A hydrogenation process for converting algae (Chlorella pyrenoidosa) to liquid products was developed. The hydrogenation was carried out in a batch autoclave at temperatures between 340 and 430 K and hydrogen pressures between 1 and 150 atm in the presence of a catalyst and a solvent. Yields of up to 50% oil in the C/sub 16/-C/sub 24/ range resulted, and by-products of ammonium carbonate and hydrocarbon gases were obtained. A kinetic model fitting the data quite well indicated that an asphaltenic substance was a reaction intermediate under all processing conditions.