Search

Biofuel generated from different organic waste substrates has been described as a sustainable option to the rapidly exhausting fossil fuels. To worsen the dependence on fossil fuels, the price is skyrocketing daily attributable to high demand for it. The high demand and usage of fossil has therefore led to increased atmospheric CO 2 , which is a major greenhouse gas. Thus, the dire need to explore the production of biofuel, of which biohydrogen is one. In spite of the several benefits linked to the application of biohydrogen as fuel, its production is currently facing some levels of practical challenges, some of which include inadequate conversion of biomass and low rate of production. In order to enhance the production of biohydrogen, some influencing factors for production need to be optimized. In view of this, this review critically discusses fundamental factors that affect biohydrogen production, like substrate composition, pretreatment of substrates, physico-chemical parameters, etc. It was found that the key constituents in fermentative biohydrogen generation are carbohydrates while proteins are not that efficient. In addition, amongst metal ions like (Ni, Fe, Cu, Mg, Zn, and Na), Mg has been found to be one of the essential cofactors that activates more than ten enzymes involved in hydrogen fermentation. Biological pretreatment method for substrate has more advantages than others in terms of low-toxicity, mild reaction and low-cost. Reduction of partial pressure to an optimum level could enhance the yield of biohydrogen production. The integration of nanoparticles into the substrate to refill the biohydrogen (H 2) production is well-thought-out as a robust approach. Finally, this paper comprehensively discusses the effects of various nanoparticles on biohydrogen fuel production while it concludes by highlighting the future prospects. [Display omitted] • The effects of pre-treatment techniques for substrate are expatiated. • The recent development in the use of nanoparticles for biohydrogen production are discussed. • Influence of physicochemical parameters are presented. • The impacts of dark fermentation bioreactor design for biohydrogen production are reviewed. • Challenges with NPs application in dark fermentation are well discussed. [ABSTRACT FROM AUTHOR]

• Dependence on fossil fuel reduces the hazard of private sector investment in renewable energy sector. • The role of fossil fuel dependence decreases in countries with prior investment projects. • Changes in oil price have competing effects on investment hazard. • Regulatory quality and renewable energy policies stimulate private sector investments in developing countries. Given the rapid population growth and subsequent increase in energy demand in developing countries, private sector investment in renewable energy projects is key for sustainable economic development. However, the current energy mix is still dependent on conventional fossil fuels. The paper examines the time duration to private sector investment in renewable energy projects and how the hazard rate is affected by dependence on fossil fuels. Using data on private sector participation in renewable energy projects in 134 developing and middle-income countries for the (1990–2012) period, this paper applies multiple failure time model. The results show significant negative effects of fossil fuel consumption and fuel rent on investment likelihood. Consistent with literature, a set of socio-economic variables, such as renewable energy policy and energy security concerns, play an important role in increasing the likelihood of private sector investment in renewable energy technologies. The findings of the paper resonate with concerns of the international community regarding the effect of fossil fuel dependence on the rate of adoption of renewable energy sources in developing countries. [ABSTRACT FROM AUTHOR]

Carbon emissions from the combustion of fossil fuels continue to be a significant barrier in the fight against global climate change. Carbon taxes are an energy policy tool for substantially carbon dioxide (CO 2) emissions reduction. This paper proposes a new strategy to promote the use of renewable energy by enterprises in industrial parks against the backdrop of a carbon tax. Using an evolutionary game model based on life cycle assessment (LCA), this study investigates the impact of dynamic carbon tax mechanisms, fines, and subsidies on the energy choices of industrial park enterprises. This paper's primary contribution is the incorporation of LCA into the evolutionary game model, which facilitates accurate calculation of the carbon tax parameter value. According to the study's findings, the carbon tax rate increases the propensity of enterprises to acquire a high percentage of renewable energy. While there is a negative relationship between fines and the propensity of enterprises to adopt a low proportion of renewable energy, an increase in subsidies decreases the proportion of enterprises that purchase a high proportion of renewable energy. This paper concludes by providing a theoretical foundation for policymakers to construct precise carbon tax schemes and promote renewable energy consumption among industrial park enterprises while simultaneously reducing carbon emissions. [Display omitted] • Carbon tax & energy decisions: life cycle assessment & evolutionary game theory. • Life cycle assessment for enterprise carbon taxes under multiple energy options. • Carbon tax mechanisms, fines, and subsidies influence enterprises energy decisions. • Excessive subsidies discourage renewable energy use, but fines can. [ABSTRACT FROM AUTHOR]

Bangladesh is a hugely populated country in South Asia. The country produces its electricity mainly from natural gas followed by liquid fuels. Although the installed electricity generation capacity of the country has been increased to 12,261 MW, there is scarcity of electricity in the hot summer season which is a barrier to industrial development as well as socio-economic development. Combustion of fossil fuels releases greenhouse gases (GHGs) into the atmosphere which causes global warming. Bangladesh can be badly affected by greenhouse effect and global warming. These problems can be mitigated by incorporating renewable energy sources (e.g., solar, wind, hydro, biomass, etc.) to the country's electricity generation. Renewable energy resources are considered as clean and can serve the electricity demand in the remote areas where grid connection is not possible. The potential of solar energy and biomass is enormous in Bangladesh and people have already started to harness energy from these sources. The government and the policy makers should come forward to encourage the people of rural areas as well as urban areas to use renewable based electricity. The government of Bangladesh has set up a plan to generate 5% of the country's total electricity from renewable sources within 2015 and 10% within 2020. However, within 2015 the country has been able to generate only 3.5% of the total electricity from renewable sources. This paper presents a thorough review of the current status and future potentials of renewable energy sector in Bangladesh. In this paper the updated information is provided for the overall renewable energy sector of the country. [ABSTRACT FROM AUTHOR]

