Methods and systems for processing cellulosic biomass

Abstract

Separation of a product of digestion of cellulosic biomass solids may be challenging due to the various components contained therein. Methods and systems for processing cellulosic biomass, particularly a reaction product of a hydrothermal reaction containing lignin-derived products, such as phenolics, comprise providing the reaction product of a further processing (such as condensation reaction) to a non-aqueous stream to at least part precipitate the lignin and removing the precipitated lignin.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]The present application claims the benefit of pending U.S. Provisional Application Ser. No. 62 / 097,756, filed 30 Dec. 2014, the entire disclosure of which is hereby incorporated by reference.BACKGROUND OF THE INVENTION[0002]This section is intended to introduce various aspects of the art, which may be associated with exemplary embodiments of the present invention. This discussion is believed to assist in providing a framework to facilitate a better understanding of particular aspects of the present invention. Accordingly, it should be understood that this section should be read in this light, and not necessarily as admissions of any prior art.[0003]The present disclosure generally relates to processing of cellulosic biomass solids, and, more specifically, to methods and systems for processing a reaction product comprising lignin that may be obtained by a hydrothermal reaction of cellulosic biomass.[0004]A number of substances of commercial...

AI Technical Summary

Benefits of technology

This patent describes a process for separating compounds from a reaction product. The process involves extracting a liquid phase containing compounds from a larger liquid phase containing non-water miscible compounds. The separated liquid phase is then treated to recover light compounds. The non-aqueous phase can also be treated to reduce its viscosity and improve product separation. The non-aqueous phase can then be distilled to separate the compounds. The process can allow for more efficient separation of compounds at lower temperatures and can recover more light compounds.

Problems solved by technology

Recovery of various compounds from a product of reactions involving cellulosic biomass may be challenging due to the various components contained therein, including lignin.

While feasible, distillation of a reaction product with multiple liquid phases that contains water into various product fractions can result in poor product separation and steam stripping, where water vapors carry heavier compounds, like phenols, into the overhead fraction.

Although this may be addressed by conducting the distillation at higher pressure and temperature where multiple phases can be reduced or minimized, the higher pressure and temperature presents additional expenses including equipment costs, as well as risks to product from onset of undesired degradation reactions at higher temperatures.

While the water in the reaction product can be removed through flashing prior to full distillation into product fractions, doing so can also result in steam stripping, thereby resulting in less efficient product separation in a subsequent distillation process.

The complex mixture of constituents that is co-present with the cellulose can make its processing difficult, as discussed hereinafter.

Lignin, in particular, may be an especially difficult constituent to deal with.

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