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.     

Technical and cost assessment of energy efficiency improvement and greenhouse gas emission reduction potentials in Thai cement industry

The cement industry is one of the most energy-consuming industries in Thailand, with high associated carbon dioxide (CO₂) emissions. The cement sector accounted for about 20.6 million tonnes of CO₂ emissions in 2005. The fuel intensity of the Thai cement industry was about 3.11 gigajoules (GJ)/tonne cement; the electricity intensity was about 94.3 kWh/tonne cement, and the total primary energy intensity was about 4.09 GJ/tonne cement in 2005 with the clinker to cement ratio of around 82%. In this study, the potential application of 47 energy-efficiency measures is assessed for the Thai cement industry. Using a bottom-up electricity conservation supply curve model, the cost-effective electricity efficiency improvement potential for the Thai cement industry is estimated to be about 265 gigawatt hours (GWh), which accounts for 8% of total electricity use in the cement industry in 2005. Total technical electricity-saving potential is 1,697 GWh, which accounts for 51% of total electricity use in the cement industry in 2005. The CO₂ emission reduction potential associated with the cost-effective electricity savings is 159 kilotonne (kt) CO₂, while the total technical potential for CO₂ emission reductions is 902 ktonne CO₂. The fuel conservation supply curve model shows a cost-effective fuel-efficiency improvement potential of 17,214 terajoules (TJ) and a total technical fuel efficiency improvement potential equal to 21,202 TJ, accounting for 16% and 19% of the total fuel use in the cement industry in 2005, respectively. CO₂ emission reduction potentials associated with cost-effective and technical fuel-saving measures are 2,229 ktonne and 2,603 ktonne, respectively. Sensitivity analyses were conducted for discount rate, electricity and fuel prices, and exchange rate that showed the significant influence of these parameters on the results. Hence, the results of the study should be interpreted with caution.     

Energy balance and greenhouse gas emissions of biodiesel production from oil derived from wastewater and wastewater sludge

It has been recognized that oils derived from microorganism and wastewater sludge are comparable replacements of traditional biodiesel production feedstock, which is energy intensive and costly. Energy balance and greenhouse gas (GHG) emissions are essential factors to assess the feasibility of the production. This study evaluated the energy balance and GHG emissions of biodiesel production from microbial and wastewater sludge oil. The results show that energy balance and GHG emissions of biodiesel produced from microbial oil are significantly impacted by the cultivation methods and carbon source. For phototrophic microorganism (microalgae), open pond system gives 3.6 GJ higher energy gain than photo bioreactor system in per tonne biodiesel produced. For heterotrophic microorganisms, the energy balance depends on the type of carbon source. Three carbon sources including starch, cellulose, and starch industry wastewater (SIW) used in this study showed that utilization of SIW as carbon source provided the most favorable energy balance. When oil extracted from municipal sludge is used for biodiesel production, the energy gain is up to 29.7 GJ per tonne biodiesel produced, which is higher than the energy gain per tonne of biodiesel produced from SIW cultivated microbes. GHG emissions study shows that biodiesel production from microbes or sludge oil is a net carbon dioxide capture process except when starch is used as raw material for microbial oil production, and the highest capture is around 40 tonnes carbon dioxide per tonne of biodiesel produced.     

The marginal impact of carbon dioxide under two scenarios of future emissions

This paper uses the PAGE2002 model to calculate the marginal impact of carbon dioxide (CO₂) under the A2 and B2 marker scenarios of the IPCC, and its distribution across regions, sectors, and over time. PAGE2002 considers the possibility of large-scale discontinuities, a major concern in the IPCC TAR. PAGE2002 estimates the mean value of the marginal impact for CO₂ under scenario A2 to be $19 per tonne of carbon (tC), equivalent to $5 per tonne of CO₂. The 95% and 5% values for the marginal impact are $49/tC and $5/tC. The mean value under scenario B2 is estimated to be $14/tC, with 95% and 5% points as $41/tC and $3/tC, respectively. The marginal impact is sensitive to the pure rate of time preference, and doubles for a 1% reduction from 3% to 2%. Additionally, adaptation policy affects the marginal impact estimates; they increase by 50% if no adaptation policy is implemented. Benefits from reductions in greenhouse gas emissions will affect the globe as a whole, but with various regions being more affected than others. Developing countries would receive about 50% of the benefit, whereas the European Union's benefits would be about 7%; only about 2% of the benefits would be felt in the USA. Benefits from an immediate reduction in CO₂ emissions peak around the year 2100. About 60% of the benefits from reducing greenhouse gas emissions are non-economic, with economic and large-scale discontinuities being about 20% each.     

