Device and method for preparing anhydrous lower alcohol mixture by using Fischer-Tropsch synthesis by-product light alcohols

Abstract

A device and method for preparing an anhydrous lower alcohol mixture by using Fischer-Tropsch synthesis by-product light alcohols are disclosed. The device includes a raw material light alcohol dehydration unit utilizing a pervaporation membrane, a hydrogenation unit, and a hydrogenated light alcohol dehydration unit utilizing a pervaporation membrane, which are sequentially connected through pipes, wherein the raw material light alcohol dehydration unit utilizing the pervaporation membrane includes a pre-dehydration column, a raw material heater and a first pervaporation membrane dehydrator which are connected in sequence through pipes; the hydrogenation unit includes a hydrogenation raw material heater, a hydrogenation reactor and a hydrogenated gas-liquid separator which are connected in sequence by pipes; the hydrogenated light alcohol dehydration unit utilizing the pervaporation membrane includes a hydrogenated light alcohol heater and a second pervaporation membrane dehydrator connected in sequence through pipes. The device and the method can effectively reduce the content of water and non-alcoholic oxygen-containing organic compounds in the lower alcohol mixture and improveproduct quality.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a device and a method for preparing anhydrous low-carbon mixed alcohols by using light alcohols produced by Fischer-Tropsch synthesis. Background technique [0002] In the indirect coal liquefaction of the Fischer-Tropsch synthesis route, a large amount of water-phase by-products are inevitably produced, and the water-phase by-products are treated by oil removal, neutralization, rectification and dehydration to obtain water-containing light alcohols, mainly low-carbon alcohols ( methanol, ethanol, propanol, butanol) and water, also contains aldehydes (acetaldehyde, propionaldehyde, butyraldehyde), ketones (acetone, methyl ethyl ketone, pentanone, hexanone), esters (methyl acetate, ethyl acetate ) and other non-alcoholic low-carbon oxygen-containing organic compounds. [0003] The water in the Fischer-Tropsch synthesis by-product light alcohol forms an alcoh...

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Problems solved by technology

[0011] 2) Extractive distillation method, the extraction agent is extracted from the tower kettle, the energy consumption is small, but the requirements for the extraction agent recovery tower are strict, the solvent is partially lost, and new components are introduced, and there are residues in the product;

[0012] 3) The molecular sieve adsorption method has a simple process, does not introduce new substances, and the process is green and environmentally friendly. The resulting product has a high purity, but the Fischer-Tropsch synthesis by-product light alcohol has a high water content. If the molecular sieve adsorption method is directly used for dehydration, the molecular sieve can be filled with a large amount. The bed is easy to overheat, the regeneration process is complicated, and the operation is difficult

[0013] When the traditional technology separates the by-product light alcohol of Fischer-Tropsch synthesis, the technical adaptability is poor, and the actual situation that both water and non-alcoholic oxygen-containing organic compounds in the light alcohol are high is not fully considered, resulting in the non-alcoholic oxygen-containing organic compound in the product High content, alcohol content is not up to standard

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