in the same vessel under heat, vacuum, and churned with a rising/lowering/rotating full-diameter blade agitator.  

This process is utilized in many industries, including pharmaceuticals, biochemicals, ultra-pure fine chemicals, electronic materials, and others.  Pope manufactures Nutsche Filter-Dryer systems from lab bench scale to pilot plant and production scale, in stainless steel and Hastelloy construction.

 

Integrated Equipment Solutions for Lithium-Ion Battery Manufacturing

Pope Scientific brings decades of specialized engineering expertise to the rapidly evolving lithium-ion battery industry, offering an integrated portfolio of equipment solutions that address critical stages of both battery manufacturing and upcycling. 

From precision CSTR reactor systems for cathode material renewal, to wiped film evaporators, fractional distillation systems, electrolyte blending vessels, and Nutsche Filter-Dryers, Pope’s capabilities span the full process chain. 

As the demand for sustainable battery technology continues to accelerate, Pope Scientific remains committed to providing the custom-engineered, high-performance systems that researchers, developers, and manufacturers need to advance next-generation energy storage solutions.

Contact us to discuss your lithium-ion battery processing requirements or to explore a custom-engineered solution.

The Ultimate Guide to Wiped Film Distillation: Efficiency, Purity, and Performance

Posted on March 9, 2026

The Ultimate Guide to Wiped Film Distillation: Efficiency, Purity, and Performance

In the world of chemical processing, heat is a double-edged sword. While it is necessary to drive evaporation, it can also be the greatest enemy of your product. For many high-value materials, such as essential oils, vitamins, cannabis extracts, and specialty polymers, traditional distillation methods often lead to “thermal degradation,” essentially cooking the very molecules you are trying to purify.

This is where Wiped Film Distillation becomes the industry gold standard. By combining high vacuum with a specialized wiping mechanism, wiped film distillation allows for the gentlest separation possible.

What is Wiped Film Distillation?

Wiped Film Distillation (also known as Short-Path or Thin-Film Distillation) is a specialized technique designed to separate volatile from less-volatile components under high vacuum.

Unlike batch distillation, where a liquid boils in a flask for hours, wiped film distillation is a continuous process. The liquid material is spread into a very thin, highly turbulent film on the inner wall of a heated cylinder. This thin film creates a massive surface area, allowing molecules to evaporate in a matter of seconds.

The Pope Difference: Since 1976, Pope has pioneered this technology. Our unique diagonally slotted wiper design does more than just move liquid; it creates “micro-mixing” and turbulence. This ensures every molecule is treated equally and moves rapidly through the system, preventing the “stagnant spots” common in lesser equipment.

How Wiped Film Distillation Works: The Step-by-Step ProcessEvaporation & condensation WFS

  1. Feed Introduction: Material is continuously fed into the heated vacuum chamber.
  2. Thin Film Creation: Rotating wipers spread the liquid to a thickness of roughly 0.1 to 0.5 mm on the heated wall.
  3. Rapid Evaporation: Under high vacuum, boiling points are significantly lowered. Volatile components vaporize almost instantly.
  4. The Short Path: The vapor travels a very short distance (often just centimeters) to an internal condenser located in the center of the chamber.
  5. Separation: Purified “distillate” and “residue” exit through separate outlets, ready for collection or further processing.

Why “Wiped Film” Beats Batch Distillation

If you are currently using traditional “Batch” or “Short Path” glassware setups, wiped film distillation offers three game-changing advantages:

  • Residence Time: In a batch still, your product might sit at high heat for 4–8 hours. In a Pope Wiped Film Still, the residence time is measured in seconds.
  • Lower Temperatures: Our systems can maintain extreme vacuum levels. This allows you to distill high-boiling materials at temperatures far below their normal boiling point, saving the integrity of the molecule.
  • Scalability: While batch setups are limited by flask size, WFD is continuous. You can run 24/7, moving from lab-scale (2″) to pilot-scale (4″ or 6″) and up to industrial production without changing your process chemistry.

Wiped Film Applications: Who Uses This Technology?

