Process for producing protein concentrate or isolate and cellulosic thermochemical feedstock from brewes spent grains

Abstract

A process for treating brewers spent grains for producing a high value protein product and a cellulosic residue, both from brewers spent grains that have not gone through fermentation. The high value protein product is useful as a protein supplement for human consumption, or feed for livestock and poultry. The cellulosic residue has value as a feedstock for a thermochemical process unit, such as for the production of a biofuel.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a non-provisional application based on provisional application 62 / 447,383 filed Jan. 17, 2017.BACKGROUND OF THE INVENTION[0002]This invention relates to a process for treating brewers spent grains, that have not gone through fermentation, for producing a high value protein product and a cellulosic residue product. The high value protein product is useful as a protein supplement for human consumption, or feed for livestock and poultry. The cellulosic residue product has value as a feedstock for a thermochemical process, such as for the production of a biofuel.BACKGROUND OF THE INVENTION[0003]Brewers spent grains (BSG) is the major by-product left after the processing of steeped, germinated, dried cereal gains (malt) for the production of beer and other malt products. Though barley is the primary grain used for brewing, beers can also be made from other grains such as wheat, rye, maize, rice, oats, sorghum and millet. In...

AI Technical Summary

Benefits of technology

The present invention provides a process for producing a protein product and a cellulosic product from brewers spent grains having a starch and protein content, and which have not gone through fermentation. The process involves introducing a mixture of brewers spent grains, water, glucoamylase, and heating it to a temperature from about 30°C to about 70°C. The mixture is then cycled to a particle size reduction stage wherein the average size of grain particles is reduced to an average size less than 500μ. The pH of the mixture is adjusted to a level from about 7 to 10.5. An alkaline protease enzyme is added to the mixture and passed through a screen to obtain a permeate comprised of proteins, the alkaline protease enzyme, and solids having a particle size less than 5 to 500μ, and a retentate comprised of solids having a particle size greater than 5 to 500μ. The permeate is then recycled back to the hydrolysis tank until there are no more proteins to hydrolyze. The resulting liquid permeate is then conducted to a nanofiltration stage to obtain a retentate with a solids content of from about 10 wt. % to about 50 wt.%. The retentate is then heated to deactivate any remaining enzymes and conduct it to an evaporation stage to remove any remaining water and obtain a protein product. The process can be used with brewers spent grains containing starch and protein content, and a mixture of brewers spent grains, water, glucoamylase, and heat can be used to produce a protein product and cellulosic product.

Problems solved by technology

BSG is available in large quantities throughout the year, but its main application has been limited to animal feeding.

Various biomass conversion technologies employ thermochemical processes, such as pyrolysis and gasification, that have relatively high capital and operating costs.

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