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Many of the gases released by industrial processes pollute the environment and are largely responsible for climate change. Also, large amounts of low-temperature waste heat are generated by the industrial sector in different production processes. The waste heat can be recovered and reincorporated into the industrial process by means of an Absorption Heat Transformer (AHT), to reduce greenhouse gas emissions, reduce the consumption of fossil fuels, and increase energy savings. Therefore, three important aspects of the AHT are emphasized in this paper: first, the thermodynamics parameters of the AHT that influencing in its performance, second, heat recovery study and third CO2 emissions avoided analysis. For this purpose, a thermodynamic model was implemented for AHT using two working mixtures, namely, LiBr- H2O and Carrol-H2O. Besides, a heat recovery study was carried out considering the Mexican textile industry as a case study, to determine the stages of the textile process in which it is possible to return the recovered heat, as well as the best location to install an AHT. The results show that the Coefficient of Performance values increase when the absorber thermal levels range from 100 to 150°C, source temperatures from 80 to 90°C and condensation temperature from 25 to 30°C. The study of heat recovery in the textile industry describes that it is possible to install an AHT at five states in Mexico, with the potential to recover and return heat in 6 of the 7 stages of the textile process, it was also determined that with the Carrol-water mixture it is possible to obtain higher thermal levels in the absorber and recover more heat than with the water/lithium bromide mixture. The emissions analysis showed that the technology is environmentally sustainable by avoiding up to 119 tonnes of CO2eq per year into the atmosphere. [ABSTRACT FROM AUTHOR]

Thanks to top-notch vehicle testing and internationally standardized inspections, the modes of transportation are cleaner and more efficient today. Though the development for conventional internal combustion engine vehicles (ICEVs) has almost saturated today, yet it retains the commercial/heavy-duty (trucks and buses) automobile market. Thus, it becomes of utmost importance to analyze the well-to-wheel efficiency for determining the overall energy consumption and greenhouse gas (GHG) emissions while transitioning toward sustainable transportation. Electric vehicles (EVs) do have environmental impacts that are directly related to the country's electricity generation, as they may involve fossil burning where other alternative sources of energy are not adequately present. This paper presents the overall energy efficiencies and GHG emissions from commercial/heavy-duty ICEVs and EVs. The study also briefly compares the other vehicle segments like 2 Wheeler, 3 Wheeler, and cars. Finally, the results show that commercial/heavy-duty ICEVs are advantageous over heavy-duty EVs when the GHG emissions are considered as of today. The commercial/heavy-duty ICEVs emit over 405 g CO2e/km, and counter EVs produce 706 g CO2e/km. The GHG emissions from 2 Wheeler ICEV were 46 g CO2e/km and by the same segment, EV is 13 g CO2e/km. Moving toward the car segment, an ICEV car produces around 158 g CO2e/km and an EV of a similar model emits 67 g CO2e/km. Furthermore, the 3 Wheeler ICEV emits around 99 g CO2e/km and a 3 Wheeler EV produces lesser at 24 g CO2e/km. Moving further on well-to-wheel energy efficiency, ICEVs have a maximum overall energy efficiency of 28%. Since EVs use various sources of energy for charging the battery, the overall efficiency was found to be at least 21% and maximum up to 39%. Thus, on an average EVs presently have a well-to-wheel efficiency of 32% when electricity generation mix is used for charging. [ABSTRACT FROM AUTHOR]