From flavor chemistry to aerospace materials, wiped film is the workhorse of high-purity processing:

  • Nutraceuticals: Isolating Omega-3 fatty acids, Vitamin E (tocopherols), and essential oils.
  • Cannabis & Hemp: Creating “water-clear” distillates by removing chlorophyll, waxes, and heavy lipids.
  • Polymers: “Stripping” leftover monomers and solvents from resins or medical-grade silicones.
  • Fine Chemicals: Purifying high-value fragrances, flavors, and cosmetic ingredients.

Choosing Your System: Glass vs. Stainless Steel

At Pope, we offer flexibility depending on where you are in your journey:

  • Glass Systems (R&D): Ideal for labs and R&D. The borosilicate glass allows you to see the process, watch the film formation, and adjust parameters visually.
  • Stainless Steel Systems (Production): 316L Stainless Steel is more robust and offers double the processing capacity of glass due to its superior thermal conductivity.
  • Hybrid Systems: For the most difficult separations where components have very close boiling points, our Hybrid Still combines a Wiped Film Evaporator with a fractional column for unmatched purity.

Elevate Your Purity

Whether you are a startup looking for your first 2″ benchtop system or a global manufacturer requiring a multi-stage turnkey skid, the goal remains the same: maximum purity with minimum degradation.

Wiped Film Distillation isn’t just an equipment choice; it’s an investment in the quality of your final product.

Ready to see what Wiped Film Distillation can do for your process? Explore Pope Wiped Film Distillation Equipment or Contact our Engineering Team today to discuss your specific application.

Wiped Film Still Stainless Steel Conversion Kits

Posted on April 8, 2025

Wiped Film Still Stainless Steel Conversion Kits

Pope Scientific offers standard 2”, 4” and 6” Wiped-Film Still systems fabricated with 316L stainless steel in addition to glass. These Wiped-Film Stills not only offer a more robust construction, but also allow you to process at greater feed-rates. Stainless-steel has a greater thermal conductivity coefficient than borosilicate glass. This provides more than double the processing capacity for a still of the same size. In addition, 4” and 6” stainless steel internal condensers have high surface area due to a multiple vertical tube design, allowing yet additional throughput

For customers with existing all-glass stills, Pope’s 316L SS conversion kits, are available. These consist of a stainless-steel body and internal condenser plus all the necessary adapters and clamps to re-attach the existing glass components. Pope recommends that operators be experienced with the Wiped-Film Stills in glass, with their greater process visibility, before switching over to stainless steel.

Pope still systems in all sizes are also available in totally stainless-steel fabrication for continuous, industrial duty. These are typically skid-mounted turnkey systems, and can be of multi-stage, once through design and with optional advanced PLC control. Contact us to discuss your specific application requirements.

Pope 6" Wiped-film Molecular Still with Glass

Pope 6″ Wiped-Film Molecular Still with Glass

Pope 6″ Wiped-Film Molecular Still with Stainless Steel

 

 

Scale Up Your Oil Purification with Pilot-Scale Wiped-Film Molecular Stills

Posted on February 26, 2025

Scale Up Your Oil Purification with Pilot-Scale Wiped-Film Molecular Stills

As demand grows for new formulations and increased purities of oils and fats, bridging the gap between lab research and industrial production has become more critical than ever. Pilot-scale molecular stills are the perfect solution if you’re looking for oil purification equipment​—a logical bridge between the lab bench and the production floor. They allow for creating drums of customer samples, meeting material demands, and serving as accurate testing and scale-up tools for large-scale commercialization projects. Whether you’re refining edible and essential oils, bio-based materials, or specialty extract distillates, these molecular short-path distillation systems are designed to meet your unique purification needs, from customer validation to compliance with cGMP, all while enabling the development of new and improved products.

Why Choose Molecular Stills for Purifying Oils and Fats?

