PTD Supporters in Academia

Seridan College, Canada

Pass-through distillation is truly the bioeconomy game changer. It has the ability to de-risk so many next-generation industrial bioprocesses that struggle techno-economically from low product concentrations heading into recovery or their use of finicky organisms. What is best about it is its ingenious yet straightforward application of the laws of thermodynamics.

“I have been working on projects with Ian and his dedicated team from Drystill for the past 4 years. Our collaboration won the York Chapter Professional Engineers Ontario Project of the Year Award for the Small Company category in 2016. The work done at Sheridan entails the use of Drystill’s patented SAM (Stripper-Absorption Module) to implement pass through distillation for separating temperature-sensitive fluids. Pass through distillation is an amazing technology which could be implemented at ambient temperature using cost effective equipment. The lower energy operation is ideal for separating temperature sensitive fluids and will ultimately lead to lower energy costs and greenhouse gas emissions.”

“Distillation is a technology that has been used to separate chemicals since antiquity, however it was not until the 19th century with the emergence of chemical engineering as a discipline that distillation became what we know it as today. Since then, considerable advancements have been made but have fallen short of being revolutionary, until now. Conventional distillation accounts for roughly 50% of the total energy used for all industrial processes worldwide. The energy requirements to perform distillation have severely contributed to our carbon footprint, but with distillation being an integral unit operation in countless industrial processes, it cannot cease to exist. A radical change must be brought forth to prevent irreparable damage to our planet, and pass-through distillation is the breakthrough we have been waiting for. With the ability to save over 50% of energy costs associated with performing distillation, PTD may be the chemical industry’s only saving grace. By making advancements in pass-through distillation, we are laying the foundation for a healthy future.”


   University of Toronto, Canada

BradSeville headshot
 Dr. Bradley A. Saville
University of Toronto

Dr. Saville is a Professor of Chemical Engineering and Applied Chemistry at the University of Toronto, with specific expertise in bioprocess technology, biofuels and renewable energy systems, industrial applications of enzymes, economics, and life cycle analysis. He has been a technical advisor and consultant to various Government agencies and to several organizations that produce biofuels and biochemicals. In addition, Brad is a Consultant and Director for Chemical Engineering Research Consultants Ltd, and Founder/Principal of Savant Technical Consulting. He is a published co-author of a number of scientific books and articles.

Pass Through Distillation has the capability to transform the way Process Engineers and Manufacturers approach thermal separation of complex aqueous liquid mixtures.  It’s a fresh, new tool in the ChemEng toolbox to draw upon, which allows a more thermally flexible and energy conscious solution to be implemented.  PTD is more than just a device or just a process, it’s an out of the box approach to an extremely relevant  separation problem for the BioEconomy.  Of particular interest is its potential application in Industrial Bio-Separations such as Cellulosic Bio-solvent Recovery.  It makes economically interesting new ways to conduct Fermentation processes (i.e. CARAF) and has the potential to augment bio-engineering and Molecular Biology’s efforts to intensify fermentation of unique metabolites and the use of advanced substrates.  PTD is a platform which scientists and engineers should consider focusing their development energy– it is a ripe field for innovation.”  


McMaster University, Canada

Dr. Amin Rajabzadeh, Program Chair, Biotechnology

• Development of novel bioseparation processes for the production of high functional proteins from bioresources
• Membrane purification processes; water treatments, food and biotechnology applications
• Enzyme immobilization and biodiesel production
• Environment and bioprocess engineering
• Computational fluid dynamics (CFD) modelling of biological processes

Dr. Rajabzadeh is supervisor for a team of M. Eng students using Aspen Plus to model the use of PTD in a biorefinery (See Below)

The McMaster M. Eng Team modelling PTD in Aspen Plus

Dr. Faiez Alani,
Associate professor of Biotechnology

Dr. F. Alani is Associate professor of Biotechnology at W. Booth School of Engineering Practice and Technology, McMaster University. His research interests & Expertise are: Microbial Biotechnology, Biochemical Engineering, Nanobiotechnology, Industrial Microbiology, Biofuel and Biorefinery, Solid-state bioprocess. Alani is a member of the Society for Industrial Microbiology & Biotechnology. He is also an Editorial Advisory Board Member for the International Journal of Engineering Education

Professor Alani writes: “Down stream processing is a challenging bioprocess in biofuel industry as highly contribute to final cost of biofuel. Of energy for biofuel separation. Innovative technique is required in down stream processing for separation of biofuel by effective and economically feasible technique. With less energy. I Think pass-through process address this challenge by using simultaneous process for fermentation and distillation.


