Search

Hydrogen as an energy vector is seen as a key for the energy transition. Recently, more than 30 countries have launched their hydrogen strategies and roadmaps. Hydrogen storage and transportation are challenging steps of the hydrogen economy since all available options have significant drawbacks. This paper evaluates a power-to-liquid hydrogen process; the system is “charged” with electricity from renewable sources to produce hydrogen via water electrolysis; the produced hydrogen gas is liquefied and stored at ambient pressure and cryogenic temperature. The purpose of this paper is to report the first evaluation results of a system including a polymer electrolyte membrane electrolyser and a hydrogen liquefier. The evaluation was conducted using exergy-based methods, i.e. exergetic, exergoeconomic and exergoenvironmental analyses. The process of hydrogen liquefaction was simulated with the aid of the Aspen Plus software. The exergetic efficiencies for the liquefaction process and for the electrolyser are 42% and 47%, respectively. While the total exergetic efficiency of the power-to-liquid hydrogen system amounts to 44%. The total exergy destruction for the liquefier amounts to 9.3 MW and for the polymer electrolyser membrane electrolyser amounts to 19.3 MW. The electrolyser followed by the hydrogen compressors were identified as the components with the highest exergy destruction values and investment costs, while the compressors and the recuperators account for the highest exergoenvironmental impact. The sensitivity analysis shows that the specific liquefaction cost of hydrogen strongly varies with the electricity price and the cost of green hydrogen.

Hydrogen is an outstanding source of energy and plays very important part in energy system. Hydrogen is one of the best energy carrier alternatives to fossil fuels because of its high energy density. It is very important to produce clean and renewable energy sources due to increasing population and pollution day by day. In 2018, the maximum hydrogen (94%) is manufactured from fossil fuels by steam reforming of natural gas, partial oxidation of the methane gas as well as coal gasification. The hydrogen production plays important role in any industrialized society, since hydrogen is required for many essential chemical processes. Several designed metal-based ideas can be employed as an efficient catalyst for hydrogen production for the alternate source of energy and society benefits. Proposed review is highlighting the different efficient strategies for hydrogen production.

Due to rapid movement of rural population to new regions and countries in order to find work and for better living conditions, population growth and economic development, there is gradual increase in production of waste and demand of electricity worldwide. According to World Bank statistics, the global Municipal Solid Waste generated was 1.3 billion tons in year 2012 and this is expected to increase above 2.2 billion tons per year by 2025. Due to lack of sites for waste disposal, it has become a serious environmental as well as health issue. Now various methods have been adopted for waste disposal. Among this, energy accessed from municipal solid waste is the most common practice adopted by developing countries. In addition, Waste to Energy and Energy from Waste technologies are used which include thermal and biological technologies. Gasification, pyrolysis and incineration are thermal technologies used in conversion of waste to energy. During these processes, syngas is produced which is used in combustion engine or turbines to generate electricity. Apart from this, biomethanation is also used in which biogas is produced. In this review article, we have discussed all the environmental and green methods used for the generation of energy from Municipal Solid Waste their advantages and drawbacks.

Usage of plastics in the form of personal protective equipment, medical devices, and common packages has increased alarmingly during these pandemic times. Though they have served as an excellent protection source in minimizing the coronavirus disease (COVID-19) spreading, they have still emerged as major environmental pollutants nowadays. These non-degradable COVID-19 plastic wastes (CPW) were treated through incineration and landfilling process, which may lead to either the release of harmful gases or contaminating the surrounding environment. Further, they can cause numerous health hazards to the human and animal populations. These plastic wastes can be efficiently managed through thermochemical processes like pyrolysis or gasification, which assist in degrading the plastic waste and also effectively convert them into useful energy-yielding products. The pyrolysis process promotes the formation of liquid fuels and chemicals, whereas gasification leads to syngas and hydrogen fuel production. These energy-yielding products can help to compensate for the fossil fuels depletion in the near future. There are many insights explained in terms of the types of reactors and influential factors that can be adopted for the pyrolysis and gasification process, to produce high efficient energy products from the wastes. In addition, advanced technologies including co-gasification and two-stage gasification were also reviewed., Graphical abstract Image 1

A huge quantity of textile effluent sludge is generated from 21 076 textile units of India and dumped in large areas, leading to contamination of soil, surface water and groundwater. Hence, effective management of this sludge is important for its reuse and safe disposal. Considering the utilization of this waste in construction activities, the current paper explores the potential of textile sludge produced from textile industry effluent treatment plants. Many researchers have attempted to reuse this sludge for the development of sustainable construction materials and suggested its optimum usage as a partial substitution for fine aggregate, cement and clay with or without additives for the manufacturing of non-structural building components. This paper provides a critical review of the production of non-structural elements – namely, sustainable building blocks, clay bricks, mortar and paver blocks – using textile effluent treatment plant sludge and recommends optimum ranges of 5–30, 5–40, 5–50 and 20–40%, respectively. The prominent gaps are suggested as the outcome of studies such as techno-economic feasibility of the product, thermal and energy building simulation along with the life-cycle assessment and fatigue life assessment of the developed paver blocks.

