| dc.description.abstract | Gasification of biomass is a process that converts organic material into a synthetic gas (syngas) by exposing it to high temperatures in an environment with limited oxygen. This technology supports green energy goals by utilizing renewable biomass, reducing greenhouse gas emissions, and providing an alternative to fossil fuels. Coffee waste, rich in organic material and oils, offers significant energy potential, making them an effective feedstock for biofuel production. This work discusses results on pelletization, sieving of bed materials, cold bed experiment, syngas composition.
In this work, the pellets produced by the pelleting machine were used as feedstock in the gasifier to produce syngas. The waste pellets consist of a mixture of coffee grounds and sawdust. The quality and strength of the pellets decreased with higher moisture contents. The particle size distribution of the bed materials was analyzed through sieving of the bed materials. Experiments were conducted on a cold fluidized bed to determine the minimum fluidization velocity. Gasification experiments were performed in a 20 kW bubbling fluidized bed (BFB) gasifier with sand and olivine as bed materials and air as the gasifying agent. Syngas composition was assessed by gas chromatography. Various equivalence ratios (0.12, 0.17, and 0.24) are experimented, showing that product gas quality declines with an increase in the equivalence ratio at a specific temperature. Olivine is shown to improve syngas concentration more effectively at 650°C than sand at 750°C and 800°C. At 650°C, olivine has produced nearly the same H2 concentration (17%) as sand at 750°C (16.9%) and almost the same CO concentration (14.39%) as sand at 800°C (15%) in product gas. across all tested ER values. At higher temperatures, it is expected that olivine will enhance syngas production, yielding more H2 and CO compared to sand at 750°C and 800°C temperatures. | |
