Fast pyrolysis (ultrapyrolysis) of cellulose

A fast pyrolysis process, termed ultrapyrolysis, has been developed at the University of Western Ontario in order to exploit the high heating rates, short residence times high temperatures and rapid quenching, which are required to produce valuable non-equilibrium intermediates (i.e. ethylene and acetylene) from finely divided biomass. Hot solids(Thermo-for) are used to carry and transfer heat to the biomass particles in a very turbulent vortical contactor (Thermovortactor). This turbulence creates an ideal environment for fast thorough mixing and extremely rapid heat transfer. Cold solids (Cryofor) are then used to quickly quench the products. Trials with cellulose were conducted at temperatures between 750 and 900°C and residence times between 250 and 450 ms. Ethylene yields, expressed as a mass fraction of the product gas, varied from 6.8 to 8.2% for temperatures ranging from 750 to 900°C. The total hydrocarbon yield, also expressed as amass fraction of the product gas, was 18.8% at 900°C. The conversion of cellulose to a permanent non-condensible gaseous product was estimated to be 98% by mass at 900°C.