• Energy Research
• MY close

Rapid growth in industrialization has led to high dependency of reliable electric power source for its operation. On the contrary, thermal power plants expel pollutants consisting of hazardous gases that result in degradation of environment and ecosystem. Thus, utmost importance is to generate clean and efficient energy from power plant. This current article resolves the problem of sustainable power production using coal-based thermal power plants, by integrating gasification technologies to the system. The performance of thermal power plant in terms of emission is numerically analyzed with varying gasifier pressure, air-fuel ratio, steam-fuel ratio and flue gas-fuel ratio. Numerical simulation of the gasification cycle with varying parameters is carried out using MATLAB. Optimum performance at gasifier pressure of 2 bar and the steam-fuel ratio of 0.25 was observed with relative air-fuel of 0.075. With increasing flue gas-fuel ratio from 0.25 to 1.00, although the mole fractions of components of syngas don’t differ much, the heating value and cold-gas efficiency of syngas produced decreases for each fuel. Considering the emissions, simulated results present co-gasification as better option over conventional systems. A reduction of two-third in kg of CO2 released per kg of fuel was observed with almost three-fourth decrement in kg of CO2 per kWh of power produced. Also, zero SOx and NOx emissions were observed compared to coal based thermal power plants. It is noted that optimum performance of gasification system at gasifier pressure of 2 bar, air-fuel ratio of 0.1, steam-fuel ratio of 0.25 and flue gas-fuel ratio of 1.00. The proposed cycle presents itself suitable for further research and its application to coal based thermal power plants, providing potential towards supplementary power generation and cleaner exhaust. This research would also significantly contribute to achieve sustainable development goals.

Abstract Phase change materials (PCMs) utilized for thermal energy storage applications are verified to be a promising technology due to their larger benefits over other heat storage techniques. Apart from the advantageous thermophysical properties of PCM, the effective utilization of PCM depends on its life span. Moreover, PCMs which are utilized for different solar thermal energy storage applications are required longer thermal and chemical stability for the extended performance of a system. This review shows the in-depth details on thermal stability and reliability of different PCMs such as organic, inorganic, eutectics, and composites materials for heat storage applications. Different methods for measuring the thermophysical properties along with the classification of PCMs based on applications and temperature ranges have been discussed. This paper also covers the selection criteria and commercial viability of PCMs for different domestic and industrial applications. In addition to this, the effect of thermal cycle testing on the properties of different organic, inorganic, eutectic, and composite PCMs has been summarized. The present article can be highly useful for researchers and practice engineers in the areas related to thermal energy storage applications.

This article offers a trend of inventions and implementations of photocatalysis process, desalination technologies and solar disinfection techniques adapted particularly for treatment of industrial and domestic wastewater. Photocatalysis treatment of wastewater using solar energy is a promising renewable solution to reduce stresses on global water crisis. Rendering to the United Nation Environment Programme, 1/3 of world population live in water-stressed countries, while by 2025 about 2/3 of world population will face water scarcity. Major pollutants exhibited from numerous sources are critically discussed with focus on potential environmental impacts & hazards. Treatment of wastewater by photocatalysis technique, solar thermal electrochemical process, solar desalination of brackish water and solar advanced oxidation process have been presented and systematically analysed with challenges. Both heterogenous and homogenous photocatalysis techniques employed for wastewater treatment are critically reviewed. For treating domestic wastewater, solar desalination technologies adopted for purifying brackish water into potable water is presented along with key challenges and remedies. Advanced oxidation process using solar energy for degradation of organic pollutant is an important technique to be reviewed due to their effectiveness in wastewater treatment process. Present article focused on three key issues i.e. major pollutants, wastewater treatment techniques and environmental benefits of using solar power for removal of pollutants. The review also provides close ideas on further research needs and major concerns. Drawbacks associated with conventional wastewater treatment options and direct solar energy-based wastewater treatment with energy storage systems to make it convenient during day and night both listed. Although, energy storage systems increase the overall cost of the wastewater treatment plant it also increases the overall efficiency of the system on environmental cost. Cost-efficient wastewater treatment methods using solar power would significantly ensure effective water source utilization, thereby contributing towards sustainable development goals.

AbstractReview: 123 refs.

Abstract In the present work, the thermal management system (TMS) for cool energy storage has been designed and studied experimentally. A prototype test room was designed to investigate the performance study of the thermal management system (TMS) with different operation conditions to maintain the temperature in under comfort range. The room air temperature, ambient temperature and PCM temperature at different locations were measured continuously. The TMS has sixty PCMs based high density polyethylene panels. The experimental room temperature was maintained between 22 and 24 °C during the cool energy storage in TMS. The different heat loads were used to know the real performance of TMS system for maintaining the experimental room temperature. The results of the study showed that there is a significant variation in the time duration to exceed the thermal comfort temperature with different heat loads. The experimental room temperature was maintained at 9 h, 3:30 h and 2:30 h in the presence of thermal management system with different heat loads. In other words, the temperature profile of the test room with room heater of 1 kW is found to be longest when it is used in the presence of TMS, while it is found to be the shortest in the case of 3 kW room heater without TMS. Thus it can be concluded that the TMS can maintain the room air temperature for long time even with an active heating load and hence, the TMS used in this study is a good alternative for both passive and active building space conditioning applications.

Abstract In order to produce process heat for drying of agricultural, textile, marine products, heating of buildings and re-generating dehumidify agent, solar energy is one of the promising heat sources for meeting energy demand without putting adverse impact of environment. Hence it plays a key role for sustainable development. Solar energy is intermittent in nature and time dependent energy source. Owing to this nature, PCMs based thermal energy storage system can achieve the more popularity for solar energy based heating systems. The recent researches focused on the phase change materials (PCMs), as latent heat storage is more efficient than sensible heat storage. In this paper an attempt has been made to present holistic view of available solar air heater for different applications and their performance.

Abstract The energy crisis and environmental degradation are currently two vital issues for global sustainable development. Rapid industrialization and population explosion in India has led to the migration of people from villages to cities, which generate thousands tons of municipal solid waste daily, which is one of the important contributors for environmental degradation at national level. Improper management of municipal solid waste (MSW) causes hazards to inhabitants. The management of MSW requires proper infrastructure, maintenance and upgrade for all activities. The MSWM (municipal solid waste management) system comprises with generation, storage, collection, transfer and transport, processing and disposal of solid wastes. In the present study, an attempt has been made to provide a comprehensive review of MSW management to evaluate the current status of waste to energy facilities for sustainable management, which will be helpful in tackling this huge quantity of waste and the problem of energy crisis. A critical review of known MSW management practices/processes in Indian scenario, which will give an idea to investors about the market potential, the maturity of the practicing technologies, and the environmental and economical aspects was also evaluated with its advantages and disadvantages.

Abstract This communication presents the thermal performance and economic evaluation of the thermal management system (TMS) for cooling applications using calcium chloride hexahydrate as a phase change material. This experimental work was done to shift the peak time cool energy demand for off peak time. The PCM was selected for TMS on the basis of availability in the desired temperature range and long term thermal behavior. The designed system was tested with air conditioning system for cool energy storage and discharged with three heating loads (1 kW, 2 kW and 3 kW) for the real life application. The energetic and exergetic efficiencies were also calculated and found to be highest for 1 kW and lowest for 3 kW heating load. The economic evaluation of the TMS has been carried with respect of per unit cost of electricity generated by coal, diesel and solar energy and found that payback time is low for solar based generation in comparison to electricity generation by other sources. The results of this study were also compared with those of the theoretical values and are found in good agreement with each other.