Energy Evaluation and Techno-economic Analysis of Low-Rank Coal (Victorian Brown Coal) Utilization for the Production of Multi-products in a Drying–Pyrolysis Process

In this paper, utilization of Victorian brown coal in a drying–pyrolysis process to make products is techno-economically assessed. The pyrolysis process is coupled with the drying and briquette making processes in order to improve the overall efficiency and quality of the products. The pyrolysis process led to the production of char, liquid oil, and hydrogen-rich noncondensable gases. A steady-state Aspen Plus simulation model was developed that provides estimated mass and energy balances for the overall system. The effect of a change in the heating mode and heating medium of the dryer on the overall energy and overall product yields was examined. Additionally, the effect of a change in the pyrolysis gas composition and coal initial moisture was studied. Results revealed that the rotary drum dryer with hot flue gas as a heating medium showed the best performance in terms of the final yields of the pyrolysis products and CO2 emission rate. In the best case scenario, when hot flue gas is used directly in a ...