Pope 6" Stainless Steel XP Wiped Film Molecular Still Pilot Plant System

Pope 6″ Stainless Steel XP Wiped Film Molecular Still Pilot Plant System

Wiped Film Molecular stills excel at purifying oils and fats due to their ability to separate heat-sensitive, high-boiling-point compounds without degradation. This is achieved through optimized designs featuring high-vacuum continuous operation, which decreases boiling temperatures, and efficiently wiped evaporation surfaces, which limit heat exposure to mere seconds. The results include greater yield and purity, as well as product separations and creations not possible by any other means. Importantly, this continuous-mode technology does not require chemical additives, preserving the integrity of natural products. This is particularly important for applications such as:

  • Edible Oils: Removing contaminants and improving yield, flavor, and shelf life.
  • Essential Oils and Fragrances: Commercial essential oil distillation equipment​ preserves aromatic compounds while ensuring purity.
  • Bio-Based Materials and Specialty Chemicals: Achieving high-purity end products for advanced applications.

Real-World Impact: Purifying Oils with Pope Wiped Film Molecular Stills

At Pope Scientific, we’ve collaborated with companies worldwide in the oils and fats industries to optimize their purification processes. For example, a specialty oil producer sought to remove undesirable compounds to meet FDA compliance while preserving the delicate flavor profile of their products. By utilizing Pope’s expert testing and tolling services and investing in a Pope pilot-scale molecular still system, they achieved:

  • Higher purity, yield, and appearance with no thermal degradation or flavor shift.
  • Scalability for larger production runs, including reduced energy consumption and material costs.
  • Market expansion with new premium-grade and customized flavor products.

Stepping Beyond Molecular Stills with Pope Hybrid Still System Technology

4” Stainless Steel Hybrid Wiped-Film Distillation

Multi-column design allowing for mid-column feed. Discreet controls and manual operation.

For applications involving compounds with multiple components close in boiling point, a greater degree of separation of heat-sensitive materials is required than molecular distillation alone can provide. For these situations, Pope has developed Hybrid Stills, combining the gentle wiped-film evaporation technique with the high-resolution separation power of multi-theoretical-plate fractional columns. These oil purification equipment​ systems deliver sharper separation cuts for feed materials. Examples include:

  • Customizing flavor variations in citrus, mint, and other oils.
  • Fine separation of C-14, C-16, and C-18 peaks in FFA and FAME for optimal yield and purity.
  • Concentrating DHA, EPA, and other Omega-3 esters from fish or fermented oils.

Prove Your Concept with In-House Lab Trials

  • Proof-of-concept validation with your material, plus determination of the optimal still system design.
  • A pathway to outsourcing through Pope’s toll processing services before your equipment delivery.
  • Actionable knowledge for experimenting, piloting, and operating your own equipment

Why Choose Pope Scientific?

With over 50 years of experience, Pope Scientific has been a trusted partner for companies looking to elevate their distillation processes. Our solutions for purifying oils and fats cater to industries including foods, flavors, fragrances, vitamins, supplements, cannabinoids, terpenes, waxes, botanical extracts, surfactants, monoglycerides, triglycerides, cosmetics, biofuels, and many other oils and derivatives. Our equipment and services offer:

  • Customizable Solutions: Tailored to meet your specific needs.
  • Proven Performance: Trusted by leading companies worldwide and validated for cGMP processing.
  • Exceptional Support: From process development to installation and beyond.

Take Your Process to the Next Level
Ready to scale up your oil purification process? Discover how pilot-scale wiped-film stills from Pope Scientific can help you achieve your goals. Contact us today to schedule an in-house lab trial and take the first step toward production success!

Utilizing Pope Scientific Wiped-Film Distillation for Medical Silicone Purification

Posted on November 21, 2024

Utilizing Pope Scientific Wiped-Film Distillation for Medical Silicone Purification

 

Pope Scientific: Leaders in Advanced Distillation Technology.

Pope 2 stage 12" Wiped Film Still

Pope 2 stage 12″ Wiped Film Still

Pope Scientific is a global leader in equipment and technology for the distillation of materials that are high in heat sensitivity, boiling

point, molecular weight, and/or viscosity. The company’s Wiped-Film Molecular (Short-Path) Stills are internationally recognized and utilized across a wide range of industries, including pharmaceuticals, foods, flavors, cosmetics, oils, vitamins, lubricants, specialty chemicals, polymers, and other high-value products.

The success of these distillation systems in such applications is attributable to their design features, which incorporate high vacuum, high-efficiency wipers that agitate and transport a thin film of continuously pumped feed material. This material undergoes short (seconds) residence time through a heated zone, where the more volatile components are evaporated and condensed in close proximity. The result is a high-purity, non-degraded product.