国外石化公司二氧化碳减排对策分析

我国2005年二氧化碳排放总量为51×10^8t．居世界第二位。炼化行业的二氧化碳排放比重也在不断增加．其中燃烧排放占绝大部分,生产过程排放其次．国外行化公司为应对二氧化碳减排,采取了改进燃料系统、提高能量利用效率、大力开发可再生能源、利用CCS技术提高油气田采收率、灵活应用二氧化碳排放贸易体系和CDM机制等对策。建议我国石化企业应重点关注常减压、催化重整、催化裂化、制氧、乙烯、合成氨等二氧化碳高排放装置的节能减排,开展二氧化碳综合利用技术的研究与应用,开发可再生能源,运用各种减排政策和机制参与减排活动。     

Evaluation of energy saving potential in China's cement industry using the Asian-Pacific Integrated Model and the technology promotion policy analysis

Much of China's cement industry still uses outdated kilns and other inefficient technologies, which are obstacles to improving energy efficiency. Huge improvements in energy consumption intensity can be made by improving this technology. To evaluate the potential for energy-saving and CO₂ emissions reduction in China's cement industry between 2010 and 2020, a model was developed based on the Asian-Pacific Integrated Model (AIM). Three scenarios (S1, S2 and S3) were developed to describe future technology policy measures in relation to the development of the cement industry. Results show that scenario S3 would realize the potential for CO₂ emissions mitigation of 361.0 million tons, accounting for 25.24% of the predicted emissions, with an additional energy saving potential of 39.0 million tons of coal equivalent by 2020. Technology promotion and industrial structure adjustment are the main measures that can lead to energy savings. Structural adjustment is the most important approach to reduce the CO₂ emissions from the cement industry; the resulting potential for CO₂ emissions reduction will be increasingly large, even exceeding 50% after 2016.     

Energy use and CO2 emissions in Mexico's iron and steel industry

Energy use and carbon dioxide emissions for the Mexican iron and steel industry are analyzed from 1970 to 1996. To assess the trends in energy use and carbon dioxide emissions, we used a decomposition analysis based on physical indicators to decompose the intra-sectoral structural changes and efficiency improvements. We used a structure/efficiency analysis for international comparisons, considering industrial structure and the best available technology. This study shows that steel production growth drove up primary energy use by 211% between 1970 and 1996, while structural changes (production and process mix) decreased primary energy use by 12% and energy efficiency changes drove down energy use by 51%. In addition, carbon dioxide emissions would have increased by 9% if the primary fuel mix had remained constant at 1970 levels.     

Energy balance and cogeneration for a cement plant

The cement industry is an energy intensive industry consuming about 4 GJ per tonne of cement produced. A thermodynamic analysis for cogeneration using the waste heat streams is not easily available. Data from a working 1 Mt per annum plant in India is used to obtain an energy balance for the system and a Sankey diagram is drawn. It is found that about 35% of the input energy is being lost with the waste heat streams. A steam cycle is selected to recover the heat from the streams using a waste heat recovery steam generator and it is estimated that about 4.4 MW of electricity can be generated. This represents about 30% of the electricity requirement of the plant and a 10% improvement in the primary energy efficiency of the plant. The payback period for the system is found to be within two years.     