At present, practically all industrial production of hydrogen either directly or indirectly (e.g., through electricity generation) relies on fossil fuels (mostly, natural gas and coal) and, according to many projections, this trend will continue in the foreseeable future. As a result, hydrogen plants are and will remain a major source of CO 2 emissions to the atmosphere, with potentially adverse consequences to our planet's ecosphere and climate. In view of these negative trends, there is an urgent need to substantially reduce or even completely eliminate CO 2 emissions from fossil fuel-based hydrogen production processes in order to underscore environmental advantages of hydrogen as an ecologically clean fuel. The main technological approaches to low to near-zero CO 2 production of hydrogen from fossil fuels can be classified into three main groups: (1) coupling hydrogen plants with CO 2 capture and storage systems, (2) dissociation of hydrocarbons to hydrogen and carbon, and (3) integrating hydrogen production processes with non-carbon energy sources such as nuclear and solar energy. The objective of this paper is to overview and analyze the current status of existing and emerging technological options and solutions to drastically reducing the amount of CO 2 emissions from fossil fuel-based hydrogen manufacturing plants. A near-to-mid term outlook for low to near-zero CO 2 hydrogen production from fossil fuels in the light of new technological trends is examined in this paper. [ABSTRACT FROM AUTHOR]

In the international trade of fossil fuel, countries are clustering into communities. The evolution of the communities can reflect the underlying trade pattern. This paper provides a new perspective in analyzing the global pattern of international fossil fuel trade by quantitatively analyze the evolution of the communities. Emergy transformity are used to unify the three different fuels into the same unit seJ. This paper creates network models of fossil fuel as well as coal, crude oil, and natural gas and detected the clustering of the countries by an algorithm. Three types of Normalized Mutual Information are designed to measure characteristics of the evolution of the communities. A matrix is also designed to show the flows between each two communities. This study finds that the natural gas trade network is the most partitioned and the most stable. In 2013, natural gas exceeded crude oil had the highest similarity with the integrated fossil fuel trade pattern. 2012 was a turning point. The trade blocs and organizations play important roles. However, their effects are limited. The geographical factor is reinforced and the roles of the USA and Russia are becoming more important. Clusters containing Asia Pacific countries are less stable. [ABSTRACT FROM AUTHOR]

Using the available information and a standard econometric approach analyzing the time series dataset, this study identifies the interactions between electricity, fossil fuel and carbon market prices in Guangdong, China. The result confirms a long running co-integration between carbon market prices and the prices of coal, diesel and liquid natural gas (LNG). Conversely, fossil fuel prices have no impact on the short term dynamics of carbon prices. The price of electricity on the monthly forward market in Guangdong is significantly and positively associated with the first difference of the price of coal, but has no significant relationship with the first differences of carbon, diesel and LNG prices. This analysis provides certain implications for ongoing power sector reform and nationwide carbon market development in China. The liberalization of the power industry should be further advanced to create conditions for carbon cost pass-through on to the electricity market. Meanwhile, the national emissions trading scheme (ETS) should apply simpler and stricter benchmarks to allocate emissions allowances for the power sector. Fewer categories of benchmarks promote competition among different types of power generators and a shift to an electricity supply portfolio with lower carbon intensity. Stricter benchmarks create more demand for emissions allowances and result in higher carbon market prices. To increase the ratio of emissions allowances by auctioning is also necessary to put substantial pressure on thermal power plants to pass their carbon costs on to end users. • This paper identifies the interactions between electricity, fossil fuel and carbon market prices. • A standard econometric approach is used to analyze the time series data in Guangdong, China. • The result confirms a long run co-integration between the prices of carbon and fossil fuels. • Carbon price change is not a significant factor to electricity prices of the monthly forward market. • This study gives insights to China's power sector reform and national carbon market development. [ABSTRACT FROM AUTHOR]

Abstract: This review paper discusses the perspectives for development of carbon capture and storage (CCS) technologies in the global fight against climate change, such as low-carbon technology which is a vital component to reduce future carbon emissions. The information on the level and growth of CO2 emissions, their source and geographic distribution, will be essential to lay the foundation for a global agreement; considering only for energy-related CO2, and not for any other greenhouse gases. We analyzed the distribution of the CO2 emission intensity related to them. Besides, in order to predict possible future situations of energy consumption, CO2 emissions intensity and the CCS role like the largest emission reduction potential, the International Energy Agency (IEA) has developed a number of scenarios; the baseline scenarios and comparative scenarios. We used the approach of the Blue Map Scenarios, bringing the 2005s emissions to a level of 50% by 2050 for a non-catastrophic human intervention in the climate system. Moreover, this paper shows the barriers, strategies for accelerating and the stages in the technology deployment. We also analyzed the CCS projects status; Challenges, SWOT analysis, and the currently Global CCS Technology Activity. For this, we consider the Large Scale Integrated Projects (LSIP), and the asset life-cycle model was used to categorize the status of a project according to its development stage. Alongside, the analysis involves: Total LSIPs by geographic region, by Industry and CO2 Capture Technology. In addition, we also made a scope on some of the most relevant international actions in order to stimulate the fulfillment of the CO2 intensity target. [Copyright &y& Elsevier]

