Method for preparing levoglucosenone through biomass catalytic pyrolysis

Abstract

The invention belongs to the field of utilization of biomass energy, and in particular relates to a method for preparing levoglucosenone through biomass catalytic pyrolysis. The method comprises the following steps: by taking biomass base phosphoric acid activated carbon as a catalyst, performing mechanical mixing on the catalyst with biomasses, performing flash pyrolysis at 250-470 DEG C under an inert anaerobic condition, and condensing a pyrolysis gas, thereby obtaining a liquid product rich in levoglucosenone. In pyrolysis products of the biomasses subjected to catalytic pyrolysis of the biomass base phosphoric acid activated carbon, the yield and the purity of levoglucosenone are both relatively high; in addition, a mixture of solid coke generated through pyrolysis and the catalyst can be used as a carbon source which is continuously adopted to prepare activated carbon; due to adoption of the biomass base phosphoric acid activated carbon which is low in price and can be recycled, the production cost and the pollution can be effectively reduced, and the method is an economic and effective method for preparing the levoglucosenone.

Description

technical field [0001] The invention belongs to the field of utilization of biomass energy, and in particular relates to a method for preparing L-glucosone by catalytic pyrolysis of biomass. Background technique [0002] Levoglucosone (LGO, 1,6-anhydro-3,4-dideoxy-β-D-pyranosen-2-one) is produced by dehydration of cellulose and part of hemicellulose during biomass pyrolysis. An important anhydrosugar derivative formed; it has high reactivity, is an important raw material for organic synthesis, and has high application value. [0003] It has been more than 40 years since L-glucosone was first discovered in 1973. However, due to its low yield and difficult purification in the conventional pyrolysis process of biomass, the market price is high, which limits its application in organic synthesis. Previous studies have proved that in the pyrolysis process of cellulose or biomass, the introduction of a suitable acid catalyst can significantly promote the formation of glucosone. Th...

AI Technical Summary

Problems solved by technology

However, among the above-mentioned catalysts, catalysts such as liquid acids need to be loaded onto cellulose or biomass raw materials through cumbersome pretreatment processes; and ionic liquids are not only expensive but also have poor thermal stability.

More importantly, the above-mentioned acid catalysts all have very strong acidity. During the pyrolysis process, due to the existence of water vapor, the acid sites are prone to be lost and enter into the pyrolysis liquid product to promote the formation of levoglucosone in the form of catalyst. Secondary reactions in the pyrolysis liquid, making it difficult for levoglucosone to exist stably

In addition, after the catalytic pyrolysis reaction, the catalyst and coke are mixed together, the catalyst is difficult to recycle, and it also affects the use of coke

And the massive use of these strongly acidic catalysts also easily causes problems such as environmental pollution.