Pope Scientific Inc. was founded in Milwaukee, WI, in 1963 for the purpose of providing a variety of apparatus to laboratories and pilot plants. There were a large number of product lines that were created, changed, and diversified over the years. By the mid 1990s, the product mix had fallen into the broad categories of Distillation, Vessel Systems, Cryogenic Dewars, and Toll Distillation Processing Services. While this breakdown remains, the various lines have evolved and advanced in size, complexity, technology, and application scope.

The Distillation line falls into Fractional Column Stills, (batch and continuous mode) and Wiped Film Stills (WFS), consisting of two main types: Wiped Film Molecular (short-path) Stills (WFMS), and Wiped Film Evaporators (WFE), both types being continuous mode. WFMSs are particularly useful when a component being distilled away is high in boiling point, molecular weight, and heat sensitivity, requiring not only high vacuum but also short heat exposure residence time. WFEs are utilized for driving off large percentages of solvents, taking the place of rotary evaporators and falling film stills, but excelling especially in very heat sensitive applications.

In 1975, Pope had started offering glass lab and pilot scale WFS units in 2”, 4”, and 6” sizes, based on designs established in the early 1950s. This required application assistance and testing of clients’ materials and thus Pope became not only equipment providers but also a company relying on and gaining experience and depth in technology and applications in many industries — basically any liquids requiring separation and being heat sensitive. Eventual addition of tolling services enhanced knowledge and system design.


Near completion of a 2X6-inch WFS PLC Control System.


Applications included pharmaceuticals, vitamins, cosmetics, natural extracts, waxes, foods, flavors, polymers, lubricants, bio-based materials, specialty chemicals of all kinds, and many others. In the mid 1980s, stainless steel stills and entire turnkey skid systems started being offered and unit sizes grew, resulting in skid-mounted systems that process up to hundreds of kg/hr. Today, the company is well established and respected worldwide in many industries as a global equipment and technology leader in distillation.

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However, it wasn’t until 2003 that Pope came into contact with its first cannabinoid application customer. This was for CBD concentration from hemp material that was being discarded as waste byproduct from hemp seed oil processing. A retired professor collected the biomass for free, then extracted, distilled, and isolated cannabinoid for sale to pharmaceutical companies at a handsome margin. Later, Pope supplied a university department a lab still for cannabinoid research, but that was it… until late 2014 when inquiries began to trickle in primarily from small scale THC extraction groups. A couple of orders for Pope’s lab scale 2” glass units resulted, and from there, both interest and orders escalated quickly.

At that time, Pope wasn’t actively pursuing the business; instead, marijuana entrepreneurs were seeking greater throughput, continuous mode WFMS systems to replace small batch-type stills, so-called “short paths,” finding Pope by word of mouth and web searches. Pope began active marketing and launched a cannabis-oriented website, popecannabisdistillation.com, separate from the main website popeinc.com, and in late 2016 followed that up with doing cannabis business tradeshows and running its first “Clearly the Best Choice” print and digital ads.

Pope’s WFMS purification technology comes into play after extraction – where desired cannabinoids like THC, CBD, and terpenes are dissolved out of plant material. Extraction has done its job but cannot be used for increasing purity any further. Extraction of high THC cannabis bud trim typically reaches roughly 65 percent total cannabinoid and is a thick opaque brown-black mass that must be kept warm to flow. Fortunately, there are boiling point (BP) differences between cannabinoid and other compounds present, so distillation is utilized to take advantage of that. Light solvents and terpenes are distilled away first, and in a second pass through the still, cannabinoid product gets distilled from heavier materials such as chlorophyll, heavy wax ends, and other botanical compounds that exit as darker, thicker residue. The distillate may reach from mid 80s to low 90s in cannabinoid percentage while becoming a light-mid yellow/amber clear product.


Turnkey Canna WFS with Hot Oil Body Heating


One of the key factors in the high performance of Pope’s WFMS units, besides high vacuum capability, is the diagonally slotted wiper blade arrangement. These wipers are designed to provide optimized thin film turbulence and evaporation efficiency and to not only propel the feed material in a circular path around the inner cylindrical heater surface, but also downwards, resulting in shorter and controllable residence time. Rollers, utilized by several other manufacturers, rely on gravity for the downward motion, are not as efficient and may also fling residue material to the internal condenser, causing contamination. Pope system design also allows incorporation of an external condenser in addition to the internal condenser, allowing greater power and control of terpenes removal and collection.

Compatible with any extraction method (hydrocarbon, ethanol, supercritical CO2, or other means), Pope’s distillation equipment assures high yield, purity, quality, and clarity. Wax removal via winterizing is not required, though without this prior step, greater cleaning and maintenance procedures of the still system will be required, and the product clarity and purity will be reduced. The Pope WFS will also do its job whether or not decarboxylation has been performed, though processing can be trickier without this prior step.

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In nearly every case, wiped film distillation is a multiple pass operation, typically two, but can be three or more. For larger scale industrial operations Pope manufactures multistage, stainless steel, PLC-controlled, fully turnkey systems with flow rates as high as to beyond 150 kg/hr, with the larger scale of equipment being procured primarily by hemp CBD processors. These high throughput production models can have up to four or more stages — providing great flexibility. For example, if there are three stages, the third can be used either for re-distilling the residue (increasing yield) or else re-distilling the distillate (increasing purity). Other approaches allow for more than one devolatilizing pass, often benefiting the overall process and end results. Having four stages also makes it possible to alternately, choose to run two, 2-stage distillations in parallel, doubling the throughput of the still system.


2-, 4- and 6-inch stills being assembled. Left to Right: Dave Block, Joe Vue, Ong Vue.


In these multistage turnkey systems, Pope incorporates vacuum pumps, liquid pumps, external condensers, cold traps, heaters, chillers, and instrumentation for control and monitoring. PLC control systems with large easy-to-use touch screens also provide an advanced data recording and storage feature.

Partly due to the rapid, continued growth in the cannabinoid industry, Pope began to run out of space for manufacturing and for the additional personnel required in all departments of the company. Among other issues, the popularity of Pope’s 2-stage turnkey six-inch 10 kg/hr WFMS systems forced the company to solve the space problem quickly and, in late 2018, additional manufacturing space was leased in a nearby building and dedicated to the turnkey 2x6-inch systems. As a longer-term measure, Pope broke ground in September 2019 to add another 20,000-sq. ft. onto its existing 44,000-sq. ft. facility. In addition to distillation equipment, this new space will be utilized to expand Pope’s offerings of evaporators, nutsche filter-dryers, custom vessel systems, reactors, winterizers, decarboxylation, and crystallization-isolation systems.

Pope Scientific is located approximately 30 minutes north of Milwaukee, Wisconsin, in Saukville. Inside its corporate headquarters you will find administrative, finance, engineering, sales and marketing, QA, electrical, and other departments; several fabrication and assembly areas; a customer training space; a glass blowing operation; shipping/storage, and a fully equipped toll processing, testing, and process development section. All of Pope’s equipment is made, fully tested, and serviced at this facility, and nearly every sub-component is likewise of domestic origin. Spare or additional parts are normally available overnight to locations throughout North America, and within two to three days to most other countries worldwide.

Pope now employs more than 50 staff members, many with scientific, chemical engineering, biochemistry and other technical backgrounds. “Solution Driven” is the company’s tagline with solutions for chemical processing excellence the everyday goal. And with its knowledgebase and experience, Pope Scientific continues to be “The Clear Choice” for cannabinoid purification equipment.