Carbon dioxide capture and geological storage

Carbon dioxide capture and geological storage is a technology that could be used to reduce carbon dioxide emissions to the atmosphere from large industrial installations such as fossil fuel-fired power stations by 80-90%. It involves the capture of carbon dioxide at a large industrial plant, its transport to a geological storage site and its long-term isolation in a geological storage reservoir. The technology has aroused considerable interest because it can help reduce emissions from fossil fuels which are likely to remain the dominant source of primary energy for decades to come. The main issues for the technology are cost and its implications for financing new or retrofitted plants, and the security of underground storage.     

Optimal planning for the supply chain of biofuels for aviation in Mexico

There are great challenges to replace fossil fuels by biofuels, including the development of efficient technologies and adequate strategic planning. For the manufacture of biofuels at the industrial scale, there is a need to optimize the overall associated supply chain. Among biofuels, the global market for the aviation biofuel has increased drastically, mainly due to the forecasted growth of the aviation sector. Nevertheless, the supply chain for the aviation biofuel has specific characteristics, which are different from the case of bioethanol and biodiesel. Therefore, this paper presents a general optimization approach for optimizing the supply chain of aviation biofuels. A case study is presented accounting for the projection of the Mexican government for implementing the use of aviation biofuel in the airport network. The application of the proposed approach generates very interesting solutions, which are grouped in a Pareto front; from these results, it can be highlighted that the demand for aviation biofuel in the Mexican market can be satisfied with a gross economic benefit of M US$ 1681 per year, and savings of 93% of carbon dioxide emissions. The generated information can contribute to the establishment of the sustainable supply chain for aviation biofuels in Mexico.     

Modern and appropriate technologies for the reduction of gaseous pollutants and their effects on the environment

Harmful effects on environment such as global warming and climate change may result from the gases emanating from fossil fuel combustion. Jordan and most Middle East countries use fossil fuels exclusively. Therefore, new technologies which could accommodate the demand for cleaner effluents, such as: combined cycles, fluidized bed combustion, magneto hydrodynamics, fuel cells, nuclear power, natural gas, renewable energy, and energy conservation have been considered. CO₂ being the most produced gas, many technical methods of reducing and reusing CO₂ have been suggested such as: Injection in oceans, storage in caverns, injection in depleted oil and gas fields, pumping during oil recovery, storage as CO₂ ice, elimination by fixation using water algae, and increasing plantation especially forestation. These methods are being used at different degrees in the Middle East countries. Reduction of formation and harmful effects of other gaseous pollutants is also discussed, with some concentration on the transportation sector, energy efficiency and fuel cells, which have special importance for the developing countries.     

Carbon neutral hydrocarbons

Reducing greenhouse gas emissions from the transportation sector may be the most difficult aspect of climate change mitigation. We suggest that carbon neutral hydrocarbons (CNHCs) offer an alternative pathway for deep emission cuts that complement the use of decarbonized energy carriers. Such fuels are synthesized from atmospheric carbon dioxide (CO2) and carbon neutral hydrogen. The result is a liquid fuel compatible with the existing transportation infrastructure and therefore capable of a gradual deployment with minimum supply disruption. Capturing the atmospheric CO2 can be accomplished using biomass or industrial methods referred to as air capture. The viability of biomass fuels is strongly dependent on the environmental impacts of biomass production. Strong constraints on land use may favour the use of air capture. We conclude that CNHCs may be a viable alternative to hydrogen or conventional biofuels and warrant a comparable level of research effort and support.     

Throwing New Light on the Reduction of CO2

While the chemical energy in fossil fuels has enabled the rapid rise of modern civilization, their utilization and accompanying anthropogenic CO₂ emissions is occurring at a rate that is outpacing nature's carbon cycle. Its effect is now considered to be irreversible and this could lead to the demise of human society. This is a complex issue without a single solution, yet from the burgeoning global research activity and development in the field of CO₂ capture and utilization, there is light at the end of the tunnel. In this article a couple of recent advances are illuminated. Attention is focused on the discovery of gas‐phase, light‐assisted heterogeneous catalytic materials and processes for CO₂ photoreduction that operate at sufficiently high rates and conversion efficiencies, and under mild conditions, to open a new pathway for an energy transition from today's “fossil fuel economy” to a new and sustainable “CO₂ economy”. Whichever of the competing CO₂ capture and utilization approaches proves to be the best way forward for the development of a future CO₂‐based solar fuels economy, hopefully this can occur in a period short enough to circumvent the predicted adverse consequences of greenhouse gas climate change.     

