Synthesis method of pentanediol, and synthesis method for preparing biomass-based pentadiene through conversion of levulinic acid and derivatives of levulinic acid

Abstract

The invention provides a synthesis method of pentanediol, and the method comprises the following steps: carrying out conversion reaction on a mixed solution obtained by mixing levulinic acid and / or levulinic acid derivatives, a catalyst and an organic solvent in a hydrogen-containing atmosphere to obtain the pentanediol. According to the method, a large amount of cheap and easily available bio-based chemical levulinic acid or derivatives thereof can be utilized, pentanediol is obtained through catalytic conversion, and m-pentadiene is further obtained. The raw materials are derived from renewable resources, the m-pentadiene is prepared through hydrogenation and dehydration, and particularly, a green and sustainable process route for synthesizing the m-pentadiene is finally obtained through a dehydration reaction route and construction of a dehydration catalyst. The invention provides a method for green and sustainable synthesis of linear pentadiene based on bio-based chemical conversion, and the method has the advantages of simple operation, short flow, no need of harsh experimental conditions, easy preparation of raw materials and catalysts, and 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 pentylene glycol and a synthesis method of piperylene, in particular to a synthesis method of pentylene glycol, levulinic acid and its A synthetic method for the conversion of derivatives to produce biomass-based piperylene. Background technique [0002] Piperylene is mainly used in the production of petroleum resins, terpene resins, ring hydrogen resin curing agents, coating inks and adhesives. The industrial preparation of piperylene adopts the extraction of C5 fraction, C5 is a by-product of cracking ethylene, generally about 10-20% of ethylene production, and C5 fraction contains 15-20% of isoprene, 15% of cyclopentadiene ~17%, piperylene 10~20%, therefore, the production capacity and economy of piperylene in industry depends on the scale of ethylene plant. Although my country's total ethylene output is large, the ...

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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 piperylene: (1) furfural is converted into methyl tetrahydrofuran through methyl furan, and finally dehydration obtains piperylene (Rubber Chemistry and Technology, 1945,18,284 –285; ACS Catalysis, 2017, 7, 5248-5256), the method has a long route, low yield (<30%), and high energy consumption; , first deoxidize and dehydrate (DODH) under the action of formic acid, and then obtain piperylene through deep deoxygenation, and the yield does not exceed 51.8%. DODH is the key to this route. Formic acid is both a catalyst and a reactant. Alcohol dehydration and DODH are in a competitive relationship, resulting in low catalytic efficiency. In addition, the DODH system lacks reducing agents, so the yield is low (Green Chemistry, 2017, 19, 638–642); (3) Our research group uses methyl ethyl ketone / formaldehyde as raw materials , first condense to obtain linear hydroxy ketones, then hydrogenate to synthesize 1,3-pentanediol, and then dehydrate to convert to piperylene. Under the conditions, the hydrogen on the methylene is more active, leading to the reaction tends to generate nonlinear hydroxy ketones, and finally generates isoprene, so the industrial value of this route for preparing piperylene is not great (CN201910044174)

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