The interest and relevance of the present paper are in the current waste plastic valorisation scenario. The rapid depletion of fossil source carbon as crude oil and its ever-increasing costs have led to an intensive search for alternative fuels. An alternative or renewable green fuel (RGF) was obtained from waste low- and high-density polyethylene or polyolefins and computer body plastics through a pyrolysis process using cadmium carbonate (CdCO3) from 23 to 400°C. Five types of hydrocarbons were observed through two-dimensional gas chromatography and time-of-flight mass spectrometry (GC×GC-TOFMS): 7.621% paraffins, 53.668% branched/cyclic hydrocarbons, 14.083% aromatics, 0.327% phenanthrenes and 24.301% unclassified compounds. The research octane number of the RGF was 88.29. The bromine number of the RGF was 34.03%. The RGF was suitable for diesel engines and diesel furnaces without any upgrading. During the first, second and third pyrolysis experiments, 98, 95 and 100 g (wt%) waste granules with 2, 5 and 0 g (wt%) cadmium carbonate into RGFs were collected at 85, 89 and 80%; uncondensed gases were collected at 14.22, 10.15 and 19.52%; and the residue was collected at 0.78, 0.85 and 0.48%.

In the present time, our main sources of energy are fossil fuels like petroleum, coal, natural gases which are burned to access the required energy for various purposes such as home, industries, agriculture, etc. The uses of these sources ultimately producing various types of pollution such as air, water, soil and adding it’s harm effects to the society. In the present state, numbers of works have been carried out to develop the useful materials to harvest the light to full fill the demand of the society. In this review, analysis of facts has been carried out on various light harvesting materials related with main group elements. As we know, the light energy source is unlimited and able to fulfill the demand of each sector of society completely if it would be harvested in large extent and further, it will be very useful for human beings or for our next generations.

As environmental crises such as global warming become more and more serious due to the large amount of carbon dioxide emitted by the burning of fossil fuels, much attention has been paid to carbon neutrality. Hydrogen, with zero carbon content, is a clean and renewable energy carrier having a large energy density. It is considered as one of the most desirable alternatives to fossil fuels. Electrochemical water splitting, unlike the steam reforming process accelerating fossil fuels depletion and CO2 emissions, can produce H2 powered by renewable energy such as solar or wind. As a promising way to promote carbon neutralization, hydrogen production by electrolysis of water is meaningful both in terms of scientific research and practical application. In order to drive electrochemical water splitting with low power consumption, efficient, durable and affordable electrocatalysts with low overpotentials are in urgent need. Therefore, this mini-review briefly introduces the current development status and mainstream obstacles of carbon-based materials used in electrochemical water splitting.

Aromatics are traditionally produced by the catalytic reforming of naphtha. However, with the demand of aromatics increasing and the reserves of petroleum resources declining, measures should be made to reduce the dependence of aromatics production on petroleum resources. Methanol-to-aromatics is proved to be an effective way to replace traditional naphtha-to-aromatics path. In order to compare the economic and environmental performance of aromatics production from naphtha and methanol, this paper carries out an emergy evaluation for each system by sorting out the simulation and literature data. Based on the emergy data collected, the emergy indices of each system are calculated. The results show that the sustainabilities of methanol-to-aromatics systems are higher than that of the naphtha-to-aromatics system, indicating the advantages of aromatics production from methanol. Among the methanol-to-aromatics systems, the aromatics from biomass-methanol system has the highest sustainability, indicating that the biomass based methanol-to-aromatics system is worth promoting. The sustainability indexes of methanol-to-aromatics systems based on coal and coke oven gas are less than 1, which means unsustainable. Meanwhile, the sustainability of natural gas based system is slightly higher than 1. The economic and environmental benefits of these systems can be optimized by improving resource utilization and reducing investment costs. Furthermore, the combination of different raw materials for methanol production should be considered.

Environmental protection and sustainability have been a serious challenge due to the excess amount of waste plastic, and the inefficient methods of its disposal. This study aims at exploring the feasibility of using plastic material in asphalt concrete followed by the design and evaluation of modified asphalt mix. Four different types of asphalt mixtures were made by mixing mineral aggregates with plastic aggregates of different shapes and sizes. The conventional dense-graded asphalt concrete incorporating mineral aggregates was selected as control material, whereas the other three types of asphalt mixtures were produced by substituting 3D-printed plastic aggregates for mineral aggregates. Marshall characteristics were utilized to evaluate the volumetric and mechanical properties of the asphalt mixtures. Test results show that the asphalt mixture containing solid plastic aggregate appears to have a 14.3% reduction in bulk density, thereby potentially reducing the haul costs. Due to the angular shape of the aggregate, the stability for the asphalt mixture containing the 3D-printed aggregate is 1.95 times higher than that for the asphalt mixture incorporating all mineral aggregates. The addition of the plastic printed aggregate enhances the strain capacity to achieve failure of the asphalt mixture. However, caution should be taken when incorporating the hollow or fine printed aggregates into the asphalt mixture due to their variation of volumetric properties.

Due to the frequent occurrence of oil spills and the large-scale production of oily wastewater, the treatment of oily sewage has become an important issue for sustainable development. Recently, materials prepared from lignocellulosic biomass (LCB) for oil-water separation have been found to be effective due to their high separation efficiency, good recyclability, and superior sustainability. However, few reviews have focused on the advantages and limitations of LCB for sewage treatment. This review summarizes the performance of modified LCB in oily wastewater treatment, in terms of the advanced modification methods applied and the structural dimensions of LCB materials according to the principle of superwetting oil-water separation. Research on the preparation technologies, separation mechanisms, and treatment efficiency of different LCB materials are briefly summarized, along with the characteristics of different LCB material types for oily wastewater treatment. Finally, the future prospects and challenges faced in the development of LCB materials are discussed.