Research Progress in MnO2–Carbon Based Supercapacitor Electrode Materials

With the serious impact of fossil fuels on the environment and the rapid development of the global economy, the development of clean and usable energy storage devices has become one of the most important themes of sustainable development in the world today. Supercapacitors are a new type of green energy storage device, with high power density, long cycle life, wide temperature range, and both economic and environmental advantages. In many industries, they have enormous application prospects. Electrode materials are an important factor affecting the performance of supercapacitors. MnO₂‐based materials are widely investigated for supercapacitors because of their high theoretical capacitance, good chemical stability, low cost, and environmental friendliness. To achieve high specific capacitance and high rate capability, the current best solution is to use MnO₂ and carbon composite materials. Herein, MnO₂–carbon composite as supercapacitor electrode materials is reviewed including the synthesis method and research status in recent years. Finally, the challenges and future development directions of an MnO₂–carbon based supercapacitor are summarized.     

Cleaner energy production with integrated gasification combined cycle systems and use of metal oxide sorbents for H2S cleanup from coal gas

 World primary energy demand increases with increases in population and economic development. Within the last 25 years, total energy consumption has almost doubled. In order to meet this demand, research into new sources of energy as well as improving the efficiency of energy production technologies is being carried out. In both cases, the production of clean energy is very important because of environmental concerns and regulations. Integrated gasification combined cycle (IGCC) technology seems to be one of the most promising technologies for production of energy by using fossil fuels, especially coal. Hot gas desulfurization is a crucial issue in the development of the IGCC system. This paper reviews the importance of clean energy production, the IGCC technology and focuses on the development of several metal oxide-based sorbents used for desulfurization of the hot coal gas in the IGCC system.     

The effect of greenhouse gas policy on the design and scheduling of biodiesel plants with multiple feedstocks

With the increasing attention to the environmental impact of discharging greenhouses gases, there has been a growing public pressure to reduce the carbon footprint associated with the use of fossil fuels. In this context, one of the key strategies is the substitution of fossil fuels with biofuels such as biodiesel. The design of biodiesel production facilities has traditionally been carried out based on technical and economic criteria. Greenhouse gas (GHG) policies (e.g., carbon tax, subsidy) have the potential to significantly alter the design of these facilities, the selection of the feedstocks, and the scheduling of multiple feedstocks. The objective of this article is to develop a systematic approach to the design and scheduling of biodiesel production processes while accounting for the effect of GHG policies in addition to the technical, economic, and environmental aspects. An optimization formulation is developed to maximize the profit of the process subject to flowsheet synthesis and performance modeling equations. Furthermore, the carbon footprint is accounted for with the help of a life cycle analysis (LCA). The objective function includes a term which reflects the impact of the LCA of a feedstock and its processing to biodiesel. A multiperiod approach is used to discretize the decision-making horizon into time periods. During each period, decisions are made on the type and flowrate of the feedstocks, as well as the associated design and operating variables. A case study is solved with several scenarios of feedstocks and GHG policies.     

Sustainability assessment of <Emphasis Type="Italic">Ricinus communis</Emphasis> biodiesel using LCA Approach

Biofuels are considered as eco-friendly fuels and can readily replace fossil fuels while helping to reduce greenhouse gas emissions and promoting sustainable rural development. Although Algeria is an oil producer and exporter, the development of renewable energies is a strategic goal for public authorities, which are giving new impetus to this sector to replace the fossil energy resources of which are becoming increasingly scarce. In this context, the life-cycle assessment (LCA) of a second-generation biodiesel derived from Ricinus communis feedstock is undertaken. LCA is a tool that can be used effectively in evaluating various renewable energy sources for their sustainability and can help policy makers to choose the optimal energy source for specific purpose. The life cycle of Castor bean-based biodiesel production includes the stages of cultivation, oil extraction, and biodiesel production. The impact categories studied were global warming, Energy return-on-energy investment (EROEI), human health, and ecosystem. We have used the impact 2002 + evaluation method which is implemented in the SimaPro© software package. Moreover, it is the most useful method for identifying and measuring the impact of industrial products on the environment. Results show that among all the production stages, the cultivation process of Ricinus communis and the conversion of oil to biodiesel are the largest contributors to most of environmental impact categories. Life-cycle analysis revealed that the use of castor for biodiesel production could have many advantages like an energy return-on-energy investment (EROEI) of 2.60 and a positive contribution to climate-change reduction as revealed by a positive carbon balance.     