University of Campinas, Brazil


University of Manchester, U. K.

Prof. Dr. Ir. Anton A. Kiss, CEng CSci FIChemE 
Royal Society Wolfson Research Merit Award holder 

Tony has worked for over a decade in the chemical industry, as Senior Project Manager and RD&I Specialist in Chemical Process Technology at AkzoNobel Specialty Chemicals – now rebranded as a new company,Nouryon. At the same time, he was appointed as (part-time) full professor at the University of Twente (SPT group). Just a few years later, he started as full professor & chair at The University of Manchester(CEAS). During the past decades, he carried out numerous research & industrial projects, published many textbooks, chapters, patents, and 100+ scientific articles. In addition, he won several prestigious awards:Royal Society Wolfson Research Merit Award, Hoogewerff Jongerenprijs, and AkzoNobel Innovation Excellence Award. Tony Kiss is also a Fellow of IChemE, research fellow of The Royal Society, and a senior member of established professional institutions: AIChE, CAPE-WP, EFCE, ESMC, IChemE, PSE-NL, SCI. Regarding PTD, he writes:

Distillation remains the most used separation technology in the chemical industry, in spite of its large energy demands caused by low thermodynamic efficiency. Pass-through distillation (PTD) is an emerging hybrid separation technology that efficiently combines distillation with absorption. The basic idea of pass-through distillation involves the decoupling of the evaporation and condensation steps of a distillation process, by means of an absorption-desorption loop that passes through the component to be separated and thus allows the use of different pressures and types of heating/cooling utilities. Its main applications are in areas where conventional distillation  does not work, and other methods are either too costly or prone to fouling.”

In the conclusions of his dissertation Scott writes “The results of the entire procedure give an indication that PTD is certainly possible and could successfully be used to separate ethanol from a fermentation broth”


Lambton College, Canada

“The Drystill technology, based on the principle of Pass-through Distillation (PTD), can solve several separation problems currently being faced by the biofuels’ sector and reduce energy consumption during the overall process. During our experimental trials, we have seen the advantages of using the CARAF system during our ethanol fermentations. Furthermore, Drystill technology applications could be extended to different bioprocess and act as a route to avoid microbial inhibition with in-situ product recovery.”

“The Drystill Project at Lambton College has been an interesting research opportunity. The project that we are working on pairs pass through distillation with a continuous alcohol production fermentation. The results that we have obtained show that this technology could be very exciting to bioprocessing companies that utilize fermentations. From an environmental and economic perspective I believe that pass through distillation has the potential to make a huge positive impact across many other industries as well.”

“I believe that the Drystill Techology is an innovated idea which can be enormously beneficial for several industries. As it is well known, ethanol has been identified as a valuable product for a wide range of purposes (i.e. beer brewing, wine making, bioethanol industry). Furthermore, this significantly contributes to the reduction of crude oil consumption and environmental pollution.”

Lambton College CARAF Team


Dr Edmund Maican, Dr. Alberto Coz, and Dr. Mariana Ferdez, collaborating  from the Universidad de Cantabria and Universitatea Politehnica Din Bucuresti, authored the paper below, featuring a thorough description of PTD.


They conclude their treatise with this paragraph:

“The pass-through distillation system has a very good chance to become a new standard among separation technologies due to the following main advantages:
– Depending on system configuration, this technology can perform with up to 60% [savings over] the energy required by conventional distillation;
– Room-temperature operation in the evaporator-absorber module offers a solution towards the recovery of biocatalysts and enzymes;
– Water lost through evaporation in cooling tower is proportional to the energy that it should remove from the system. In pass-through distillation, up to 80% reduction in water consumption can be achieved due to the less energy used and also because of the replacement of energy-inefficient equipment (distillation columns, evaporators, rectifier columns, etc.);
– Possibility to work with high solids fermentable broth;
– Overall reduction in energy consumption proportionally translates into GHG reduction;
– Lower maintenance and capital expenditure.”