The utilization of biomass energy is important from both an energetic and environmental point of view. Saudi Arabia has a considerable amount of biomass waste that can be converted to renewable energy using different technologies. This study evaluated and analyzed the quantity and energy potential of biomass waste, Greenhouse gases (GHG) emissions, and cost estimation of power generation using different conversion techniques. The results showed that the annual biomass waste in Saudi Arabia could reach approximately 31.50 million tons, which can generate 15 TWh of electricity. Municipal solid waste (MSW) is the largest contribution to the total waste and total power generation potential, which is approximately 70% and 74% of the total, respectively. Although incineration of MSW has the highest cost requirements, it has the highest power generation potential compared with the other studied techniques. However, the anaerobic digestion of other biomass types has the advantages of low costs and GHG emissions and generates considerable energy. The findings of this study can support decision-makers in developing sustainability strategies using eco-friendly and economical technologies for efficient power generation from biomass wastes.

This paper presents a critical literature review on the use of supplementary cementitious materials (SCMs) from agricultural wastes (mainly from crop residues) in cementitious systems. The current utilisation of these materials as partial replacement of Portland cement is reviewed with respect to the influence of the materials' characteristics on the performance and the limit of replacement in cementitious systems. In spite of the benefits of SCMs from agricultural wastes (such as rice husk ash, palm oil fuel ash and sugarcane bagasse ash), their unavailability in the required form, heterogeneous nature and insufficient data make it difficult to generalise their performance. Therefore, a review of the existing information available will help to unravel areas of further research, any relationship between the influence of the processing method and materials characteristics on the limit of replacement and performance in cementitious systems and assist in their standardisation and sustainable utilisation. This, coupled with the reproducibility of results, will assist the processing and adoption of other agricultural wastes in cementitious systems.

The applications of fumigation and the challenges that high-containment facilities face in achieving effective large volume decontamination are well understood. The Biosecurity Research Institute at Kansas State University sought to evaluate a novel system within their biosafety level 3 (BSL-3) and animal biosafety level 3 agriculture (ABSL-3Ag) facility.The system chosen for this study is the CURISAfter cycle optimization, the smaller laboratory had a total of 60 BIs over two treatments that demonstrated a greater than 6-log reduction of bacterial spores. The larger laboratory (192 BIs) and the necropsy suite (206 BIs) had no BIs positive for spore growth when incubated at 60°C for 24 h per manufacturer's specifications.Overall successful results through multiple components of this study demonstrate that the HHP device, paired with the pulsed 7% H

The establishment of rapid and efficient contamination detection methods in agricultural fields is of great significance for safeguarding agricultural production and human health, and for ensuring the healthy development of agricultural industries. As a booming analytical method, photoelectrochemical (PEC) sensors, which combine the advantages of electrochemical analysis and optical analysis, have received increasing research attention. Due to the complete separation of the excitation source (light) and the detection signal (current), the background signal of PEC sensors is greatly decreased, and their sensitivity is high. This review aims to cover the advances in PEC sensors for contamination analysis in agricultural fields over the past 5 years, including the analysis of heavy metals, antibiotics, pesticides, and toxins. The future prospects in this field are also discussed.

Wastewater is of general concern for environmental sustainability. At the industrial level, carbon-laden aqueous streams must be treated and should be valorized to reduce environmental and economic concerns. Lignocellulosic biomass processing (such as hydrolysis, pyrolysis, and hydrothermal liquefaction) results in secondary aqueous streams in which a high fraction of the initial carbon content of the biomass is virtually lost; food industry (like breweries and cheese factories) produces streams with a variety of organic load and salinity, which may complicate conventional valorization treatments; biodiesel production leads to glycerol excess in the market, which needs to be valorized. Among other alternatives, aqueous phase reforming (APR) has been proposed as a process driven at relatively mild conditions, able to convert oxygenated molecules into hydrogen. Despite its potential, APR has commonly been investigated with model compounds, and a systematic study on the possible fields of application of this technology is lacking. In the present review, the study of the available literature was focused on the valorization of complex feedstocks, such as real waste streams or synthetic mixtures, showing the outcome derived from laboratory-scale experiments. The results were critically discussed, pointing out the present limitations for the full development of this process and its application to the industrial scale. Despite the challenges of APR, its potential is noteworthy for the development of a circular low-waste economy.

HFC-134a is a widely used environment-friendly refrigerant. At present, China is the largest producer of HFC-134a in the world. The production of HFC-134a in China mainly adopts the calcium carbide acetylene route. However, the production route has high resource and energy consumption and large waste emission, and few of the studies addressed on the environmental performance of its production process. This study quantified the environmental performance of HFC-134a production by calcium carbide route via carrying out a life cycle assessment (LCA) using the CML 2001 method. And uncertainty analysis by Monte-Carlo simulation was also carried out. The results showed that electricity had the most impact on the environment, followed by steam, hydrogen fluoride and chlorine, and the impact of direct CO2 emissions in calcium carbide production stage on the global warming effect also could not be ignored. Therefore, the clean energy (e.g., wind, solar, biomass, and natural gas) was used to replace coal-based electricity and coal-fired steam in this study, showing considerable environmental benefits. At the same time, the use of advanced production technologies could also improve environmental benefits, and the environmental impact of the global warming category could be reduced by 4.1% via using CO2 capture and purification technology. The Chinese database of HFC-134a production established in this study provides convenience for the relevant study of scholars. For the production of HFC-134a, this study helps to better identify the specific environmental hotspots and proposes useful ways to improve the environmental benefits.

