Method for separating and recycling organic solvent from dregs evaporation tail gas

Abstract

The invention discloses a method for separating and recycling an organic solvent from dregs evaporation tail gas. An adsorption tower is filled with high-microporous-hydrophobicity adsorption resin to adsorb the tail gas. The recycling method comprises the following steps: coarse filtering of the tail gas, initial cooling of the tail gas, secondary cooling of the tail gas, removal of tiny dreg powder, VOCs adsorption, resolving and condensation recycling, wherein the adsorption tower in the separating and recycling method is of a semi-fixed bed structure, and an adsorption material can be always retained below a pore plate and a stainless steel net, so that no fluidization phenomenon is caused, and crushing of the adsorption material is avoided. The method disclosed by the invention overcomes the shortcoming that VOCs in the dregs evaporation tail gas cannot be adsorbed and recycled in the prior art; and according to the method, the VOCs can be recycled, and the tail gas is discharged to reach standard, so that the blank of the industry is filled.

Description

technical field [0001] The invention relates to the technical field of treating tail gas from meal distillation, in particular to a method for separating and recovering organic solvents in tail gas from meal distillation. Background technique [0002] China is a country with a large population and a large consumption of edible oil. According to statistics, the annual production and consumption of edible oil in the country is about 28.5 million tons. Edible oils are mainly soybean oil, rapeseed oil, peanut oil, corn oil, etc. More than 95% of the processes used to produce these edible oils are leaching processes. The fat components are extracted and then refined for public consumption. Necessary treatment is generally required for the remaining product meal. The meal is steam-heated to evaporate the solvent in the meal and form a qualified product for sale. The evaporated solvent and water vapor are mixed and discharged at high altitude after treatment to form The mixed dis...

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Problems solved by technology

Due to its light specific gravity and particle size between 0.4mm-1.0mm, it is difficult for the packing layer to achieve the same compactness and density. When the gas is forced to pass through the adsorption resin packing layer under the action of a certain wind pressure induced fan, A place with relatively low compactness and density will generate a high flow rate, which will cause the adsorption resin to churn locally, so that a large amount of gas will be discharged without sufficient contact with the adsorption material, and the removal rate of VOCs will be seriously reduced; at the same time, the tumbling of the adsorption resin will cause Broken and pulverized, the fine adsorption resin will be discharged out of the adsorption tower with the air flow, causing losses, so it is necessary to replenish the adsorption resin regularly and increase the operating cost

Therefore, in order to prevent the adsorption resin from being broken due to fluidization during use, it is necessary to increase the diameter of the adsorption tower to reduce the gas flow rate, which undoubtedly increases equipment investment and the amount of adsorption resin used, and limits the popularization and application of resin adsorption technology. Especially for gas with a large air volume, the air volume of the tail gas from meal solvent evaporation in edible oil production enterprises is generally above 10,000 cubic meters per hour

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