Study of solid fuel from coconut shell produced by extrusion technique using treated rice straw and molasses as binders

Abstract

The objective was to study solid fuel produced from biomass by cold extrusion technique. The raw materials used comprised crushed coconut shell char and coconut fiber char mixed with two kinds of binders produced from treated rice straw and molasses. In order to investigate the effects of the amounts of binder used on the physical properties of the solid fuel produced, the mass ratio of molasses was varied, at 10:100, 15:100, and 20:100, whereas that of the treated rice straw was 15:100, 20:100, and 25:100. In addition, the effects of mixing the ratios of crushed coconut shell char and coconut fiber char were studied by varying their ratios in the mixture (shell: fiber), at 40:60, 50:50, 60:40 and 70:30. The results showed that when molasses were used as a binder, increasing both the amount of molasses and coconut shell enhanced the compressive strength of the solid fuel produced. When treated rice straw binder was used, compressive strength also increased with the increasing of coconut shell ratios in the raw material mixture, but decreased with increases in the binder ratio. Regarding product output and specific energy consumption, when the amounts of both binders were increased, product output increased, while specific energy consumption decreased. However, the converse was true regarding increasing the amount of coconut shell char. Generally, the compressive strength varied between 2.60-3.00 MPa (molasses) and 0.49-0.79 MPa (treated rice straw), which were considerably higher than acceptable commercial levels. Regarding energy consumption, considerably low electrical energy was used in the extrusion process, at 0.032-0.056 kWh/kg.

Keywords

• extrusion
• binder
• extrusion die
• molasses
• treated rice straw
• solid fuel