不同碳达峰时点选择下的投资结构变化和经济社会影响——以广东省为例

中国提出2030年前碳达峰、2060年前碳中和的目标将对全社会经济发展、能源消费带来深刻的变革。通过构建广东省气候-经济-环境-健康综合评估模型(ICEEH-GD),设计了如期达峰(2030年达峰)和率先达峰(2025年达峰)两个情景,研究不同碳达峰时点下的投资结构变化和经济社会影响。结果表明,率先达峰情景促进全社会投资从电力、水泥、油品开采、焦炭、钢铁等低增加值高碳排放部门转向服务业、电子信息、机械制造、建筑业、化工业等高增加值低碳排放部门,投资量总计转移了819亿元,带动相关部门的增加值增长135亿元。率先达峰情景强化对电力、水泥、钢铁、陶瓷等高碳排放行业的限制,在2030年全社会就业岗位比如期达峰情景增加82000人,但全省国内生产总值(GDP)比如期达峰情景减少424亿元,占届时全省GDP总量的0.242%。到2030年,率先达峰情景比如期达峰情景降低CO₂排放7 610万t和节约能源消费2 535万t标准煤,其中碳减排和节能贡献部门主要来自电力、水泥、钢铁、石油开采、陶瓷行业,分别占全社会碳减排量和节能量的65.0%和74.3%。从投资与增加值、就业、碳...     

Energy conservation potential in Taiwanese textile industry

Since Taiwan lacks sufficient self-produced energy, increasing energy efficiency and energy savings are essential aspects of Taiwan’s energy policy. This work summarizes the energy savings implemented by 303 firms in Taiwan’s textile industry from the on-line Energy Declaration System in 2008. It was found that the total implemented energy savings amounted to 46,074 ton of oil equivalent (TOE). The energy saving was equivalent to 94,614 MWh of electricity, 23,686 kl of fuel oil and 4887 ton of fuel coal. It represented a potential reduction of 143,669 ton in carbon dioxide emissions, equivalent to the annual carbon dioxide absorption capacity of a 3848 ha plantation forest. This study summarizes energy-saving measures for energy users and identifies the areas for making energy saving to provide an energy efficiency baseline.     

Reducing greenhouse gas emissions by inducing energy conservation and distributed generation from elimination of electric utility customer charges

This paper quantifies the increased greenhouse gas emissions and negative effect on energy conservation (or “efficiency penalty”) due to electric rate structures that employ an unavoidable customer charge. First, the extent of customer charges was determined from a nationwide survey of US electric tariffs. To eliminate the customer charge nationally while maintaining a fixed sum for electric companies for a given amount of electricity, an increase of 7.12% in the residential electrical rate was found to be necessary. If enacted, this increase in the electric rate would result in a 6.4% reduction in overall electricity consumption, conserving 73 billion kW h, eliminating 44.3 million metric tons of carbon dioxide, and saving the entire US residential sector over $8 billion per year. As shown here, these reductions would come from increased avoidable costs, thus leveraging an increased rate of return on investments in energy efficiency, energy conservation behavior, distributed energy generation, and fuel choices. Finally, limitations of this study and analysis are discussed and conclusions are drawn for proposed energy policy changes.     

The net greenhouse warming forcing of methanol produced from biomass

Recent national and international actions regarding atmosphere warming mitigation, clean technology, and technology transfer have emphasized the need for a method for unambiguous greenhouse gas emissions analysis for comparing technologies, documentation of application of the method, and proof of applicability. We have developed and applied such an approach to production of methanol fuel from woody biomass. The entire approach is detailed, whereby the system was defined, its emissions for its entire lifetime delineated, and the atmospheric warming forcing calculated for that lifetime plus after effects. The results are presented with material and energy balances including ancillary equipment, external energy subsidies and invested quantities. These extend the analysis considerably beyond those possible using the global warming potential (GWP). For wood input of 283 mg day⁻¹, 70 mg of methanol are produced. System carbon dioxide emissions are 3.18 tonne/tonne methanol produced, with another 1.37 mg emitted when that tonne methanol is burned in a vehicle. System energy usage efficiency was 41.2%, and 41.1% with inclusion of energy to construct the system. In essence, more than two Joules of carbon must be produced in wood for every Joule burned in the vehicle.     

