Authors:
Romero-Perezgrovas Ricardo; Víctor Arboleda, Mildred Linkimer, María Fernanda Romero, Sam Bentson, Alejandra Arroyo, Bert Kohlmann Pages: 1 - 8 Abstract: Biomass is the primary source of energy for cooking in rural Central America. The intensity of labour required to collect wood, levels of pollution resulting from incomplete burning, health problems linked to smoke inhalation, and pressure on forests are among the problems commonly associated with cooking with traditional stoves utilized in the region. Since the 1980s, improved stoves programs have been implemented in the region, but exogenous-developed models have had low adoption rates due to a lack of know-how for construction and repairments, expensive materials, and lack of understanding of local culinary traditions and culture. Sustainable Harvest International (SHI), a non-profit organization, has successfully developed two local improved stoves: the Damak model in Panama and the Mani model in Honduras. In both cases, anecdotal evidence of high rates of long-term adoption has been noted by SHI. Nonetheless, before this study, there has been no systematic evaluation of the efficiency of these two models in respect to 1) daily household wood consumption (kg); 2) particulate matter (PM2.5 ug/m3) concentration in the kitchen, and 3) carbon monoxide (CO ppm) concentration in the kitchen when compared to the traditional stoves used in rural households of both countries. The results presented herein were generated from a study using a random representative sample of 174 stoves and a portable Indoor Air Pollutant Meter manufactured by Aprovecho Research Center (ARC). An analysis of variance processed the data under the general and mixed model frameworks. The results showed that there was a statistically significant average decrease in wood consumption per day per stove for the improved models, as well as a statistically significant average decrease in personal exposure to particulate matter and carbon monoxide for the improved models when compared to those self-same measurements generated by traditional stoves. PubDate: 2021-08-16 DOI: 10.12691/rse-9-1-1 Issue No:Vol. 9, No. 1 (2021)
Authors:
Alhaji Bukar Abubakar; Mohammed B. Oumarou, Fasiu A. Oluwole, Sahabo Abubakar Pages: 9 - 21 Abstract: This paper treats exergy analysis of rice husk at various loading rates of 1 kg, 1.5 kg and 2 kg of feedstock, using a batch type, fixed-bed gasifier, equipped with a gas filtering system and between the operating temperatures of 690 K and 1100 K, operated for the whole year. Exergy analysis is a thermodynamic technique which uses conservation of mass and energy principles to design thermal systems with maximum efficiency and it is based on First and Second law of thermodynamics. Formulas from literature and previous researches as well as Microsoft Excel 2007 were used to make calculations and graphically interpret the results. The exergoeconomic analysis is based on location specific and national data collected from official sources. A MATLAB based hybrid model developed from a combination of other studies is used to generate the exergoeconomic analysis results. Methane was found with the highest total exergies where values of exergies were varying between 1110126 kJ and 1066279 kJ for 2kg; 1037525 kJ and 1004639 kJ for 1.5 kg and finally, 965559.3kJ and 943635.6kJ for a feedstock mass of 1 kg between 690 K and 960 K respectively. From the overall results obtained, the gasification efficiency can be improved by increasing the temperature with an addition of heat in the process. The R2 values of 0.999 to 1 show the true behavior and similarities of the graphs and highlighting the enormous exergy destruction rate in the process. The CO2, CO and NOx capture/avoidance increases the plant efficiency by producing more electricity thereby increasing the financial potential of the plant. From the total exergies of CO2, CO and NOx, $0.156/kg, $0.20/kg and $12.335/kg could be made when sold respectively. The total exergies of gases considerably assist in the exergoeconomic analysis of the gasification plant, when the environmental aspect is considered. PubDate: 2021-09-22 DOI: 10.12691/rse-9-1-2 Issue No:Vol. 9, No. 1 (2021)