Abstract Reducing the total emissions of energy generation systems is a pragmatic approach for limiting the environmental pollution and associated climate change problems. Socio economic activities in the 21st century is highly determined by the energy generation mediums, particularly the renewable resources, across the world. Therefore, a thorough investigation into the technologies used in harnessing these energy generation mediums should contribute to their further advancement. Concentrated Solar Photovoltaics (CSP) and Enhanced Geothermal Energy (EGE) are considered as emerging renewable energy technologies with high potential to be used as suitable replacements for fossil products (petroleum, coal, natural gas etc.). Despite the accelerated developments in these technologies, they are still facing many challenges in terms of cost. This review paper presents a detailed background about these renewable energy technologies and their main types such as solar tower, parabolic trough, and so on. Also, the principle challenges impeding the advancement of these energy technologies into commercialisation are discussed. Possible solutions for the main challenges are presented and the future prospects for such energy generation mediums are reported. Graphical abstract Unlabelled Image Highlights • Technologies for harnessing concentrated solar photovoltaics and enhanced geothermal energy are thoroughly discussed. • Challenges impeding the advancement of these energy generation mediums are also presented. • The future prospects of concentrated solar photovoltaics and enhanced geothermal energy are captured in this investigation. • Some recommendations for easy commercialization of these technologies are also reported. [ABSTRACT FROM AUTHOR]

Abstract Presently, the crisis of energy has become a growing concern all over the world and a serious barrier for the developing nations. Conversely, the resources of fossil fuels are limited and depleting due to the exploration and higher production activities around the glove. The impact of fossil fuels exploration has become a serious threat for naturalism and creates environmental hazardous accidents. However, the demand for energy in Bangladesh is increasing day by day and fossil fuel reserves continue the countries demand almost only 50 years. So, it is the high time to utilize its natural biomass resources to fulfill energy demand. The climate condition and waste generation rate of Bangladesh is key factors for biomass energy production. Nowadays the Bangladeshi government has made an agenda "waste to electricity" thus the utilization of biomass resources has become a blessing for the static economic growth in the nation. Recently Bangladeshi government has made an extra effort for the commercialization and marketable of biomass energy engendering and production in the country. This paper explored the potential of biomass energy as a sustainable energy source and their future implementation challenges in Bangladesh. [ABSTRACT FROM AUTHOR]

Abstract: Energy is indispensible in modern society and is one of the most important components of socio-economic development. Nepal is one of the least developed countries with more than 80% of its population residing in rural communities. Per capita energy usage – often viewed as a key index of the development – in the country is far less than the global average per capita energy usage. The energy sector is dominated by the traditional energy sources such as fuel woods, crop residues and animal dung mainly for domestic usage contributing to about 86% of the national energy consumption. Currently 40% of the population has access to electricity, and the rural electrification accounts for only 29%. The majority of rural populations are meeting their energy needs by burning biomass in traditional stoves which has several environmental and public health issues. Nearly all fossil-derived fuels consumed in the country are imported in a refined form, and the perpetual increase in petroleum imports has adversely impacted the existing fragile economy of the country. Despite a huge potential in harnessing various renewable energy resources such as hydropower, solar power, wind energy and biofuels/bioenergy, these resources have not been sustainably captured due to geographical, technical, political and economical reasons. This paper presents a brief account of Nepal''s renewable energy resources and the current status of various renewable energy technologies (RETs) such as micro-hydro, solar power, wind energy, biofuel/bioenergy, improved cook stoves, and improved water mill. It also highlights the opportunities and barriers for the development of RETs. Finally this paper presents some recommendations for the promotion, development and implementation of RETs in the country. [Copyright &y& Elsevier]

Abstract: In this paper, I present a theoretical argument that fossil fuel represents a historically specific and internally necessary aspect of the capitalist mode of production. Despite sustained attention to distributional conflicts between international capital and energy rich nation–states, few historical-materialists have paid attention to the relations between fossil fuel and capital accumulation in industrial capitalist societies. In opposition to ecological economic notions of fixed thermodynamic “laws”, I first propose a dialectical conception of energy as embedded in dynamic social processes and power relations. Second, I review the historical importance of the energy shift from solar or biological sources of energy (muscles, wind, and water) to fossilized sources of energy (coal, oil, and gas). I then demonstrate how attention to fossil fuel energy forces a reexamination of the core insights of ecological Marxism and the political economy of nature. In the core argument of the paper, I reconsider the shift from biological to fossil energy as internal to the generalization and extension of capitalist social relations from two basic vantage points – (1) capitalist production based on wage labor; (2) the spatial conditions of capitalist circulation. I conclude by asking whether it is accurate to conceptualize capitalism as a “fossil fuel mode of production” and highlight the political urgency of a historical materialist perspective that takes seriously the importance of energy to the reproduction of capitalist social relations. [Copyright &y& Elsevier]

Abstract: This paper demonstrates the application of exergy to gain a better understanding of coal properties, especially chemical exergy and specific chemical exergy. In this study, a BASIC computer program was used to calculation of the chemical exergies of the coal-based fuels. Calculations showed that the chemical composition of the coal influences strongly the values of the chemical exergy. The exergy value of a coal is closely related to the H:C and O:C ratios. High proportions of hydrogen and/or oxygen, compared to carbon, generally reduce the exergy value of the coal. High contents of the moisture and/or the ash cause to low values of the chemical exergy. The aim of this paper is to calculate the chemical exergy of coals by using equations given in the literature and to detect and to evaluate quantitatively the effect of irreversible phenomena increased the thermodynamic imperfection of the processes. In this paper, the calculated exergy values of the fuels will be useful for energy experts studied in the coal mining area and coal-fired powerplants. [Copyright &y& Elsevier]

