Potentials for energy efficiency improvement in the US cement industry

This paper reports on an in-depth analysis of the US cement industry, identifying cost-effective energy efficiency measures and potentials. Between 1970 and 1997, primary physical energy intensity for cement production (SIC 324) dropped 30%, from 7.9 GJ/t to 5.6 GJ/t, while specific carbon dioxide emissions due to fuel consumption and clinker calcination dropped 17%, from 0.29 tC/tonne to 0.24 tC/tonne. We examined 30 energy-efficient technologies and measures and estimated energy savings, carbon dioxide savings, investment costs, and operation and maintenance costs for each of the measures. We constructed an energy conservation supply curve for the US cement industry which found a total cost-effective energy saving of 11% of 1994 energy use for cement making and a saving of 5% of total 1994 carbon dioxide emissions. Assuming the increased production of blended cement, the technical potential for energy efficiency improvement would not change considerably. However, the cost-effective potential would increase to 18% of total energy use, and carbon dioxide emissions would be reduced by 16%. This demonstrates that the use of blended cements is a key cost-effective strategy for energy efficiency improvement and carbon dioxide emission reductions in the US cement industry.     

Energy efficiency and carbon dioxide emissions reduction opportunities in the US iron and steel sector

This article presents an in-depth analysis of cost-effective energy efficiency and carbon dioxide emissions reduction opportunities in the US iron and steel industry. We show that physical energy intensity for iron and steelmaking (at the aggregate level, standard Industrial Classification 331, 332) dropped 27%, from 35.6 GJ/tonne to 25.9 GJ/tonne between 1958 and 1994, while carbon dioxide intensity (carbon dioxide emissions expressed in tonnes of carbon per tonne of steel) dropped 39%. We provide a baseline for 1994 energy use and carbon dioxide emissions from US blast furnaces and steel mills (SIC 3312) disaggregated by the processes used in steelmaking. Energy-efficient practices and technologies are identified and analyzed for each of these processes. Examination of 47 specific energy efficiency technologies and measures found a total cost-effective reduction potential of 3.8 GJ/t, having a payback period of three years or less. This is equivalent to a potential energy efficiency improvement of 18% of 1994 US iron and steel energy use and is roughly equivalent to 19% reduction of 1994 US iron and steel carbon dioxide emissions. The measures have been ranked in a bottom-up energy conservation supply-curve.     

Carbon dioxide emission scenarios for the USA

A model of carbon dioxide emissions of the USA is presented. The model consists of population, income per capita, economic structure, final and primary energy intensity per sector, primary fuel mix, and emission coefficients. The model is simple enough to be calibrated to observations since 1850. The model is used to project emissions until 2100. Best-guess carbon dioxide emissions are in the middle of the IPCC SRES scenarios, but incomes and energy intensities are on the high side, while carbon intensities are on the low side. The confidence interval suggests that the SRES scenarios do not span the range of non-implausible futures. Although the model can be calibrated to reflect structural changes in the economy, it cannot anticipate such changes. The data poorly constrain crucial scenario elements, particularly energy prices. This suggests that the range of future emissions is wider still.     

A decomposition analysis of CO2 emissions from energy use: Turkish case

Environmental problems, especially “climate change” due to significant increase in anthropogenic greenhouse gases, have been on the agenda since 1980s. Among the greenhouse gases, carbon dioxide (CO₂) is the most important one and is responsible for more than 60% of the greenhouse effect. The objective of this study is to identify the factors that contribute to changes in CO₂ emissions for the Turkish economy by utilizing Log Mean Divisia Index (LMDI) method developed by Ang (2005) [Ang, B.W., 2005. The LMDI approach to decomposition analysis: a practical guide. Energy Policy 33, 867–871]. Turkish economy is divided into three aggregated sectors, namely agriculture, industry and services, and energy sources used by these sectors are aggregated into four groups: solid fuels, petroleum, natural gas and electricity. This study covers the period 1970–2006, which enables us to investigate the effects of different macroeconomic policies on carbon dioxide emissions through changes in shares of industries and use of different energy sources. Our analysis shows that the main component that determines the changes in CO₂ emissions of the Turkish economy is the economic activity. Even though important changes in the structure of the economy during 1970–2006 period are observed, structure effect is not a significant factor in changes in CO₂ emissions, however intensity effect is.     

