Browsing by Author "Kihedu, Joseph"

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Catalytic tar conversion and the prospective use of iron-based catalyst in the future development of biomass gasification: a review
(Springer Nature Switzerland AG., 2020-06-27) Ramadhani, Bakari; Kivevele, Thomas; Kihedu, Joseph; Jande, Yusufu
Biomass is a promising renewable energy source which is available globally, mostly in developing countries where access to clean and affordable energy is a critical problem. Biomass gasification is an interesting technology that can convert biomasses to a more versatile fuel known as syngas, the energy which can substitute conventional fossil fuels in the future. Syngas can amenably be combusted to produce power and heat as well as a feedstock for synthesis of chemicals and other fuels. The biomass gasification is facing severe operational challenges, one of the problems being tar formation and its removal techniques. Tar condenses at reduced temperature, thus causing blockage in the downstream equipment such as compressors and engines. Many studies have considered syngas cleaning by physical removal and thermal cracking unsuitable as they need downstream processing of scrub liquor and utilizes a part of the produced gas in maintaining the thermal cracking temperature, respectively. The utilization of catalysts has been an interesting focus; however, it has not yet been fruitful as many of the developed catalysts deactivate rapidly, and they are expensive or toxic. The motives of the current study are to review tar formation characteristics and trends on catalytic conversion. In addition, the study elucidates the fascinating behaviour of metallic and oxides of the iron-based catalyst under different syngas composition (oxidizing and reducing environments). The behaviours of the iron-based catalyst indicate its fundamental role in developing a catalyst for tar cracking with respect to less toxic, inexpensive, abundant, and regenerable alternatives.
Mass And Energy Balance For Fixed Bed Incinerators
(Journal of Multidisciplinary Engineering Science and Technology (JMEST), 2015-09) Omari, Arthur; Njau, Karoli; John, Geoffrey; Kihedu, Joseph; Mtui, Peter
An estimation of mass and energy balance of an incinerator is an important consideration toward the design and operation of the incineration process. This paper is aimed to study the mass and energy balance of a locally made fixed bed incinerator. The results shows that the total mass rate of 49 kg/h of municipal solid waste and 9.75 kg/h of diesel consumed 458.9 kg/h of air. The incineration process generates 379,287.14 kJ/h with ash and flue gases emissions at a total mass rate of 528.51 kg/h.