Hybrid Coal: Effects of Coal and Biomass Types Towards Product Quality

• Main Author: Malvino Sianipar, Alwyn
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/38383
• Institution: Institut Teknologi Bandung

Coal is an abundant source of energy in Indonesia, but its utilisation is limited because Indonesia’s coal reserves are dominated by low rank coal. On the other hand, biomass is an alternative source of energy which are also abundant in Indonesia. Coal and biomass can be utilised together using co-torrefaction to form hybrid coal. The purpose of this research is to analyse the effects of coal and biomass types on hybrid coal solid yield, calorific value, energy yield, and potential non-neutral CO2 emission reduction. The feedstocks used in this research are two types of lignite coal, namely X and Y, and three types of biomass, namely sugarcane bagasse, rubberwood, and empty palm fruit bunch. Co-torrefaction is done for mixture containing 30%-w/w biomass in a vertical tubular furnace reactor in an inert environment, at ambient pressure and temperature of 300oC for 60 minutes. Results show that solid yield ranges from 57.0 to 63.8% and only biomass type gives a significant effect. There is an increase in fixed carbon content and there are decreases in moisture content, volatile matter content, and O/C and H/C values in the product which increase the calorific value of hybrid coals by 37.6 - 44.1% to 5681 - 6288 kcal/kg. The calorific value of hybrid coal from Coal Y is higher than those from Coal X. The energy yield ranges from 77.0 to 89.0% with similar trend found as the solid yield. The product reduces non-neutral CO2 emissions in the range of 18.1 - 22.2%. Y coal and rubberwood sawdust produce hybrid coal with the largest CO2 emission.