Supercritical esterification modification process for bio-oil

Abstract

The invention provides bio-oil supercritical esterification modifying technology. After being mixed evenly by a static mixer, the reaction raw materials added in a bio-oil high-pressure pump and a methanol high-pressure pump firstly exchange heat with the modified bio-oil by a secondary heat exchanger, then exchange heat with the esterification reaction mixture by a primary heat exchanger, and then are heated by a heating furnace and enter into a supercritical esterification tower; after heat exchange, the esterification reaction mixture goes through an alcohol recovery tower to get the modified bio-oil and alcohol; the alcohol is recycled to use before being returned to the methanol high-pressure pump; after heat recycle, the modified bio-oil is water-separated by an oil-water separating tank and discharged as product.

Description

1. Technical field [0001] The invention relates to a bio-oil supercritical esterification modification process and belongs to the technical field of biomass energy. 2. Background technology [0002] Bio-oil is a thermal cracking liquid product of biomass, with carbon, hydrogen and oxygen content accounting for more than 99.7%. It is a mixture of complex oxygen-containing organic matter and water. Aldehydes, ketone alcohols, phenols and other oxygen-containing organic compounds have low calorific value (half of them are about 20MJ / kg). Unrefined bio-oil has high water and oxygen content (about 40%), contains a large amount of organic carboxylic acid, low pH value (2-3), low volatility, unstable and easy to corrode, and cannot be directly used as vehicle fuel It is only used as a low-end product. In order to convert it into high-quality fuel oil, the current upgrading methods mainly include catalytic hydrogenation, catalytic cracking and catalytic esterification. However, t...

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Problems solved by technology

However, the catalytic hydrogenation of bio-oil needs to consume a large amount of hydrogen, the reaction conditions are harsh, and the investment and operation costs are huge. It is urgent to develop high-efficiency catalysts. 2 and H 2 The form of O is removed, and the liquid yield is reduced; catalytic cracking is also the conversion of oxygen in bio-oil to CO 2 and H 2 The form of O is removed, the cracking catalyst is easy to coke, and the liquid yield is too low, so it is urgent to develop a high-efficiency catalyst; catalytic esterification makes full use of the oxygen element of bio-oil, and the liquid yield is high, but the esterification efficiency is low, and catalyst recycling is difficult. higher processing costs

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