Processes and systems for conversion of animal manure to thermal gas and biochar

A process for converting animal manure into a purified thermal gas, said process comprising:

• (a) providing starting animal manure, wherein said starting animal manure has an average moisture content from about 30 wt % to about 90 wt % H2O;
• (b) drying said animal manure in a manure dryer operated at a drying temperature selected from about 50° C. to about 350° C. to generate a dried animal manure, wherein said dried animal manure has an average moisture content from about 15 wt % to about 40 wt % H2O;
• (c) pelletizing said dried animal manure in a manure pelletizer to generate manure pellets, wherein said manure pellets have an average moisture content from 0 wt % to about 20 wt % H2O;
• (d) thermally reacting said manure pellets in a thermal reactor operated at a reaction temperature selected from about 600° C. to about 1500° C., to generate an intermediate thermal gas and a solid biochar from said manure pellets, wherein said intermediate thermal gas contains at least H2, CO, CO2, CH4, and H2O, and wherein said solid biochar contains at least carbon and ash;
• (e) separating said solid biochar from said intermediate thermal gas;
• (f) optionally, feeding said intermediate thermal gas to a tar-reforming reactor operated at a tar-reforming temperature selected from about 1200° C. to about 1600° C.;
• (g) feeding said intermediate thermal gas to a condensing unit, to generate a cooled thermal gas and a separated liquid stream;
• (h) compressing said cooled thermal gas using a compression unit, to generate a compressed thermal gas, wherein said compressed thermal gas is at a pressure from about 5 bar to about 55 bar;
• (i) catalytically reacting said compressed thermal gas in a water-gas shift reactor operated at a water-gas shift temperature selected from about 200° C. to about 550° C., to generate a shifted thermal gas having an adjusted H2/CO ratio compared to a H2/CO ratio of said compressed thermal gas;
• (j) treating said shifted thermal gas using an acid-gas removal unit operated to remove at least a portion of carbon dioxide as well as at least a portion of sulfur-containing compounds from said shifted thermal gas, to generate a purified thermal gas;
• (k) optionally, removing water and/or light gases from said purified thermal gas;
• and
• (l) recovering or further processing said purified thermal gas.