A Focus on Pyrolysis Coproducts

by Sue Retka Schill (Biomass Magazine) CHAR Technologies builds its business case around flexibility in feedstock and outputs. -- With three projects in development, Toronto-headquartered CHAR Technologies is poised for commercialization of its high-temperature pyrolysis (HTP) process, producing biocarbon and renewable gases. “We’re in the right time with the right technology, and the opportunities are pretty substantial,” CEO Andrew White says.

CHAR Technologies commissioned its demonstration/small commercial-scale plant in London, Ontario, in 2018, using anaerobic digestate as the feedstock and producing five tons per day of biocarbon for testing. Now, a California project, also using digestate, will double the throughput of the London plant and test hydrogen production from syngas. That project is expected to be online this fall. Two Canadian projects have been announced that will use woody biomass and quadruple the demo’s throughput.

The company’s approach has been to develop multiple products geared to existing markets, White says. “The financial viability of a project isn’t limited to a single output like biocarbon, but it’s biocarbon and syngas. The syngas can be used for direct energy, as renewable natural gas (RNG) or for green hydrogen.” On the feedstock side, the technology fits places where the biomass is challenging to handle or there are disposal issues. “Put all those pieces together, and you get a viable opportunity,” he says.

By adjusting temperature and holding time, CHAR Technologies produces either an activated charcoal, trademarked SulfaCHAR, or a biocoal, trademarked CleanFyre, that has a slightly higher energy density than the best coal it can displace. “In the Canadian context, biocoal to help heavy industry decarbonize is in huge demand,” White says.

SulfaCHAR can be used in the digester itself, or be used to help in cleaning the digester’s gas stream. The added benefit, White says, “is because of the chemistry of the SulfaCHAR, it converts hydrogen sulfide into elemental sulfur, so it has a second use as a sulfur-rich biochar for soil amendment.” By applying it to the soil, the material would be eligible for voluntary carbon credits.

CleanFyre’s carbon intensity ranges in the single digits above and below net neutral, mostly dependent upon the feedstock source, its transportation and handling, he says.

RNG production uses a standard catalytic methanation process. “Our goal is to provide consistent, clean syngas to the catalytic process that has been built on the back end of the plant,” White says. “After that, you take it through standard biogas separation because it’s just like a biogas plant or landfill point at that point.”

The hydrogen upgrade has two options, depending on budget and hydrogen prices. “Directly off the kiln, we’re 40% hydrogen, sometimes 50% by volume. At that level of hydrogen, we can take it through a pressure swing adsorption unit to separate the hydrogen from the rest of the gas to get a nice, clean hydrogen. The other option is a catalytic process where we can boost the hydrogen to the order of 60 to 65% and take it through separation.” READ MORE