Preparation method and application of carbon molecular sieve for separating olefin and alkane

Abstract

The invention discloses a preparation method and application of a carbon molecular sieve for separating olefin and alkane. The method comprises the following steps of: adding a starch carbon precursor into a distilled water solvent to prepare a starch aqueous solution, uniformly stirring and dispersing, and then carrying out medium-pressure medium-temperature hydrothermal controllable polymerization and dehydration carbonization reaction in a reaction kettle to obtain homogeneous carbonaceous microspheres; and washing and drying the obtained carbonaceous microspheres, performing controlled high-temperature defunctionalization treatment at 700-1000 DEG C in an inert atmosphere, and controlling carbon layer rearrangement and heteroatom pyrolytic reaction to obtain the carbon molecular sieve material with uniform and adjustable ultra-microporous channels. Starch biomass which is low in price, non-toxic and harmless serves as a carbon source, carbonaceous microspheres are formed through a direct hydrothermal polymerization carbonization process, the defect content and the graphitization degree of the microspheres can be controlled by adjusting the reactant concentration, the carbon molecular sieve is obtained through pyrolysis at a corresponding calcination temperature, and fine adjustment of the aperture within a sub-angstrom precision range is realized.

Description

technical field [0001] The invention relates to the field of adsorption and separation materials for alkenes and alkanes, in particular to a carbon molecular sieve material with low cost, stable structure, uniform and adjustable pore size distribution, and the best characteristics of sieving and separating alkenes and alkanes. Background technique [0002] Propylene and ethylene are the two organic chemical raw materials and one of the basic petrochemical products with the largest output and consumption in the world. Owing to often containing unreacted alkane in the olefin product, and it and corresponding alkane (C 2 h 4 / C 2 h 6 , C 3 h 6 / C 3 h 8 ) have similar physical and chemical properties, making their separation and purification face great challenges. For more than 70 years, the industry still uses energy-intensive high-pressure cryogenic distillation columns for separation, and its energy consumption accounts for 10-15% of global energy consumption. Adsorp...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the problems of high defect content, difficult fine adjustment and wide pore size distribution in the current carbon molecular sieve carbon precursor, the present invention innovatively provides a preparation method and application of a carbon molecular sieve material with sieving properties for the separation of alkenes and alkanes. The production process of porous carbon materials is simple and low cost, and the defect content and graphitization degree of carbon precursors can be precisely adjusted. The prepared carbon molecular sieve has uniform and controllable pore size, and has excellent adsorption performance for sieving and separating alkenes and alkanes.

Images