EFFECT OF LIGNITE PRE-TREATMENT ON COAL BIO-SOLUBILIZATION PRODUCT SPECIFICATION

• Main Author: Nurramdani Solihah, Nendry
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/42303
• Institution: Institut Teknologi Bandung

Indonesia has an enormous amount of resources coal with about 166 billion ton and reserve of 37 billion ton. Coal production in Indonesia at 2018 reach 548,58 million ton where about 20,96% is used locally while the rest is exported. Utilization of coal as fuel is still limited due to the problem of ash and emission generated from coal combustion. There are several coal processing technology, such as carbonization, combustion, gasification, and solubilization that can be carried out thermally or biologically. Coal solubilization that uses microorganism as solubilizing agent is called bio-solubilization. Coal needs to undergo pre-treatment changing hydrophobic structure to be hydrophilic structure. Coal structure influences the enzyme adsorption onto the coal. This research focuses on the effect of coal pre-treatment toward the result of coal bio-solubilization. Coal bio-solubilization was done by Neurospora intermedia in Vogel agar media for five days in a petri dish. Coal used for bio-solubilization process consists of initial coal (B1), physical treatment by exposing the coal with 511 Watt microwave radiation for 5 minutes (B2), chemical treatment by immersing the coal in 8 M HNO3 for 48 hours (B3), and combination of microwave radiation and HNO3 immersion with varied concentration of 2, 4, 6 and 8 M for 48 hours (B4, B5, B6, and B7). Result of isothermal adsorption, proximate and ultimate analysis shown that there were differences in surface area, volume, pore diameter, and coal content between initial coal and pre-treatment coal. The black liquid above surface of Vogel agar indicates that bio-solubilization process has occurred. Sample B1, B2, B4, and B5 could not be solubilized by N. intermedia, while B3, B6, and B7 were solubilized easily since the first day. Humic acid concentration of black liquid produced from B3, B6, and B7 were 186,12; 42,32; and 91,5 mmol/L, respectively. The proximate analysis shown that bio-solubilization percentage for B3, B6, and B7 was, in sequence, 67,66%; 51,75%; and 45,83%.