Optimization and performance prediction of a new near-zero emission coal utilization system with combined gasification and combustion

In accordance with the new near-zero emission coal utilization system with combined gasification and combustion, which is based on the CO₂ acceptor gasification process, the product gas composition of the gasifier and the combustor was calculated by means of thermodynamic equilibrium calculation software FactSage 5.2. Based on these calculations, the whole system efficiency calculation method that complies with the mass and energy conservation principle was established. To enhance the system efficiency, the system pressure and the gasifier carbon conversion ratio were optimized. The results indicate that the system efficiency increases with increasing pressure and gasifier carbon conversion ratio. After taking into consideration the influence of the pressure and carbon conversion ratio on the performance of the system, the gasifier and the combustor were synthetically studied. The optimum system pressure and carbon conversion ratio were obtained as 2.5 MPa and 0.7, respectively. The system efficiency could reach around 62.1% when operated in these two optimum parameters. If the advanced ion transport membrane (ITM) air separation technology is used, there would be an increase of another 1.3%. Translated from Proceedings of the CSEE, 2006, 26(9): 7–13 [译自: 中国电机工程学报]     

China’s regional CO2 emissions: Characteristics,inter-regional transfer and emission reduction policies

This paper analyzes the characteristics of China’s regional CO₂ emissions and effects of economic growth and energy intensity using panel data from 1997 to 2009. The results show that there are remarkable regional disparities among eastern, central and western areas, regional elasticities of per capita GDP and energy intensity on CO₂ emissions, which reflect the regional differences in economic development, economy structure and restraining function of energy intensity decrease on the emission. Energy intensity reducing is more effective to emission abatement for provinces with higher elasticity of energy intensity, but may not be significant for provinces with lower elasticity. The inverse distribution of energy production and consumption, regional unfairness caused by institutional factors like energy price and tax system result in inter-regional CO₂ emission transfer embodied in the power transmission. The calculation indicates that the embodied emission transfer was gradually significant after 2003, from eastern area to the central and western areas, especially energy production provinces in central area, which leads to distortion on the emission and emission intensity. The regional emission reduction targets and supporting policies should be customized and consistent with the actual situations rather than setting the same target for all the provinces.     

Decomposition analysis of CO2 emission in long-term climate stabilization scenarios

To achieve the stabilization of greenhouse gas (GHG) concentrations in the atmosphere, the international community will need to intensify its long-term efforts. Many EU countries have released national long-term scenarios toward 2050, and their ambitious targets for CO₂ emission reduction are aiming at a decrease of more than 50% of today's emission. In April 2004, Japan began a research project on its long-term climate policy. This paper discusses the long-term scenarios in other countries and the medium-term scenarios in Japan to support the development of a Japan's long-term climate stabilization scenario. In this study, CO₂ emission is decomposed with an extended Kaya identity (indexes: CO₂ capture and storage, carbon intensity, energy efficiency, energy intensity, economic activity) and a Reduction Balance Table is developed.     

Swedish industry and Kyoto—An assessment of the effects of the European CO2 emission trading system

We assess the effects on Swedish industry input demands and output of different climate policy scenarios connected to energy policy induced by the Kyoto protocol. We use a unique dataset containing firm-level data on outputs and inputs between 1991 and 2001 to estimate a factor demand model, which we use to simulate different policy scenarios. Sector-specific estimation suggests that the proposed quadratic profit function specification exhibits properties and robustness that are consistent with economic theory; that is, all own-price elasticities are negative and all output elasticities are positive. Furthermore, the elasticities show that the input demands are, in most cases, relatively inelastic. Simulation of the model for six different policy scenarios reveal that effects on the Swedish base industry of a EU-level permit-trading system depends on (i) the removal or maintenance of the current CO₂ tax, (ii) the price of permits, and (iii) the future price of electricity. Our analysis shows that changes in electricity price may be more important than the price of permits for some sectors.     

The future choice of technologies and co-benefits of CO2 emission reduction in Bangladesh power sector

This paper examines the impacts of CO₂ emission reduction on future technology selection and energy use in Bangladesh power sector up to 2035 considering the base year 2005. It also examines the implications of CO₂ emission reduction targets on energy security of the country. The analysis is based on a long-term energy system model of Bangladesh using the MARKAL framework. The results show that the introduction of the CO₂ emission reduction targets directly affect the shift of technologies from high carbon content fossil-based to low carbon content fossil-based as well as clean, renewable energy-based technologies compared to the base scenario. With the CO₂ emission reduction target of 10–30%, the cumulative net energy imports during 2005–2035 would be reduced in the range of over 1400 PJ to 4898 PJ compared to the base scenario emission level. The total primary energy requirement would be reduced in the range of 5.5–15.2% in the CO₂ emission reduction targets and the primary energy supply system would be diversified compared to the base scenario.     

