Modified coal tar pitch and preparation method thereof

Abstract

The invention relates to modified coal tar pitch and a preparation method thereof. The technical scheme is as follows: the preparation method comprises the steps of firstly, putting 30-40 parts by mass of coal tar pitch into a reaction kettle with a reflux device, then adding 57-67 parts by mass of a mixed solvent into the reaction kettle at 75-95 DEG C, and stirring for 10-15 minutes at a stirring speed of 100-150r / min; secondly, under the condition that the temperature and stirring speed are same, adding 1.8-3.5 parts by mass of a modifier and 0.20-0.35 part by mass of a catalyst, and stirring for 1-4 hours to obtain a modified coal tar pitch mixture; finally, performing reduced pressure distillation on the obtained modified coal tar pitch mixture at 95-110 DEG C to recycle a solvent so as to obtain the modified coal tar pitch. The modified coal tar pitch and the preparation method thereof disclosed by the invention have the characteristics of simple process, low reaction temperature, small dose of the modifier, recyclable solvent and low cost, and can effectively reduce the content of polycyclic aromatic hydrocarbon 3,4-benzopyrene in the coal tar pitch.

Description

technical field [0001] The invention belongs to the technical field of coal tar pitch. Specifically relates to a modified coal tar pitch and a preparation method thereof. Background technique [0002] Coal tar pitch is a bulk product separated during coal tar processing, accounting for 50-60 wt% of the total coal tar. Its processing utilization level and benefits are crucial to the entire coal tar processing. At present, coal tar pitch is mainly used as binder and impregnating agent for carbon electrodes, and also used in carbon black, anti-corrosion coatings, needle coke and carbon fiber, etc. Due to limited downstream demand, coal tar pitch is severely overcapacitated. [0003] Since the 1970s, many countries such as Germany, Switzerland, France and Poland have successively produced and used coal-petroleum-based mixed asphalt for road paving. Long-term use shows that the road surface paved with coal-petroleum-based mixed asphalt has strong deformation resistance, good we...

AI Technical Summary

Problems solved by technology

In this regard, people have carried out a lot of research and achieved certain results: Germany adopts the vacuum distillation method (US 5262043), which uses an evaporation area of ​​330-1000m2 / m3 evaporator, when the pressure is 1MPa and the temperature is 300~380℃, the coal tar pitch is distilled under reduced pressure. The residence time of the coal tar pitch in the evaporator is 2~10min. Although the obtained coal tar pitch contains 3,4 - Benzo[a]pyrene in coal tar pitch: chemical conversion in situ by alkylation, fuel ,75, 1543-1548,1996), using polyethylene glycol (molecular weight>1500) as a polymerization modifier, reacting at 160°C for 0.5~5h, the reduction rate of 3,4-benzopyrene can reach 90%, but The amount of polymer required by this method is as high as 30%, and the cost is high; Chinese scholars (Zhang Qiumin's research on reducing 3,4-benzopyrene in coal tar pitch with polymer reagents, Coal Chemical Industry, 2007 (1), 58-60) added 4 % of coumarone-indene resin into coal tar pitch, the removal rate of 3,4-benzopyrene reached 46.78%, but this method is limited to the removal of 3,4-benzopyrene, which cannot reach coal tar pitch road construction Access Standard Requirements

[0005]In short, there is no efficient and industrialized production technology