Current situation of energy conservation in high energy-consuming industries in Taiwan

Growing concern in Taiwan has arisen about energy consumption and its adverse environmental impact. The current situation of energy conservation in high energy-consuming industries in Taiwan, including the iron and steel, chemical, cement, pulp and paper, textiles and electric/electrical industries has been presented. Since the energy consumption of the top 100 energy users (T100) comprised over 50% of total industry energy consumption, focusing energy consumption reduction efforts on T100 energy users can achieve significant results. This study conducted on-site energy audits of 314 firms in Taiwan during 2000–2004, and identified potential electricity savings of 1,022,656 MWH, fuel oil savings of 174,643 kiloliters (KL), steam coal savings of 98,620 ton, and natural gas (NG) savings of 10,430 kilo cubic meters. The total potential energy saving thus was 489,505 KL of crude oil equivalent (KLOE), representing a reduction of 1,447,841 ton in the carbon dioxide emissions, equivalent to the annual carbon dioxide absorption capacity of a 39,131-ha plantation forest.     

The case study of furnace use and energy conservation in iron and steel industry

This work was performed on-site energy audits of 118 firms in the Taiwanese iron and steel industry during 2000–2008. It was found that the total potential energy savings was estimated about 79,160.8 KL of crude oil equivalent (KLOE). It was identified to generate potential electricity savings of 170,322.8 MWH, fuel oil savings of 22,235.1 kL, steam coal savings of 4922 tons, and natural gas (NG) savings of 10,735 kilo cubic meters. It was represented a total reduction of 217,866.5 tons in carbon dioxide emissions, equivalent to the annual carbon dioxide absorption capacity of a 5836 ha plantation forest. This study has established a national database presenting information and energy saving methods for energy users and has identified the potential areas for making energy savings to provide a energy conservation reference. It can assist the energy users in performing energy audits and increasing energy utilization efficiency.     

中国电力工业为节能减排做出贡献——记2009年中国发电领域的十件大事

到2020年,我国非化石能源占一次能源消费比重将达到15%左右,单位GDP二氧化碳排放比2005年下降40%～45%。2009年,我国电力工业特别是发电企业贯彻国家的大政方针,在发展低碳经济、节能减排方面充分体现了国家意志并有所作为。重视煤电的节能减排,努力发展常规水电、常规核电,在煤电清洁利用、第三代和第四代核电以及风电、太阳能利用方面也取得了显著成果。2009年中国发电领域的一些事件值得关注,主要包括全国发电设备容量突破8×108kW;电价调整,大用户直购电试点启动;电煤订货会一单未签,电企海外购煤;2009环评风暴;长江三峡工程竣工,中国水电装机稳居世界第一;三门核电、海阳核电开工,核电井喷式发展;甘肃酒泉千万千瓦级风电基地开工;用电量回升,发电量正增长,发电企业开始扭亏;节能减排成效显著;煤电清洁发展,华电IGCC电厂奠基。     

Measuring improvement in energy efficiency of the US cement industry with the ENERGY STAR Energy Performance Indicator

The lack of a system for benchmarking industrial plant energy efficiency represents a major obstacle to improving efficiency. While estimates are sometimes available for specific technologies, the efficiency of one plant versus another could only be captured by benchmarking the energy efficiency of the whole plant and not by looking at its components. This paper presents an approach used by ENERGY STAR to implement manufacturing plant energy benchmarking for the cement industry. Using plant-level data and statistical analysis, we control for factors that influence energy use that are not efficiency, per se. What remains is an estimate of the distribution of energy use that is not accounted for by these factors, i.e., intra-plant energy efficiency. By comparing two separate analyses conducted at different points in time, we can see how this distribution has changed. While aggregate data can be used to estimate an average rate of improvement in terms of total industry energy use and production, such an estimate would be misleading as it may give the impression that all plants have made the same improvements. The picture that emerges from our plant-level statistical analysis is more subtle; the most energy-intensive plants have closed or been completely replaced and poor performing plants have made efficiency gains, reducing the gap between themselves and the top performers, whom have changed only slightly. Our estimate is a 13 % change in total source energy, equivalent to an annual reduction of 5.4 billion/kg of energy-related carbon dioxide emissions.     