Regional haze over China has severe implications for air quality and regional climate. To effectively combat these effects the high uncertainties regarding the emissions from different sources needs to be reduced. In this paper, which is the third in a series on the sources of PM 2.5 in pollution hotspot regions of China, we focus on the sources of black carbon aerosols (BC), using carbon isotope signatures. Four-season samples were collected at two key locations: Beijing-Tianjin-Hebei (BTH, part of Northern China plain), and the Pearl River Delta (PRD). We find that that fossil fuel combustion was the predominant source of BC in both BTH and PRD regions, accounting for 75 ± 5%. However, the contributions of what fossil fuel components were dominating differed significantly between BTH and PRD, and varied dramatically with seasons. Coal combustion is overall the all-important BC source in BTH, accounting for 46 ± 12% of the BC in BTH, with the maximum value (62%) found in winter. In contrast for the PRD region, liquid fossil fuel combustion (e.g., oil, diesel, and gasoline) is the dominant source of BC, with an annual mean value of 41 ± 15% and the maximum value of 55% found in winter. Region- and season-specific source apportionments are recommended to both accurately assess the climate impact of carbonaceous aerosol emissions and to effectively mitigate deteriorating air quality caused by carbonaceous aerosols. [ABSTRACT FROM AUTHOR]

The key principle in resource management is sustainability which consists of operational robustness, attenuation of environmental footprint and socio-economic considerations. Dependence on fossil fuels is unviable due to their continuous depletion all over the world and also the inexperienced greenhouse gas emissions related to their utilization. Therefore, the continuous initiatives geared towards developing various renewable and probably carbon neutral biofuels as energy resources are being taken up. Alternate energy resources such as 1st generation biofuels derived from terrestrial crops like sugarcane, sugar beet, corn and wheat place a colossal stress on global food markets, but this potential food versus fuel conflict is palliated by using sweet sorghum as a bioenergy crop. It can be processed into both biofuel and valuable co-products, thus meeting the various requirements of food, fuel and fodder. This paper mainly reviewed the technologies for bioethanol production from sweet sorghum, focussing on its potential benefits as feedstock for ethanol production over other substrates and recent advancements to enhance ethanol yield. It also reviewed the advances in pretreatment along with the novel process of ethanol production from sweet sorghum stalks, biogas production from sweet sorghum and environmental cum socio-economic aspects. No doubt, there are outstanding issues related to ethanol production and yield, still sweet sorghum derived bioethanol could progressively substitute a significant proportion of the fossil fuels required to meet the growing energy demand. [ABSTRACT FROM AUTHOR]

[Display omitted] • Significant transition is expected in world energy system over the next 30 years. • Inclusion of blue hydrogen is inevitable for the transition toward hydrogen economy. • Oxygen-based processes are most efficient for greenfield blue hydrogen applications. • Carbon intensity and thermal efficiency are crucial factors in blue H 2 technologies. • Mature carbon capture technologies can remove 95% of CO 2 in blue H 2 production. Hydrogen is expected to play a key role in the world's energy-mix in the near future within the context of a new energy transition that has been ongoing over the past decade. This energy transition is aiming for hydrogen to meet 10–18% of total world energy demand by 2050. However, such a transition requires addressing numerous technological and economic challenges in the complete value chain: production, storage, transport, distribution, and application. This energy transition is backed by policies and roadmaps by many countries of high energy consumption, as well as many companies that cover the complete value chain. The transition targets green hydrogen as a priority, which may happen if electrolysis technologies significantly advance. However, blue hydrogen, produced from fossil fuels with CO 2 capture, is currently viewed as the bridge between the high-emission grey hydrogen and the limited-scale zero-emission green hydrogen. This review highlights the features of different commercially deployed and new emerging hydrogen production processes from fossil fuels and biofuels, along with the recent advancements in hydrogen storage and transport. The review also reports the status of latest key developments in carbon capture technologies, which are critical for blue hydrogen production. The paper also critically reviews the costs and the carbon footprints of emerging technologies, identifies the requirements to attain large-scale production for commercialization, and provides background information for the fossil fuels industry to be an active player in the current energy transition. The techno-economical assessment of many recent studies has indicated that the oxygen-based system, such as auto-thermal reforming and partial oxidation, is the most efficient for producing greenfield blue hydrogen. [ABSTRACT FROM AUTHOR]

In this paper, a three-variable TVP-SV-VAR model is developed and estimated to investigate the dynamic relationships among the stock prices of new energy, high-technology and fossil fuel companies. The results show that the stock prices of new energy companies correlate more highly with high-technology stock prices than with coal and oil stock prices. We also find empirical evidence of Chinese stock market turbulence in 2015 through our analyses of stochastic volatilities and dynamic correlations. Moreover, the impulse responses of all three of our variables to all three of the shocks have meaningful shapes, indicating that the Chinese government is faced with the double pressure of economic development and environmental protection. [ABSTRACT FROM AUTHOR]

The concept of ‘unburnable carbon’ emerged in 2011, and stems from the observation that if all known fossil fuel reserves are extracted and converted to CO 2 (unabated), it would exceed the carbon budget and have a very significant effect on the climate. Therefore, if global warming is to be limited to the COP21 target, some of the known fossil fuel reserves should remain unburnt. Several recent reports have highlighted the scale of the challenge, drawing on scenarios of climate change mitigation and their implications for the projected consumption of fossil fuels. Carbon Capture and Storage (CCS) is a critical and available mitigation opportunity and its contribution to timely and cost-effective decarbonisation of the energy system is widely recognised. However, while some studies have considered the role of CCS in enabling access to more fossil fuels, no detailed analysis on this issue has been undertaken. This paper presents a critical review focusing on the technologies that can be applied to enable access to, or ‘unlock’, fossil fuel reserves in a way that will meet climate targets and mitigate climate change. It also quantifies the impact of CCS in unlocking unburnable carbon in the first and in the second half of the century. [ABSTRACT FROM AUTHOR]

