A process and an apparatus for the manufacture of
biogas and a solids fraction from an organic waste feedstock is provided. The process involves
thermal hydrolysis of the organic waste feedstock at a temperature from about 100 to about 220° C., a pressure from about 5 to about 20 bars, for a period of time from about 15 minutes to 4 hours, to produce a
hydrolysate. The
hydrolysate undergoes
anaerobic digestion at a temperature from about 25 to 60° C., for a period of time from about 1 to 35 days to produce a
biogas stream and a
digestate. The
digestate is separated into a solids fraction and a
liquid fraction, and a portion of the solids fraction is recycled for further
anaerobic digestion. The
biogas stream, characterized as having a
methane content from between 55 to 80% by volume, and the solids fraction, are recovered. The apparatus includes a receiving bin for receiving and supplying organic waste feedstock to a
thermal hydrolysis reactor. The
thermal hydrolysis reactor for
processing the organic waste feedstock at a temperature from about 100 to about 220° C., a pressure from about 5 to about 20 bars, for a period of time from about 15 minutes to 4 hours to produce a
hydrolysate. An anaerobic digester for
processing the hydrolysate at a temperature from about 25 to 60° C., for a period of time from about 1 to 35 days to produce the biogas and a
digestate, and a solids thickening tank for separating the digestate into the
solid fraction, a
liquid fraction and a secondary biogas fraction.