To maintain the global temperature, increase below 2°C, efficient bioenergy use is necessary. Many developed countries have successfully adopted biofuel into their energy mix, but sub-Sahara African (SSA), which has a comparative advantage in terms of land, labor, and climatic conditions for energy crops is trailing. Transportation in SSA is petroleum dependent and driven, with diesel fuel being the most used for heavy-duty vehicles, contributing significantly to the greenhouse gas (GHG) emissions in the region. Bioenergy has been identified as one of the energy resources that will play an essential role in reducing GHG emissions. Throughout the SSA region, different energy crops are grown and cashew nuts with shells, in which the waste are used to produce cashew nut shell liquid (CNSL), are cultivated and harvested in an area of 1,157,001–4,704,272 hectares, which is an increase of 406% from 2000 to 2019. As a result, 30,104,678 metric tons of cashew nuts with shell are produced, representing 51% of global production within the years under review, and approximately 6,020,935 metric tons of CNSL agro-industrial waste are generated. The paper discusses cashew nut post-harvest residue suitable for production of CNSL an inedible biodiesel feedstock for diesel engines. It also discusses CNSL extraction procedures, viscosity reduction methods, and fuel characteristics of various blends with additives. The study concluded that utilization of CNSL biodiesel can reduce the dependence of SSA on petroleum diesel while reducing GHG emissions. [ABSTRACT FROM AUTHOR]

Cryptococcus albidusandSaccharomyces cerevisiaewas used for separate hydrolysis and fermentation of sugar cane bagasse for production of ethanol. Lignocellulolytic enzymes, CMCase (34 U/ml), FPase (3 U/ml), β-glucosidase (2.3 U/ml), laccase (32 U/ml), and xylanase (12 U/ml), were assayed by fungus, however, after optimization of process parameters, an increase of 1.5-fold sugar (375 mg/g) from bagasse and production of lignocellulolyic enzymes were determined. The sugar produced by sugar cane bagasse was subsequently treated bySaccharomyces cerevisiae, indicating enhanced production of ethanol at 40 h was 38.4 g/L, reached to a maximum at 50 h, and then it was decreased. [ABSTRACT FROM PUBLISHER]

CO2 enhanced shale gas recovery has the merits of both increasing the natural gas production to address the global energy crisis as well as simultaneously the geological storage of CO2 to reduce the anthropogenic greenhouse gas emissions. Although it has huge development potential and wide application prospects, this technology is still in a very preliminary stage of deployment. The research status of the CO2 enhanced shale gas recovery is summarized in this paper in order to stimulate further research and development in this field worldwide to address the dual problem of energy crisis and environmental degradation. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emissions contribute considerably to global warming and climate change. Since energy systems notably influence GHG emissions, such emissions can be modeled at the national level based on the energy sources utilized by a country. Economic activity also affects GHG emissions. In this work, an Artificial Neural Network (ANN) approach, Group Method of Data Handling (GMDH), is used for determining emissions of carbon dioxide, the most significant GHG, on the basis of shares of various energy sources used as primary energy supply and GDP as an indicator of economic activity. Five countries are considered as case studies: Iran, Kuwait, Qatar, Saudi Arabia, and United Arab Emirates (UAE). Comparing the results achieved by the developed model and actual quantities shows that the ANN model has acceptable accuracy for predicting CO2 emissions. The average absolute relative error and the R-squared values of the GMDH model are 2.3% and 0.9998, respectively. These values demonstrate the precision of the model in forecasting emissions of CO2. [ABSTRACT FROM AUTHOR]

The transport sector is one of the main contributors to gas emissions and the greenhouse effect. Mobility as a Service seeks to combine different means of transport (public transport, bicycles, cars, etc.) in an integrated way to solve this problem. Raising drivers' awareness and advising them to drive more efficiently and economically can help reduce environmental impact. Ultimately, eco-driving can help save fuel, money and provide higher passenger satisfaction during the trip. The research uses a contextually enriched automotive data set collected via OBD, during passenger transportation in private cars. A multilevel analysis was conducted using a variety of approaches. With AI-based analysis, using unsupervised learning, we identified five groups of similarities as a function of speed and acceleration. The efficiency of each driver was examined and speed and acceleration/deceleration were noted as the most influential factors. Also, passengers' perception of driving quality is negatively affected by sudden acceleration and deceleration. Passengers have a poor perception of the driving efficiency and additional efforts should be made to educate them about the environmental aspect of driving. Finally, the main contribution is the eco-aware framework, which covers and describes the entire process from data collection to analysis. The collected data are publicly available and include 110 trips represented by more than 65,000 data points. [ABSTRACT FROM AUTHOR]