Growing concerns of energy security and environmental issues have posed a great challenge in sustainable energy planning. Renewable energy (RE) resources as well as carbon capture and storage (CCS) are the common alternatives to reduce the impact of carbon emission. However, integration of RE and CCS into the current energy system requires thorough planning. With consideration of existing power fossil based power plant, this paper aims to provide a carbon-constraint energy generation that includes optimal capacities of new power plants and energy storage to meet with the increasing energy demand by using an extended version of the Electric System Cascade Analysis (ESCA) methodology. This method is applied on an hourly scale of a hypothetical case study. The demand side is supplied by an existing 40 MW coal-fired power plant, subjected to a maximum carbon emission constraint of 850 ton CO 2 /day. The result reveals that additional of 15 MW of new solar photovoltaic power plant and 82 MW of new natural gas power plant with CCS are required to meet with the increasing demand under carbon constraint. The system is integrated with an energy storage of 86 MW in capacity. [ABSTRACT FROM AUTHOR]

• Microwave assisted pyrolysis oil has been tested in the diesel engine. • Pyrolysis oil tested for performance and emission characteristics. • Increased concentration of the waste pyrolysis oil reduces the engine performance. • No sign of superior reduction in the NOx emissions. The fossil fuel crisis can be effectively tackled by the use of alternative fuels. Among the variety of biofuels, production of the biodiesel from the plastic waste seems much more attractive. Conversion of plastic waste into sustainable biodiesel plays a major role in combating the serious concern over the depletion of fossil fuels. The current research paper deals and explores the production of biodiesel from pyrolysis and transesterification method. Further the procured biodiesel was tested for performance and emission characteristics by varying the engines load. Microwave assisted pyrolysis process has been used to for obtaining the bio-oil from the plastic waste. All experimental tests were conducted in a naturally aspirated-inline, direct injection diesel engine at different engine speeds at constant load condition. The performance of the engine measured via Brake Power (BP), Brake Torque (BT), Brake Thermal Efficiency (BTE) and the emission are calculated via Carbon monoxide (CO), Carbon dioxide (CO 2) and Nitrogen oxide (NO). Each test blends WPO10, WPO20 and WPO30 were tested for the above parameters at the engine speed of 1000 rpm to 3000 rpm. All the procured results were comparatively examined with neat diesel. From the results, it is found that the brake power, brake torque and brake thermal efficiency were little lower for all taken blends compared to pure diesel. However, the major problem of emitting CO was considerably reduced while using plastic fuel blends. The CO 2 and NO emission were increased. There is no evidence of increase in the thermal efficiency due to the lower calorific value of the pyrolysis oil. Further, the viscosity and the poor presence of oxygen molecules reduced the overall combustion process which leads to high emission rates. [ABSTRACT FROM AUTHOR]

In the last few years, there has been considerable interest in closed-cycle gas turbine power plants due to the important contribution it can make to meeting worldwide energy demands. Closed-cycle gas turbine has the potential to serve as power conversion system for a wide range of energy sources such as fossil fuel, concentrated solar power, nuclear, biomass and waste heat. However, there is a need to provide an update on the development of closed-cycle gas turbine with a view to identifying the challenges and the opportunities for future commercialisation. This paper is a review of the research activities and studies carried out worldwide so far on closed-cycle gas turbine. The historical development in chronological order was presented first, followed by a review of some fundamental features such as heat sources, working fluids, heat exchangers and cycle layouts/configurations. Important research programmes and experimental/pilot plants as well as previous commercially operated plants were also reviewed. Moreover, various studies based on modelling and simulation of closed-cycle gas turbine were reviewed, in addition to the operation and control strategies. Based on the review studies, the challenges ahead and potential future breakthroughs were highlighted in different aspects such as heat source technologies, power conversion system and demonstration plant. [ABSTRACT FROM AUTHOR]

Bioenergy products appear to be practical, effective, and environmentally sustainable renewable energy resources which simultaneously reduce fuel-associated environmental impacts and increase economic value of the products. The use of bioproducts may not always have a net positive environmental or economic attributes, therefore, an adequate sustainability evaluation tool for the products which incorporates life-cycle approach is generally desired. This paper presents an informative value analysis which couples concepts of life cycle energy efficiency and production cost ratios, for a feasible assessment of function value for bioenergy products. Bioenergy products that are selected for the value assessment in this study include biodiesel, bioethanol and biocharcoal. This study is divided into two parts: value factor development along with discussions on the results of value analysis for bioenergy products, and, a sensitivity analysis in determining influential factors for value factor estimations. The results showed that microalgae biodiesel and biochar had the lowest and the highest function values, respectively, among assessed bioenergy systems. This was mainly due to the significant difference in energy input in manufacturing design and production cost. Future improvements in bioenergy production can be anticipated for developing bioenergy products with high value factors which demonstrate high economic viability, environmental performance and social acceptability. This analysis can be of interest to bioenergy production planners for sustainable product development. [ABSTRACT FROM AUTHOR]