Applications in Polymers

Pope’s distillation technology is highly effective in processing various types of polymers, such as acrylics, latexes, isocyanates, epoxies, fluoropolymers, and silicones. Common goals in these applications include devolatilization, degassing, solvent removal, and the distillation of unwanted monomers, dimers, and other contaminants from the higher molecular weight product. In some cases, the monomers or shorter chains are distilled as the end products, with the heavier residue stream being a byproduct.

Silicones targeted for high-performance use must meet higher purity standards than commodity grades. This often requires enhanced devolatilization using molecular stills. Achieving these purity levels demands greater vacuum levels, carefully controlled temperatures, and multi-stage distillation strategies. Pope’s equipment and process expertise make it a trusted partner for the silicone industry. High-grade silicones are critical in applications such as specialized encapsulants, adhesives, and lubricants, with medical applications being among the most stringent. In medical-grade silicones, it is particularly vital to eliminate harmful components, such as cyclic siloxanes.

Medical Applications and Silicone Purification

Several years ago, significant issues arose in the use of silicone in breast and other implants. Patients experienced severe health problems, sometimes long after implantation. One cause was the migration of smaller chain silicone molecules and other insufficiently removed materials, leading to complications. Molecular distillation to achieve greater purity was a key solution to this problem. Pope’s technology played a significant role in resolving these issues.

Pope’s Wiped-Film Stills have also been instrumental in producing ophthalmological materials. Vitreous humor, the gel-like fluid filling the space between the iris and retina, may require replacement in certain medical conditions or traumas. A small number of European specialty vendors manufacture artificial vitreous humor fluids, often formulated with silicone. The development and processing of these fluids were conducted in Pope’s testing and tolling labs, enabling companies to procure molecular stills for use in their facilities.

Other ophthalmological applications for Pope’s equipment include materials for artificial corneas (keratoprostheses), which are implanted into patients who are not candidates for human donor transplants. While silicone is used in some cases, other polymers are also applied. Pope’s distillation equipment is also employed in the production of materials for contact lenses, eyeglasses, and UV inhibitors.

Biomedical Silicone Purification

Other Medical and Pharmaceutical Applications

Pope’s technology has been critical in refining medical materials such as artificial heart valves, aortic repair sleeves, polymers for severe burn treatments, suture formulations, dental cement, and various implanted devices and prostheses. Additionally, Pope distillation equipment is widely used in the production of pharmaceuticals, vitamins, and dermatological creams and ointments.

For more information or to discuss your silicone application, contact us today.

How it Works: Wiped Film Molecular Cannabinoid & Terpene Distillation

Posted on August 28, 2024

How it Works: Wiped Film Molecular Cannabinoid & Terpene Distillation

 

Wiped Film Molecular Distillation

The Pope Difference in Cannabinoid Purification and Terpene Distillation

Pope Wiped-Film Molecular Stills are a special type of short-path distillation equipment. These are continuous mode systems, as opposed to simple batch mode boiling flask stills (the latter often referred to as “short-paths”, though ironically, these are not truly short path designs as discussed in the next paragraph). The diagram below of the cannabinoid distillation purification process illustrates the means of this technology and shows the flow of the feed material and the separation of component fractions within the equipment. This same purification process and equipment can be used for various cannabinoid distillation such as the processing of CBD, THC, THCV, CBG, CBT, CBN, CBC & others.

In wiped film processes, feed material is delivered from a feed flask or a pump into the inner wall of a vertical cylindrical evaporation section, heated from the outer wall, (either electric resistance or circulating hot fluid jacket type).   Internally, rotating diagonally slotted wipers force liquid around and downward in as highly turbulent, thin film on the inner wall.  The moving liquid is heated via conduction through the wall. During the quick journey downward, lighter (lower boiling point) fractions of the liquid begin to vaporize.  Heavier residue material (Chlorophyll, large lipids, salts, sugars, heavy wax fractions), does not evaporate and continues the travel down the full length of the still body, falling into a residue receiver flask or discharge pump.