The inefficient food processing and food leftover management strategies often lead to the wastage of untapped carbohydrate-rich feedstocks. The conversion of these feedstocks into bioethanol can mitigate the emission of greenhouse gases (GHGs) while providing a sustainable and eco-friendly method for disposing of food wastes. In light of the above, the current review scrutinizes various types of food wastes (homogeneous and heterogeneous) and pretreatment methods (physical, chemical, physicochemical, and biological) for their valorization into bioethanol. The main constraints to commercial production of food-waste-derived bioethanol, that is, the requirement for sterilization and collection of feedstocks, are also discussed. The former issue can be addressed by developing an optimized solid-state fermentation process. Employing selective conditions to enrich bioethanol-producing microorganisms can increase the feasibility of this process configuration while inhibiting ethanol-consuming strains. The feedstock collection issue can be minimized by determining the hot spots that are in the vicinity of the large food processing sites.

Since the early years of the 21st century, the whole world has faced two very urgent problems: the depletion of fossil energy sources and climate change due to environmental pollution. Among the solutions sought, 2,5-Dimethylfuran (DMF) emerged as a promising solution. DMF is a 2nd generation biofuel capable of mass production from biomass. There have been many studies confirming that DMF is a potential alternative fuel for traditional fuels (gasoline and diesel) in internal combustion engines, contributing to solving the problem of energy security and environmental pollution. However, in order to apply DMF in practice, more comprehensive studies are needed. Not out of the above trend, this paper analyzes and discusses in detail the characteristics of DMF's combustible laminar flame and its instability under different initial conditions. The evaluation results show that the flame characteristics of DMF are similar to those of gasoline, although the burning rate of DMF is much higher than that of gasoline. This shows that DMF can become a potential alternative fuel in internal combustion engines.

This is the first study to apply a combination of two thermoeconomic approaches (UFS and H&S) with Life Cycle Assessment (LCA) to a chilled water system installed in a shopping mall. The objective is to obtain monetary and environmental costs for the thermal energy stored by developing both thermoeconomic and thermoenvironmental assessments. The thermoeconomic study determined internal flows, defined inputs and products, and described the productive structure to obtain exergy and monetary costs. The LCA methodology quantified the greenhouse gas emissions associated with equipment operation and energy flows. The results indicated efficient thermoeconomic behavior for the heat exchangers. The monetary and environmental costs of chilled water are, respectively, US$ 0.2267/MJ and 0.8186 kg CO2-eq/MJ.

Recycling waste materials for transport infrastructure such as coal wash (CW), steel furnace slag (SFS), fly ash (FA) and recycled tyre products is an efficient way of minimising the stockpiles of waste materials while offering significant economic and environmental benefits, as well as improving the stability and longevity of infrastructure foundations. This paper presents some of the most recent state-of-the-art studies undertaken at the University of Wollongong, Australia on the use of waste materials such as (a) CW-based granular mixtures (i.e. SFS + CW, CW + FA) for port reclamation and road base/subbase and (b) using recycled tyre products (i.e. rubber crumbs, tyre cell, under-sleeper pads and under-ballast mats) to increase track stability and reduce ballast degradation. Typical methods of applying these waste materials for different infrastructure conditions are described and the results of comprehensive laboratory and field tests are presented and discussed.

At present, the situation of coal mine safety production is still grim. The key to solve the problem is to analyze the risk of management activities in the process of coal mine safety production. This paper takes the management activities in the process of coal mine safety production as the research object. Firstly, according to the coal mine safety production standardization management system, the safety production management activities are carried out layer by layer. Then, the Failure Mode and Effect Analysis (FMEA) is used to identify the human errors that lead to the failure of management activities at all levels of coal mine. Furthermore, the Fuzzy Set Theory is used to determine the evaluation results of experts on the risk level of coal mine safety production management activities. Combined with Bayesian network (BN), the risk assessment model of coal mine safety production management activities is established. Through the model, the risk probability of coal mine enterprise management activities is accurately calculated. According to the evaluation results, the risk of management activities in coal mine safety production is analyzed.

Coal mining technologies always lead to tremendous environmental pollution of air, water resources, lands and biodiversity, both in regional and global scale. The level of environmental safety and ecological quality of the coal-mining region significantly decreases due to mining operations. In particular, mine waters with solid particles and dissolved chemicals are discharged surface reservoirs. Suspended substances of mine waters, both in solid and dissolved forms, pose a high threat for ecological and chemical balance of natural waters. Due to the ability to adsorb heavy metals they play a significant role in the pollution of nearby water bodies. Chemicals not only change the quality of water bodies, but also pose an increased environmental risk to aquatic organisms and the health of the population. The purpose of the paper is to revise the mine water drainage technological scheme of the coal mine “Stepova” as the subdivision of the Public Joint-Stock Company “DTEK Pavlogradvugillya” (Ukraine) and justify technical considerations concerning implementation of a horizontal settling tank with unique design. It is justified that such mechanical treatment facility with vertical perforated partitions will significantly improve the overall water quality and further additional treatment in the storage pond. The modeling of the mine water purification process for the conditions of the coal mine “Stepova” is carried out due to the investigation of the kinetics of suspended particles precipitation simulated in laboratory conditions. The obtained dependences allow select the most optimal design and technological parameters of the proposed settling tank of advanced design. The values of the expected technological parameters of the proposed settling tank are determined, namely the predicted value of mine water purification efficiency, approximate depth of particles sedimentation in the point of treated water removal from the settling tank, and hydraulic size of suspended solids. It is established that the implementation of the proposed technological scheme of mine water purification will reduce the concentration of suspended solids to the normative concentrations allowed for discharge into surface water bodies.