High-temperature proton exchange membrane fuel cells (PEMFCs) are becoming more appealing to researchers around the world due to several advantages such as high energy conversion efficiency, lightweight due to the use of polymeric materials, low noise due to the lack of mechanical components, zero or low emission of harmful greenhouse gases, simple design, first reaction kinetics, and simple water management. The performance, limitations, and possibilities for the practical implementation of different high-temperature proton exchange membranes (PEMs) utilized in fuel cells are discussed in this review paper. A suitable PEM must be developed to improve the performance of membrane electrode assemblies for high-temperature PEMFCs (working temperature above 100 °C). Various PEMs such as sulfonated poly(ether ether ketone) (SPEEK), sulfonated polystyrene (SPS), sulfonated polyimide (SPI), sulfonated polysulfone (SPSU), phosphoric acid doped polybenzimidazole (PA-PBI), perfluorosulfonic acid (PFSA) polymer-based membranes have been investigated as PEMs for fuel cell applications by several research groups. Among the various PEMs, PA-PBI membranes are the most promising high-temperature PEM for fuel cell applications because of their higher proton conductivity at high temperatures and anhydrous conditions, good chemical and thermal, mechanical stability, and high durability. However, the performance of high-temperature PEMs based on pristine PA-PBI is insufficient to fulfill the need for practical implementation of high-temperature PEMFCs, which needs to be enhanced further before they can be used commercially. Therefore, PA-PBI composite membranes containing various multifunctional inorganic, organic, and hybrid fillers are being actively explored to produce high-temperature PEMs. The PA-PBI composite membranes' proton conductivity increases with rising temperature and maintains conductivity in anhydrous conditions, as well as chemical, thermal, and oxidative stability under operating conditions and long-term performance stability. [Display omitted] [ABSTRACT FROM AUTHOR]

The aim of this paper is to study the physical and chemical properties of Moringa oleifera biodiesel and its blends of 10%-90% by volume with petro-diesel according to the American society for testing and materials (ASTM D6751) standards and European standards (EN 14214). It was found that when Moringa biodiesel is blended with diesel fuel, all its fuel properties such as kinematic viscosity (KV), density (D), calorific value (CV), flash point (FP), cloud point (CP), pour point (PP), and cold filter plugging point (CFPP). For example, B10 reduce the viscosity of B100 from 5.05 mm 2 /s to 3.54 mm 2 /s (1.4:1). Then developed empirical models of properties are show high regression value (R 2 ) between properties and MOME-diesel blend. It is believed that the results obtained and empirical model proposed in this study will help the researchers to predict the properties of biodiesel-diesel blend which are important parameters to design the fuel system of biodiesel engine. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to analyze the impact of changes in fuel prices and the imposition of a carbon tax on emissions from transport on shipment lot sizes and supply chain costs. An analysis is done to show that increases in fuel prices should be dealt with differently than other costs. Further, a function to calculate future fuel prices has been developed. This function has been used to calculate transport cost in the future. The EOQ models have been modified to include increasing transport cost and a carbon tax to demonstrate its impact on various inventory policies. Due to increases in fuel prices, the cost of every subsequent order will also increase, thus resulting in an increase of average order cost for all the shipments in a production cycle. Organizations that have their vendors in relatively close proximity will be at an advantageous position in managing their supply chain costs more effectively in the future. On the other hand, organizations that have invested heavily in global supply chains will need to re-examine their supply chain strategy to overcome cost challenges. This research presents a new challenge for supply chains/logistics management strategies for organizations with global supply chains. [ABSTRACT FROM AUTHOR]

A developing country such as Bangladesh, where economic development without compromising the eco-friendly environment is a burning issue, needs huge supply of power. Having very limited fossil fuels, sources of renewable energy such as solar, wind, biomass and limited hydro power are the probable alternatives to offset energy crisis in Bangladesh and similar other countries. Over three-quarters (76 percent) of Bangladeshi people are out of on-grid connected electrical power supply. Undeniably, it has limited natural gas being used for a large variety of purposes. Energy demand is estimated to increase exponentially, implying alarming supply and demand gap. Despite prospects of huge renewable energy sources, presently, this country has only 0.3 percent of renewable energy share to the total energy supply. This paper reviews the renewable energy status and its prospective use in Bangladesh as well as renewable energy technologies obtainable in Bangladesh. It also attempts to provide future research directions and show ways to harness renewable energies to meet the future demand. [ABSTRACT FROM AUTHOR]

Abstract: Energy is a key indicator of the nation's overall economic as well as social development. Looking at the present energy demand scenario in Bangladesh, electricity demand has significantly increased over the past years. Most of the Bangladesh's power plants are heavily dependent on expensive imported fossil fuel energy resources. Thus, the power failure has become an acute problem for the country and adversely affects the socio-economic development of the country. Consequently, the shortage and constraint in availability of fossil fuels appeal to boost up the renewable energy sector in Bangladesh in order to bring down the gap between demand and supply. Hence, decisive steps to reform the power sector with a mandate to oversee these sectors urgently need to overcome current energy crisis facing in the country. In this paper, efforts have been made to summarize the availability, current status, strategies, perspectives, promotion policies, major achievements and future potential of energy options in Bangladesh. [Copyright &y& Elsevier]

Abstract: Desulfurization is an important process for crude oil upgrading. Electrochemical desulfurization technologies have advantages over conventional hydrodesulfurization technologies in terms of low temperature and pressure operation with high product selectivity and therefore less energy consumption. In this paper the authors reviewed the research done in the past decades on electrochemical desulfurization for fossil fuels. The principles, electrochemical methods, electrochemical reactors, catalysts and electrolytes employed in the electrochemical desulfurization process were discussed; and future research work is recommended. [Copyright &y& Elsevier]

Abstract: Since the relationship between supply and demand of fossil fuels is on edge in the long run, the contradiction between economic construction and limited resources will hinder the sustainable development of Chinese society. This paper aims to analyze the input of fossil fuels in China during 2000-2007 via material flow analysis (MFA) that takes hidden flows into account. With the coal, oil and natural gas quantified by MFA, three indexes, total material requirement, resource consumption intensity and resource productivity, are proposed to reflect the interaction about population, GDP and fossil fuels. The results indicated that in the past 8 years, China''s requirement for fossil fuels has been increasing continuously because of the growing mine productivity in domestic areas, which also leads to single energy consumption structure as well as excessive dependence on domestic exploitation. It is suggested to enhance the utilization efficiency, recycle the materials, and develop new energy resource as well as strengthen international cooperation and increase the import fossil energy to promote the mode of fossil fuels consumption and create lower carbon economy in China. Finally, according to the correlation-analysis, the increasing GDP is found to be based on material requirement associated with excessive resource exploitation, although it improves the resource productivity. [Copyright &y& Elsevier]

