STUDY OF COAL BIODESULFURIZATION BY BIOFLOTATION COMBINED WITH PRE-CONDITIONING USING IRON OXIDIZING BACTERIA AND IRON SULFUR OXIDIZING BACTERIA

• Main Author: ALGAFARI (NIM : 12512005), AZIZ
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/21366
• Institution: Institut Teknologi Bandung

Each year energy needs in Indonesia always increase, for example in the household, transportation, and industrial sector. The largest consumption of energy is from oil, biomass and coal resources in fuel. Coal has more resources and reserves than any other fossil energy, but the main problem in coal exploitation is the sulfur content in it. High level of sulfur can cause SO2 gas emissions, environmental polution in the form of acid rain that can damage industrial equipment, and can be harmful to human. Nowadays coal desulfurization research is being developed primarily to reduce organic sulfur which is difficult to separate even in physical and chemical ways. In this research, biodesulfurization process is done by applying pre-conditioning (biooxidation) method, bioflotation method, and pre-conditioning followed by bioflotation method to the coal from Todongkura, South Sulawesi using Alicyclobacillus ferrooxidans and Pseudoclavibacter aromaticivorans SKC/XLW-1 bacteria. <br /> <br /> The experiment began with a sample preparation of coal by crushing, grinding, sieving and sampling. Coal sample then performed proximate analysis, total sulfur and form of sulfur analysis, FTIR (Fourier Transform Infrared Spectrofotometry) analysis and SEM (Scanning Electron Microscopy) analysis. Pre-conditioning was performed in growth medium variable of bacteria with a constant speed shaker of 180 rpm and a room temperature 25&#730;C within 7 days. Bioflotation is done in several variables including degree of acidity (pH), bacterial concentration and conditioning time. Pre-conditioning followed by bioflotation performed under optimum conditions of biooxidation and bioflotation experiments that have been obtained. These three processes were carried out to study their effects on ash elimination percentage, sulfur elimination and recovery of fixed carbon. Concentrate from pre-conditioning followed by bioflotation were performed another bioflotation to achieve lower percentage of sulfur. <br /> <br /> The initial coal characterization results showed a high total sulfur of 2.34% (%db) with 0.69% pyritic sulfur composition, 0.81% sulfate sulfur and 0.84% organic sulfur. The highest elimination percentage of ash, sulfur and recovery of fixed carbon was achieved by applying pre-conditioning followed by bioflotation method, with 85.92% for total sulfur elimination, 91.70% in sulfate sulfur, 80.15% in pyritic sulfur, and 67.35% in organic sulfur using Alicyclobacillus ferrooxidans bacteria.