Application of tungsten-based catalyst in lignin catalytic hydrogenation for producing aromatic compound

Abstract

The invention relates to hydrocracking of lignin, and specifically relates to a method for applying a tungsten-based catalyst to catalyze lignin hydrocracking for producing an aromatic compound. The catalyst comprises a main active component of non-zero-valent tungsten, and a second metal component of a small amount of one or more transition metals selected from zero-valent nickel, cobalt, ruthenium, iridium, palladium, platinum, iron, and copper. According to the method, raw materials such as lignin, biomass hydrolysis residue, lignosulfonate, and alkaline lignin are subject to catalytic hydrogenation under a hydrothermal condition with a temperature of 120 to 450 DEG C and a hydrogen pressure of 1 to 20MPa; the raw materials are cracked into C6-C9 phenolic compounds with high selectivity. A maximal phenol yield reaches 55.6%. Compared to existing technologies, according to the invention, renewable natural biomasses are adopted as raw materials, such that the raw materials are cheap, and have wide sources; inorganic acid and alkali are not required, such the production of a large amount of alkaline solution in traditional lignin catalysis is avoided; the tungsten-based catalyst is cheap; the reaction process is green, and has atom economical characteristics.

Description

technical field [0001] The invention relates to the preparation of aromatic compounds, in particular to a method for preparing monophenolic aromatic compounds by catalyzing hydrocracking of lignin resources with a supported tungsten carbide catalyst. Background technique [0002] The rapid development of the world economy has benefited from the wide application of fossil energy, such as oil, natural gas, and coal. With the continuous consumption of non-recyclable fossil resources, the energy crisis and environmental problems have become increasingly severe. The development of renewable new energy to replace fossil resources has become an inevitable trend of social development. [0003] Biomass resources exist in large quantities in nature, and are the most abundant and cheapest renewable resources that meet the requirements of sustainable development on the earth. In biomass, the content of lignin is second only to cellulose, and it is the most abundant resource of natural...

AI Technical Summary

Problems solved by technology

[0005] However, due to the complex structure and stubborn physical and chemical properties of lignin, it is extremely difficult to crack it catalytically.

U.S. Patent (US 4,900,873) uses biphenyl or naphthalene as a solvent to pyrolyze lignin to prepare aromatic compounds at 300-400°C, but the yield is less than 20%

According to the research results of the literature, most of the currently reported lignin hydrogenation catalysts are based on noble metals such as Pd and Pt. There has not been any report using lignin as a raw material. Preparation of aromatic compounds by catalytic degradation with high efficiency and high selectivity

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