The analysis of CO2 emission reduction using an ExSS model of Guangdong province in China

This paper studied the CO₂ emission scenarios of Guangdong province in 2020 and divided the CO₂ emission increment and reductions into various departments and driving factors. Based on the Extended Snapshot model, two CO₂ emission scenarios, Business as Usual (BaU) and Counter Measure (CM) scenario were constructed. CM scenario was completed by using reduction technical measures to achieve the reduction emission goal. The results showed that the amount of CO₂ emission is less 189 million tonne in 2020 CM scenario than BaU scenario. By decomposing the emission reduction measures in CM scenario, it showed that the main means to reduce CO₂ emissions were the industrial structure adjustment, the advanced energy efficiency and the power sector structure adjustment, and the emission reduction contribution rates were 36.85%, 34.55% and 21.74%, respectively. The analysis results could be recommended to the government to make the low-carbon development policy and path.     

The impact of coal consumption and CO2 emission on economic growth

This study examined the long-run and the causal relationship between total coal consumption, CO₂ emission, and GDP growth in China, the United States, India, Germany, Russia, South Africa, Japan, Australia, Poland, and South Korea. The panel model was employed during the period 1992–2009. The results showed that total coal consumption and CO₂ emission have a long-run relationship with the GDP growth. In addition, there was a short-run positive bidirectional causal relationship between total coal consumption and CO₂ emission. However, total coal consumption and CO₂ emission have no short-run or long-run causal relationship with GDP growth. Thus energy conservation policies on total coal consumption such as rationing energy consumption and controlling CO₂ emissions are likely to have no negative impact on the real output growth of the investigated countries.     

CO2 emission trading within the European Union and Annex B countries: the cement industry case

The cement industry is the third largest carbon emitting industrial sector in the EU. This article presents the foreseeable technological evolution of the cement industry under business as usual circumstances, and examines the effects on the sector of carbon trading. For those purposes a global dynamic simulation model of the cement industry (CEMSIM) has been developed. The model is composed of a series of interconnected modules on cement consumption and production, international trade and capacity planning. This study quantifies the benefits achieved from emission trading in different markets (EU15, EU27 and Annex B), derived both from the revenues of emission trading, and from the lower compliance costs. The magnitude of the potential carbon leakage effect is also assessed.     

Accounting for energy-related CO2 emission in China, 1991–2006

As the country with the second largest emitter of energy-related CO₂ gas, China experienced a dramatic decline in CO₂ emission intensity from 1991 to 2000, but since then the rate of decline slowed and CO₂ emission intensity actually increased in 2003. In this paper, the complete decomposition method developed by Sun is used to analyze the nature of the factors that influence the changes in energy-related CO₂ emission and CO₂ emission intensity during the period 1991–2006. We find that: (1) energy intensity effect is confirmed as the dominant contributor to the decline in CO₂ emission and CO₂ emission intensity, (2) economic activity effect is the most important contributor to increased CO₂ emission, and (3) economic structure and CO₂ emission coefficient effects are found to contribute little to the changes in CO₂ emission and CO₂ emission intensity, which actually increased CO₂ emission and CO₂ emission intensity over the period 1991–2006 except for several years.     

The forecast of motor vehicle,energy demand and CO2 emission from Taiwan's road transportation sector

The grey forecasting model, GM(1,1) was adopted in this study to capture the development trends of the number of motor vehicles, vehicular energy consumption and CO₂ emissions in Taiwan during 2007–2025. In addition, the simulation of different economic development scenarios were explored by modifying the value of the development coefficient, a, in the grey forecasting model to reflect the influence of economic growth and to be a helpful reference for realizing traffic CO₂ reduction potential and setting CO₂ mitigation strategies for Taiwan. Results showed that the vehicle fleet, energy demand and CO₂ emitted by the road transportation system continued to rise at the annual growth rates of 3.64%, 3.25% and 3.23% over the next 18 years. Besides, the simulation of different economic development scenarios revealed that the lower and upper bound values of allowable vehicles in 2025 are 30.2 and 36.3 million vehicles, respectively, with the traffic fuel consumption lies between 25.8 million kiloliters to 31.0 million kiloliters. The corresponding emission of CO₂ will be between 61.1 and 73.4 million metric tons in the low- and high-scenario profiles.     