Abstract: Transport vehicles greatly pollute the environment through emissions such as CO, CO2, NO x , SO x , unburnt or partially burnt HC and particulate emissions. Fossil fuels are the chief contributors to urban air pollution and major source of green house gases (GHGs) and considered to be the prime cause behind the global climate change. Biofuels are renewable, can supplement fossil fuels, reduce GHGs and mitigate their adverse effects on the climate resulting from global warming. This paper presents the results of performance and emission analyses carried out in an unmodified diesel engine fueled with Pongamia pinnata methyl ester (PPME) and its blends with diesel. Engine tests have been conducted to get the comparative measures of brake specific fuel consumption (BSFC), brake specific energy consumption (BSEC) and emissions such as CO, CO2, HC, NO x to evaluate the behaviour of PPME and diesel in varying proportions. The results reveal that blends of PPME with diesel up to 40% by volume (B40) provide better engine performance (BSFC and BSEC) and improved emission characteristics. [Copyright &y& Elsevier]

Extensive fossil fuel consumption in almost all human activities led to some undesirable phenomena such as atmospheric and environmental pollutions, which have not been experienced before in known human history. Consequently, global warming, greenhouse affect, climate change, ozone layer depletion and acid rain terminologies started to appear in the literature frequently. Since 1970, it has been understood scientifically by experiments and researches that these phenomena are closely related to fossil fuel uses because they emit greenhouse gases such as carbon dioxide (CO2) and methane (CH4) which hinder the long wave terrestrial radiation to escape into space, and consequently, the earth troposphere becomes warmer. In order to avoid further impacts of these phenomena, the two concentrative alternatives are either to improve the fossil fuel quality with reductions in their harmful emissions into the atmosphere or more significantly to replace fossil fuel usage as much as possible with environmentally friendly, clean and renewable energy sources. Among these sources, solar energy comes at the top of the list due to its abundance, and more evenly distribution in nature than any other renewable energy types such as wind, geothermal, hydro, wave and tidal energies. It must be the main and common purpose of humanity to sustain environment for the betterment of future generations with sustainable energy developments. On the other hand, the known limits of fossil fuels compel the societies of the world in the long run to work jointly for their gradual replacement by renewable energy alternatives rather than the quality improvement of fossil sources.Solar radiation is an integral part of different renewable energy resources. It is the main and continuous input variable from practically inexhaustible sun. Solar energy is expected to play a very significant role in the future especially in developing countries, but it has also potential prospects for developed countries. The material presented in this paper is chosen to provide a comprehensive account of solar energy sources and conversion methods. For this purpose, explanatory background material has been introduced with the intention that engineers and scientists can have introductory preliminaries on the subject both from application and research points of view. Applications of solar energy in terms of low and high temperature collectors are given with future research directions. Furthermore, photovoltaic devices are discussed for future electric energy generations based on solar power site-exploitation and transmission by different means over long distances such as fiber-optic cables. Another future perspective use of solar energy is its combination with water and as a consequent electrolysis analysis generation of hydrogen gas, which is expected to be another form of clean energy sources. Combination of solar energy and water for hydrogen gas production is called solar-hydrogen energy. Necessary research potentials and application possibilities are presented with sufficient background. Possible future new methodologies are mentioned and finally recommendations and suggestions for future research and application directions are presented with relevant literature review. [Copyright &y& Elsevier]

Integrated coal gasification combined cycle (IGCC) power plants have been looked to as a key technology for the 21st century in order to realize high efficiency and good environmental performance for electricity generation, replacing existing coal fired power plants.Following successful completion of a 200 ton/d pilot project in Nakoso, IGCC technology development in Japan is moving from the stage of a feasibility study to a detailed study to allow final decisions for demonstration plant construction. The feasibility study, jointly conducted by the domestic electric power companies, found MHI''s IGCC technology to have several advantages in efficiency and reliability. In parallel with the study, a number of R&D tests have been executed as a national project to facilitate scaling up from the pilot plant to the demonstration plant. This paper introduces the current status of the MHI''s IGCC technological development. [Copyright &y& Elsevier]

Electric power consumption in KWh Per capita is a key factor in determining the progress of technological growth and the socio-economic development of any country. Bangladesh is a lower middle-income country, and its population density is around 1118 per square kilometer. The vision of the country is to become a high-income nation by the year 2041. Governed by this vision, the net electricity demand forecasted to 61 GW by 2041. The power generating sector of Bangladesh largely depends on natural gas since the reserve of natural gas is higher compared to all other fossil fuel-based energy resources. However, natural gas is predicted to deplete by the year 2028, which threatens the future energy security of Bangladesh. Therefore, Bangladesh needs immediate attention to the modification of its existing energy mix to meet future energy demands for sustainable economic growth. In this paper, we report a detailed overview of the present energy scenario by taking into account the numerous available energy resources and simultaneously proposed a best-suited energy solution for the sustainable development of Bangladesh. We have considered the economic value and the environmental value of the energy supply to estimate the prospective primary energy mix of Bangladesh for electricity generation. Our estimation suggests for the use of 25% Coal, 25% Natural Gas, and 35% Renewable Energies that ensure the best energy mix of Bangladesh. This study has critically examined the performance matrices of all the existing energy resources and such the outcome of this study may bring a long term sustainable energy solution in the energy market of Bangladesh. • Present electrical energy scenario and transformation of electrical energy market of Bangladesh. • Role of indigenous fuels in electricity generation. • Diversification of existing primary energy mix for ensuring long-term energy security. • Scope of utilizing renewable energies, especially solar energy harvesting. • Scope of importing large hydropower from neighboring countries through regional grids. [ABSTRACT FROM AUTHOR]

