Method for preparing isosorbide taking supported heteropoly acid as catalyst

Abstract

The invention discloses a method for preparing isosorbide by taking supported heteropoly acid as a catalyst. Sorbitol from a biological radical is used as a raw material to prepare the isosorbide directly through dehydration reaction. The method comprises the following steps: putting the catalyst into a constant temperature section of a fixed-bed reactor; introducing a reactant sorbitol solution into a reactor, and performing reaction through a catalyst bed after gasification; and separating a mixture obtained after the reaction to obtain the isosorbide. The method has simple operation process of the reaction, low production cost and light environmental pollution; the selectivity and yield of the isosorbide reaches up to 75.2 percent and 71.4 percent respectively, and the catalyst is easy to separate and recycle; and the method is a novel method which meets industrial demands and has strong practicality.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a method for preparing isosorbide from biomass raw materials. Background technique [0002] Isosorbide is a secondary dehydrated derivative of D-sorbitol, which is absorbed immediately after oral administration. It is an effective osmotic oral dehydration diuretic and an excellent antihypertensive drug for the treatment of intracranial hypertrophy. In foreign countries, isosorbide has been used clinically, but in China it is only used as an intermediate for the synthesis of anti-anginal drugs isosorbide dinitrate and isosorbide mononitrate. The research focus in recent years is to use it as a comonomer to synthesize modified commercial polymers, such as PET, polyether, polyester, polyurethane, polycarbonate, etc. Adding it to PET can increase the glass transition temperature of the polymer and increase the strength of the polymer. It can also be used in packaging bott...

AI Technical Summary

Problems solved by technology

There are some common deficiencies in these production processes: kettle reaction, which requires dehydration under certain pressure or vacuum conditions, is not suitable for continuous production; inorganic acid as a catalyst has higher requirements for catalytic reactors, long life but easy to generate dark by-products Product, although the ion exchange resin produces few by-products, its service life is short; the operating temperature range is narrow, high temperature can easily lead to sorbitol decomposition or product carbon deposition, and low temperature can easily cause the water generated by the reaction to be unable to be removed in time to reduce the reaction rate; Separation often requires organic solvents such as toluene or xylene to participate in distillation and recrystallization, and a small amount of inorganic acid ions in the product are difficult to remove

[0004] Along with the inconvenience that inorganic acid catalyst brings in the production, gradually appeared some relevant replacement catalysts, the most notable is exactly solid acid catalyst, as HY and HZSM-5 molecular sieve (USP 6013812 and 7420067), but under the catalysis of these molecular sieves The yield of isosorbide obtained is not high