A review of biodiesel production from microalgae

As the search for alternatives to fossil fuels continues, microalgae have emerged as a promising renewable feedstock for biodiesel. Many species contain high lipid concentrations and require simple cultivation—including reduced freshwater and land area needs—compared to traditional crops used for biofuels. Recently, technological advancements have brought microalgae biodiesel closer to becoming economically feasible through increased efficiency of the cultivation, harvesting, pretreatment, lipid extraction, and transesterification subsystems. The metabolism of microalgae can be favorably manipulated to increase lipid productivity through environmental stressors, and “green” techniques such as using flue gas as a carbon source and wastewater as a media replacement can lower the environmental impact of biodiesel production. Through life cycle assessment and the creation of process models, valuable insights have been made into the energy and material sinks of the manufacturing process, helping to identify methods to successfully scale up microalgae biodiesel production. Several companies are already exploring the microalgae industry, offsetting operating costs through isolation of co-products and careful unit operation selection. With numerous examples drawn from industry and the literature, this review provides a practical approach for creating a microalgae biodiesel facility.     

Do innovation in environmental-related technologies cyclically and asymmetrically affect environmental sustainability in BRICS nations?

This study contributes to the current research by identifying the cyclical and asymmetrical impact of innovation in environmental-related technologies on carbon dioxide emissions in BRICS economies, as well as control variables such as fossil fuels, export taxes, household consumption expenditures, and exports, for the period 1990(Q1)-2016 (Q4). Following are some of the key findings. First, the data analysis indicated a significant long-term positive link between negative shocks to innovation in environmental-related technologies and carbon dioxide emissions during the economic downturn. Second, positive shocks to innovation in environmental-related technologies minimize carbon dioxide emissions during the economic upturn. Third, the relationship between innovation shocks in environmental-related technologies and carbon dioxide emissions was counter-cyclical during business cycles. Fourth, impact of positive shocks to innovation in environmental-related technologies on carbon dioxide emissions was more than the impact of negative shocks to innovation in environmental-related technologies on carbon dioxide emissions. Fifth, increasing the export tax serve as an effective measure to mitigate carbon dioxide emissions. Sixth, an increase in exports, use of fossil fuels, and household consumption expenditures contributed to the carbon dioxide emissions. Based on estimated results, the paper suggests policy implications for policymakers to reduce carbon dioxide emissions.     

Membranes set to play important role in hydrogen economy: Edited by Simon Atkinson

This brief feature identifies the important role that membranes may play in a so-called hydrogen economy by considering recent developments in technologies that are being used to generate and store hydrogen.In such an economy, hydrogen — the most abundant element in the universe — replaces fossil fuels as the primary source of energy.A shift to a hydrogen economy will have widespread benefits to society by reducing environmental pollution and global climate change, as well as greatly reducing our dependence on sources of non-renewable energy.Furthermore, if hydrogen fuel cells are ever to replace petrol engines in cars, they will need a cheap source of highly pure hydrogen.     

Biofuel Production: Utilizing Stakeholders’ Perspectives

Abstract

The use of biofuels as a replacement for fossil fuels is growing in the United States and other countries in part because of economic and environmental concerns. One of the technologies for biofuels production is fast pyrolysis; however, to increase manufacturing of fast pyrolysis units, a better understanding of stakeholders’ requirements and perspectives is needed. This is a complex decision problem. Due to the diversity of perspectives, each group of stakeholders has their own unique requirements, which in total will determine the right manufacturing approach. Previous studies either investigated optimal sizing from a single viewpoint or have combined a subset of perspectives. This study applies multiple tools to develop a more comprehensive view of stakeholders’ perspectives. Individual subject matter experts were asked to review and prioritize a set of requirements that reflected different stakeholders’ perspectives, including economic, environmental, technical, social, and legal. The perspectives were then used to analyze multiple fast pyrolysis units to determine which size was the most effective in meeting the perspectives in total. The analysis indicated that the smallest unit, able to process an average of 50 tons per day, is the best alternative when viewed from the economic, technical, social, and legal perspectives. However, when viewed from the environmental perspective, a medium-sized unit, able to process in the range of 200–500 tons per day, is the best alternative. This work provides the basis for further discussions about the individual perspectives, including the economic and environmental perspectives of biofuel production. Potential avenues for further work in assessment of stakeholders’ requirements are also noted.     