Methodology for assessing emission reduction of truck-only toll lanes

The emissions of carbon dioxide (CO₂), the largest component of greenhouse gases (GHG) emissions, emitted from heavy trucks is second only to passenger cars in terms of GHG emissions from the transportation sector. Truck-only toll (TOT) lanes have been proposed in several cities as a means of improving truck flows and reducing freeway congestion. This paper describes an analysis that utilized the US EPA's MOBILE6.2 vehicle emissions modeling software to identify freeway locations with large pollutant emissions and estimated the changes in emission associated with TOT lanes. Emissions including hydrocarbon (HC), carbon monoxide (CO), nitrogen oxide (NO_x), and CO₂ were estimated by multiplying vehicle kilometers traveled by emission factors associated with various vehicle types and average speeds. The CO₂ calculation was limited due to lack of sensitivity in the model of speed variation, which is one of the benefits of the implementation of TOT lanes. Mechanical equations of engine horsepower involving the change in vehicle speeds is applied to estimate the change in CO₂ fuel consumption and then converted to estimate the change in CO₂ emissions. The results show that voluntary and mandatory use of TOT lanes would reduce total CO₂ emissions on all freeway lanes by 62% and 60%.     

Oil consumption, CO2 emission and economic growth in MENA countries

This study examines the impact of oil consumption on the economic growth of the MENA countries during the period 1980–2009. The panel model is employed in this study. Based on the cointegration test results, it was found that CO₂ emission, and oil consumption has a long run relationship with economic growth. Moreover, there is also a bi-directional Granger causality between oil consumption, CO₂ emission and economic growth in both the short run and the long run. The results of this study show clearly that oil consumption plays an important role in the economic growth of the MENA countries.     

Intake charge dilution effects on control of nitric oxide emission in a hydrogen fueled SI engine

Though hydrogen fueled spark ignition engine can operate at high thermal efficiency with almost zero emission of HC and CO, the high level of _NOx${\mathrm{NO}}_x$ poses problems. The high combustion temperature and lean mixtures used are the reasons. In this work, the effect of _N2${\mathrm{N}}_2$, _CO2${\mathrm{CO}}_2$ and hot EGR gas as diluents in the intake charge to suppress NO emission in a manifold injected hydrogen fueled SI engine was studied. Nitrogen as a diluent is not so effective at low loads while inducting smaller amounts, but very effective at higher loads where the mixture becomes richer and the dilution effect (oxygen depletion) is significant. On other hand, carbon dioxide is a good diluent with relatively better thermal effect and diluent effect and effectively controls NO emission at all output regions. However this is at the expense of thermal efficiency. Recirculating hot exhaust gas which contains both _N2${\mathrm{N}}_2$ and steam comes in between _N2${\mathrm{N}}_2$ and _CO2${\mathrm{CO}}_2$ in terms of its effectiveness. On the whole _N2${\mathrm{N}}_2$ is the most effective as it has minimum impact on thermal efficiency for a given level of permissible NO emission. Thus it is felt that cold EGR could be a good option. In all cases, a good control system is necessary to supply correct quantity of diluent.     

Energy and environmental implications of carbon emission reduction targets: Case of Kathmandu Valley,Nepal

This paper analyzes the sectoral energy consumption pattern and emissions of CO₂ and local air pollutants in the Kathmandu Valley, Nepal. It also discusses the evolution of energy service demands, structure of energy supply system and emissions from various sectors under the base case scenario during 2005–2050. A long term energy system planning model of the Kathmandu Valley based on the MARKet ALlocation (MARKAL) framework is used for the analyses. Furthermore, the paper analyzes the least cost options to achieve CO₂ emission reduction targets of 10%, 20% and 30% below the cumulative emission level in the base case and also discusses their implications for total cost, technology-mix, energy-mix and local pollutant emissions. The paper shows that a major switch in energy use pattern from oil and gas to electricity would be needed in the Valley to achieve the cumulative CO₂ emission reduction target of 30% (ER30). Further, the share of electricity in the cumulative energy consumption of the transport sector would increase from 12% in the base case to 24% in the ER30 case.     

