RTP™ Biocrude: A Combustion / Emissions Review

Abstract

The thermochemical conversion of solid biomass wastes to liquid fuels via fast pyrolysis is now firmly established with a number of research, pilot plant and commercial systems producing sufficient quantities for applied combustion tests. Biocrudes produced with Ensyn’s RTP™ technology have undergone characterization and combustion tests in flame tunnels, furnaces, combustors and boilers, including work at MIT (USA), ERL (Canada), SANDIA (USA), ENEL (Italy), NESTE (Finland) and ARSTA (Sweden).

Data on flame temperatures, heat release profiles and emissions have been collected for systems using mechanical, air and steam atomization nozzles. These tests have conclusively established that biocrudes can be burned with steady-state self-sustaining flames that closely resemble those from petroleum-based fuel-oils.

Results have confirmed that conversion to a liquid permits better combustion control resulting in significantly lower emission levels than those typically obtained by direct combustion of the solid biomass wastes. Emission levels for carbon monoxide, nitric oxide, and total suspended particulate are close to those obtained from No. 2 fuel-oil and lower than from No. 6 fuel-oil. Sulphur emissions are dramatically lower than for either fuel-oil. It is therefore reasonable to expect that existing combustion systems for fuel-oils can be modified to burn biocrudes with emission levels that will allow permitting in normal situations.