The challenges faced by the fossil fuel industry has led to the exploration of biomass-derived fuel. Biomass can be converted to biofuels via pyrolysis and can be paired with plastic waste to improve biofuel yield and quality. This mini review provides concise information on recent advances in pyrolysis, focusing on using waste, specifically agricultural residues and plastic waste, as resources. Next, discussion is made on pyrolysis of biomass and plastic waste, respectively, followed by co-pyrolysis of biomass and plastic waste. Catalytic co-pyrolysis, including zeolite catalysts and metal-modified HZSM-5 is then reviewed. Finally, the future perspective of this research is discussed.

Driven by the high energy demand and environmental concerns, biodiesel as a substitute for fossil fuels is recognized as promising renewable and clean energy. Biodiesel has gained interest around the world over the last few years because it could be used to reduce most regulated exhaust emissions. Herein, we discuss the application of catalytic transesterification by using ionic liquids (ILs) catalyst with alcohol and waste oil for the clean synthesis of biodiesel in order to reduce the emission of NOx and CO. However, the running cost of this process is still higher than that of the conventional chemical transesterification. Non-edible sources such as waste oil, non-edible vegetable oil, and waste animal oil are commonly used to produce biodiesel due to their low cost and no dependency on the food chain. This review provides an overview of the recent progresses in improving the biodiesel production process by using ILs and determining the activation energy and the properties of the finished product. In addition, the future direction in biodiesel production via ILs catalysis in the transesterification has been discussed.

The continuous rise of global carbon emissions demands the utilization of fossil fuels in a cleaner and sustainable way. Gasification is a potential technology that can convert the dirty fossil fuels for the production of clean and environment friendly fuels in an economical manner. In this study, vacuum residue is employed as a feedstock to produce high grade methanol. A vacuum residue to methanol (VRTM) process is simulated using Aspen Plus for a methanol production capacity of 90 t/h with 99.9 wt.% purity. The developed VRTM process is bench-marked with the conventional steam reforming to methanol (SRTM) process through energy, environmental and economic analysis. The performance of vacuum residue gasifier, natural gas reformer and the methanol synthesis reactor are validated against the plant data and the simulation results are found to be in good agreement. The results showed that the VRTM process offers a process energy efficiency of 49.5% which is 1.6 % higher than the SRTM process. The unit cost of methanol product from the VRTM process is $ 317/tCH3OH which is 14% lower compared to the SRTM process. In terms of environmental analysis, SRTM process emits less carbon emissions than the VRTM process. However, the VRTM process offers a high purity captured CO2 stream that can be utilized for another application that can further offset the methanol production cost.

In this study an investigation of Turkey's overall industrial waste heat potential is conducted, and possible power and hydrogen conversion technologies are considered to produce useful energy such as power and hydrogen. The annual total industrial waste heat was has a 71 PJ in 2019 and is expected to double by 2050. The temperature range of the waste heat differs by sector at a large range of 50 °C–1000 °C. Absorption power cycle (APC), Organic Rankine Cycle (ORC), Steam Rankine cycle (SRC) and Gas Turbine (GT) systems are adapted for power production based on the waste heat temperature while electrochemical and electro-thermochemical hydrogen production systems are adapted for hydrogen generation. Proton Exchange Membrane, Alkaline, and high temperature steam electrolysis methods are selected for pure electrochemical conversion technologies and Hybrid Sulfur (HyS), Copper Chlorine (CuCl), Calcium–Bromine (CaBr), and Magnesium Chlorine (MgCl) cycles are utilized as hybrid thermochemical technologies. Many cases are formed, and best temperature matching power-hydrogen system couples are selected. It is possible to produce enough hydrogen to compensate up to 480 million m3 natural gas equivalents of hydrogen annually with selected technologies which corresponds to ~5% of residential natural gas consumption in Turkey. Economic analysis reveals that lowest hydrogen generation cost belongs to the GT-HyS system. When hydrogen is used for heating applications by a certain mixture fraction to NG pipelines, it may reduce more than 720 thousand tons of CO2 reduction annually due to natural gas use.

Hazardous waste (HW) management is challenging because of their extreme toxicity to the environment and human beings. In the meantime, the occurrence of safety incidents that is caused by HW disclo...

The available natural energy sources are insufficient to meet everyone's needs. Due to an increased population, dwindling natural resources, limited natural sources, and environmental issues, it is critical to focus on reproducing, recycling, and reused techniques. Coal is a major source of energy generation in India, but it causes significant environmental pollution. The use of petroleum oil for transportation contributes to global warming, and domestic and industrial waste contributes to pollution. It is critical to consider waste water treatment as well as alternative energy sources such as biofuel. Conventional technology is insufficient in terms of both economics and the environment. Membrane technology is an effective and efficient technology. This paper provides an overview of recent research on membrane technology applications in waste water treatment, biofuel production (such as biodiesel and bioethanol). It also discusses membrane reactors, membrane bioreactors, and mixed matrix membrane reactor applications for biodiesel production, as well as hybrid pervaporization membrane bioreactors, integrated pervaporization membrane bioreactors for bioethanol production, the membrane bioreactors application for waste water treatment.

