Least cost SO2 emission minimization for a petroleum refinery by optimum use of source reduction, tail gas treatment and flue gas desulphurization

With the growing awareness on the necessity to preserve the environment, pollution standards are turning more stringent and minimization of waste at the source has become the first choice option rather than the end-of-pipe treatment. The objective of the present research is to identify the optimum combination of source reduction (SR), tail gas treatment (TGT) and flue gas desulphurization (FGD) to minimize the total cost of overall SO₂ emission from a petroleum refinery to various desired limits. It has been found that for the typical refinery considered, the TGT is the lowest cost option than either SR or FGD; however, only a maximum of ~12.5% reduction is achievable through the TGT. After full utilization of TGT, for the next range of SO₂ emission reductions from ~12.5% to ~64%, the SR is more economical than FGD. For a still stringent SO₂ emission limit, i.e. SO₂ emission reduction higher than ~64%, the full utilization of the TGT and the optimum use of SR and FGD are the best options.     

Collaborative model for a two-echelon supply chain with uncertain demand under carbon tax policy

Consideration of carbon policies while optimizing supply chain operations has become imperative as governments and regulatory bodies throughout the world have implemented different carbon policies to reduce emissions of greenhouse gasses, especially CO₂. “Carbon tax” is one of the major carbon policies, initiated by several governments to curtail emissions. In this study, we have considered this policy to optimize the total expected cost (TEC) of a two-echelon integrated supply chain with stochastic demand, where both backorders and lost sales are permitted. An unconstrained mixed integer non-linear programming (MINLP) problem is formulated and further solved to find the optimal production rate, order quantity, number of shipments and reorder point while minimizing the TEC. Emissions from all the major sources such as production, inventory and transportation have been taken into consideration. It is assumed that the emission from production is a function of production rate, and emission from transportation depends on payload and vehicle type. This study will help organizations to reduce cost and emissions, and regulatory bodies to decide proper tax rate on carbon emission.     

新能源汽车国家发展战略研究

新能源汽车作为当前和未来全球汽车产业发展的重点,对我国能源、环境、经济、科技、社会等方面都将产生较大影响。为更好地支撑我国新能源汽车产业后续发展决策,促进产业健康快速发展,课题组充分分析了产业持续发展对我国未来能源安全、减排环保及产业升级的影响,进一步明确其重大战略意义,并在全面对比国内外产业支撑政策及产品技术发展水平、总结评价我国产业优劣势的基础上,对未来产业发展的战略定位、路线选择和培育重点等给出思路建议。     

Availability analysis of integrated gasification combined cycle power plants with backup fuel and NOx reduction

Backup fuel can be utilised to improve the effectiveness (energy availability) of an integrated gasification combined cycle power plant. The gas turbine can be operated independently, also, with a backup fuel. By independent operation, the selective catalytic reduction (SCR), which is installed in the heat recovery steam generator for lower NO_x, emission is bypassed and a relatively high level of NO_x is emitted. Improving the effectiveness of a power plant by using backup fuel involves increased cost for backup fuel and higher NO_x emission.The object of this paper is to improve the effectiveness of a power plant with a minimum of backup fuel and NO_x emissions.The study shows how the application of appropriate reserve capacity (active redundancy) and a suitable repair policy can minimize the use of backup fuel and NO_x emissions, and, at the same time, improve the effectiveness of integrated gasification combined cycle power plants.     

