Convertion of Spent Coffee Grounds into Environmentally Friendly Solid Fuel Using Wet Torrefaction and Briquetting

• Main Author: Rizky Nugraha, Pratama
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/43767
• Institution: Institut Teknologi Bandung

Spent Coffee Grounds (SCG) is a waste that derived from coffee brewing process. In Indonesia, coffee consumption is increasing each year without any effort to utilize the SCG. Wet Torrefaction is a thermochemical process using water at high temperature and pressure. In previous experiments, this process was able to produce high quality solid fuel. These are the reasons why this research propse the ussage of Wet Torrefaction to increase SCG quality. It’s important to improve the transport-ability of wet torrefaction product, to increase the density of wet torrefaction product briquetting process without binder was used. In this research, the wet torrefaction processing temperature was varied between 150– 200 o C with 0 and 30 min holding time. The solid product from wet torrefaction process was briquetted at the pressure range of 500–1500 bar. The wet torrefaction products and it’s briquettes were then analyzed for their characteristics of heating value, nitrogen content, density, and briquette durability. By comparing their characteristics, the recommended parameters of wet torrefaction and briquetting processes were determined using energy balance of the processes, called the “self-sustainability ratio”. The experiment results showed that wet torrefaction at 175oC and 30 min holding time produce solid product with 31,930.18 kJ/kg heating more than that of Subbituminous C coal . The product nitrogen content of 1.03% similar to that of Indonesian Coal. Solid product from the process could be briquetted at 500 bar of pressure, and had the Drop Shatter Index (DSI), fulfilling the standard of briquette durability.