Coal spoil-heaps cause man-made pressure on the environment of the coal mining area. Coal mining, and in recent years the mass closure of mines has been accompanied by a negative impact on natural objects and engineering structures - the basements of houses and buildings are flooded, walls and wooden fences rot, crops, trees and bushes are destroyed. Reclamation is carried out on spoil-heaps of coal mines to reduce man-made pressure. However, in the process of rock dumping on the spoil-heaps a neorelief begins to emerge causing the vegetation development. The emergence of vegetation groups is a positive phenomenon, as phytomass decomposition promotes the formation of humus. The development of vegetation on the surface of coal spoil-heaps is called vegetative reclamation or phytomelioration. Efficiency of vegetative reclamation is calculated in points and is an indicator of the suitability of a particular man-made object for natural overgrowth. The aim of the work is to establish the features of spatial arrangement of plants in populations on the surface of coal spoil-heaps. It is established that on the coal spoil-heaps, as well as in natural conditions, vegetation tends to aggregate, thus forming phytogenic fields. It should be noted that at different stages of successions, phytogenic fields are formed in different ways. Monocentric phytogenic field arises on the waste heaps during the syngenetic stage of succession. The initial endecogenetic stage of succession provides the formation of phytogenic fields of two types. The first type is the initial polycentric phytogenic field. It is characterized by the ability to combine several individuals of the same species. The second type is a mature polycentric phytogenic field. It is characterized by higher resistance, and plant community is already able to convert geoprocesses. The mature endoecogenic stage of succession is characterized by the development and expansion of tree species, and the phytogenic field is acentric and global. This kind of phytogenic fields is found on tailings with artificial vegetative reclamation.

Direct steam generating parabolic trough power plant is an important technology to match future electric energy demand. One of the problems related to its emergence is energy storage. Solar-to-hydrogen is a promising technology for solar energy storage. Electrolysis is among the most processes of hydrogen production recently investigated. High temperature steam electrolysis is a clean process to efficiently produce hydrogen. In this paper, steam electrolysis process using solar energy is used to produce hydrogen. A heat recovery steam generator generates high temperature steam thanks to the molten carbonate fuel cell's waste heat. The analytical study investigates the energy efficiency of solar power plant, molten carbonate fuel cell and electrolyser. The impact of waste heat utilization on electricity and hydrogen generation is analysed. The results of calculations done with MATLAB software show that fuel cell produces 7.73 MWth of thermal energy at design conditions. 73.37 tonnes of hydrogen and 14.26 GWh of electricity are yearly produced. The annual energy efficiency of electrolyser is 70% while the annual mean electric efficiency of solar power plant is 18.30%. The proposed configuration based on the yearly electricity production and hydrogen generation has presented a good performance.

In the present research work, effect of hydrogen (H₂) flow rate, on the performance of modified dual fuel (DF) engine powered with two biodiesels is studied. Biodiesels derived from Jack fruit seed (JKFSDOB) and Nigella Sativa oils (NLSTVAOB) and their B20 blends are used as pilot injected fuels while H₂ is used as the manifold inducted fuel in the modified DF engine. Further influence of H₂ gas flow rate on the modified DF engine by using conventional mechanical fuel injection (CMFIS) for optimal performance of engine is investigated. Increasing the hydrogen gas flow rates reduces brake thermal efficiency (BTE), smoke, CO (Carbon monoxide) and HC (Hydrocarbon) emissions while NOx (Nitric oxide) emissions from DF engine increased. The engine operated by renewable fuel combinations of biodiesels and H₂ in DF mode engine can facilitate partial as well as complete substitution for fossil fuels and reduce the greenhouse gas emissions.

The concept of utilizing industrial and agricultural waste materials in concrete contributes to recompensing lacking natural resources, solving the waste disposal problem, and finding alternative techniques to protect nature. Environmental awareness regarding potential harmful effects has significantly increased, and, thus, recycling or using agricultural and industrial waste by-products has become an increasingly attractive alternative for waste disposal. Several related studies investigated the utilization of waste materials and by-products like coal bottom ash, rice husk ash, coconut shells, plastic, glass, and wood. In this paper, a thorough assessment has been conducted about the industrial and agricultural waste substances that can be effectively utilized in concrete as an alternative to cement or aggregate in the concrete mixture. This paper also aims to promote utilizing wastes by improving pozzolanic performance and material properties as part of concrete constituents.

Electricity is predicted to be the energy vector that will undergo major changes in the future, and a transition would be observed in the resources such as waste and residual biomass that we use to satisfy the energy demand. Therefore, this study aims to highlight the main economic and environmental performances of different biowaste-to-energy technologies for small-scale electricity generation by comparing the direct combustion of refined vegetable oil obtained from waste cooking oils (thermal pathway), anaerobic digestion of biowaste (bio-chemical pathway), and gasification of wood residues (thermo-chemical pathway). The economic analysis is mainly based on personal experiences in the energy sector and shows an overview of the performance in investment of combined heat and power (CHP) systems, ranging from 100 to 500 kW for a period of 20 years. The environmental assessment is conducted considering the life-cycle thinking approach using support from the openLCA software, product environmental footprint (PEF) data-base, and previous studies that have reported environmental inventory data from real industrial cases.

Fossil fuels are used as a fuel for wide range of applications around the world, as per the statistics it is found that the depletion rate of fossil fuel is reducing rapidly. To satisfy the needs of mankind we are in search of an alternative fuel. The present research work is carried out using pongamia pinnata and silkworm oil, on a four-stroke diesel engine as an alternative fuel to find the efficiency of the diesel engine using above specified mixture along with fossil fuel with various blends at different flow rates of engine and calorimeter cooling water. In present investigation the biodiesel is prepared from pongamia oil, and it is blended with silkworm oil. The performance parameters of single cylinder 4 S diesel engine are evaluated.