A systematic technique for cost-effective CO<Subscript>2</Subscript> emission reduction in process plants

There has been growing interests to reduce the environmental impact caused by greenhouse gas emissions from process plants through various energy conservation strategies. CO₂ emissions are closely linked to energy generation, conversion, transmission and utilisation. Various studies on the design of energy-efficient processes, optimal mix of renewable energy and hybrid power system are driven to reduce reliance on fossil fuel as well as CO₂ emissions reduction. This paper presents a systematic technique in the form of graphical visualisation tool for cost-effective CO₂ emission reduction strategies in industry. The methodology is performed in four steps. The first step involves calculating the energy consumption of a process plant. This is followed by identification of potential strategies to reduce CO₂ emissions using the CO₂ management hierarchy as a guide. In the third step, the development of “Investment” versus “CO₂ Reduction” (ICO₂) plot is constructed to measure the optimal CO₂ emission reductions achieved from the implementation of possible CO₂ reduction strategies. The Systematic Hierarchical Approach for Resilient Process Screening (Wan Alwi and Manan in AIChE J 11:3981–3988, 2006) method is used in the fourth step via substitution or partial implementation of the various CO₂ reduction options in order to meet the cost-effective emission reduction within the desired investment limit or payback period (PP). An illustrative case study on a palm oil refinery plant has been used to demonstrate the implementation of the method in reduction of CO₂ emissions. The developed graphical tool provides an insight-based approach for systematic CO₂ emission reduction in the palm oil refinery considering both heat and power energy sources. Result shows that 31.2 % reduction in CO₂ emissions can be achieved with an investment of USD 38,212 and PP of 10 months based on the present energy prices in Malaysia.     

Aspen Plus-based simulation of a cement calciner and optimization analysis of air pollutants emission

The cement industry is a typical high energy consumption and heavy pollution industry, in which amounts of CO₂, NO, NO₂, and SO₂ discharge from the pre-calciner kiln system and cause severe greenhouse and acid rain effects. Meanwhile, reasonable division of the combustion environment in the calciner is the main method to control the formation of pollutant gases. In this article, a calciner process model in Aspen Plus is proposed based on the combustion mechanism analysis of the Dual Combustion and Denitration calciner (DD-calciner) and verified by industrial data. Then, for a concrete DD-calciner, the article studies the effects of the flow rate of coal and tertiary air on flue gas compositions and effects of the staging combustion technology on the NO _x , SO₂, and CO concentrations in the flue gas. Through comparing the model results with the relevant environmental standards, the optimization analysis for staging combustion parameters of the calciner is done, and the result shows that when the proportion of tertiary air entering the pyrolysis and combustion zone is controlled within the range of 57–65.52% (0.89 < α < 1.004), all the gas pollutants emit within accepted standards simultaneously. The calciner process model outlined in this article describes the key processes of the physical and chemical reactions in the calciner. It can be used to study the key operation and design parameters which influence the flue gas constituents, so as to provide data support for determining the pollutant emission reduction plan of the cement industries with a view to reduce air pollutant emission.     

系统动力学的碳排放政策对供应链影响

随着低碳经济的发展,碳排放政策对于供应链的影响越来越受到关注。建立了基于系统动力学的单个供应商和销售商的供应链模型,并在此基础上引入强制排放和碳税两种碳排放政策。利用模型仿真,分析两种排放政策对于供应商、销售商及整个供应链的总成本和碳排放的影响。研究表明在强制排放模型中,不同的碳排放额度会使销售商选择不同的订货周期,发现合理的排放额度才能引导供应链双方降低排放,否则不仅达不到减排的目的,反而影响供应链效率;而在碳税模型中,提高碳税税率虽然会使政府获取一定的收益,但是实际上可能带来供应链总成本的上升和碳排放的增加,需要合理制定碳税税率引导绿色供应链发展。     

α-Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> based nanomaterials as gas sensors

Interest in detecting and determining concentrations of toxic and flammable gases has constantly been on the increase in recent years due to increase of modernization, industrialization and high standards of life. Detection of such gases is very important in many different fields such as industrial emission control, household and social security, vehicle emission control and environmental monitoring. Metal oxide gas sensors are among most important devices to detect a large variety of gases. α-Fe₂O₃, an environmental friendly semiconductor (E _g = 2.1 eV), is the most stable iron oxide under ambient atmosphere and because of its low cost, high stability, high resistance to corrosion, and its environmentally friendly properties is one of the most important metal oxides for gas sensing applications. This is the first review about gas sensing properties of α-Fe₂O₃ nanostructures. In this paper gas sensing properties of α-Fe₂O₃ are extensively reviewed. After a brief explanation about metal oxide gas sensors and α-Fe₂O₃, sensors based on α-Fe₂O₃ nanomaterials have been reviewed. Gas sensing section is divided into five subsections: pure α-Fe₂O₃ gas sensors, metal/α-Fe₂O₃ gas sensors, metal oxide/α-Fe₂O₃ gas sensors, polymer/α-Fe₂O₃ gas sensors and graphene/α-Fe₂O₃ gas sensors.     

