Experimental investigation of different characteristics of biodiesel derived from waste cooking and pure sunflower oil

In this investigation, waste cooking and pure sunflower oil were selected as feedstock for biodiesel synthesis under microwave irradiation and conventional heating systems. Experiments were conducted in order to evaluate the effects of reaction variables, such as catalysts amount (0.5- 1.5wt %), oil: methanol volumetric ratio (4:1-8:1) and time (1-6 min) in microwave method and time (30-60 min) in conventional method. The best yield of biodiesel (97%) was obtained by the condition of 1 wt% NaOH, 4:1 oil to methanol volumetric ratio, and 4 min using microwave heating system. The important properties of biodiesel were analyzed and found to be within the limits of biodiesel standards. Compared with the conventional heating method the results show that microwave heating can be applied effectively to obtain high yield and reducing the reaction time from 1 h to 4 minutes. The use of microwave will help in providing an energy efficient and economical route for biodiesel production. Results also showed that the biodiesel obtained under optimum conditions from pure sunflower oil (PSO) and waste cooking sunflower oil (WCSO) exhibited no considerable difference but the cost of producing biodiesel from WCSO was lower than PSO. This research demonstrated that biodiesel obtained under optimum condition from PSO and WCSO was of good quality and could be used as a diesel fuel which is considered as renewable energy and environmental recycling process from waste oil after frying

Feasibility analysis of implementing anaerobic digestion as a potential energy source in Bangladesh

Biogas technology is one of the prevalent alternative ways to mitigate energy crisis in Bangladesh. This approach of renewable energy is becoming popular to the rural population due to its economic viability and environmental attractiveness. The aim of this review paper is to illustrate the current status of domestic biogas plants in Bangladesh. The study also assesses the total biomass potential including livestock manure and agricultural residue available for biogas generation. The assessment shows that the total estimated amount of residues is 106.27 million tons comprises 42.49 million tons from agricultural residue, and 63.78 million tons from livestock manure and municipal solid waste (MSW) which is equivalent to 5.045 billion m3 of biogas. The economic analysis of 2.0 m3, 2.6 m3, and 3.2 m3 family size biogas plants are found to be a viable option in substitution of biomass and other commercial energy. The reliable supply of low-cost feed materials for biogas production has found to be an important factor to make the plant more feasible

Design, Fabrication, and Efficiency Study of a Novel Solar Thermal Water Heating System: Towards Sustainable Development

This paper investigated a novel loop-heat-pipe based solar thermal heat-pump system for small scale hot water production for household purposes. The effective use of solar energy is hindered by the intermittent nature of its availability, limiting its use and effectiveness in domestic and industrial applications especially in water heating. The easiest and the most used method is the conversion of solar energy into thermal energy. We developed a prototype solar water heating system for experimental test. We reported the investigation of solar thermal conversion efficiency in different seasons which is 29.24% in summer, 14.75% in winter, and 15.53% in rainy season. This paper also discusses the DC heater for backup system and the current by using thermoelectric generator which are 3.20 V in summer, 2.120 V in winter, and 1.843 V in rainy season. This solar water heating system is mostly suited for its ease of operation and simple maintenance. It is expected that such novel solar thermal technology would further contribute to the development of the renewable energy (solar) driven heating/hot water service and therefore lead to significant environmental benefits