Thermochemical Processing of Algal Biomass

A thermolysis process for treating algal biomass, consisting substantially of dried algal cells, in which the algal biomass is heated from ambient to 460° C. in a flowing stream that contains one or more of carbon dioxide, acetic acid or other organic acids and that produces a condensable hydrocarbon product whose mass yield is greater than the dry, ash-free mass fraction of lipids in the starting algal biomass and whose higher enthalpy of combustion exceeds 25 MJ/kg plus a char, and a hydrocarbon-laden gaseous product. In another feature, the present invention includes heating the previously dried, algal biomass in a readily available, waste acid gas, such as flue gas that is rich in carbon dioxide, or to intimately mix the algal biomass with a solid acid, such as a protonated, large pore zeolite, and then heating the mixture in a non-oxidizing sweep gas.