Pre-Treatment of Coal using Acid Leaching Method as Co-gasification of Low-Rank Coal and Biomass Feed

• Main Author: NISRINA FIRDAUSI (NIM : 13014038) - RYZKA PRANATA (NIM : 13014093), HASNA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/27772
• Institution: Institut Teknologi Bandung

<p align="justify"> Conventional coal utilization creates problems for the environment. One of the environmentally friendly coal utilization process is gasification. Gasification is able to produce hydrogen gas which is widely used in chemical industry. However, most of Indonesian coal is low-rank coal, so if it’s gasified will result in low gas conversion. Increasing hydrogen gas can be carried out by the addition of catalyst in the form of alkali and alkaline earth compounds. These compounds can be found in biomass ash, so co-gasification of coal and biomass is the right solution. However, coal contains silica, a compound that deactivate alkali and alkaline earth compounds in gasification process. Silica can be removed by demineralization process. One of demineralization method is washing coal with acidic solutions, such as HF and HCl, or often called acid leaching. <br /> <br /> This research aims to determine the effect of the solution type, solution concentration, reaction temperature, reaction time, and coal particle size of demineralization process. The raw material that used is two types of coal, namely subbituminus and lignite. The acid solution used in this research is HF and HCl. This research conducted by washing coal with acid solution at certain temperature for a certain time. Ash content of coal analyzed before and after demineralization process. At some variation, the surface area and element content of coal were analyzed. <br /> <br /> Demineralization using HF and HCl could decrease ash content of coal, including silica. The silica content was reduced by 75.24-92.57% with HF solution and 68.57% with HCl solution. The type and concentration of acid solution, temperature, time, and particle size have a significant effect on the decrease of coal ash content. The surface area of coal increases after demineralization process both on the use of HF and HCl solutions. <p align="justify">