MST-Department of Energy Engineering

Permanent URI for this collection

https://repository.ku.ac.ke/handle/123456789/3662

Browse

Browsing MST-Department of Energy Engineering by Author "Laichena, Justus K."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Enhancing efficiency of biomass carbonization for high Quality and quantity charcoal production by using Metallic clay insulated kiln
    (Kenyatta University, 2014) Mulei, Fredrick Mwange; Laichena, Justus K.; Okwach, Silvester
    The main objective of this study was to construct a metallic clay insulated kiln to enhance charcoal yield in quality and quantity. This research project aims at improving the charcoal quality in terms of calorific value and smoke - free, and maximum yield of charcoal (per kilogram of biomass substrate loaded). The quantity of charcoal harvested per kilogram of primary four biomass materials loaded as substrates was determined in four tests in each substrate. The main objective was to develop metallic clay insulated kiln with high efficiency, economical and environmentally friendly. metallic clay insulated kiln would offer solution to the problems of low efficiencies of existing charcoal kilns, for example, Traditional Earth Mould Kiln, Mark V. Kiln, Beehive kiln, and Half Orange kiln, among others. These kilns have efficiency of 10%, 31%, 32% and 28.8%, respectively, compared to the achieved 40.85 ± 5.04 % for this metallic clay insulated kiln. In this research a metallic clay insulated kiln was constructed and tested. The major aspect is that a proto type 0.15 m' drum was used to provide feedstock housing. This was tightly covered such that no fraction of feedstock was burned to provide carbonization heat. Clay insulation housing was constructed while the drum was provided with metallic stands and each of the substrates was loaded in the drum. Insulation wall made of clay/mud was constructed to prevent heat loss from the drums and combustion area. The quantity of charcoal produced from the metallic clay insulated kiln was compared with the quantity of wood substrate used. To determine the quality of the charcoal (in terms of calorific value and smoke), universal standard charcoal testing method was used that is Water Boiling test. The quality of charcoal produced from the kiln was then compared with charcoal produced from other different existing kilns in the literature. The data analysis was done by the help of statistical package for social science (SPSS) and Microsoft Excel. In conclusion, efficiency of charcoal production should be emphasized so as to make the practice of charcoal production sustainable by use of metallic clay insulated kiln. It was also found that metallic clay insulated improved kiln had higher efficiency (40.85 ± 5.04 %) than existing kilns such as Beehive, Mark V, Half Orange, Traditional Earth Mould, drum kilns adopted by FAO and others. Adoption! utilization of the metallic clay insulated kiln (with high efficiency as obtained in this research project (40.85 ± 5.04 %)) will reduce/cut-off the problems experienced in use of the _existing low - efficiency kilns. It is both an economical benefit, and environmental friendly. Charcoal production using improved charcoal kilns with high efficiency would give much higher yields of charcoal of excellent quality (in sense of HHV and smoke-free). This can make the practice very profitable, and users will have motivation for sustainable production of charcoal.
  • Thumbnail Image
    Item
    Utilization of energy saving Cookstove Technology: The case of improved institutional cookstoves in Kisii and Nyamira Districts of Kenya
    (Kenyatta University, 1999) Mosomi, Evans Nyamweya; Laichena, Justus K.
    The main objective of this study was to determine the factors that influence the adoption and utilization of improved institutional cookstoves, which have a higher thermal efficiency, are safer to use, and are more user-friendly than the traditional cookstoves. Evaluation of the utilization, operation, and maintenance of the improved cookstoves, by those using them, was another major objective of the study. The study was carried out in institutions that offer catering services in Kisii and Nyamira Districts of Kenya. These included schools, colleges, hospitals and hotels. The study area falls under the highly populated regions of the country, where the shortage of fuelwood is currently acute. Institutions used in the study were randomly selected and constituted 61% all of the institutions offering catering services in the study area. These included 53 schools, 4 colleges, 10 hospitals, 10 hotels and restaurants. Three manufacturers-cum-disseminators of improved institutional cookstoves were also interviewed, two of which were based in Nairobi and one in the study area. The study was conducted by use of questionnaire and interview method. By use of three different sets of questionnaires, responses from the interviewee and observations by the interviewer were recorded. The first set of questionnaires was for cateresses and/or administrators of the study institutions, the second for kitchen staff, and the third for the cookstove manufacturers-cum-disseminators. Only 57% of the sample institutions were found to have adopted and were using the improved cookstoves. This is rather low considering the acute shortage of fuelwood in the study area, hence the need for use of energy-saving devices. The study established the main factors causing hindrance to the adoption of institutional improved cookstoves as the lack of awareness, among the non-users, on the existence and advantages of the improved cookstoves and the lack of information on where to acquire them. A reasonable number of the non-users knew about the improved cookstoves, had interest of acquiring them, but did not know where to buy them from. The initial cost of the improved cookstove was also reported as a limiting factor, though not rated very high. Reduction in the fuelwood used for a given cooking activity was generally acknowledged as being attainable with usage of the improved cookstoves. Such fuelwood saving translated directly to monetary gain through reduced expenditure on the cost of purchasing fuelwood. The study also found that the most desired characteristics of the improved cookstoves, by the kitchen staff, are that they provide a smoke-free and cool kitchen environment, are safer to work with, cook faster and keep the food hot for a long period after cooking. They however did not like their lack of tilting mechanism. In spite of the numerous advantages cited, the study showed that there were some users of the same cookstoves who did not realise their advantages. This was due to misuse of the cookstove through improper operation, poor preparation of fuelwood, poor or no maintenance of the cookstove system, and failure to repair or replace broken or damaged parts of the cookstove. This was mainly due to lack of training on the operation, repair, and maintenance of the improved cookstoves. Manufacturers-cum-disseminators of improved cookstoves by conceded that they had not marketed the cookstoves widely. This was actually the cause of the lack of awareness to potential buyers. There is, therefore, a clear need for better promotion strategies by the disseminators of the improved cookstoves since there is an existing large market.