Preparation method of environmentally friendly modified coal tar pitch

Abstract

A preparation method of environmentally friendly modified coal tar pitch comprises the steps that medium-temperature coal tar pitch and a potassium hydrogen sulfate catalyst are mixed evenly, meanwhile an aprotic organic solvent low in boiling point and easy to recover and a 10-undecenal modifier are added to make the mixture fully dissolved, continuous stirring is performed at a certain rotation speed, and reflux condensation reaction is performed at the temperature of 30-70 DEG C for 1-8 hours; after reaction is completed, the aprotic organic solvent low in boiling point and easy to recover is recovered, aeration drying is conducted on the obtain solid substance for 24 hours, namely the environmentally friendly modified coal tar pitch is obtained. The operation process is simple, the usage amount of the modifier is small, the usage amount of the catalyst is also small, the reaction temperature is low, the solvent can be recycled, and the industrial production cost is low. The total content of 16 types of emphasized toxic polycyclic aromatic hydrocarbons, detected by coal tar pitch American EPA, in the coal tar pitch after modification is greatly reduced, and medium-temperature coal tar pitch is modified into low-temperature coal tar pitch.

Description

Technical field [0001] The invention relates to a preparation method of environmentally-friendly modified coal tar pitch. The specific method is a preparation method of environmentally-friendly coal tar pitch using 10-undecenal as a modifier. [0002] technical background [0003] China is the country with the largest metallurgical coke production and consumption in the world. The National Bureau of Statistics announced that China’s coke production in 2014 was 476 million tons. Calculated on the basis of 5% coal tar by-product per ton of coke, China’s annual high-temperature coal tar output can reach more than 20 million tons. According to a 50-60% yield, the high-temperature coal tar pitch that can be produced by coal tar processing enterprises (hereinafter referred to as Coal pitch) can reach more than 10 million tons, and the price is low. Except for a very small amount of coal pitch used as electrode pitch binders and carbon materials, most of these by-products are used for fue...

AI Technical Summary

Problems solved by technology

The method is to fully freeze the coal tar pitch at a brittle temperature, and then pulverize it to obtain asphalt powder less than 80 meshes, add the pitch powder to the potassium permanganate solution at room temperature, keep the stirring speed, and react for 180 minutes. The reduction rate of benzo[a]pyrene content in modified coal tar pitch is more than 65%. However, since the modifier uses highly oxidizing potassium permanganate, it is very easy to cause premature oxidation and aging of coal tar pitch during the modification process, thereby reducing Properties of coal tar pitch

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