Lignin dewatering process

摘要

A lignin plastics solids mass containing lignin solids and liquids with up to 85% liquids can be partially dewatered by heating the lignin plastics solids mass to above a critical temperature at which time the lignin plastics solids agglomerate into lower moisture granular solids with between about 45% to 55% liquids releasing excess liquid which can be easily removed from the solids. The process is particularly useful for lignin plastics solids removed from black liquor from paper mills, or for similar lignin plastics solids masses, which can contain up to 85% liquids and which need to be dried to form useful lignin solids, which can be used for example for fuel. The dewatering process can be combined with the process for separating the lignin from the black liquor to separate the dewatered lignin directly from the black liquor.

主权项

1. A method of at least partially dewatering lignin plastic solids in the form of a lignin plastic mass having a moisture content of more than about 60%, comprising:
heating the lignin plastic mass to a temperature above a critical temperature; cooling the heated lignin plastic mass to a temperature below the critical temperature thus causing lignin plastic solids to agglomerate into lower moisture granular lignin solids and a residual liquid, said lower moisture granular lignin solids having a moisture content of less than about 60%; and separating at least a portion of the residual liquid from the lower moisture granular lignin solids to obtain dewatered granular lignin plastic solids.