Continued investments in coal-fired power plants (CFPPs) and coal mining are incompatible with the Paris Agreement. As a major investor of both upstream coal mining and downstream CFPP construction, Japanese firms play a large role in sustaining the international coal market. Yet since mid-2018 numerous Japanese companies have announced a range of coal divestment policies. This situation, however, has not been unexamined by scholarship. Additionally, divestment literature outside Japan has focused overwhelmingly on financial institutions rather than the roles of other industry players driving the coal market. To address this gap, this paper examines four industries comprising Japan's international coal market (trading companies, electric utilities, plant equipment manufacturers and financial institutions) to empirically assess the extent of divestment behaviour and identify drivers and barriers. The empirical data reveal a slowdown, but not a cessation, of new and existing coal-related investments. Results also show that the extent of divestment trends can be largely explained by commercial factors, although institutional and structural factors are also at play. These findings have important policy implications. • We examine coal divestment and decarbonisation trends in Japanese firms with overseas coal businesses. • We cover four industry types involved in upstream (mining) and downstream (power plant development). • Findings show a slowdown but not a cessation of new or existing coal investments. • Divestment behaviour is mostly driven by commercial rather than normative factors. • Commercial, institutional and structural factors are hampering further divestment and creating path dependency. [ABSTRACT FROM AUTHOR]

During a period of transition towards decarbonised energy networks, maintaining a reliable and secure energy supply whilst increasing efficiency and reducing cost will be key aims for all energy supply chain (ESC) networks. Renewable energy sources, such as biomass, will play an important role in future ESCs as climate change mitigation becomes an increasingly important priority. This paper seeks to address these requirements by presenting an optimisation model for the design and planning of biomass integration into the ESC networks. A supply chain model was derived and the governing equations were solved using the General Algebraic Modelling System software (GAMS) to achieve an optimal solution. The results of the study indicate that a reduction in the emissions cost of up to 4.32% is achievable on integration of 5–8% of biomass into the ESC network. However, a 4.57% increase in the total cost of the ESC network was recorded at the biomass fraction in the mixed fuel of 7.9%, with the fixed assets cost having the largest impact on the total cost of the ESC network. It has been shown that the cost increment in the assets and operational costs of a biomass and coal co-fired combined heat and power plant can be offset by the cost reductions obtained from reduced carbon dioxide emissions. Economic arguments for dual-fuel plants, therefore, require the introduction of effective carbon pricing legislation. It is concluded that such policy implementations can be effective at mitigating the effects of climate change and would assist in achieving a global carbon neutral economy. • Renewable energy sources are key to decarbonization of energy supply chain (ESC). • Optimisation model for ESC design and planning with biomass integration is derived. • State-task network approach was employed in GAMS to represent the ESC network. • ESC network with a 7.9% of biomass showed a 4.32% reduction in the emission cost. • Integration of biomass resulted in a 4.57% rise in the total ESC network cost. [ABSTRACT FROM AUTHOR]

Greenhouse gas emission is increasing alarmingly due to bulk electricity generation from fossil fuel such as coal, gas and oil with its limited stock. While researchers are struggling to minimize the emission using suitable mitigation techniques including renewable energy sources, the Government of Bangladesh is implementing several Coal based power plants. This paper presents mathematical model of parameters related to Greenhouse gas emission and demonstrates its emission rates resulting from various fuels used in Bangladeshi power plants. The Greenhouse gas emission from the existing fossil fuel power plants using HOMER (Hybrid Optimization of Multiple Energy Resources) software is analyzed in this research. The result shows that power plants of coal, diesel and natural gas emit 0.90 kg, 0.76 kg and 0.566 kg of CO 2 per kWh, respectively. Furthermore, several Greenhouse gas mitigating procedures are proposed for fossil fuel-based power generating stations. Image 109589 [ABSTRACT FROM AUTHOR]

This article deals with the waste management of post-consumer plastics in Germany and its potential to save fossil fuels and reduce CO2 emissions. Since most of the experience available is for packaging the paper first gives an outline of the legislative background and the material flows for this sector. The recycling and recovery processes for plastics waste from all sectors are then assessed in terms of their potential contribution to energy saving and CO2 abatement. Practically all the options studied show better performance regarding these two aspects than waste treatment in an average incinerator (which has been chosen as the reference case). High ecological benefits can be achieved by mechanical recycling if virgin polymers are substituted. The cost effectiveness of reducing energy use and CO2 emissions is determined for a number of technologies. There is large scope to reduce the costs, with an estimated overallsaving potential of 50% within one to two decades. The paper then presents scenario projections which are based on the assumption that the total plastics waste in Germany in 1995 is treated in processes which will be available by 2005; considerable savings can be made by moving away from the business-as-usual path to highly efficient waste incinerators (advanced waste-to-energy facilities). Under these conditions the distribution of plastics waste among mechanical recycling andfeedstock recycling has a comparatively small impact on the overall results. The maximum savings amount to 74 PJ of energy, i.e. 9% of the chemical sector's energy demand in 1995 and 7.0 Mt CO2, representing 13% of the sector's emissions and 0.8% of Germany's total CO2 emissions. This shows that plastics waste managementoffers some scope for reducing environmental burdens. The assessmentdoes not support a general recommendation of energy recovery, mainlydue to the large difference between the German average and the best avail [ABSTRACT FROM AUTHOR]