People Power

Our expertise stems from the of knowledge and experience of our team. With decades of combined experience in process, chemical, environmental and mechanical engineering, our talented professionals have executed numerous successful projects. Our strength lies in our cohesive team, backed by extensive industry knowledge, and an unwavering commitment to innovation. We are driven by a desire to create cutting-edge solutions and deliver exceptional results that surpass expectations. We strive to lead the way in our field, leveraging our collective experience to tackle complex challenges and drive meaningful impact.

What We Do

CH Four Biogas was originally incorporated in 2006 as Genesys Biogas Inc. as part of the Genesys Group, an international bioenergy consortium. In January 2009, CH Four Biogas was officially launched as the independent, wholly North American-owned successor of Genesys Biogas Inc. Since its launch, CH Four has staked its place as a leader in the North American biogas market.

CH Four is a design and consulting firm dedicated to the development of innovative and progressive anaerobic digestion (AD) technology. Our services range from technical feasibility studies, complete system engineering and design, project development, construction management, and system optimization. We believe strongly in innovation and optimization, and routinely work together with our clients to develop novel methods to meet there needs or increase the productivity and flexibility of our systems. Our strong research and development focus includes the operation of laboratory space in Ottawa to develop emerging technologies and processes.

CH Four has extensive experience in the design, construction and operation of anaerobic digesters for both agricultural facilities and municipalities. To date CH Four Biogas has designed and built over 25 farm and commercial-scale anaerobic digesters, with AD tanks ranging in size from 400 cubic meters to 45,000 cubic meters. The first anaerobic digester designed by CH Four was completed in 2006 in Ontario, Canada, and since that time our systems have evolved and adapted to provide unique solutions to organic management challenges. We currently have anaerobic digesters in Canada, the United States, Chile, Argentina and Jamaica. Our projects are typically complete mixed mesophilic anaerobic digestion, with a focus on co-digestion of both on and off farm feedstocks. Our focus on co-digestion has led us to develop and use a computer model of the anaerobic digestion processes to better understand the biochemical interactions that occur between different substrates with the anaerobic digester.

Who We Are

Benjamin Strehler, M.Sc.


Benjamin is the CEO of CH Four Biogas and is one of the founders of food-waste AD in North America. He arrived from Switzerland in the early 2000’s with ideas and know-how from Europe, and adapted practical, scaled systems to develop in North America. The result has been successful AD systems installed from coast-to-coast in the northern and southern hemispheres. Benjamin holds a M.Sc. in Environmental Engineering from ETH, Zurich.

Ethan Werner, MBA, M.Sc.

Managing Partner

Ethan joined CH Four Biogas in early 2011 and began working on project development and operational management on farm-based municipal and industrial AD projects. In this capacity he developed numerous working relationships with government, NGO’s private sector industry to enhance and progress the industry throughout North America. He is now a partner in CH Four and has grown the company from a small engineering firm into a family of companies providing a full suite of services to digester owners, developers and operators. Ethan received a dual MBA and M.Sc in Sustainable Management and Operations from the University of Kent at Canterbury.

John Brewer, CET


John is the Senior Vice President at CH Four Biogas. He has over a decade of experience leading the engineering design and construction of CH Four Biogas plants across Canada, the US and South America. He is one of the authors of the Canadian Biogas Gas Code (B149.6). John is a CET member of OACETT and holds a degree in Engineering and Environmental Technology from Algonquin College. He is also a member of the CSA and TSSA.

Claire Allen, P.Eng.

VP Operations

Claire joined the team in 2008 and oversees the permitting, start-up and operations of our biogas plants. She is a P.Eng. member of the PEO and Engineers and Geoscientists BC and holds a degree in Chemical Engineering from the University of Waterloo. She is a former board member of the Canadian Biogas Association.







Julien Chartrand, CET

Senior Designer

Julien has been with the company since 2018 and is responsible for the production of engineering drawings. He is a CET member of OACETT and holds an advanced diploma in Mechanical Engineering Technology from Algonquin College.

Gregory German, MET

CAD Technologist

Greg has been with the company since 2022 and is responsible for the production of engineering drawings. He holds an advanced diploma in Electromechanical Engineering Technology from George Brown College.

Olga Lozinsky, B.Sc.

CAD Technologist

Olga has been with the company since 2021 and is responsible for the production of engineering drawings. She holds a B.Sc in Chemical Engineering from Ariel University.

Selena Nasser, BSc

Research Scientist

Selena joined CH Four in 2020 as a research scientist. She holds a bachelor’s degree in Chemical Engineering from the University of Ottawa. Selena works on various research projects at CH Four, with her main focus being the anaerobic digestion process and developing tools for mass flow, nutrient and heat calculations.

Mohamad Adghim, PhD

Research Scientist

Mohamad Adghim holds a PhD in Civil Engineering from the University of Ottawa. He completed his Masters and Bachelor in Civil and Environmental Engineering. His current research is focused on anaerobic digestion and how to improve the process, specifically how to remove ammonia using ammonia-stripping to alleviate inhibitory effects off the process. Aside from anaerobic digestion, Mohamad's research interests and publications cover Life Cycle Assessment, Life Cycle Costing, and smart waste collection systems.

Marsa Toloui

Research Assistant

Marsa is a Ph.D. candidate in Chemical and Biological Engineering from Ottawa University. She is experienced in the field of biodegradable and antibacterial films and coatings, food-grade control and food plastic packaging. She is passionate about the applicability of polymers in chemical engineering to mitigate environmental issues. Her Ph.D. project focuses on developing an integrated and cost-effective process to recover NPK nutrients from digestate at optimized operating conditions by reducing polymer flocculants and freshwater in the coagulation/flocculation step while maximizing NPK removal.