The effects of changes in the UK energy demand and environmental legislation on atmospheric pollution by carbon dioxide

It has been demonstrated that the combustion of fossil fuel accounts for 97% of the carbon dioxide generated in the UK. The demand for primary energy over the 1970–1994 period has only marginally increased, however the demand for natural gas which has a significantly lower carbon content per unit of energy than other fuels accounts largely for the lowering of carbon dioxide emissions. The enactment UK/EU Environmental Legislation coupled with World Agreements accounts for a significant lowering of carbon dioxide emissions over this period. Future predictions suggest that a further downturn in carbon dioxide emissions will take place over the 1990–2000 period, followed by a pronounced increase over the 2000–2020 period. The expansion of the use of CCGT and/or the introduction of the IGCC and the SUPC in the power generating sector provides an opportunity for a further reduction in carbon dioxide emissions.©     

Carbon emissions reduction in China's food industry

In this paper, we evaluate the changes in carbon dioxide emissions from energy consumption in China's food industry from 1986 to 2010 based on the Logarithmic Mean Divisia Index (LMDI) method. The results show that energy intensity (EI) and industrial activity (IA) are the main determinants of the changes in carbon dioxide. Energy intensity (EI) contributes to decrease in emissions within 25 years while industrial activity (IA) acts in a positive way to increase the emissions level. Industry scale (IS) mostly contributes to increase in emissions except for the time interval 1996–2000. However, for both carbon intensity (CI) and energy structure (ES), they have a volatile but not significant influence on emissions in the different time intervals. To further understand the effects, we analyze the cumulative emission during the whole period 1986–2010. The results further testify that energy intensity and industrial activity are the most important factors affecting reduction and growth of carbon emissions. The results indicate that efforts to reduce emission in China's food industry should focus on the enhancement of energy efficiency, the optimization of industrial scale and the restructuring energy use. Finally, recommendations are provided for the reduction of carbon dioxide in China's food industry.     

我国二氧化碳排放的特点、趋势及政策取向

改革开放以来。我国二氧化碳排放总量从1978年的148329×10^4t增加到2008年的689654×10^4t．年均增长5．3％。与此同时,二氧化碳排放强度总体上呈较快下降趋势,但1999年以后下降速度放缓。我国二氧化碳排放强度明显高于国际水平。分析其原因,从需求结构看是经济增长过度依赖出口：从产业结构看是由于过度依赖工业,尤其是重化工业：而以煤为主的能源资源结构和能源生产结构,直接导致我国单位能源使用排放的二氧化碳高于其他国家。我国2015年二氧化碳排放量预测值在82．28×10^8-90．508×10^8t之间,减排形势不容乐观。由于我国还处在工业化、城镇化加快发展阶段,在以煤为主的特定资源禀赋条件下,减缓二氧化碳排放的主要路径是减少能源消费,即节能。节能的主要着力点在于充分发挥政府和市场的作用,加快提高能源技术效率,包括深化能源产品定价机制改革;加强政府的社会性管制,使环境社会成本充分内部化;建立绿色税收体系,支持低碳经济发展;培育碳排放交易市场。     

Driving factors behind carbon dioxide emissions in China: A modified production-theoretical decomposition analysis

Research on the driving factors behind carbon dioxide emission changes in China can inform better carbon emission reduction policies and help develop a low-carbon economy. As one of important methods, production-theoretical decomposition analysis (PDA) has been widely used to understand these driving factors. To avoid the infeasibility issue in solving the linear programming, this study proposed a modified PDA approach to decompose carbon dioxide emission changes into seven drivers. Using 2005–2010 data, the study found that economic development was the largest factor of increasing carbon dioxide emissions. The second factor was energy structure (reflecting potential carbon), and the third factor was low energy efficiency. Technological advances, energy intensity reductions, and carbon dioxide emission efficiency improvements were the negative driving factors reducing carbon dioxide emission growth rates. Carbon dioxide emissions and driving factors varied significantly across east, central and west China.     

Industrial structural transformation and carbon dioxide emissions in China

Using provincial panel data from the period 1995–2009 to analyze the relationship between the industrial structural transformation and carbon dioxide emissions in China, we find that the first-order lag of industrial structural adjustment effectively reduced the emissions; technical progress itself did not reduce the emissions, but indirectly led to decreasing emissions through the upgrading and optimization of industrial structure. Foreign direct investment and intervention by local governments reduced carbon dioxide emissions, but urbanization significantly increased the emissions. Thus, industrial structural adjustment is an important component of the development of a low-carbon economy. In the context of industrial structural transformation, an effective way to reduce a region’s carbon dioxide emissions is to promote the upgrading and optimization of industrial structure through technical progress. Tighter environmental access policies, selective utilization of foreign direct investment, and improvements in energy efficiency can help to reduce carbon dioxide emissions.     

