The effect of molasses addition as binder on properties of dry cow dung pellet Ari Diana Susanti (a*), Wusana Agung Wibowo(b), Paryanto(c)
Department of Chemical Engineering Universitas Sebelas Maret Jl. Ir. Sutami No. 36 A Surakarta, Indonesia
Indonesia has abundant availability of low calorie-density waste biomass, such as dry cow dung. Improving of this low properties is needed to fulfil the requirements as renewable fuel in thermochemical process. Biomass pelletizing is a promising technology to improve the physical and thermal properties of biomass. Binders may be employed to improve the particle adhesion, compressive strength, and energy content of densified biomass. In addition, molasses as abundant waste of sugar industries is possible to be used as binder. This study dealed with the influence of molasses addition on physical, chemical, and thermal properties of dry cow dung pellet. Molasses addition of 0%, 5%, 10%, and 15% by weight from total mass of mixture were then used as raw material of pellet production by hydrolic press machine with 5 tons pressure for one minute pressing time. We found that, the heating value of loose dry cow dung was 4122 kcal/kg and the addition of molasses will reduce the heating value of biomass mixture by 3% to 5%. The addition of molasses increase the water content, ash content, and fixed carbon content of mixture by 2.5% to 5.8%, 0.8% to 2.0%, and 4.0% to 2.6%, respectively, but decrease volatile matter content by 4.0% to 6.0%. Pelletization of these mixtures reduced the water content by only 1% to 4%, while increased volatile matter content by 1% to 8%. Therefore, the heating values were slightly increase by 0.2% to 0.6%. In term of pellet density, the addition of molasses will reduce its density to 1.11, 1.04, and 1.02 g/cm3, respectively, compared to 1.17 g/cm3 for 0% molasses. Therefore, significant reduction on energy densities were found to be 7%, 14%, and 17%, respectively, compared to 4828 kcal/dm3 for 0% molasses. Furthermore, the addition of molasses were signicantly reduce the compressive strength of pellet.