Tamarindus Indica fruit shell ash: a low cost and effective catalyst for biodiesel production from Parinari curatellifolia seeds oil

This research article published by Springer Nature Switzerland AG., 2019The study evaluated the potential use of agricultural waste, Tamarindus indica fruit shell ash, as a solid base catalyst for production of biodiesel. The catalyst was prepared by calcination of T. indica fruit shell at 800 °C in mufe furnace for 3 h. Branauer-Emmett-Teller, thermal gravimetric analysis, X-ray difraction, scanning electron microscope, X-ray forescence, and Hammett indicator techniques were used to characterize the physicochemical properties of the produced catalyst. The catalyst had basic strength of greater than 9.7 and mesoporous structure with pore size d=3.2 nm. The crystalline phase was made up of calcium oxide, potassium oxide, and magnesium oxide. The catalyst was tested for biodiesel production using Parinari curatellifolia seeds oil. The results showed that the best operating parameters for the production of biodiesel were 9:1 methanol to oil molar ratio, 125 mg catalyst (5 wt% of oil), 2 h reaction time, and 60 °C reaction temperature. These optimized operating parameters aforded a maximum yield of 96.2%. Also, fuel properties of biodiesel: acid value, viscosity, and fash, pour, and cloud points were investigated and compared to the ASTM standards limits D6751. The results were observed to be in good agreement with the ASTM standards limits for biodiesel. In addition, the catalyst was easily separated and subsequently reused for four runs in biodiesel production. Thus, Tamarind fruit shell derived catalyst is very promising for the production of biodiesel due to its high performance, low-cost, easy preparation and availabilit

Experimental Study of a Lab Scale Hybrid Fixed Bed Gasifier

This research article published by Science Publishing Group, 2020Thermo-chemical conversion technologies (incineration, gasification and pyrolysis) have emerged as potential technologies for municipal solid waste management (MSWM). This is happening due to the increase of the need for clean and sustainable energy as a result of fossil fuel depletion. The increase in municipal solid waste (MSW) generation as well as land scarcity for MSW disposal is another reason in raising the potential for thermal technology. Incineration has been the most common thermo-chemical technology for solid waste disposal. However, due to environmental concern, gasification technology is currently becoming more preferable since it is environmental friendly for MSW disposal as well as energy recovery. The aim of this study is to analyze the flue gases obtained from the hybrid fixed bed gasifier during gasification of MSW. The fire was initiated by wood charcoal and six kilograms of MSW was fed in the gasifier. The combustion was supported by the air supplied by electric blower. The flue gas analyzer, TESTO 327-1 was used to analyze the concentration of CO, CO2 and O2. Results show that after 150 minutes of the gasification process, O2 concentration increased by 17.2% while CO and CO2 decreased by 0.0% and 3.77% respectively. The experimental results show that, during gasification process the O2 concentration was increasing with time while CO and CO2 concentration decreased

Theoretical and Experimental Performance Analysis of a Novel Domestic Biogas Burner

This research article published by Hindawi, 2020The inefficient indoor burning of fuelwood on traditional cookstoves generates pollutants, primarily carbon monoxide and many other human health-damaging emissions. It is from this risk that it is necessary to have an immediate shift to alternative cleaner fuel sources. Biogas, which is among the biofuels from biomass, is one of the resources that play a considerable part in a more diverse and sustainable global energy mix. For domestic purposes in rural areas of Tanzania, biogas provides a better option that can supplement the use of fossil fuels such as wood, charcoal, and kerosene, which is nonrenewable. However, the low efficiency experienced in the locally made biogas burners hinders the large-scale use of biogas among the population in the country. With the locally made burners, the users of biogas for the domestic application face problems including heat loss and high gas consumption which affects the whole cooking process. It is against this backdrop that the current study objectives incline on designing and improving the efficiency of the locally manufactured burners to achieve the uniform flow of fuel in the mixing chamber, which will result to the consistent heat distribution around the cooking pot. The optimization of the burner was done by using computational fluid dynamics (CFD) through varying the number of flame portholes and air holes as well as the size of the jet before fabrication. The increased efficiency of the burner has also contributed by the addition of the fuel distributor. The results showed that the optimum hole diameter of the jet was 2.5 mm and that of the manifold was 100 mm. The currently developed biogas burner was tested and compared with the other two locally made burners. The water boiling test (WBT) on these three burners showed that the developed burner has a thermal efficiency of 67.01% against 54.61% and 58.82% of the Centre for Agricultural Mechanization and Rural Technology (CARMATEC) and Simgas, respectively. Additionally, the fuel consumption of the developed burner was 736 g/L as compared to 920 g/L for CARMARTEC and 833 g/L for that of Simgas. The developed burner and its corresponding cookstove are both environmentally friendly and economical for household utilization in Tanzania and other developing countries

Performance investigation of the slaughterhouse wastewater treatment facility: a case of Mwanza City Slaughterhouse, Tanzania