China's pilot emission trading schemes (CP-ETS) have been operating for five years since the first pilot ETS launched its carbon market in 2013. The seven pilots have a common framework but different details. In this study, an assessment model which is used to evaluate mitigation efficiency, is constructed by combining the DID method and an evaluation matrix. Results show that the five CP-ETS have been effective in promoting emission reduction, whereas the pilot ETS of Shanghai and Chongqing have failed to drive the covered enterprises to reduce their GHG emission directly. Our findings reveal that at least three key elements, namely, allowance cap, the covered enterprises' potential emission reduction capacity, and economic structure stability, affect the mitigation efficiency of the CP-ETS. The mitigation efficiency of the CP-ETS may be enhanced by conducting a pre-evaluation of the potential mitigation capacity of the covered enterprises, setting a mechanism for the evaluation and adjustment of the allowance cap, and employing financial tools to maintain the carbon price within a reasonable range that most covered enterprises can afford. [ABSTRACT FROM AUTHOR]

This study summarizes the results of a comparative analysis for the use of refuse-derived fuel (RDF) as opposed to the use of conventional fuel (CF) specifically for Thailand’s palm oil industry and the possible environmental impacts. RDF in this study was prepared by using municipal solid waste (MSW) from the Lamae Municipality in Chumphon, which has one of the largest palm oil industries in Thailand. The RDF was prepared from two main waste components, paper and low-density polyethylene plastic (LDPE) in five various ratios. The RDF and CF from the palm oil industry, such as wood and biomass, were analyzed for their heating properties and potential environmental impacts in terms of their global warming potential, acidification, and human toxicity. From this analysis it was concluded that RDF0:100 has greater value and is highly recommended to co-combust or replace CF in the palm oil industry. [ABSTRACT FROM PUBLISHER]

This article aims to introduce biodiesel as a possible solution, describing its evolution in Brazilian energy. It was concluded that the use of biodiesel leads to several advantages, such as significant reductions in rates of emission of some greenhouse gases and wide job creation and social inclusion in the poorest regions of the country. Besides the aspects already mentioned, within a national situation of growing imports of diesel oil and with oil prices rising, the article shows that biodiesel becomes an interesting alternative, reducing diesel imports and resulting products, thus enabling development in other industrial chains. [ABSTRACT FROM PUBLISHER]

Using cattails to produce biofuel will add value to the land and will also reduce emissions of greenhouse gases by replacing petroleum products. In order to investigate the feasibility of converting cattails into ethanol, cattails from constructed wetlands on the North Carolina A&T Farm underwent three kinds of pretreatment processes: NaOH, hot water, and dilute sulfuric acid. All three pretreatment methods were able to effectively increase enzymatic digestibility of cattail cellulose. The glucose yields resulting from enzymatic hydrolysis after pretreatment with NaOH, hot water, or dilute sulfuric acid pretreatment were 66.8, 62, and 54.8% of the cellulose (raw cattails basis), respectively. For both dilute sulfuric acid and hot water pretreatment, a high temperature (453–463 K) pretreatment was more effective compared to a lower temperature (394 K) pretreatment. It is recommended that further studies be carried out at a faster heating rate and shorter residence time for the pretreatment process.Saccharomyces cerevisiae(ATCC 24858) andPichia stipitis(ATCC 58784) were used to ferment the sugars released by cattail cellulose. When using diluted pretreated cattails, both stains were able to ferment glucose to produce similar amounts of ethanol. [ABSTRACT FROM PUBLISHER]