Hydrocarbons, which are found in plastic, are an excellent energy source due to their high energy density. The disposal of plastic waste presents significant energy saving and recovery opportunities. The purpose of this study is to determine how much energy can be recovered from waste plastics as a possible alternative fuel source for cars. This research aims to assess the performance of waste plastic pyrolysis oil (WPO) generated by polyethylene pyrolysis. Ethanol is an appealing alternative fuel since it is made from renewable bio-resources and works as an oxygenated fuel in diesel engines, allowing for emission reductions. Three different percentages of WPO were combined with ethanol to create a tertiary fuel blend. This research examines the performance and emission requirements of a single-cylinder direct injection diesel engine. With diesel, D70W20E10′s specific fuel consumption reduces by about 7.5 %. Carbon monoxide emissions from D70W20E10 were about 6.5 % lower than diesel and 13.5 % lower than hydrocarbon at various loadings. The most optimum running condition was further examined using the Full Factorial Design method.

In present scenario fossil fuels are getting depleted, in addition to this dependency and price is increasing. A time may come in future there might fuel crises. Hence, in order to make a better future. Renewable fuels from different and large number of sources can be typically used as fuel to generate electricity and for transportation in replacement of fossil fuels. This background view describes the of injection timing (IT) effect on engine performance, combustion and characteristics of Emission using waste cooking oil methyl ester (WCOME) and induction of producer gas with pilot injection of diesel on dual fuel mode of working. Thus, experiment shows the optimization of different injection timing (IT) (19–31° in step of 4°) to improve the dual fuel engine performance. Investigation of WCOME with producer gas operation at 27° bTDC showed reduced emission levels with increased brake thermal efficiency.

Recent splurge in the civil engineering industry is fuelled by the growth of industrial clusters across nation and also by conversion of villages into towns and cities. The technological developments and changes are results of industrial growth which resulted in tremendous use of natural resources as a raw material and mass production of manufacturing goods. The development of new technologies and their use in industry also effected the non-industrial sectors. Agriculture sector is also influenced by the industrial growth, with the advent of newer processing technologies it grown manifold. Surging population had put thrust on more production of agricultural produce, the production ended up only with huge amount of waste materials and by products. Among those materials Phosphate is one valuable material which is a nutrient that is very essential for the survival of plants and animal, this is derived from Phosphate rock. Phosphate rock is converted into fertilizer through industrial process, and it is being used widely for agricultural purpose. Also, phosphate is used in many products that produces wastes including phosphogypsum which is generated as waste from phosphate industry. This waste is discharged in sea, rivers and other water courses which has huge adverse effects on ecological system and human life. Much research is carried out to reuse the waste products for making sustainable goods and reduce the problem of disposal. In construction industry, phosphogypsum can be used in concrete. In this work, an attempt is made to utilise waste phosphogypsum in concrete that is widely used construction material to produce light weight panels for industrial and residential purpose. Thrust is given to understand the strength and durability characters of the produced composite so that its industrial usage can be defined. Promising results were obtained with decent increasing in strength and durability which shows that the material can be used effectively in Civil engineering industry.

The environmental effect of petroleum, refinery, and oily wastewater pollution is considerable owing to the large quantity of water produced throughout the process. Petroleum has mainly negative environmental effects due to its toxicity in nearly all lifestyles. Pollution of the air and water with oil may be harmful and hazardous to people's health. Petroleum industry effluent is often strong and may include hazardous contaminants. Inorganic and organic materials in various quantities, as well as heavy metals, surfactants, and other salts, are often found in wastewater generated by the petroleum industry. Discharging untreated or partly processed petroleum refinery effluents into the environment causes aquatic ecosystem pollution, an unsightly environment, expensive wastewater remediation costs, and the loss of cropland and fish. In the remediation of petroleum effluent, many traditional and common techniques such as biological, physicochemical, and chemical approaches are employed. Physical (mechanical) pre-remediation is often used to remove free oil, grease fractions, and suspended particles from petroleum effluent. The second step is a more advanced remediation that uses a mix of biological and physicochemical techniques to bring the contaminant level down to permissible discharge limits.

Severe ecological and environmental problems such as acid rain, greenhouse gas emission, atmospheric pollution etc. emerged with the wide application of fossil fuels force human beings to seek new green energy to alleviate the heavy dependency on those petrochemical products. Converting renewable microalgae biomass into liquid fuels is one of the promising way. However, the existence of nitrogen heteroatom and metal elements in microalgal bio-crude oil will extremely deteriorate the quality and inhibit the commercial utilization of microalgal bio oil. It is highly necessary to remove those nitrogen and metal elements from microalgal bio oil phase to meet the strict environmental and clean production requirements. Therefore, this paper extensively reviewed the updated results on catalytic denitrogenation and demetallization of microalgal bio-crude oil, including summary on the mechanism of C–N bond breaking, reaction pathways of major N-containing and metalloporphrins model compounds. Besides, the challenges facing the catalytic process, for example, catalyst stability and operating conditions during the denitrogenation and demetallization reactions were appraised as well.