Regional development and carbon emissions in China

China announced at the Paris Climate Change Conference in 2015 that the country would reach peak carbon emissions around 2030. Since then, widespread attention has been devoted to determining when and how this goal will be achieved. This study aims to explore the role of China's changing regional development patterns in the achievement of this goal. This study uses the logarithmic mean Divisia index (LMDI) to estimate seven socioeconomic drivers of the changes in CO₂ emissions in China since 2000. The results show that China's carbon emissions have plateaued since 2012 mainly because of energy efficiency gains and structural upgrades (i.e., industrial structure, energy mix and regional structure). Regional structure, measured by provincial economic growth shares, has drastically reduced CO₂ emissions since 2012. The effects of these drivers on emissions changes varied across regions due to their different regional development patterns. Industrial structure and energy mix resulted in emissions growth in some regions, but these two drivers led to emissions reduction at the national level. For example, industrial structure reduced China's CO₂ emissions by 1.0% from 2013 to 2016; however, it increased CO₂ emissions in the Northeast and Northwest regions by 1.7% and 0.9%, respectively. Studying China's plateauing CO₂ emissions in the new normal stage at the regional level yields a strong recommendation that China's regions cooperate to improve development patterns.     

Carbon dioxide emissions in OECD service sectors: the critical role of electricity use

From the early 1970s to mid 1990s, service sector CO₂ emissions have increased significantly in OECD countries, despite marked declines in energy intensity. This development is underscored by a widespread shift from fuel use to electricity use in commercial buildings. Service sectors in countries that produce low-carbon electricity, particularly those that operate nuclear- and hydro-powered utilities, have most successfully restrained CO₂ emissions. This study analyzes the impact of activity, structure, energy intensity, fuel mix, and utility mix on carbon emissions in the service sector for 13 OECD countries, and contrasts the developments before 1990 with those afterwards. The major findings of this analysis are:

(i) Carbon emissions, which rose in 9 of the 13 countries investigated, were bolstered in every country by an expansion of floor area and service sector GDP,

(ii) Declines in energy intensity and carbon intensity lessened the magnitude of emissions increases,

(iii) Electricity's share of final energy use rose in all 13 countries, but affected carbon emissions quite differently among countries,

(iv) After 1990, energy intensity improvements applied less downward pressure on emissions, while reductions in the average carbon content of final energy restrained emissions more strongly.     

Life cycle analysis of vehicles powered by a fuel cell and by internal combustion engine for Canada

The transportation sector is responsible for a great percentage of the greenhouse gas emissions as well as the energy consumption in the world. Canada is the second major emitter of carbon dioxide in the world. The need for alternative fuels, other than petroleum, and the need to reduce energy consumption and greenhouse gases emissions are the main reasons behind this study. In this study, a full life cycle analysis of an internal combustion engine vehicle (ICEV) and a fuel cell vehicle (FCV) has been carried out. The impact of the material and fuel used in the vehicle on energy consumption and carbon dioxide emissions is analyzed for Canada. The data collected from the literature shows that the energy consumption for the production of 1 kg of aluminum is five times higher than that of 1 kg of steel, although higher aluminum content makes vehicles lightweight and more energy efficient during the vehicle use stage. Greenhouse gas regulated emissions and energy use in transportation (GREET) software has been used to analyze the fuel life cycle. The life cycle of the fuel consists of obtaining the raw material, extracting the fuel from the raw material, transporting, and storing the fuel as well as using the fuel in the vehicle. Four different methods of obtaining hydrogen were analyzed; using coal and nuclear power to produce electricity and extraction of hydrogen through electrolysis and via steam reforming of natural gas in a natural gas plant and in a hydrogen refueling station. It is found that the use of coal to obtain hydrogen generates the highest emissions and consumes the highest energy. Comparing the overall life cycle of an ICEV and a FCV, the total emissions of an FCV are 49% lower than an ICEV and the energy consumption of FCV is 87% lower than that of ICEV. Further, CO₂ emissions during the hydrogen fuel production in a central plant can be easily captured and sequestrated. The comparison carried out in this study between FCV and ICEV is extended to the use of recycled material. It is found that using 100% recycled material can reduce energy consumption by 45% and carbon dioxide emissions by 42%, mainly due to the reduced use of electricity during the manufacturing of the material.     

