Patent ID: 7883884

Claim:
A method for producing a processed organic material characterized by a reduced number of viable microbial organisms, infectious agents, and/or prions relative to that present in an organic material from which it is derived, and for producing biogas from at least some of said processed organic material, said method comprising the steps of i. providing an organic material comprising solid parts or solid and liquid parts, wherein said organic material comprises viable microbial organisms, infectious agents, prions, or combinations thereof, and wherein said solid parts comprise a plant material, an animal material, or a combination thereof, said plant material comprising cellulose, hemicellulose, lignin, or combinations thereof and said animal material comprising slaughterhouse waste, meat, bone meal, or combinations thereof; ii. subjecting said organic material, to the processing steps of: a. lime pressure cooking under pressure at a temperature of 120° C. to 250° C. and a pH-value of above 9 obtained at least in part by adding lime prior to or during said lime pressure cooking, said lime pressure cooking resulting in hydrolysis of the organic material, wherein when said organic material comprises plant material said lime pressure cooking further comprises hydrolysis of the cellulose, hemicellulose, and/or lignin of said solid parts, wherein the lime is Ca(OH)2 and/or CaO; and b. stripping ammonia from said lime pressure cooked organic material, thereby obtaining a processed organic material comprising a reduced number of viable microbial organisms, infectious agents and/or prions, and further comprising hydrolysed solid parts of the provided organic material of step (i); iii. directing at least some of the processed organic material comprising hydrolysed solid parts of organic material to one or more biogas fermenters; iv. fermenting the processed organic material in the one or more biogas fermenters, thereby producing a biogas; and v. obtaining the biogas from the biogas fermenter.