Method for preparing aromatic aldehyde compounds from sodium lignosulfonate

Abstract

The invention discloses a method for preparing aromatic aldehyde compounds from sodium lignosulfonate, which comprises the following steps: adding sodium hydroxide into deionized water to obtain a sodium hydroxide water solution, adding sodium lignosulfonate, stirring uniformly, adding an oxidizer and a catalyst to react while keeping the temperature at 5-60 DEG C, regulating the pH value of the reaction solution to 1-3, carrying out vacuum filtration to remove the unreacted sodium lignosulfonate, extracting the obtained supernate with an organic solvent ethyl acetate or chloroform, and carrying out rotary evaporation concentration on the obtained organic phase at the controlled temperature of 30-55 DEG C, thereby obtaining an aromatic aldehyde mixture; and carrying out column chromatography separation on the obtained aromatic aldehyde mixture to respectively obtain vanillin, p-hydroxybenzaldehyde and syringaldehyde. The preparation method has the advantages of low preparation cost, simple technical operation, mild reaction conditions and no secondary pollution, reduces the pollution of papermaking wastewater on the environment, effectively utilizes the lignin resources, and obtains the high-added-value aromatic aldehyde compounds.

Description

technical field [0001] The invention relates to a method for preparing aromatic aldehyde compounds by using sodium lignosulfonate, belonging to the field of biomass chemical industry. Background technique [0002] At present, the preparation of aromatic aldehyde compounds is based on petrochemical resources, using chemical methods to convert the existing groups on the benzene ring into aromatic aldehyde substances through a series of chemical reactions, or directly introducing aldehydes on the benzene ring through a series of chemical reactions. However, these methods often have high cost, poor reaction selectivity, strict requirements on reaction equipment, harsh reaction conditions, complicated process, and even harm to nature. Environmental pollution and other technical issues. [0003] With the continuous development of social economy, the enhancement of people's awareness of environmental protection and the increasing scarcity of petrochemical resources, the renewable ...

AI Technical Summary

Problems solved by technology

The oxidative degradation of lignin mainly includes enzymatic degradation, biomimetic degradation and transition metal catalyzed degradation. However, in the process of enzymatic degradation, the enzyme culture conditions are relatively high and the repeatability is poor; the biomimetic degradation reaction conditions are relatively harsh and the catalyst activity Volatile, high cost, and potential impact on the environment; transition metal catalyzed oxidation degradation usually requires high reaction temperature and harsh reaction conditions, etc.

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