This research article published by Water Practice & Technology, 2020The present study engaged onsite operations and laboratory analysis for Mwanza City Slaughterhouse (MCS) wastewater to improve the efficiency of wastewater treatment of a newly installed facility. The MCS wastewater treatment facility is integrated with various units-biodigester, aeration unit, retention, clarifier, and a constructed wetland. During the initial runs, the MCS facility removed 87.5%, 92.2%, 43%, and 65.4% of effluent biochemical oxygen demand (BOD5), chemical oxygen demand (COD), ammonium, and nitrate, respectively. After conducting effective plant operations for five months, the removal efficiencies of BOD5, COD, ammonium, and nitrate improved to 97.4%, 98.3%, 97.4%, and 97.6%, respectively. In the present study, the unit-by-unit performance values achieved as a result of alterations to the facility’s running conditions are presented. The MCS wastewater treatment facility was found to be energy-positive, as it produced an average of 158.2 m3 biogas per day. This amount of biogas, if converted to electricity, would be sufficient to run the facility operations. Generally, the MCS wastewater treatment facility attained the best performance as per design, achieving the effluent levels recommended by the Tanzania Bureau of Standards (TBS)

Influence of Duct Configurations on the Performance of Solar-Assisted Heat Pump Dryer for Drying Tobacco Leaves

In the present study, a solar-assisted heat pump dryer (SAHPD) has been designed, fabricated, and tested its performance on drying tobacco leaves. The hot air generated from the solar collector and condenser unit of the heat pump was used as a source of heat in the drying chamber. In this study, we investigated the influence of three duct configurations (open, partially closed, and completely closed) on the thermal performance of SAHPD to establish the best configuration for drying tobacco leaves. The average drying temperature was found to be 66, 64, and 60°C; the coefficient of performance of the heat pump was 3.4, 3.2, and 3.0; the heat energy contribution from the solar collector was 6.6%, 5.0%, and 5.1% while for the condenser was 93.4%, 95.0%, and 94.9%, and electrical energy consumption was 2.3, 2.8, and 2.6 kWh, for the open, partially closed, and completely closed duct system, respectively. Based on these results, the open system demonstrated the best performance. According to the study’s findings, SAHPD has been shown to be an energy-efficient method of drying tobacco leaves and is environmentally friendly as opposed to the conventional use of wood fuel, which results in environmental pollution, desertification, and deforestation

Effect of Antioxidants Extracted from Clove Wastes and Babul Tree Barks on the Oxidation Stability of Biodiesel made from Water Hyacinth of Lake Victoria Origin

This research article published by Springer Nature Switzerland AGBiodiesel from water hyacinth has shown to have poor oxidative stability due to the presence of significant amounts of unsaturated fatty acids. Most studies have been using synthetic antioxidants to improve oxidation stability of biodiesel but they are expensive and proved to be toxic at higher concentrations. This study assessed the possibility of using natural antioxidants extracted from clove wastes and babul tree barks since they are cheap, easy to extract and locally available and blends of these with synthetic antioxidant such as 1,2,3-trihydroxybenzene (Pyrogallol, PY) in improving the oxidation stability of biodiesel. Non-edible water hyacinth collected from Lake Victoria Tanzania was used as feedstock for biodiesel production. The biodiesel was analyzed for physicochemical properties and fatty acid composition. Most of the physicochemical properties were within the acceptable limits for ASTM D6751 and EN 14214 except for oxidation stability which recorded 2.4 h and was below limits. Fatty acid analysis showed the presence of unsaturated fatty acids at 42% which contributed to the poor oxidation stability of the biodiesel. Clove waste and babul barks displayed significant total phenolic contents of 220.0 ± 0.1 and 48.0 ± 0.2 mg GAE/g, respectively. Clove antioxidant displayed an improvement of 153% in oxidation stability at 1000 ppm while babul improved by 236% at 800 ppm. Blends of clove with PY displayed much higher improvements in oxidation stability by 398% at 800 ppm while babul with pyrogallol showed a general decrease in performance by 46%

Techno-economic analysis of a solar-assisted heat pump dryer for drying agricultural products

Postharvest losses (PHLs) of biomaterials, such as vegetables and fruits, significantly impact food security and economic stability in developing nations. In Tanzania, PHLs are estimated to range between 30% and 40% for cereal crops and even higher for perishable crops such as fruits and vegetables. Open-sun drying (OSD) is the most extensively employed method because of its affordability and simplicity. However, OSD has several drawbacks, including difficulties in managing drying parameters, long drying times owing to adverse weather, and product contamination. The solar-assisted heat pump dryer (SAHPD) is a technology designed as an alternative solution for drying biomaterials and reducing PHL. A limited number of SAHPDs have been constructed in developing nations. Most of the works have concentrated on the performance analysis of the systems. This neglects the techno-economic assessment, which is important to provide both a quantitative and qualitative understanding of the financial viability of the technology. The present study therefore investigates the techno-economic analysis of a novel SAHPD for drying agricultural products, particularly vegetables and fruits. To determine whether the SAHPD technology is technically and economically viable, tomatoes and carrots were dried and analyzed to determine their thermal and economic performance. The results show that the initial moisture contents of tomatoes (Lycopersicum esculentum) and carrots (Daucus carota) were reduced from 93% and 88% to 10% in 11 and 12 h, respectively. The coefficient of performance (COP), drying time (DT), specific moisture extraction ration (SMER) and thermal efficiency ( ) were found to be 3.4, 2.3 kg/h, 1.33 kg/kWh and 54.0%, respectively. The economic analysis was assessed using the annualized cost, lifecycle savings, and payback period for the dryer's life span of 15 years. The initial investment of the SAHPD was $5221.8 and the annualized cost was$1076.5. The cumulative present worth for 15 years was found to be $23,828.8 and$27,553.1 for tomatoes and carrots, respectively. The payback period for tomatoes was found to be 3 years, whereas for carrots it was 2.6 years. Based on thermal and economic performance assessment results, the developed SAHPD is technically and economically viable to be considered for further investments