Quantitative analysis of policy decisions

The use of quantitative models for highway safety policy analysis is discussed. The importance of interaction between managers and model analysts is emphasized for the development and application of these models. Two examples are presented. First, the trade-off between injury cost and fuel savings as a function of vehicle weight reduction is analyzed. Second, passive restraint effectiveness and its interaction with vehicle size is studied.     

汽车节油迫在眉睫

石油是关系到国家安全的重要战略资源,中国是石油资源相对缺乏的国家,节约用油、提高资源利用效率尤为重要。指出了现阶段我国汽车用油存在的问题;分析了汽车节油技术发展趋势和政策措施;提出通过政策措施倡导节约优先、效率为本的观念,重点开发和应用各种节油技术,提高油品质量,加快淘汰老旧车型,积极开发替代资源,大力发展公共交通和现代物流是现阶段我国汽车节油减排的有效途径。     

Carbon substance flow analysis and CO2 emission scenario analysis for China

China in 2009 announced the binding target of its CO₂ emissions in 2020: reduce its CO₂ emission intensity by 40–45% relative to 2005. In this article, stocks and flows model is used to carry out substance flow analysis toward energy- and limestone-related carbons in China from 1991 to 2007. Then, the possible paths which China can take to achieve this target are presented and discussed in scenario analysis. It is found that (1) conversion into secondary energy, electricity and heat, and limestone calcinations contributed most to the ever-increasing carbon consumption of China during 1991–2007, (2) secondary industry is the biggest carbon consumer and emitter within Chinese economy, and the percentage of carbons emitted by households fell from 1991 to 2007, (3) CO₂ emission intensities of three industries and China fell from 1991 to 2002, and then fluctuated during 2002–2007, and (4) both the adjustment in economic structure and the decline in secondary industry’s CO₂ emission intensity can influence China’s CO₂ emission intensity in an independent way. The emission target can be realized in 2020 when the former becomes 6%:40%:54% and meanwhile the latter decreases to 4.01 tons CO₂/10,000 RMB in constant 2000 price. Finally, several policy suggestions are made.     

碳限额及交易下低碳补贴和低碳宣传成本分摊的双渠道供应链联合减排策略

为了研究碳限额及交易下考虑低碳补贴和零售商低碳宣传的双渠道供应链联合减排策略问题,构建由一个制造商和一个零售商组成双渠道供应链,分别建立碳减排补贴与低碳宣传的双渠道供应链集中式决策模型以及无碳减排补贴且无低碳宣传成本分摊、有碳减排补贴但无低碳宣传成本分摊、碳减排补贴且低碳宣传成本分摊的双渠道供应链分散式决策模型,分析其最优决策,并指出政府碳减排补贴、碳减排成本和低碳宣传成本分摊能够实现双渠道供应链协调。研究结果表明,在碳限额及交易下,最优碳减排率、最优低碳宣传水平和双渠道供应链利润与政府补贴比例、低碳偏好对需求的影响系数、低碳宣传对线上消费者需求的影响系数、低碳宣传对线下消费者需求的影响系数都成正向变化关系;最优碳减排率、最优低碳宣传水平和双渠道供应链利润与低碳宣传成本系数、最优碳减排成本系数成反向变化关系;最优碳减排率与碳排放交易价格成正向变化关系,而最优低碳宣传水平、双渠道供应链利润与碳排放交易价格成反向变化关系。     

