Comparison of suitaility of different binding materials in briquette forming

Abstract

The process ofmanual saw dust briquette making was tested with different binding agents in the laboratory with 1.5 ton hydraulic jack. Dry cow dung, wheat flour and paper pulp were selected as binding agents. This briquette was designed with size 35mm Diameter x 35mm length and cylindrical shape. Saw dust was sieved through 2mm screen mesh and 6 different samples were prepared with sieved saw dust and each binding agents as 5%, 10%, 20%, 30%, 40%, and 50% dry basis. Cow dung samples were shown difficulties of mould detaching. Wheat flour and paper pulp binder samples with 5%, 10%, and 20% (dry basis) binders also failed onmould detaching due to breaking of briquettes. The minimum requirement of binder percentage was found to be with 30% dry binder of wheat flour and paper pulp to form stable briquette and hence it was selected for comparison of properties. Densities of briquettes with 30% binder of wheat flour and paper pulp were 373.7 kg/m3 and 289.8 kg/m3 respectively. Compression behavior of briquettes with 30% (dry basis) binding agents was examined for cyclic loading applied using the hydraulic jack. Maximum load of 110kg (35.9 kg/cm2 pressure) was maintained for all the experiments. Number of force cycles needed to reach the pre-determined load was recorded; paper and wheat flour binder briquettes were needed five cycles and cow dung briquettes were needed additional two cycles. Natural drying time was evaluated at 86~89% relative humidity and 25~30oC ambient temperature, It was recorded that briquettes came to 25% moisture content (Wet basis) within 33 hours and 20% moisture content (Wet basis) within 35 hours. Compressive strength of the briquettes was tested for binder percentages of 30%, 40% and 50% (dry basis)of wheat flour and paper pulp binders. Results have indicated that compressive strength increased with the increase of binder percentage. Paper binder briquettes have comparatively high compressive strength in the range of 0.124N/mm2 to 0.238N/mm2 while wheat flour briquettes have 0.032N/mm2 to 0.055N/mm2. Calorific values of raw materials and briquettes were tested. Briquettes obtained from 30% paper binder and 30% wheat flour binder has calorific values of 18.14MJ/kg and 20.04MJ/kg respectively.