Background/Aim. Among the other challenges of the 21st century, medical waste has become an arising problem for both the environment and people because of its increasing amount, variety, and complexity. With this, medical waste management started to present a highly important environmental issue. Serbia with no potential for appropriate disposal of all medical waste is forced to export medical waste to countries with medical waste incineration facilities. The reason lies in the fact that the incinerator facility represents an adequate way and a priority in handling medical waste in its end-of-life phase. It must be noted that incineration lowers the possible risks of inappropriate disposal and the emission of environmental pollutants, which leads to the need for a “clever” choice of the incinerator facility location which needs to meet diverse environmental, economic and technical criteria to manage successful processing of medical waste. Methods. In the paper, we applied the criteria for the choice of optimal locations for a medical waste incinerator facility as follows: the amount of waste that needs to be transported, the transport time from other locations, the current pollution of the location, the unemployment rate and the location safety in terms of natural disasters and accidents. By using the obtained results for seven efficient locations gained by Data Envelopment Analysis, we used a goal programming for the analysis of the most suitable location for a medical waste incineration facility. Results. After applying the proposed methodology on the chosen scenario and analysing the criteria relevant for selecting the most suitable location, optimal location is determined for a medical waste incineration facility. Conclusion. Based on the obtained results, we demonstrated that it is possible to develop a methodology that can used goal programming in optimal location selection for a medical waste incineration facility in risk and medical waste management.

The World Environmental Forum, taking into account the global nature of most of the environmental problems of humanity, suggests using the term "global environmental safety" in international research. First of all, this is due to the strengthening of the economic and political split. Therefore, humanity, more than ever before, needs world leaders and major companies to take steps to address threats to climate, ecology, health and technological systems together, as part of achieving the Sustainable Development Goals. If cooperation is avoided, the world expects a further split and a slowdown in economic growth. Geopolitical turbulence makes international relations more unstable and leads to increased competition between the largest powers, while world leaders must focus on working together to combat common risks. For more information about the specifics, principles and directions of implementing such cooperation in the framework of achieving global environmental safety, see the following sections of the work. Scientists defines the features of environmental security that prove its cross-border nature, among them: diversity, interrelation of all elements of national security, compliance with environmental rights of all population groups, etc. Here it is worth adding that, given the cross-border nature of most environmental threats, environmental security as a category of "component of national security" should be considered in the plane of international relations. World leaders and the development of the international economy now put environmental issues at the head of a multi-faceted world policy. So, in 1957, when the EU was founded, there was no environmental policy, environmental bureaucracy and laws on nature protection. Today, the EU has one of the most progressive environmental policies in the world. The network of its environmental legislation covers all industries: Air Pollution Control, Water Environment, Waste Management, nature protection and chemical control, biotechnology and other industrial risks. The body of EU environmental law consists of more than 500 directives, regulations and decisions. It can be argued that environmental policy has thus become one of the main areas of European policy.

The fuel efficiency of gas engines is effected by the temperature of intake air at the suction of turbocharger. The data on dependence of fuel consumption and engine electric power on the intake air temperature were monitored for Jenbacher gas engine JMS 420 GS-N.LC to evaluate its influence. A waste heat of engine is rejected for heating water to the temperature of about 90°С. The heat received is used in absorption lithium-bromide chiller to produce a cold in the form of chilled water. A cooling capacity of absorption chiller firstly is spent for technological needs and then for feeding the central air conditioner for cooling the ambient air incoming the engine room, from where the air is sucked by the engine turbocharger. The monitoring data revealed the reserves to enhance the efficiency of traditional cooling system of intake air by absorption chiller through deeper cooling. This concept can be realized in two ways: by addition cooling a chilled water from absorption chiller to about 5-7°С for feeding engine intake air cooler or by two-stage cooling with precooling ambient air by chilled water from ACh in the first stage and subsequent deep cooling air to the temperatures 7-10°С in the second stage of intake air cooler by using a refrigerant as a coolant. In both cases the ejector chiller could be applied as the most simple in design.

The oxy-fuel co-firing of solid fuels (such as coal, biomass, and solid waste) in fluidized beds is one of the most promising technologies for the industrial application of CO2 capture and waste disposal. However, both the practical experimentation and numerical simulations for elucidating co-firing in an oxy-fuel fluidized bed are still limited. In this study, a multiphase particle-in-cell scheme based on a 3D Eulerian–Lagrangian model was further developed following our previous research on oxy-fuel co-firing in a micro fluidized bed (Powder Technol. 2020, 373, 522–534). The refined JL 4-step mechanism for the CO-CO2 homogeneous reactions, the heterogeneous reactions of char oxidation and gasification, the heterogeneous reactions of NO and N2O formation from char-N, and the self-desulfurization effect were comprehensively considered. The improvement of the models was verified through the continuous operation of 10 kWth oxy-fuel fluidized bed tests (Fuel 2021,286,119,312; Energy Fuels, 2020, 34, 7373–7387), and the effects of the biomass blending ratio (Mb) on co-firing characteristics were discussed. It was found that the improvements could enhance the adaptability of the models to the oxy-fuel atmosphere, and the accurate prediction of NO, N2O, SO2. With an increase in Mb, the main reaction zone expanded or moved up along the riser height, and the volume of the high-temperature area increased, which promoted the burnout of particles and CO2 emission when Mb is 50%. The high volatility of biomass increased O2 consumption and CO concentration at the upper part of the riser, reduced N2O formation, and had a significant impact on NO reduction. The low sulfur content and high Ca/S ratio of the biomass considerably reduced the SO2 concentration. The simulation results also provided helpful information for the design and operation control of oxy-fuel co-firing of coal and biomass in a fluidized bed, such as the oxidant supply in different areas and grades, appropriate increase in the riser height, and reasonable adoption of Mb.