ABSTRACT
The tannery industry makes use of hides and skin which are by-products of meat industry to produce leather. In the course of leather production, a huge amount of solid waste is generated. For instance, processing 1000 kg of hide will produce 870 kg of solid waste which implies that only 270 kg goes into the finished leather. The problem of the tanner is to find an economic use for the collagen and other by-products not sold as leather which are polluting the environment and posing a threat to health. This thesis was aimed at the development of briquette from tannery solid waste. The compression molding machine installed in Nigerian Institute of Leather and Science Technology, Zaria, Kaduna State was employed in the briquette production. Cassava starch was used as a binder. The elemental analysis of the raw material shows that 372,300 3,351 mg/kg, 68,580 274 mg/kg, 15,190 198 mg/kg, 6,770 528 mg/kg, 6,5627 mg/kg, 4,9095 mg/kg, 4,15375 mg/kg and 1,259180 mg/kg for Calcium Chlorine, Aluminum, Magnesium, sodium, Chromium, iron, and potassium, respectively. The briquette properties such as particle size, presence of binder, moisture content, volatile matter, ash content and calorific value were found to affect the quality of the briquettes. Briquettes with high moisture content such as 0.6844%, 1.0767% and 1.2615% had the highest calorific values of 20,140.2 kJ/kg, 22,141.3 kJ/kg and 24,101.3 kJ/kg respectively. These briquettes had in their composition high content of fleshing with a calorific value of 14,570 kJ/kg. Cassava starch used as binder had a calorific value of 159.48kJ/kg and was observed to have affected the briquette calorific value and compressive strength. The ratio of solid waste to binder were 40:60, 50:50 and 100:0. Briquettes with varying particle sizes of waste were found to be of better quality than those with uniform particle sizes. The particle sizes were 0.5 mm for fleshing, chrome shavings and buffing dust, and 1.0mm for hair. Briquettes with compressive strength of 0.2173 kN/cm 2, 0.1910 kN/cm2 and 0.1742 kN/cm2 were found to be more durable with durability of 99.23%, 99.27% and 99.77% respectively. The briquette without binder was the least durable by 98.12% even though it had the highest calorific value of 24,101.3 kJ/kg. The economic analysis shows that the production of briquette from tannery solid waste was feasible and also viable. Briquette production plant with 8460 tons capacity will require a total investment of N3,732,056 and pay-back period will be within five years at the rate of about 19% per year. Acceptability survey showed that in Hayin Danyaro and Zango, Samaru, Kaduna state, 96% of female respondents and 86% of male respondents were willing to switch over to using fuel briquettes to meet their cooking and heating needs.