Convergence of energy productivity in Australian states and territories: Determinants and forecasts

The Australian government has recently launched a National Energy Productivity Plan that calls for a 40% increase in energy productivity (economic output divided by energy use) before 2030. Improving energy productivity would help boost economic competitiveness, reduce energy costs, and reduce carbon dioxide emissions in Australia. Understanding energy productivity dynamics at the state level is essential for the success of this program. This research analyses the convergence path of energy productivity in Australian states and territories. Club convergence analysis applied to data over the period 1990–2015 reveals two converging energy productivity clubs. Initial energy productivity, industry structure, and automobile fuel prices are important determinants of higher energy productivity. Based on Australian state energy productivity forecasts to 2030, New South Wales and Victoria will be the forerunners in maintaining higher energy productivity in 2030. Australia will not achieve a 40% increase in energy productivity before 2030 without significant changes to its fuel mix and industry structure.     

Multiple calibration decomposition analysis: Energy use and carbon dioxide emissions in the Japanese economy, 1970–1995

The purpose of this paper is to present a new approach to evaluating structural change of the economy in a multisector general equilibrium framework. The multiple calibration technique is applied to an ex post decomposition analysis of structural change between periods, enabling the distinction between price substitution and technological change to be made for each sector. This approach has the advantage of sounder microtheoretical underpinnings when compared with conventional decomposition methods. The proposed technique is empirically applied to changes in energy use and carbon dioxide (CO₂) emissions in the Japanese economy from 1970 to 1995. The results show that technological change is of great importance for curtailing energy use and CO₂ emissions in Japan. Total CO₂ emissions increased during this period primarily because of economic growth, which is represented by final demand effects. On the other hand, the effects such as technological change for labor or energy mitigated the increase in CO₂ emissions.     

Decomposition of CO2 emissions change from energy consumption in Brazil: Challenges and policy implications

This study evaluates the changes in CO₂ emissions from energy consumption in Brazil for the period 1970–2009. Emissions are decomposed into production and consumption activities allowing computing the full set of energy sources consumed in the country. This study aims to develop a comprehensive and updated picture of the underlying determinants of emissions change from energy consumption in Brazil along the last four decades, including for the first time the recently released data for 2009. Results demonstrate that economic activity and demographic pressure are the leading forces explaining emission increase. On the other hand, carbon intensity reductions and diversification of energy mix towards cleaner sources are the main factors contributing to emission mitigation, which are also the driving factors responsible for the observed decoupling between CO₂ emissions and economic growth after 2004. The cyclical patterns of energy intensity and economy structure are associated to both increments and mitigation on total emission change depending on the interval. The evidences demonstrate that Brazilian efforts to reduce emissions are concentrated on energy mix diversification and carbon intensity control while technology intensive alternatives like energy intensity has not demonstrated relevant progress. Residential sector displays a marginal weight in the total emission change.     

Future carbon dioxide emissions in the global material flow of primary aluminium

This study assesses the future carbon dioxide emissions in the global material flow of primary aluminium. The model of the global aluminium industry (GlobAl model) is used for scenario calculations. It simulates a market economy and allows an integrated analysis of the material flow and the corresponding carbon dioxide emissions. 1995 is the base year and the future horizon of the scenario calculations is 2010. The critical parameter ‘global demand for primary aluminium’ is varied. According to the scenario calculations, the absolute carbon dioxide emissions in the global material flow of primary energy will not increase until the growth rate of demand reaches 2% per year. World average specific emissions will decrease remarkably, especially due to the reduced energy-related emissions for smelting. There are three reasons for this. In the first place, the lower CO₂-emission factor of electricity generated from fossil fuels leads to reduced emissions. Secondly, modern point-feeder pre-baked plants need less electricity than the Soderberg plants they replace. And, thirdly, the production of primary aluminium is being shifted to regions in which the production of electricity is mainly based on hydropower.     

A model for sustainable land use in biofuel production: An application to the state of Alabama

The Renewable Fuel Standard aims to increase the production of biofuels to improve energy efficiency and decrease carbon dioxide emissions in the US. The effectiveness of this regulation is being debated by the scientific community regarding carbon emissions from direct and indirect land-use change. A valid alternative may be to design policies that stimulate sustainable land use in biofuel production. This article develops a model that simulates a voluntary program to increase the land use efficiency in production of biofuels. This stochastic dynamic model optimizes the sustainability of biofuels producible by including climate information and participatory decisions on land use. The model is parameterized using the Maximum Entropy econometric technique to present a simulation of the program in the State of Alabama. The results of this simulation show that participatory decisions on land-use may increase the net energy value of produced biofuel up to 215.68% and reduce the carbon emissions by 19.67% towards the state energy goals.     