Pollutant emissions from passenger cars in traffic congestion situation in the State of Kuwait: options and challenges

Rapid population growth in Kuwait, accompanied with rising standard of living, has resulted in a sweeping increase in the use of passenger vehicles for transportation. Consequently, deterioration of ambient air quality near major roadways has become an issue of public concern. The knowledge of real world road vehicle emission factors is an essential element to the development of any strategy aimed at the reduction of air pollution in urban areas. This work focuses on investigating exhaust emission pollutants from passenger cars for idle and slow acceleration (stop-and-go) traffic conditions. We found that vehicle emissions are minimal during idle mode for all vehicle categories. However, it was interesting to observe that during the slow acceleration mode HC and CO emissions increased for light vehicles with relatively high mileage (higher than 40,000?km). We can conclude from this study that with the growing vehicle ownership, and congestion it causes, the vehicular exhaust emissions is a major sources of air pollution in densely populated centers in the state of Kuwait, where idle and stop-and-go driving cycle is a common occurrence.     

Evaluation of China's new energy vehicle policy texts with quantitative and qualitative analysis

As one of the strategic emerging industries, the new energy vehicle (NEV) industry receives strong support from the Chinese government. The Chinese government has formulated a large number of policies to promote the development of NEV industry. Evaluating and analyzing the NEV policies are of great significance for improving policy formulation. In this study, we comprehensively analyze 253 NEV policy texts by employing quantitative and qualitative methods. We present the policy instrument types and semantic structure characteristics of policy texts based on the content analysis. The advantages and disadvantages of policy texts are identified by using a quantitative evaluation model. Our results show that the most frequently used policy instrument is regulatory, and the main policy objective is the demand-pull. The policies with higher scores are more comprehensive. Three suggestions are put forward to improve NEV policies.     

Cost-efficient emission abatement of energy and transportation technologies: mitigation costs and policy impacts for Belgium

In the light of global warming, this paper develops a framework to compare energy and transportation technologies in terms of cost-efficient GHG emission reduction. We conduct a simultaneous assessment of economic and environmental performances through life cycle costing and life cycle assessment. To calculate the GHG mitigation cost, we create reference systems within the base scenario. Further, we extend the concept of the mitigation cost, allowing (i) comparision of technologies given a limited investment resource, and (ii) evaluation of the direct impact of policy measures by means of the subsidized mitigation cost. The framework is illustrated with a case of solar photovoltaics (PV), grid powered battery electric vehicles (BEVs), and solar powered BEVs for a Belgian small and medium sized enterprise. The study’s conclusions are that the mitigation cost of solar PV is high, even though this is a mature technology. The emerging mass produced BEVs on the other hand are found to have a large potential for cost-efficient GHG mitigation as indicated by their low cost of mitigation. Finally, based on the subsidized mitigation cost, we conclude that the current financial stimuli for all three investigated technologies are excessive when compared to the CO₂ market value under the EU Emission Trading Scheme.     

Study of two concrete mix-design strategies to reach carbon mitigation objectives

The building and construction sector is a major CO₂ producer and climate change perspectives urged to reduce CO₂ emissions. The impact of concrete buildings on environment is mainly due to clinker, which is the main material used all over the world to produce cement and which releases a bit less than 1 ton of CO₂ per ton of clinker produced.In this study, we first evaluate if the medium term CO₂ emission reduction objectives for the cement industry are realistic according to our current scientific and technologic knowledge. We consider two environmental strategies. The first one is the substitution of clinker by mineral additions in cement in order to reduce the environmental cost of the material for a given volume of material; the second one is the reduction of the concrete volume needed for a given construction process by enhancing the concrete performances. The impact on CO₂ emissions of a combination of these options is also roughly evaluated. We show that medium term objectives can be reached although long term objectives will need further research developments. We moreover present here a first step towards mix-design methods associating environmental costs and performance requirements which could allow for a better balance between societal demand in terms of environment and technical building requirements.     

