A method for producing single-cell protein from pulping waste liquid

Abstract

The invention relates to a process method for high-yield producing single-cell protein by using pulping waste liquor as a yeast nutritional source. The research shows that according to the pulping process, amount of alkali addition is small and poisonous auxiliaries such as anthraquinone and sulfide are not added, so that less waste liquor is produced, and the waste liquor has low basicity, high amount of nutrient, low acid amount for neutralization and salinity, and is suitable for the microbial growth without detoxification and attenuation process. According to the method, waste liquor stoste with COD (chemical oxygen demand) of 100000mg / L is acidized, carbon sources and the other nutritional ingredients in the water liquor can be directly used for culturing a yeast, the produced highest single-cell protein yield can be 8.42g / L, the highest protein level can be 52.42%, the amino acid amount can be 39.82%, 20 types of essential amino acid are contained, the COD removal rate of the waste liquor after fermentation can be about 60%, and most of N, P and K can be used. The method provided by the invention is especially suitable for black liquor utilization of a new pulping process invented in the earlier stage and develops a new approach for plant full-price development and high value-added utilization, and the residue liquor after lignin is extracted from the pulping waste liquor can be used as the yeast nutritional source. The high-yield single-cell protein can be directly used as a feedstuff or control release fertilizers, thereby effectively reducing the COD of the waste liquor, reducing the post-treatment loading greatly and being capable of creating a valuable industry chain.

Description

technical field [0001] The invention relates to a production method of single-cell protein, specifically, the nutrients such as reducing sugars, oligosaccharides, soluble fibers, N, P, and K in the alkaline pulping waste liquid can be cultivated under optimized culture conditions. Yeast produces single-cell proteins. Background technique [0002] This study hopes to explore the feasibility of using the waste liquid produced by our new alkaline pulping process (patent publication number CN102337687A) as a nutrient source for yeast. The pulping process and the semi-chemical pulping process have the advantages of less alkali consumption, no addition of anthraquinone, sulfide and other toxic additives, less waste liquid, low alkalinity, rich in N, P, K organic matter, etc. Nutrients, and the amount of acid used for neutralization is low, the salt concentration is low, no detoxification is required, and the higher concentration may be suitable for the growth of microorganisms. I...

AI Technical Summary

Problems solved by technology

[0005] At present, the mainstream treatment process of alkaline pulping black liquor is through concentration, incineration, and causticization treatment, and most of the alkali is recovered and applied mechanically. Although the pollution problem of black liquor is partially solved, the waste of resources is serious, and a large amount of carbon dioxide and nitrogen oxides are produced at the same time. pollutants, sulfur dioxide, dioxin and other secondary pollution waste gas and residual alkali, alkali sulfide, aluminosilicate and other white mud wastes mainly composed of calcium carbonate, etc., causing secondary environmental pollution

The black liquor treatment process has the disadvantages of large equipment investment, high cost, and large energy consumption

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