Effect of Carbonization Temperature on the Product Distributions and Characteristics for Integrated Mild Liquefaction and Carbonization of Low-Rank Coals

Abstract

In order to realize the efficient conversion of low-rank coals, an integrated mild liquefaction and carbonization (IMLC) technology was proposed, and the effect of carbonization temperature (CT) on the product distributions and characteristics from the simulated IMLC technology was investigated. Results show that about 30.34–40.02% of liquid products (LPs) and 40.64–56.25% of semicokes (SCs) can be obtained from the IMLC process at the CT of 410–600 °C. The adopted carbonization process is an effective measure to separate the solid and liquid products from the coal liquefaction process, and the obtained SCs contain no n-hexane soluble fractions (HSs). The LPs present a quite high HS content (82.20–90.80%) and a small quantity of asphaltenes and preasphaltenes, and the HSs are predominantly abundant with aliphatics, alkyl benzenes, and alkyl naphthalenes, indicating that the LPs are potentially suitable for utilization to produce liquid fuels by further refining. The obtained SCs could be used as a binder to reduce the use of high-coking coals in the coke-making of coal blends or as fuel of boilers to substitute for anthracite, depending on the conditions of the carbonization process. The proposed IMLC process could realize the economic and efficient conversion of low-rank coals into LPs and SCs under mild conditions.