Modeling Wyoming's Carbon Dioxide Pipeline Network

Abstract

A model of Wyoming's carbon dioxide pipeline network has been developed and used to analyze its capacity. The inlet to this pipeline is at Exxon Mobil's Shute Creek gas processing plant, and supercritical gas is then sent to Rangeley (Colorado), Rock Springs, Monell, Baroil and Salt Creek (all in Wyoming) fields. Along the way, the supercritical gas is cooled to a liquid. Here it is shown that the pipeline could easily accommodate a rate increase from the current 250 MMSCFD to 325 MMSCFD, utilizing the gas that is currently being vented from the Shute Creek intermediate separator, while maintaining the current inlet temperature and pressure. If new CO₂ supplies became available it would be possible to increase the carbon dioxide throughput from 250 MMSCFD to 600 MMSCFD while extending the pipeline to other oilfields such as Beaver Creek and Hartzog Draw. In certain circumstances, this high rate may produce output pressures below the required miscibility pressures and also produce phase changes in the pipeline. However, this could be easily remedied by adding relatively modest horsepower pumps at intermediate pipeline locations.     

Japanese potential of CO2 sequestration in coal seams

As a reduction strategy for global warming by green-house gases underground storage or sequestration of CO₂ into coal beds or seams has been studied by the Japanese government and some associated organizations.     

The impact of lifestyle on energy use and CO2 emission: An empirical analysis of China's residents

Based on the application of a Consumer Lifestyle Approach (CLA), this paper quantifies the direct and indirect impact of lifestyle of urban and rural residents on China's energy use and the related CO₂ emissions during the period 1999–2002. The results show that approximately 26 per cent of total energy consumption and 30 per cent of CO₂ emission every year are a consequence of residents’ lifestyles, and the economic activities to support these demands. For urban residents the indirect impact on energy consumption is 2.44 times greater than the direct impact. Residence; home energy use; food; and education, cultural and recreation services are the most energy-intensive and carbon-emission-intensive activities. For rural residents, the direct impact on energy consumption is 1.86 times that of the indirect, and home energy use; food; education, and cultural recreation services; and personal travel are the most energy-intensive and carbon-emission-intensive activities. This paper provides quantitative evidence for energy conservation and environmental protection focused policies. China's security for energy supply is singled out as a serious issue for government policy-makers, and we suggest that government should harmonize the relationships between stakeholders to determine rational strategies.     

Electricity consumption,CO2 emission,and economic growth in the Middle East

This study examines the impact of electricity consumption on the economic growth in the Middle East countries during the period 1990–2008. The panel model is used in this study. Based on the cointegration test results, it is found that CO₂ emission and electricity consumption have a long-run relationship with economic growth. Moreover, there is also a bi-directional Granger causality between electricity consumption, CO₂ emission, and economic growth in both the short run and the long run. The results of this study show clearly that electricity consumption plays an important role in the economic growth of the Middle East countries.     

Development of a scalable infrastructure model for planning electricity generation and CO2 mitigation strategies under mandated reduction of GHG emission

In a power-generation system, power plants as major CO₂ sources may be widely separated, so they must be connected into a comprehensive network to manage both electricity and CO₂ simultaneously and efficiently. In this study, a scalable infrastructure model is developed for planning electricity generation and CO₂ mitigation (EGCM) strategies under the mandated reduction of GHG emission. The EGCM infrastructure model is applied to case studies of Korean energy and CO₂ scenarios in 2020; these cases consider combinations of prices of carbon credit and total electricity demand fulfilled by combustion power plants. The results highlight the importance of systematic planning for a scalable infrastructure by examining the sensitivity of the EGCM infrastructure. The results will be useful both to help decision makers establish a power-generation plan, and to identify appropriate strategies to respond to climate change.     

Estimation of the potential for reduced greenhouse gas emission in North-East Russia: A comparison of energy use in mining,mineral processing and residential heating in Kiruna and Kirovsk-Apatity

The energy demand at Murmansk Oblast in North-East Russia is covered at 60% by fossil fuels and at 40% by electricity. This study estimates the potential for reduction of fossil fuel consumption and CO₂-emissions at Murmansk Oblast. The study focus on the municipalities of Apatity and Kirovsk and the apatite ore mining company Apatit JSC . The potential for energy efficiency, reduced fossil fuel consumption and greenhouse gas emissions is estimated by comparison with the of city Kiruna in Northern Sweden, with a climate similar to that of North-East Russia, and with the iron ore mining company LKAB. This study shows that the potential for reduced CO₂-emissions is about 630,700 tons CO₂ annually in the municipalities of Apatity and Kirovsk or 6.3 tons of CO₂ per capita, Apatit JSC not included. These results applied on Murmansk Oblast gives a potential for reduced CO₂-emissions of about 6 Mtons annually in the municipalities together. The specific energy consumption at Apatit JSC is 6–7 times per ton product compared to LKAB. The mining has 4 times higher specific energy consumption per ton raw ore compared to LKAB.