Carbon charges and natural gas use in China

Substitution of natural gas for coal in China's power sector could significantly reduce emissions of carbon dioxide, but gas-fired power is generally more costly than coal-fired power in China today. This paper explores how carbon charges and carbon sequestration technology might tip the balance in favour of gas. The costs of electricity from new coal-fired and gas-fired power plants in China are compared under various assumptions about fuel costs, exchange rates, carbon dioxide charges, and application of carbon sequestration technology. Under average cost conditions today, gas-fired power is roughly two-thirds more costly than coal-fired power. But with a charge of $20/tonne of carbon dioxide, the costs of gas- and coal-fired power would typically be about equal. Over the longer term, carbon sequestration technology could be economical with a carbon dioxide charge of $22/tonne or more under typical cost conditions, but gas with sequestration would not have a clear cost advantage over coal with sequestration unless the charge exceeded $35/tonne.     

Prospective on the energy efficiency and CO2 emissions in the EU cement industry

The cement industry is the third largest carbon emitting industrial sector in the EU. The present work analyses the potential for improvement in the energy efficiency and CO₂ emission reduction for this sector up to 2030. Three scenarios are analysed: baseline scenario (BS) representing the current evolution of the cement sector and two alternative scenarios (AS1 and AS2) studying respectively the sensitivity of fuel prices and CO₂ emission prices. The results for the BS show an improvement in the thermal energy efficiency and the CO₂ emissions per tonne of clinker respectively of 11% and 3.7% in 2030 compared with the level of 2002. However, for AS1 and AS2, these scenarios are insensitive to fuel and CO₂ emission prices, respectively. This can be explained by the fact that a large number of retrofits are economically feasible in the BS, leading to a significant reduction in the thermal energy consumption.     

The use of conservation supply curves in energy policy and economic analysis: The case study of Thai cement industry

The cement industry is one of the largest energy-consuming industries in Thailand with high carbon dioxide (CO₂) emissions. Using a bottom-up electricity Conservation Supply Curve (CSC) model, the cost effective and the total technical electricity-efficiency potential for the Thai cement industry in 2008 is estimated to be about 265 and 1697 gigawatt-hours (GWh) which account for 8% and 51% of the total electricity used in the cement industry in 2005, respectively. The fuel CSC model shows the cost-effective fuel-efficiency potential to be 17,214 terajoules (TJ) and the total technical fuel-efficiency potential equal to 21,202 TJ, accounting for 16% and 19% of the total fuel used in cement industry in 2005, respectively. The economic analysis in this paper shows how the information from the CSCs can be used to calculate the present value (PV) of net cost savings over a period of time taking into account the energy price escalation rate. The results from the policy scenario analysis show that the most effective and efficient policy scenario is the introduction of an energy-related CO₂ tax for the cement industry under a voluntary agreement program. This scenario results in 16.9% primary energy-efficiency improvement over a 5-year implementation period.     

Policies to reduce energy use and carbon emissions in the UK

The UK differs from may other industrialized nations in that its carbon dioxide (CO₂) emissions from energy use have declined in recent years despite relatively rapid economic growth. In all sectors but transport, substantial reductions have already occurred in the level of carbon emissions per unit of GDP output. At the same time, a number of official and unofficial studies have pointed out that the UK has one of the largest remaining potentials amongst comparable industrialized countries for achieving further CO₂ reductions through the implementation of cost-effective energy efficiency and fuel switching measures. This paper discusses past and present patterns of energy use and carbons emissions in the UK. The analysis then examines historical trends in UK energy policy and presents policy options for further reducing the UK's energy-use and carbon emissions in the future.