Study on autoclave evaluation test conditions of direct coal liquefaction

Autoclave test is one of the most important means to study the reactivity of coal in direct coal liquefaction.The results of autoclave test is used to evaluate the reactivity of direct liquefaction of coal and provide basis for the determination of continuous pilot test conditions.In order to establish the national standard of the test method of autoclave in direct coal liquefaction,the autoclave test was carried out on several kinds of coal under different conditions and the test products were analyzed. The results show that the direct liquefaction test of coal is superior by using the 0.5 L batch stirred autoclave and the optimal conditions are: the reaction temperature is 450 ℃,the initial H2 pressure is 8 MPa, the constant temperature time is 120 min,the weight of coal sample loading is 20 g (dry-ash-free), the ratio of the iron-based catalyst is 3%, the heating rate is (8±0.5)℃/min and the stirring speed is (400±20) r/min. The repeatability limit of oil yield is 3.0% and the reproducibility limit is 5.0%, the repeatability limit of conversion rate is 3.0% and the reproducibility limit is 4.0%. Establishing and unifying the method to estimate the reactivity of coal in direct coal liquefaction as well as stipulating the repeatability limit and the reproducibility limit. This also makes the data comparable,so as to provide accurate analytical data for industrial production and technical study.