The Effect of Wood Tar and Molasses Composition on Calorific Value and Compressive Strength in Bio-coke Briquetting

Abstract

According to the Forest Department, industrial waste is up to 60%, which means that only 40% of wood is used in the wood processing industry. Biomass-based materials have the potential to replace fossil fuels for blast furnaces in the steel manufacturing industry. The purpose of this study was to determine the effect of a composition mixture of wood tar and molasses as a binder on the calorific value and compressive strength of bio-coke. Redwood waste carbonization to produce high-quality charcoal was carried out at a temperature of 500 °C with a 20 rpm kiln rotation speed and a slope of 5 °. The resulting charcoal showed a promising result with a calorific value of 5701 kcal/kg. The redwood carbonization process increased the fixed carbon value by up to 130% and the calorific value also increased 40%. The second part of this work focuses on bio-coke production by blending coking coal with redwood charcoal at 90:10 by weight. The particle sizes of coking coal and redwood charcoal are 40 and 50 mesh, respectively. 15% wt. binder is added to increase the compressive strength of bio-coke; the binder ratio between molasses: wood tar is 15:0, 12.5:2.5, and 10:5 percent by weight. The briquette was pressed to form a cylinder die with a height:diameter of 2.7:5 cm, then compacted at 20 MPa followed by heating at 1100 °C for 4 hours. Bio-coke with a binder composition (2.5% by weight wood tar + 12.5% by weight molasses) produces a compressive strength up to 5.57 MPa with a sulfur content of 0.8% by weight and produces a calorific value of 7463 kcal/kg with an ash content of 9.6%. The study shows that bio-coke production meets some requirements for blast furnace applications.