Modern bioenergy is seen as a promising option to curb greenhouse gas emissions. There is, however, a potential competition for land and water between bioenergy and food crops. Another question is whether biomass for energy use can be produced in a sustainable manner given the current conventional agricultural production practices. Other than the land and water competition, this question is often neglected in scenarios to meet a significant part of global energy demand with bioenergy. There are sustainable alternatives, for example organic agriculture, to avoid the negative environmental effects of conventional agriculture. Yet, meeting a significant part of global energy demand with biomass grown sustainably may not be possible, as burning significant quantities of organic matter is likely to be incompatible with the principles of such alternatives, which often rely on biomass input for nutrient balance. There may, therefore, be a trade-off between policies and practices to increase bioenergy and those to increase sustainability in agriculture via practices, such as organic farming. This is not a general critique of bioenergy but it points to additional potential dangers of modern bioenergy as a strategy to meet significant parts of world energy demand. [ABSTRACT FROM AUTHOR]

Carbon dioxide capture and geological storage are considered to be imperative practical means for reducing greenhouse gas emissions into the atmosphere. Among geological formations for carbon dioxide capture and geological storage, deep saline aquifer is tracked as a key site due to its huge potential and common occurrence when compared to oil and gas reservoirs. But, the two-phase behavior of CO2 accompanied with water formation under conditions equivalent to geological storage are mostly unknown. In this study, relative permeability experiments have been conducted to measure the end-point relative permeability of CO2 and investigations have been carried out to calculate injectivity using the relative permeability. In CO2 and water system, the injectivity is the function of the CO2 endpoint relative permeability. An experimental apparatus for CO2-water relative permeability was designed and experiments were carried out under six different temperatures varying from 70°F to 120°F, while the cell pressure was varied from 500 to 1,300 psi for every respective temperature. From the results, it was evident that, in general, the endpoint relative permeability of carbon dioxide increases with decrease in viscosity ratio, while the endpoint relative permeability in the transition region between gas and supercritical decreases even with decreasing viscosity ratio. Also, based on the sensitivity studies carried out by varying pressure and temperature, it was experimentally confirmed that porous and permeable aquifers at a minimum depth of more than 800 m are the most appropriate storage sites. [ABSTRACT FROM AUTHOR]

Turkey's demand for energy is increasing rapidly and heavily dependent on expensive imported energy resources. As would be expected, the rapid expansion of energy production and consumption has brought with it a wide range of environmental issues at the local, regional, and global levels. With respect to global environmental issues, Turkey's greenhouse gas emissions have grown along with its primary energy consumption. In this regard, renewable energy resources appear to be one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. Turkey has substantial reserves of renewable energy sources, including approximately 1% of the total world hydropower potential. There is also significant potential for wind power development. Turkey's geothermal potential ranks seventh worldwide, but only a small portion is considered to be economically feasible. This article presents the role of renewables in meeting the energy demand of Turkey as a sustainable manner. [ABSTRACT FROM AUTHOR]

Utilization of CO2 for enhanced oil recovery and sequestration processes not only reduces greenhouse emissions but also awards economical benefits. Enhancing oil recovery in a sequestration is an optimization process that requires careful analysis. In CO2-enhanced oil recovery the main purpose is to maximize oil recovery with the minimum quantity of CO2 while a maximum amount of CO2 is aimed to store in a sequestration. Kartaltepe field having 32° API gravity oil in a carbonate formation from southeast Turkey has been considered in this study. Reservoir rock and fluid data were evaluated and merged into CMG/STARS simulator. History matching study was done with production data to verify the results of the simulator with field data. From the results of simulation runs, it was realized that CO2 injection can be applied to increase oil recovery, but sequestering of a high amount of CO2 was found to be inappropriate for Kartaltepe field. Therefore, it was decided to focus on oil recovery while CO2 was sequestered within the reservoir. Oil recovery was about 23% of original oil in place in 2006 for the field, it reached to 43% of original oil in place by injecting CO2 after defining production and injection scenarios properly. [ABSTRACT FROM AUTHOR]

