Complex acid catalyst

Abstract

A complex acid catalyst is provided, which comprises MCP, phosphorous acid, nitric acid, magnesium sulfate and potassium primary phosphate. The catalyst has moderate catalyzing condition, high catalyzing efficiency and little erosion to equipment, which also can be used in circle and solves the problem of the existing technology has strict catalyzing reaction condition, large erosion to the equipment and can't be recycled. The invention is especially suitable for the catalyst used for producing furfural by two-steps way, which not only can be used as hydrolysis catalyst during plant fiber being hydrolyzed to pentose, but also can be used as dehydratingcatalyst during pentose being dehydrated to produce furfural, therefore the invention can be used repeatedly and in circle, and is discharged with waste water as the catalyst used during the production of furfural in the existing technology, thus really realizing nonpolluting and solving the difficult problem in the production of furfural with complying with the environment-protected concept.

Description

technical field [0001] The present invention relates to a kind of catalyst, especially relate to a kind of compound acid catalyst, its composition comprises calcium dihydrogen phosphate, phosphoric acid, nitric acid, magnesium sulfate and potassium dihydrogen phosphate etc. catalyst. Background technique [0002] Furfural, also known as furan formaldehyde, has two double bonds and an aldehyde group on the furan ring. This unique chemical structure can make it undergo oxidation, hydrogenation, chlorination, nitration and condensation reactions to produce many chemical products. , so it is widely used in many production fields such as pesticides, medicines, petrochemicals, food additives, and casting. [0003] Furfural is produced from plant fibers rich in pentosans, such as corn cobs, bagasse, corn stalks, straw, cottonseed hulls, rice husks, etc. The principle is that pentosans in plant fibers are first hydrolyzed into pentosans sugar, and then dehydration of the pentose s...

AI Technical Summary

Problems solved by technology

Above-mentioned acid has following shortcoming as the used catalyst of producing furfural: sulfuric acid and hydrochloric acid are as catalyst, and its shortcoming is that furfural yield is low, and equipment corrosion is serious, must use non-metallic equipment or steel lining equipment; The acetic acid produced by the hydrolysis of the acetyl group in the straw is used as a catalyst, that is, the process is self-catalyzed, and its disadvantage is that it requires high catalytic conditions (high temperature and high pressure), so the energy consumption is very large, which does not meet the principles of economy and energy saving

[0008] In addition, it is disclosed in the patent document GB786321 that the catalyst used in the production of furfural is tricalcium phosphate and hydrochloric acid, which is a composite catalyst. The use of this catalyst can improve the yield of furfural to a certain extent, but this process uses One-step method, so the catalyst is a one-time use, can not be recycled, does not meet the economic principle

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