Life cycle assessment of bio-methane and biogas-based electricity production from organic waste for utilization as a vehicle fuel

Clean Technologies and Environmental Policy - The concerns about climate change, energy security and price fluctuation of fossil fuels are driving the growing interest in the development and...     

Energy policy shifts towards sustainable energy future for Malaysia

As a developing country, Malaysia’s prosperity and welfare depends heavily on having access to reliable and secure supplies of energy. As a result, the country’s future energy requirements have become a policy priority in recent years. Energy is essential for human life, and a secure and accessible supply of energy becomes important for the modern societies. Fossil fuels such as coal, oil, and natural gas are currently the world’s primary energy sources and continue to provide energy source to the world. These energy sources have depleted in reserves in recent years and they can also cause irreparably damage to the environment such as global warming and climate change. These environmental concerns can be addressed, to some extent, through more sustainable solutions such as the use of renewable energy resources. In Malaysia, the economic and environmental impacts of fossil fuels use have become hard to ignore. The government has introduced and implemented policy measures to address concerns surrounding the use of fossil fuels and to promote energy efficiency and renewable energy use. In this paper, we review the historical evolution of Malaysian energy policies and initiatives designed to secure diverse energy sources and avoid over-reliance on fossil fuels. In recent years, Malaysia has been catching up with global call to shift to renewable energy use and is now putting a focus on renewable energy in its future energy mix. The paper also discusses challenges and concerns over the future of sustainable energy of the country.     

Impact of including land-use change emissions from biofuels on meeting GHG emissions reduction targets: the example of Ireland

The greenhouse gases (GHG) emissions from land-use change are of particular concern for land-based biofuels. Emissions avoided by substituting fossil fuels with biofuels may be offset by emissions from direct and indirect land-use changes (LUC). There is an urgent need to investigate what impact land-use change emissions may have on the expansion of bioenergy and biofuels, in the context of EU mitigation policies. This paper focuses on Ireland, which faces a number of challenges in delivering its renewable energy and GHG reduction targets. The Irish TIMES energy systems model was used to assess the impact of a range of land-use change emissions’ levels on the evolution of Ireland’s low-carbon energy system. A reference scenario was developed where LUC is ignored and Ireland achieves a least-cost low-carbon energy system by 2050. If high indirect land-use change (ILUC) emissions are included, this results in a decrease by 30 % in bioenergy and a 68 % increase in marginal abatement costs by 2050. Hydrogen is used instead of bioenergy in the freight sector in this scenario, while private cars are fuelled by renewable electricity. If GHG emissions from ILUC were considered less severe, indigenous grass biomethane becomes the key biofuel representing 31 % of total bioenergy consumption. This is in line with recent research in Ireland of the key role that grass biomethane can play.     

碳中和目标背景下包装行业发展的对策

目的 为了应对日益恶化的全球气候变化,并实现碳中和的目标,研究低碳化技术在包装行业的应用成为当下至关重要的任务。为了推动包装行业在碳中和背景下的低碳化转型,有必要对现有的低碳化技术进行分类和梳理。方法 从碳减排和碳移除两方面对包装行业已有的低碳化技术进行了研究。综述当前可降解生物塑料和聚合物单体化学循环技术在包装中的应用,介绍了几种清洁能源以及碳捕捉、碳利用和碳储存技术的发展现状。结论 对包装行业而言,实现碳中和的目标还面临着很多挑战。包装行业在推进碳中和目标时要选取与发展适合的低碳能源和碳中和技术。     

Towards cleaner technologies: emissions reduction, energy and waste minimisation, industrial implementation