Global energy consumption is expected to increase dramatically in the next decades, driven by rising standards of living and a growing population worldwide. The increased need for more energy will require enormous growth in energy generation capacity, more secure and diversified energy sources, and a successful strategy to tame greenhouse gas emissions. Solar energy systems provide significant environmental benefits in comparison to the conventional energy sources, thus contributing, to the sustainable development of human activities. Sometimes however, their wide scale deployment has to face potential negative environmental implications. These potential problems seem to be a strong barrier for a further dissemination of these systems in some consumers. We assess the potential environmental intrusions in order to ameliorate them with new technological innovations and good practices in the future power systems. The analysis provides the potential burdens to the environment, which include noise and visual intrusion, greenhouse gas emissions, water and soil pollution, energy consumption, labor accidents, impact on archaeological sites or on sensitive ecosystems, and negative and positive socio-economic effects. [ABSTRACT FROM AUTHOR]

During the last two decades, significant advances have been made in the reduction of emissions from coal-fired power generating plants. New technologies include better understanding of the fundamentals of the formation and destruction of criteria pollutants in combustion processes (low nitrogen oxides burners) and improved methods for separating criteria pollutants from stack gases (FGD technology), as well as efficiency improvements in power plants (clean coal technologies). Future demand for more environmentally benign electric power, however, will lead to even more stringent controls of pollutants (sulphur dioxide and nitrogen oxides) and greenhouse gases such as carbon dioxide. [ABSTRACT FROM AUTHOR]

The main objective of this study is to identify the possible hazerdous emissions deriving from uncontrolled and incomplete combustions of biomass fuels that are reviewed based on the results of some investigations. Biomass combustion is a contributor of toxic air pollutants, particulate matter (PM), and greenhouse gases. PM emissions and detrimental metal emissions from biomass combustion, emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from the combustion of different biomass and solid wastes are reviewed. [ABSTRACT FROM AUTHOR]

The gases with higher heat capacities than those of O2 and N2 cause greenhouse effects. Carbon dioxide (CO2) is the main greenhouse gas associated with global climate change. At the present time, coal is responsible for 30-40% of world CO2 emissions from fossil fuels. There was a higher correlation between the amount of carbon dioxide emission and percentage of carbon in the fuel for all equations. The squares of correlation coefficients were 0.9999, 0.9978, and 0.9995. The gas sensing characteristics of MgO and CaO as the CO2 gas sensors and CO2 emission capacities selected carbonaceous fuels have been investigated. It was found that increasing the percentage of carbon in carbonaceous fuel caused CO2 emission increase. Carbonation is a stabilization of CO2 by solidification process. The availability of a CO2 fixation technology would serve as insurance in case global warming causes severe restrictions on CO2 emissions. In order to prevent rapid climate change, it will be necessary to stabilize CO2 as carbonate by the carbonation process. The carbonation was carried out using MgO and CaO as CO2 sensors. The yield of carbonation increased with increasing temperature. The rate of carbonation conversion sharply increased in the initial 20 min and then reduced and reached a plateau value after about 40 min. The carbonation conversion with MgO is higher than that of CaO. [ABSTRACT FROM AUTHOR]

Energy has been one of the most important factors in keeping our society running smoothly. However, in the past few decades, terms such as 'energy crisis' and 'green house gases emission' have been brought to our attention more frequently than ever. It is well recognized that this world will be a different place in the future than it is today with shortages in the energy supply. In order to meet the rising global demand for energy, rapid development of conventional fossil fuels (i.e., coal, oil, and natural gas) have been experienced by many nations, bringing dramatic economic benefit and prosperity to fossil-fuel industries as well as wellbeing of human society. However, various fossil-fuel related activities emit huge quantities of gaseous, liquid, and solid waste materials, posing a variety of impacts, risks, and liabilities to the environment. Therefore, on the one hand, control measures are desired for effectively managing pollution issues; on the other hand, it becomes extremely critical to invest efforts in finding promising alternative energy sources as solutions to the possible energy shortage crisis in future. This article focuses on both aspects through: (1) a discussion of waste materials generated from fossil-fuel industries and waste management measures; and (2) an exploration of some well-recognized alternative fuels in terms of their nature, availability, production, handling, environmental performances, and current and future applications. The conclusion restates the urgency of finding replaceable long-term alternatives to the conventional fuels. [ABSTRACT FROM AUTHOR]