Optimization of Aceh Low-Rank Coal Upgrading Process with Combination of Heating Media to Reduce Water Content through Response Surface Method

Abstract

This research aims to improve the rank of coal in Aceh, which is known to have a relatively high moisture content of 44-52%. The upgrading process uses hot water and hot oil as media combined with microwaves to remove moisture content in coal. The process was carried out using microwave rotary dryer equipment by varying the coal particle size of 10, 20, and 30 mesh and the time for 20, 40, and 60 minutes. Response surface methodology using the Central Composite Design (CCD) method was used to determine the optimum conditions for low-rank coal, which resulted in 9 runs of low-rank coal experiments. The quadratic polynomial model was validated with the correlation coefficient, R2 value being 0,994. Optimization has been done by maximizing the moisture content of low-rank coal at 4,906 Kg and decreasing it by 20% by setting the particle size and time at 5 Mesh M and 20 minutes, respectively. As a result, this research is projected to be a reference for developing coal upgrading methods in Aceh that can be applied from the laboratory to the commercial scale.