This editorial introduces and provides an overview of a Special Issue dedicated to the jubilee 10th Conference of Process Integration, Modelling and Optimization for Energy Saving and Pollution Reduction—PRES’07. It contains thirteen selected papers covering various fields of cleaner technologies and environment policy problems. The technologies address recent developments in CO₂ capture in Combined Cycle power plants, CO₂ reduction in pulp and paper mills, process efficiency increases combined with energy savings at a mill, distillation separation enhancements and emissions control at gas plants, pre-combustion decarbonisation for polygenertion from fossil fuels, minimisation of CO₂ emissions in steam and power plants, a study of co-pyrolysis of biomass and plastic wastes, waste-to-energy system design (with a focus on incineration and gasification technologies), optimal design of wastewater treatment systems, and integrated production of sugar and biofuels from sugar beet. Among these topics, The Special Issue includes demonstration of the technologies in the form of Advanced Case studies.     

Changes in the use and management of forests for abating carbon emissions: issues and challenges under the Kyoto Protocol

The global carbon cycle is significantly influenced by changes in the use and management of forests and agriculture. Humans have the potential through changes in land use and management to alter the magnitude of forest-carbon stocks and the direction of forest-carbon fluxes. However, controversy over the use of biological means to absorb or reduce emissions of CO(2) (often referred to as carbon 'sinks') has arisen in the context of the Kyoto Protocol. The controversy is based primarily on two arguments: sinks may allow developed nations to delay or avoid actions to reduce fossil fuel emissions, and the technical and operational difficulties are too threatening to the successful implementation of land use and forestry projects for providing carbon offsets. Here we discuss the importance of including carbon sinks in efforts to address global warming and the consequent additional social, environmental and economic benefits to host countries. Activities in tropical forest lands provide the lowest cost methods both of reducing emissions and reducing atmospheric concentrations of greenhouse gases. We conclude that the various objections raised as to the inclusion of carbon sinks to ameliorate climate change can be addressed by existing techniques and technology. Carbon sinks provide a practical available method of achieving meaningful reductions in atmospheric concentrations of carbon dioxide while at the same time contribute to national sustainable development goals.     

锂硫电池硫正极材料研究进展

由化石燃料的大量使用导致的全球能源和环境问题日益严重,已对人们的生产和生活产生了明显的影响.开发利用储量丰富的清洁能源(如太阳能、水能和风能等)有望较好地解决全球能源和环境问题.由于这些清洁能源存在地域性、间歇性等特点,高效的能量转化和存储技术是实现清洁能源规模化利用的关键和基础.锂离子电池作为绿色环保的储能器件,已在手机、笔记本电脑、相机等便携电子产品中广泛使用.近年来,锂离子电池开始在电动汽车等动力电池领域得到应用.但是,由于其能量密度不够高,导致锂离子电池电动汽车续航短、充电频繁及购车成本高.由金属锂为负极和硫为正极组成的锂硫电池的能量密度(2600 Wh·kg-1)远高于目前广泛使用的锂离子电池.此外,硫正极材料具有储量丰富、毒性低、价格便宜、环境友好等突出优点.因此,锂硫电池被认为是当前最具研究前景的高能量密度二次电池之一.硫正极材料的本征导电性差、在充放电过程中存在较大的体积膨胀和收缩,储放锂过程中形成的多硫化锂易溶于电解液,使得锂硫电池的倍率性能、循环寿命和库伦效率等电化学性能离实际应用仍有较大距离.迄今为止,关于硫正极材料的研究工作,主要集中于如何提升其导电性、抑制或消除由多硫化锂的溶解引起的穿梭效应以及在反复的循环过程中保持电极材料微结构的稳定性等方面.相关研究表明,将硫与不同形貌的碳材料复合构筑成具有特殊微观结构的硫/碳复合正极材料可显著提高其导电性、抑制多硫化锂的穿梭效应和减缓储放锂前后的体积变化,进而改善倍率性能、循环稳定性和充放电效率等.此外,在硫正极材料中引入异质元素掺杂碳材料、金属氧化物和导电集合物均可通过化学吸附实现对易溶解多硫化锂的有效吸附.将上述多种改性方法结合也可使硫正极材料具有优异的电化学储锂性能.本文从锂硫电池的工作原理出发,总结了硫正极材料存在的主要问题,综述了近几年锂硫电池复合正极材料的研究进展,最后对锂硫电池正极材料的研究思路与发展趋势进行了分析和展望.