Renewable technologies are considered as clean sources of energy and optimal use of these resources minimize environmental impacts, produce minimum secondary wastes and are sustainable based on ...current and future economic and social societal needs. Sun is the source of all energies. The primary forms of solar energy are heat and light. Sunlight and heat are transformed and absorbed by the environment in a multitude of ways. Some of these transformations result in renewable energy flows such as biomass and wind energy. Renewable energy technologies provide an excellent opportunity for mitigation of greenhouse gas emission and reducing global warming through substituting conventional energy sources. In this article a review has been done on scope of CO2 mitigation through solar cooker, water heater, dryer, biofuel, improved cookstoves and by hydrogen.
The biochar produced from agricultural crop residues through thermochemical processes helps in crop waste management. Biochar has paid more attention due to its distinctive features such as high ...organic carbon content, stable structure, large surface area, and cation exchange capacity. The biochar obtained from crop residues can be readily converted into activated biochar. This review paper systematically summarised the preparation of activated biochar, characterisation, and analytical techniques of activated biochar based on more than 150 literatures published in the last 10 years. The physicochemical properties of activated biochar varies according to the type of feedstock, pyrolysis condition, and mode of activation. The selection of the activation method mainly depends on its further end environmental application. Physical activation or steam purging at high temperature creates pores inside biochar. Gas purging increases the surface area and pore volume, although steam activation is not much suitable to improve the BC surface functionality as compared to chemical and impregnation activation. Sulphuric and oxalic acid–modified biochar was found to be most suitable for the soil amendment. Alkaline activation enhances the surface area and oxygen-containing functional group in activated biochar. Metal oxide–modified biochar had better surface functionalities than did physical- and chemical-activated biochar and better sorption of organic and inorganic contaminants from potable water and waste water. In summary, activated biochar has a wide environmental prospect in remediation.
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Biomass is indirect source of solar energy and it is renewable in nature. It is one of the most important energy source in near future because of its extensive spread availability and promising ...potential to reduce global warming. Thermo chemical conversion of biomass yield variety of solid, liquid and gaseous fuels and have equal importance both at industrial and ecological point of views. Present review gives holistic view of various thermo-chemical conversion route of biomass. Gasification technology, pyrolysis options and scope of potential by product from there routes like hydrogen and charcoal production comprehensively reviewed with present context.
The ever increasing penetration of renewable energy systems (RESs) in today deregulated intelligent power grids, necessitates the use of electrical storage systems. Energy storage systems (ESSs) are ...helpful to make balance between generation and demand improving the performance of whole power grid. In collaboration with RESs, energy storage devices can be integrated into the power networks to bring ancillary service for the power system and hence enable an increased penetration of distributed generation (DG) units. This paper presents different applications of electrical energy storage technologies in power systems emphasizing on the collaboration of such entities with RESs. The role of ESSs in intelligent micropower grids is also discussed where the stochastic nature of renewable energy sources may affect the power quality. Particular attention is paid to flywheel storage, electrochemical storage, pumped hydroelectric storage, and compressed air storage and their operating principle are discussed as well. The application of each type in the area of power system is investigated and compared to others.
The environmental concern and availability of fuels are greatly affecting the trends of fuels for transportation vehicles. Biodiesel is one of the options as alternative transport fuel. This can be ...produced from straight vegetable oils (SVOs), oils extracted from various plant species and animal fats. Amongst many resources, availability and cost economy are the major factors affecting the large scale production of the biodiesels. The transesterification is one of the production processes for biodiesel, but incomplete esterification of all fatty acids in the starting material, lengthy purification methods such as water washing, relatively long reaction times, contamination and separation difficulties associated with co-production of glycerol and saponification of the starting material under certain reaction conditions are still being major challenges in the biodiesel production. Technological advancement and enhanced production methods are the demand of present time for large scale and sustainable production of biodiesel. In the present paper, comprehensive review on its production process, feed stock and its applications have been made. From many case studies it was concluded that engine performance with B20 biodiesel blends, and mineral diesel were found comparable.
Recent petroleum crises, rapidly increasing its prices and uncertainties concerning petroleum availability threaten the sustainable development of the world economy. Both the environmental concern ...and availability of fuels greatly affect fuel trends for transportation vehicles. The present work aims to compile a holistic scenario of different resources, production technologies, and properties of alternative fuels for transportation vehicles. Detailed descriptions of production technologies and fuel properties would help to refine and further enhance the technologies. While many production technologies have been developed, still more attention is needed to develop an effective, economical and efficient conversion process. As a broad overview of the subject, this article includes information based on the research carried out globally by scientists according to their local socio-cultural and economic situations. The integration of different technologies and hybridization is the demand of the present time for sustainable power generation and economic development.
Poor grain drying facilities, along with the burden of drying cost, bound the farmers to market their produce soon after harvest. Thus, this research paper intends to study the influences of a novel ...cylindrical solar-assisted dryer on farmers’ income and its impact on the environment. The paper also presents the design and fabrication of a drying system for maize cobs using non-conventional solar energy. The performance of the solar-assisted drying system was also investigated for drying of yellow dent maize cobs. As a very energy-intensive post-harvest process, drying consumes a lot of electricity, which is usually provided by conventional energy. Here, solar dryers are the perfect solution in terms of efficiency, uniform drying of agricultural food products, less drying time, increased marketability of agricultural products, and reducing the load on farmer’s pocket for drying. With a high internal rate of return of 66 percent, the designed dryer proved to be technically and economically viable. Compared to open sun drying, the solar drying system produced better quality and drying time results. Compared to other models, the Midilli model fits the experimental maize drying data better, with a coefficient of determination of
R
2
= 0.89729. Energy analysis inferred savings of 1352.97 kWh electrical energy and 128.18 liters of diesel fuel plus a reduction of 1.22 t CO
2
per annum can be achieved by using this dryer.
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.
Wind power is rapidly expanding worldwide, and so is the installation of wind turbines. The concept of wind power as a clean-energy alternative will be questioned if the waste from these turbines is ...not and adequately controlled. The goal of this review paper is to evaluate the various approaches for end-of-life management of wind turbine blades emphasizing on fibre recovery. Different methods for recovering carbon and glass fibres are described, including thermal treatment and chemical treatments and their economic and environmental comparisons. Life cycle assessment and comparative analysis of different recycling processes are also presented. Natural composites, modified thermoset composites, and thermoplastic composites are also covered as alternative environmentally friendly blade materials.
Cooking is the prime requirement for people all over the world. It accounts for a major share of energy consumption in developing countries. Solar energy is contributing major energy requirements of ...the world's population particularly in developing countries. Among the different energy end uses, energy for cooking is one of the basic and dominant end uses in developing countries. There are number of solar energy based cooking appliances has been design, developed and tested for various applications across the globe. In this paper attempt has been made to provide comprehensive view on standard testing approach of solar cooker, energy and exergy analysis approach and economic evolution of different types of solar cooker. Thermal performance of box type and concentration type solar cookers in both laboratories and actual field conditions also rigorously reviewed and presented in this paper.
