METHODS FOR VALORIZATION OF LIGNIN-RICH SOLIDS FROM ANAEROBIC DIGESTATE

摘要

A liquid suspension of lignin-rich microparticles can be recovered from anaerobic digestion of ruminant animal manure. This has similar particle size distribution to that obtained from anaerobic digestion of steam pretreated lignocellulosic feedstocks. This demonstrates that similar lignin-rich microparticles can also be formed biologically, in the absence of thermal treatment that melts lignin. As a consequence, given a sufficiently complete digestion, lignin-rich microparticles will be formed during anaerobic digestion of ruminant manure and of lignocellulosic feedstocks that have never been steam pretreated to temperatures above the lignin melting point. Methods for recovering and valorizing this lignin are disclosed.