Economic Analysis of Residential Distributed Solar Photovoltaic

Under the huge challenges of global energy conservation, emission reduction and energy security, distributed solar photovoltaic industry has become the key means to achieve economic restructuring and low carbon economy. Based on System Advisor Model software, the authors choose Baoji as the sample plot. Household load, unit investment, loan interest rate and loan fraction are used as influence factors to analyze the economic benefits of distributed solar photovoltaic in China. The result demonstrates that government incentives help to increase the profitability of distributed solar photovoltaic by a large extent; other factors that influence the profitability includes household load, unit investment cost, loan interest rate and loan fraction.     

Motor vehicle fatalities among oil and gas extraction workers

Motor vehicle crashes are the leading cause of work-related fatality in the U.S. as well as in the oil and gas extraction industry. This study describes the characteristics of motor vehicle-related fatalities in the oil and gas extraction industry using data from the U.S. Bureau of Labor Statistics’ Census of Fatal Occupational Injuries. It compares the risk of dying in a motor vehicle crash in this industry to other major industries and among different types and sizes of oil and gas extraction companies. There were 202 oil and gas extraction workers who died in a work-related motor vehicle crash from 2003 to 2009. The motor vehicle fatality rate for workers in this industry was 8.5 times that of all private wage and salary workers (7.6 vs. 0.9, p < .0001). Workers from small oil and gas establishments (<20 workers) and workers from well-servicing companies were at greatest risk of dying in a motor vehicle crash. Pick-up trucks were the most frequent type of vehicle occupied by the fatally injured worker (n = 104, 51.5%). Safety belt non-use was identified in 38.1% (n = 77) of the cases. Increased focus on motor vehicle safety in this industry is needed, in particular among small establishments. Extraction workers who drive light duty vehicles need to be a specific focus.     

Will researching digital technology really empower green development?

The information industry has become a “new engine” driving the growth of the world economy. However, there are many controversies about whether digital technology can reduce the intensity of carbon emissions. Based on OECD data, KPWW method and multiple panel regression, this paper explores the impact and mechanism of digital technology innovation and technology spillover to the domestic carbon emission intensity. Through impulse response analysis and variance decomposition, the comprehensive impact of digital technology on carbon intensity is clarified. This paper concludes that technology innovation in the information industry will increase the intensity of carbon emissions, while cross-industry technology spillovers are persistent for reducing the intensity of domestic carbon emissions. Since the emission reduction effect of technology spillover is greater than the emission increase effect of technology innovation, the digital technology would empower domestic green development. Increasing the proportion of non-fossil energy use and optimizing the industrial structure are effective mechanisms for digital technology innovation to reduce carbon emission intensity.     

Nanostructure Engineering of Sn-Based Catalysts for Efficient Electrochemical CO2 Reduction

Excessive anthropogenic CO₂ emission has caused a series of ecological and environmental issues, which threatens mankind's sustainable development. Mimicking the natural photosynthesis process (i.e., artificial photosynthesis) by electrochemically converting CO₂ into value-added products is a promising way to alleviate CO₂ emission and relieve the dependence on fossil fuels. Recently, Sn-based catalysts have attracted increasing research attentions due to the merits of low price, abundance, non-toxicity, and environmental benignancy. In this review, the paradigm of nanostructure engineering for efficient electrochemical CO₂ reduction (ECO₂R) on Sn-based catalysts is systematically summarized. First, the nanostructure engineering of size, composition, atomic structure, morphology, defect, surficial modification, catalyst/substrate interface, and single-atom structure, are systematically discussed. The influence of nanostructure engineering on the electronic structure and adsorption property of intermediates, as well as the performance of Sn-based catalysts for ECO₂R are highlighted. Second, the potential chemical state changes and the role of surface hydroxides on Sn-based catalysts during ECO₂R are introduced. Third, the challenges and opportunities of Sn-based catalysts for ECO₂R are proposed. It is expected that this review inspires the further development of highly efficient Sn-based catalysts, meanwhile offer protocols for the investigation of Sn-based catalysts.