Fiseha Mekonnen Guangul

Gasifier selection, design and gasification of oil palm fronds with preheated and unheated gasifying air.

Oil palm frond biomass is abundantly available in Malaysia, but underutilized. In this study, gasifiers were evaluated based on the available literature data and downdraft gasifiers were found to be the best option for the study of oil palm fronds gasification. A downdraft gasifier was constructed with a novel height adjustment mechanism for changing the position of gasifying air and steam inlet. The oil palm fronds gasification results showed that preheating the gasifying air improved the volumetric percentage of H(2) from 8.47% to 10.53%, CO from 22.87% to 24.94%, CH(4) from 2.02% to 2.03%, and higher heating value from 4.66 to 5.31 MJ/Nm(3) of the syngas. In general, the results of the current study demonstrated that oil palm fronds can be used as an alternative energy source in the energy diversification plan of Malaysia through gasification, along with, the resulting syngas quality can be improved by preheating the gasifying air.

The Study of Temperature Profile and Syngas Flare in Co-gasification of Biomass Feedstock in Throated Downdraft Gasifier

Biomass gasification is a common technology, which converted solid biomass into gaseous fuel at high temperature reactions in the presence of gasification agent. In this paper, co-gasification of lignocellulosic biomass materials with oil palm fronds (OPF) in a downdraft gasifier is presented. The biomass feedstocks considered were sugar cane bagasse (SCB) and wood (acacia mangium). Only one material was co-gasified with OPF at a time, with blending ratios of 80:20, 50:50 and 20:80. The resulting temperature profiles in the reactor and the syngas flare duration were recorded. It was found that the blend of 80:20 wood and OPF gave the best result as it produced the longest steady flare duration (49.5 min). On the other hand, a significant bridging problem was observed in the co-gasification OPF and SCB, and thus implying the need for process improvement.

Temperature profile and producer gas composition of high temperature air gasification of oil palm fronds

Environmental pollution and scarcity of reliable energy source are the current pressing global problems which need a sustainable solution. Conversion of biomass to a producer gas through gasification process is one option to alleviate the aforementioned problems. In the current research the temperature profile and composition of the producer gas obtained from the gasification of oil palm fronds by using high temperature air were investigated and compared with unheated air. By preheating the gasifying air at 500?C the process temperature were improved and as a result the concentration of combustible gases and performance of the process were improved. The volumetric percentage of CO, CH4 and H2 were improved from 22.49, 1.98, and 9.67% to 24.98, to 2.48% and 13.58%, respectively. In addition, HHV, carbon conversion efficiency and cold gas efficiency were improver from 4.88 MJ/Nm3, 83.8% and 56.1% to 5.90 MJ/Nm3, 87.3% and 62.4%, respectively.

Elemental and thermo-chemical analysis of oil palm fronds for biomass energy conversion

Oil palm frond is the most abundant yet untapped biomass waste in Malaysia. This paper investigates the characteristics of raw oil palm fronds and its ash to evaluate its potential utilization as a biomass fuel for gasification process using single throat downdraft gasifier. The morphological nature, elemental content, proximate and ultimate analysis and calorific value were studied. Field emission scanning electron microscopy and x-ray fluorescence were used to investigate the surface morphology, elemental and mineralogical nature of oil palm frond and its ash. The results were compared with other agricultural and forestry biomass wastes. From proximate analysis volatile matter, fixed carbon and ash were found to be 83.5%, 15.2% and 1.3%, respectively on dry basis. From ultimate analysis result values of 44.58%, 4.53%, 0.71% and 0.07% for carbon, hydrogen, nitrogen and sulfur were found respectively on dry basis. Oxygen was determined by difference and found to be 48.81%. The proximate and ultimate analy...

Gasification and effect of gasifying temperature on syngas quality and tar generation: A short review

Corrosion, erosion and plugging of the downstream equipments by tar and ash particle and, low energy content of syngas are the main problems of biomass gasification process. This paper attempts to review the findings of literature on the effect of temperature on syngas quality, and in alleviating the tar and ash problems in the gasification process. The review of literature indicates that as the gasification temperature increases, concentration of the resulting H2 and carbon conversion efficiency increase, the amount of tar in the syngas decreases. For the same condition, CH4 and CO concentration do not show consistent trend when the feedstock and gasification process varies. These necessitate the need for conducting an experiment for a particular gasification process and feedstock to understand fully the benefits of controlling the gasification temperature. This paper also tries to propose a method to improve the syngas quality and to reduce the tar amount by using preheated air and superheated steam as a gasifying media for oil palm fronds (OPF) gasification.Corrosion, erosion and plugging of the downstream equipments by tar and ash particle and, low energy content of syngas are the main problems of biomass gasification process. This paper attempts to review the findings of literature on the effect of temperature on syngas quality, and in alleviating the tar and ash problems in the gasification process. The review of literature indicates that as the gasification temperature increases, concentration of the resulting H2 and carbon conversion efficiency increase, the amount of tar in the syngas decreases. For the same condition, CH4 and CO concentration do not show consistent trend when the feedstock and gasification process varies. These necessitate the need for conducting an experiment for a particular gasification process and feedstock to understand fully the benefits of controlling the gasification temperature. This paper also tries to propose a method to improve the syngas quality and to reduce the tar amount by using preheated air and superheated steam as ...