Patent ID: 8470567

Claim:
A process for manufacture of biogas and a solids fraction from an organic waste feedstock comprising: i) 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; ii) combining the hydrolysate with an external balancing organic feedstock material or an external carbon balancing feedstock material to produce a blended hydrolysate to achieve a carbon: nitrogen ratio from about 12:1 to 30:1; iii) anaerobic digestion of the blended hydrolysate 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; iv) separating the digestate into a solids fraction and a liquid fraction, and recycling a portion of the solids fraction to the step of anaerobic digestion (step iii); v) recovering the biogas stream characterized as having a methane content from between 55 to 75% by volume, and the solids fraction.