Cannabinoid Purification
Within the evaporation body there is a vertical internal condenser positioned central, parallel, and close to, the full length of the cylindrical evaporation surface, providing a short path for evaporated vapor molecules traveling from the heated surface to the condenser surface. For cannabinoid distillation, the internal condenser fluid must be kept elevated (~70°C) to prevent high viscosity or freeze-up of the condensed THC, CBD, and other component vapors.

Due to the optimized, continuous Pope equipment design, this all happens with high evaporation efficiency and within a number of seconds, (instead of hours of high-temperature exposure in batch type “short-paths”), and under vacuum-lowered temperatures, thus minimizing any possibility of product degradation.

Prior to the cannabinoid distillation pass through the wiped film still, there is a first pass in which terpenes and any other lighter end components are removed by distillation from the feed material and collected as a distillate.  The terpenes and other light components can be condensed in the internal condenser and an optional external condenser.  The residue from this pass is collected in a different flask or vessel until all the feed material has been depleted.  The residue contains the cannabinoids and heavy compounds and this fraction will then be fed through the still again as a second pass as has been previously described.  This first pass boosts the cannabinoid percentage and decreases the volatility of the feed material such that the cannabinoid distillation pass will behave better, resulting in optimized purity and yield.

While cannabinoids are caught and collected by the internal condenser, a different, external condenser, maintained at a chilled temperature, can capture terpenes (which are lighter than cannabinoids). The terpene isolate is then collected in another, separate receiver flask. Depending on the composition of the feed material and the goals of the operator some quantities of terpene isolation are obtainable which can be very useful for various product formulations. Any remaining vapors which escape both the internal and external condensers and which may contain small amounts of solvents, water, or lighter terpene components, are collected in a cold trap maintained at an ultra-low temperature. The trap serves the purpose of maintaining lowered vacuum levels in the still system and protecting the vacuum pump from contamination from the light vapors.

It is important to maintain a steady feed rate, body temperature, and vacuum level. In the standard glass molecular still systems, feed rate and vacuum are maintained manually. Pope also offers positive displacement feed pumps, automatic flow rate controllers, automatic vacuum controllers, and other advanced features including product discharge pumps, multiple in-series staged still unit skid mounted systems, and computer/PLC control. As clients’ product production requirements increase, Pope can assist with technology consistent throughout the product line, allowing straightforward process equipment scale-up. Equipment for processing 24/7 at more than 200 kg/hr is offered, well more than sufficient for any cannabinoid application!

The Molecular Background:

Wiped-Film still technology takes advantage of the fact that each chemical substance has a characteristic vapor pressure. It is this relative difference in vapor pressures that dictates how easily a complex compound can be separated into its constituent components.

Since the molecules of all matter are in constant motion in varying degrees, depending upon the chemical composition of that matter and the temperature and pressure applied to it, molecules near the surface tend to escape into the surrounding atmosphere. As temperature increases and pressure decreases, this escaping tendency usually increases, and the substance is said to vaporize.

The force generated by these escaping molecules is referred to as the vapor pressure of that material at a particular temperature and pressure. It is the relative difference in vapor pressure of substances that dictates how easily a complex compound can be separated into its constituent compounds.

How the Wiped-Film Still Works:

The Pope Wiped-Film Still consists of a heated body into which a fluid system requiring some degree of separation is continuously fed. The fluid is spread into a thin film by a rotating wiper blade assembly driven at a predetermined speed. The film, while being forced into turbulent flow by the wiper blades, progresses down the inside body wall aided by gravity and the slots in the wiper blades.

Have any further questions on short-path distillation? Contact us for further information!

Pope Wiped Film Diagram

Wiper blade moves each plug of material around and downward.

Thin films are created in Pope Wiped-Film Stills for a variety of reasons:

  • Turbulence and micromixing created by a rapidly moving diagonally slotted blade greatly assist in heat transmission, thereby lowering the temperature required on the inside evaporator wall for a given system pressure.
  • A maximum resulting surface area per unit volume of flow is generated, facilitating rapid, efficient evaporation.
  • The liquid exposure time to the elevated wall temperature can be controlled and completed within a matter of seconds. This minimizes product degradation of heat-sensitive materials by controlling the wiper assembly speed.
  • Pope diagonally slotted wiper blades promote plug flow with little back mixing and direct motion both circumferentially and downward. This minimizes dwell time distribution, ensuring that material flowing through the system has a uniform exposure to process conditions.

