Method for preparing furfural by xylose dehydration through fixed bed catalysis

Abstract

The invention discloses a method for preparing furfural by xylose dehydration through fixed bed catalysis, which comprises the following steps: adding a 1-3 mol / L acid catalyst solution into a reaction vessel, adding a cocatalyst of NaCl till saturation is achieved, heating to backflow, stirring to form a rotating liquid level of a catalyst layer with a fixed volume and concentration, jetting 10-20 wt% of xylose solutions obtained by straw hydrolyzation through dilute acid catalysis into the reaction vessel with a certain speed, performing xylose dehydration, and performing rectification to obtain a furfural solution with a purity of up to above 99% and a furfural yield of 50-70 wt%. The advancement of the invention is that the heating temperature is adjustable, which allows the volume of the xylose solution jetted into the reaction vessel to be maintained to be equal to the volume of the distilled furfural solution; the concentrations of the acid catalyst and the cocatalyst are constant; the volume of the catalyst layer is constant; the reaction process is maintained to be stable; continuous production is realized; the water phase of furfural-water separation returns to the hemicellulose hydrolyzation procedure for recycle; no waste water is discharged; the furfural yield is increased twice when compared with the yield of traditional production processes.

Description

technical field [0001] The invention relates to a method for preparing furfural by catalytic dehydration of xylose in a fixed bed, in particular to a water phase return hydrolysis process for preparation of xylose liquid by acid-catalyzed hydrolysis of straw, preparation of furfural by catalytic dehydration of xylose in a fixed bed, and separation of aldehyde and water method of recycling. Background technique [0002] In the 1980s in my country, there were more than 150 furfural manufacturers nationwide, with a total annual output of more than 100,000 tons; in the 1990s, with the development of China's furfural market and the improvement of profitability, a new round of The investment boom in furfural production; after entering the 21st century, with the continuous expansion of furfural application fields and the increase of profits at home and abroad, nearly 100 furfural production enterprises have been newly established in the country. At present, there are more than 300 ...

AI Technical Summary

Problems solved by technology

[0009] The above methods still have problems such as large steam consumption, large waste water, and environmental pollution by catalysts.