Synthesis method of pentanediol and synthesis method for preparing biomass-based linear pentadiene based on lactic acid conversion

Abstract

The invention provides a method for synthesizing pentanediol. The method comprises the following steps: carrying out hydrogenation reaction on a mixed solution obtained by mixing pentanedione, a hydrogenation catalyst and an organic solvent in a hydrogen-containing atmosphere to obtain the pentanediol. According to the invention, a large amount of cheap and easily available bio-based chemical lactic acid can be utilized to obtain pentanediol, and linear pentadiene is further obtained; the raw materials are from renewable resources, and linear pentadiene is obtained through the following steps: (1) condensing lactic acid to prepare pentanedione, (2) hydrogenating pentanedione to prepare pentanediol, and (3) dehydrating pentanediol to obtain linear pentadiene; linear pentadiene, especially 1, 3-pentadiene, is prepared from lactic acid through a process route of condensation, hydrogenation and dehydration; and a green and sustainable linear pentadiene synthesis method based on bio-based chemical conversion is provided, and is simple to operate, short in process, free of harsh experimental conditions, easy to prepare raw materials and catalysts, and has a large-scale synthesis prospect.

Description

technical field [0001] The invention belongs to the technical field of conversion and synthesis of bio-based chemicals, and relates to a synthesis method of pentanediol and a synthesis method of linear pentadiene, in particular to a synthesis method of pentanediol and a production method based on lactic acid conversion. Synthesis of Substance-Based Linear Pentadiene. Background technique [0002] Linear diene compounds are widely used in polymer materials, cosmetics, spices, pesticides and other fields. Linear pentadiene mainly includes 1,3-pentadiene and 1,4-pentadiene. In addition to being used to synthesize polyolefin materials, 1,3-pentadiene is mainly used to prepare curing agents, such as methyl tetrahydrophthalic anhydride, methyl hexahydrophthalic anhydride, methylcyclohexene, tetracarboxylic acid, etc., and can also be used in Leaf alcohol is synthesized to make fragrances, and 1,3-pentadiene is also used in the production of paints. 1,4-Pentadiene can be used to...

AI Technical Summary

Problems solved by technology

The biological fermentation method involves bioengineering (metabolism, fermentation process), genetic technology (genetic modification), etc. Although the conditions are mild, the process is complicated, the efficiency is low, and the process flexibility is poor.

And in the field of catalytic transformation of biomass, so far, only three routes can prepare 1,3-pentadiene: (1) furfural is converted into methyl tetrahydrofuran through methyl furan, and finally dehydration obtains 1,3-pentadiene (RubberChemistryand Technology, 1945, 18, 284–285; ACS Catalysis, 2017, 7, 5248-5256), this method has a long route, low yield (<30%), and high material and energy consumption; Xylitol is used as a raw material, deoxygenation and dehydration (DODH) under the action of formic acid, and then deep deoxygenation to obtain linear pentadiene, the yield is not more than 51.8%. DODH is the key to this route. Formic acid is both a catalyst and a reactant. As a catalyst , formic acid catalyzed xylitol dehydration and DODH are in a competitive relationship, resulting in low catalytic efficiency, and the lack of reducing agent in the DODH system, so the yield is low (Green Chemistry, 2017, 19, 638–642); Ketone / formaldehyde is used as raw material, which is first condensed to obtain linear hydroxy ketone, then hydrogenated to 1,3-pentanediol, and then dehydrated to convert to linear pentadiene. The chemical environment is different, and the hydrogen on the methylene is more active under the reaction conditions, which leads to the reaction tends to generate nonlinear hydroxy ketones, and finally generates isoprene, so the industrial value of this route for preparing linear pentadiene is not great

Images