中国中长期碳减排战略目标初探(Ⅶ)——中国能源需求暨碳排放情景分析讨论

预测世界二氧化碳排放量峰值40Gt/a出现在2025年,此后年均下降4.1%,2050年才能达到IEA Blue Map情景要求的14Gt/a,届时人均排放量为1.5t,由于总降幅未达到80%,仍需努力减排,争取2070年世界二氧化碳排放量达到10Gt/a。中国2005~2025年累积二氧化碳排放量约160Gt,2025~2050年间约194Gt,2050~2070年间约75Gt,2005～2070年间合计约472Gt,约占当时世界份额的27%。希望中国碳排放峰值出现在2025年而不是2030年,即使能控制当年二氧化碳排放量达到10.5Gt/a的水平,此后年均下降2.9%,2050年达到5Gt/a的较高水平,年人均排放量降低到3.4t,仍高于世界均值。为了与世界总降幅同步,还需要进一步减排,争取2070年二氧化碳排放量达到2.5Gt/a。为了在2050年达到期望的碳减排目标,必须优化中国的产业结构和能源结构,发电、钢铁、水泥是中国节能减排的重点。受生物质资源不足、煤化工生产油品只能适度发展、氢燃料替代目前尚无确切时间推广节点的制约,预计2050年中国替代石油燃料的比率在20%左右,低于欧美地区50%～70%的比率。但通过提倡绿色出行、提高发动机燃油效率、乘用车过渡到以纯电动汽车和混合动力汽车为主、石油替代步伐加快且替代方式多样化、提高石油加工轻质化程度、加大天然气在CHP或DES/CCHP的高效利用等措施,将2050年的原油消费量控制在6.0×108t仍然有可能。加工6×108t原油可生产1.08×108t化工轻油,CBTL生产的油品总量中还包含1200×104t石脑油,合计化工轻油量为1.20×108t,加之还可由煤化工MTO/MTP生产一定量的烯烃,可满足基本有机化工原料的需求。只有通过各部门的综合努力,低碳排放的A或B情景才有可能实现,任何部门的牵制都将影响全国碳减排目标的实现。     

Role of natural gas in meeting an electric sector emissions reduction strategy and effects on greenhouse gas emissions

With advances in natural gas extraction technologies, there is an increase in the availability of domestic natural gas, and natural gas is gaining a larger share of use as a fuel in electricity production. At the power plant, natural gas is a cleaner burning fuel than coal, but uncertainties exist in the amount of methane leakage occurring upstream in the extraction and production of natural gas. At higher leakage levels, the additional methane emissions could offset the carbon dioxide emissions reduction benefit of switching from coal to natural gas. This analysis uses the MARKAL linear optimization model to compare the carbon emissions profiles and system-wide global warming potential of the U.S. energy system over a series of model runs in which the power sector is required to meet a specific carbon dioxide reduction target across a number of scenarios in which the availability of natural gas changes. Scenarios are run with carbon dioxide emissions and a range of upstream methane emission leakage rates from natural gas production along with upstream methane and carbon dioxide emissions associated with production of coal and oil. While the system carbon dioxide emissions are reduced in most scenarios, total carbon dioxide equivalent emissions show an increase in scenarios in which natural gas prices remain low and, simultaneously, methane emissions from natural gas production are higher.     

中国能源消费碳排放变化的影响因素分析——基于投入产出模型

从产业关联的角度出发,采用结构分解分析法(SDA)给出了中国能源消费碳排放的投入产出分析模型.基于投入产出模型,利用1997年、2002年、2005年、2007年的投入产出数据和能源消费数据,依据政府间气候变化专门委员会(IPCC)给出的二氧化碳排放量的计算公式计算了各产业部门的碳排放量,并进而计算了各部门的直接碳排放强度,然后依据结构分解方法对中国能源消费碳排放的影响因素进行了详细的分解分析.研究结果发现:碳排放强度在1997 ～ 2002年和2005～2007年均有大幅度的降低,而在2002～2005年却有一个小幅上升.反映能源使用效率的部门直接碳排放强度系数和反映生产技术的完全需求系数是我国碳排放强度变化的两个最主要的影响因素.建议各行业各部门要用高新技术和先进适用技术改造和提升传统产业,加大投资结构调整力度,坚决淘汰落后产能,切实抑制低水平重复建设和高耗能产业的扩张,逐步加大对环保产业、新能源产业和高新技术产业的投资倾斜.