Keys To The Success Of Pope Scientific’s Wiped-Film Stills

Posted on July 30, 2024

Keys To The Success Of Pope Scientific’s Wiped-Film Stills

Distillation is one of the most important means of separation and purification of liquids in chemical processing. In a mixture of different chemicals, the various components will have differing characteristics, including physical properties such as levels of volatility.  A component with greater volatility than another (or “lighter” than the other), will boil at a lower temperature than the other. If the mixture is maintained at a temperature in between the boiling points (BP) of two components, the lighter component will vaporize while the heavier component(s) will not. If a surface (condenser), is placed in the vapor space and is kept cooler than any of the boiling points, the vapor will condense and can be collected as a liquid distillate with a composition having a greater percentage of the lighter component. The BP’s can be reduced by lowering the prevailing pressure, thus vacuum conditions are often used.

For simple molecules such as low molecular weight solvents, the temperature and the duration of the time of exposure to elevated temperature is typically not critical, in other words, prolonged boiling times, will not degrade these chemicals due to their thermal stability.  However, there exist chemicals of very high BP’s and molecular weights (MW) that are prone to chemical degradation by cracking, reacting or polymerizing.  These cannot survive the required elevated boiling temperatures for extended periods. The degradation effect is enhanced with increased temperatures, but often overlooked is the effect of the duration of time of the exposure to heat, which when extended, can cause far more degradation than the temperature level itself.

For these delicate materials, a special distillation technique is required.  The technique must include; provision for a very short period of heat exposure, a highly efficient mechanism to allow sufficient evaporation to occur within this short period, and high vacuum capability to reduce the extreme boiling points of the components.  Pope wiped-film stills are specially designed to include these and other important features.

Wiper Diagram

Wiped-Film Distillation Process

Wiped-Film Distillation Process

Feed liquid is continuously fed onto the inner wall of a heated vertical cylinder where it is immediately spread evenly as a thin film by rotating wipers around and down the cylinder.  The wipers are specially designed with diagonal slots, each of which causes a highly turbulent micro-mixing of the film. This dynamic causes a high degree of mass and heat transfer to take place, quickly heating the liquid and greatly increasing the effective surface area of the liquid-vapor interface, necessary for allowing the more volatile molecules to escape and vaporize rapidly from the liquid, (as opposed to being held back from reaching the interface by significant depths of liquid as is the case in, for example, a batch mode boiling vessel).  It is this efficiency that allows even high percentages of volatiles to evaporate within a matter of only seconds of travel in the cylinder.  The less volatile, heavier components don’t evaporate and remain as a liquid, leaving quickly out of bottom of the heated cylinder as residue.

Heated walls (orange) and high vacuum (yellow) drive the more volatile components (distillate) to the closely positioned internal condenser as the less volatile components (residue) continue down the cylinder. The resulting fractions from high vacuum distillation separate, and then exit through individual discharge outlets. Depending on the application, the desired product is either the distillate or the residue fraction. Small amounts of condensable low MW compounds collect in cold trap upstream of the vacuum system. For high solvent loads, an optional external condenser may be installed immediately.

The success of the wiped film technique is further enhanced by other special design features including capabilities of high temperatures to beyond 300°C and high vacuum down to 0.001 torr, a requirement for high boiling point distillates.  The high vacuum capability also allows substantial reduction in evaporation temperatures.  Yet another important design feature positions condensers a close distance from the evaporation surfaces, reducing pressure drop at high vacuum, allowing increased vapor transport efficiency and thus increased throughput through the still system. All is accomplished within an average pass through the system measured in seconds, decreasing thermal product degradation by levels of magnitudes compared to other distillation techniques.   Plus, the design allows for a straightforward scaleup from lab to pilot to production scale.  In addition to equipment provision, Pope has hands-on experience via our toll distillation, process development and testing services.  You can rely on Pope to work with your team from concept to commercialization!

Understanding Cannabis Distillate and Pope Scientific’s Wiped Film Distillation Equipment

Posted on July 11, 2024

Understanding Cannabis Distillate and Pope Scientific’s Wiped Film Distillation Equipment

What is Cannabis Distillate? Cannabis distillate is a highly refined form of cannabis extract, known for its purity and potency. It typically contains 80-95% cannabinoids, making it ideal for various products like edibles, vape cartridges, and topicals. This distillation process removes impurities and unwanted compounds, resulting in a clean and versatile product.

Steps Involved Before Distillation

  1. Extraction: Cannabinoids are extracted from the cannabis plant using solvents such as ethanol or CO2.
  2. Winterization: The crude extract is mixed with ethanol and chilled to remove fats, waxes, and lipids.
  3. Decarboxylation: The extract is heated to convert inactive cannabinoids (like THCA and CBDA) into their active forms (THC and CBD).

Wiped-Film Distillation Technology Pope Scientific’s wiped-film distillation equipment is renowned for its efficiency and precision in producing high-quality cannabis distillate. Here’s how it works:

  • Thin Film Formation: The cannabis extract is continuously fed onto a heated surface where it forms a thin film. This thin film allows for rapid and uniform heating, ensuring that cannabinoids are efficiently separated from other compounds.
  • Wiping Mechanism: A mechanical wiper or roller spreads the extract into a thin film and moves it along the heated surface. This enhances the evaporation rate and ensures even exposure to the heating element.
  • Vacuum Application: The distillation process occurs under vacuum, which lowers the boiling points of the cannabinoids. This allows for the separation at lower temperatures, preserving the integrity and potency of the cannabinoids.
  • Condensation: As the cannabinoids evaporate, they are immediately condensed on a cooled surface and collected as purified distillate.
  • Multiple Passes: For achieving the highest purity, the distillate can undergo multiple passes through the wiped-film apparatus, further refining the product with each pass.

Advantages of Pope Scientific’s Wiped-Film Distillation Equipment

  • High Efficiency: Maximizes cannabinoid yield and purity with minimal thermal degradation.
  • Precision Control: Advanced temperature and vacuum controls optimize the distillation process.
  • Scalability: Suitable for various production scales, from small labs to large industrial facilities.
  • Robust Design: Durable construction ensures long-term reliability and performance.

Pope Scientific’s wiped-film distillation technology is trusted by industry professionals to deliver consistent, high-quality cannabis distillate. This equipment’s precision and efficiency make it an indispensable tool for producing top-tier cannabis products.

For more information, contact Pope. 

Optimize Lab-Scale Purification with Pope Scientific’s Benchtop Nutsche Filter Dryers

Posted on July 8, 2024

Optimize Lab-Scale Purification with Pope Scientific’s Benchtop Nutsche Filter Dryers

Pope Scientific leads the way in laboratory separation equipment with its proven Benchtop Nutsche Filter Dryers. These compact units have been a staple in laboratories for years, offering researchers a powerful tool for testing, piloting, and small-scale processing.  Pharma, fine chemicals, cannabinoids, electronics, and specialty materials are just a few of the many applications.

Transition From Lab Büchner Funnels to Industrial Operations

Pope’s fully enclosed sanitary design provides numerous advantages over the traditional, open Buchner funnel apparatus. Materials are contained and isolated from the user for maintenance of purity and safety. Featuring ASME-certified pressurizability, filtering, and cake washing is faster than via vacuum. Drying of the solids is also performed in the nutsche, e

fficiently accomplished under vacuum and jacket heating, plus a raising/lowering cake agitator to break up lumps and churn the solids.  This is the same operation as industrial nutsches, but smaller!

In-Stock and Ready for Action!

Pope’s Benchtop Nutsche Filter Dryers are stocked in 1, 3, 4, and 5-liter sizes.  All come pre-tested and pre-fitted with essential components including valves, sight glasses, pressure relief, spray assembly, pressure/vacuum gauge, and a manual with a full documentation package.

Custom Nutsches Too!

In addition to stocked units, Pope specializes in custom-designed lab, pilot, and production nutsches in a wide range of sizes, features, and functionality, and are optimized to meet clients’ processing needs and preferences.  We have your solution – contact us!