Energy efficiency and environmental impact of biogas utilization in landfills

This study investigates the utilization of landfill biogas as a fuel for electrical power generation. Landfills can be regarded as conversion biogas plants to electricity, not only covering internal consumptions of the facility but contributing in the power grid as well. A landfill gas plant consists of a recovery and a production system. The recovery of landfill gas is an area of vital interest since it combines both alternative energy production and reduction of environmental impact through reduction of methane and carbon dioxide, two of the main greenhouse gases emissions. This study follows two main objectives. First, to determine whether active extraction of landfill gas in the examined municipal solid waste sites would produce adequate electric power for utilisation and grid connection and second, to estimate the reduction of sequential greenhouse gases emissions. However, in order to optimize the designing of a plant fed by biogas, it is necessary to quantify biogas production over several years. The investigation results of energy efficiency and environmental impact of biogas utilization in landfills are considering satisfactory enough both in electric energy production and in contribution to greenhouse gases mitigation.     

Determinants of the increased CO<Subscript>2</Subscript> emission and adaption strategy in Chinese energy-intensive industry

Climate change has not only brought about many natural hazards but also threaten the sustainable development of industry. This study is to investigate the adaptive implications for energy-intensive industries of China in response to climate change impacts. For this purpose, a deep and comprehensive analysis on the change of CO₂ emission for 6 energy-intensive sectors is explored over the period of 2000–2007. A Log-Mean Divisia Index based on time series is also introduced in our study to identify the key factors toward the change of CO₂ emission. It is shown that there were 146.1 million metric tons carbon increased in energy-intensive industries from 2000 to 2007. And the excessive growth of industrial output and increasingly fossil-intensive energy consumption structure were the main driving forces for the increased CO₂ emission. Nevertheless, energy intensity change and declining emission coefficient of electricity played negative role in the growing trend of CO₂ emission. On the basis of these four determinants (namely industrial output, energy intensity, fuel mix effect, and emission coefficient), it is suggested that both economic motives and technologically feasible approaches should be implemented to control the scale of excessive productions and improve energy efficiency toward the energy-intensive industries. And more importantly, strengthening energy-intensive sectors’ awareness of climate change adaptation should be given stronger emphasis as long-term work with the help of some propaganda campaigns for instance.     

Assessment of greenhouse gas emissions from coal and natural gas thermal power plants using life cycle approach

The importance of mitigation of climate change due to greenhouse gas (GHG) emissions from various developmental and infrastructure projects has generated interest at global level to reduce environmental impacts. Life cycle assessment may be used as a tool to assess GHG emissions and subsequent environmental impacts resulting from electricity generation from thermal power plants. This study uses life cycle approach for assessing GHG emissions and their impacts due to natural gas combined cycle (NGCC) and imported coal thermal power plants using the IPCC 2001 and Eco-Indicator 99(H) methods in India for the first time. The total GHG emission from the NGCC thermal power plant was 584 g CO₂ eq/kWh electricity generation, whereas in case of imported coal, it was 1,127 g CO₂ eq/kWh electricity generation. This shows that imported coal has nearly ~2 times more impacts when compared to natural gas in terms of global warming potential and human health as disability-adjusted life years from climate change due to GHG emissions such as carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O).     

Feasibility study of CO2 geological storage in China

It has been proved to be one effective means to reduce emissions of CO2 to mitigate the worsening global climate change through lots of projects and tests about CO2 geological storage. The sites that are suitable for CO2 geological storage include coal seams that can not be mined, deep saline aquifers, oil fields, and depleted gas fields. The emission of CO2 from fuel combustion is about 3.54 Gt in China in 2003, which is the second biggest in the world. Because the energy consumption in China mainly depends on fossil fuels for a long time in the future, China will become a country with the biggest emission of CO2 in the world, which will make China have to reduce the emissions of CO2 by some methods including geological storage. Based on lots of information about the reserves of coal seam methane and the rank of coal in the 68 coal basins in China, the total CO2 storage capacity in these coal basins was estimated according to the recovery coefficient and exchange ratio of CO2 to CHa.The total storage capacity in deep saline aquifers can be regarded as the total quantity of CO2 that can be dissolved in the saline aquifers at the depth from 1000m to 3000m under ground. The quantity can be estimated by multiplying the solubility of CO2 in the saline water and the volume of the appropriate aquifers. According to the reserve and quality of crude oil in 46 main oil basins in China, the CO2 storage capacity and the quantity of enhanced oil were calculated. The storage capacity of depleted gas fields can be derived from the reserve and depth of the gas fields. The total CO2 geological storage capacity is about 196.2 Gt CO2 that is as against 55.4 times the CO2 emission from fuel combustion in China in 2003. According to the results of the finished projects and tests about CO2-EOR and CO2-ECBM, the CO2 geological storage capacities in coal seams, deep saline aquifers, oil fields and depleted gas fields will be estimated.     

Implementation of green productivity management in airline industry

Compilation and implementation of green productivity mechanism in each governmental and nongovernmental organization has several environmental, social and economic achievements.In this paper for management of green productivity in Iran Aseman Airline Company current situation are analyzed such as the consumption of energy, water, airplanes fuel and evaluating environmental pollutants. At the end of this study some applicable techniques for increasing the productivity and consideration of environmental aspects in this company are recommended. Maximum water consumption had been 7500 m3 in the year 2005 during August until September, the maximum of electricity consumption was 759300 kWh in the year 2004 during July until August, the maximum of natural gas consumption had been 83647 m³ in the year 2004 during Feb until March, Also averages of 661500 L of fuel were consumed in this company’s vehicles yearly and in the last nine month of the year 2005, amount of 60263155 liters of airplane fuel has been consumed.     

苏南地区温室气体CO2地质处置的探讨

化石能源是现代工业飞速发展的重要保障。但从工业革命以来,无节制的能源消耗导致越来越多的温室气体被排入大气,带来了一系列的环境问题,全球气候变暖就是其中最严重的问题。业已觉悟的国际社会,已经认识到问题的严重性,并开始行动起来,其中二氧化碳(CO₂)的回收及安全处置就是一项减缓大气变暖的重大工程。针对全球温室气体减排的压力,详细分析了CO₂的地质处置机制与措施,并探讨了工业发达的苏南地区进行CO₂地质处置的方式,认为存在苏北油田注CO₂增产、句容盆地深层盐水层或贫油气储层的CO₂地质处置和薄煤层CO₂吸附处置等3种方式,提出句容盆地将是未来苏南地区进行CO₂地质处置的重要场所,同时认为进行CO₂地质处置存在巨大的商机。     

中国的温室气体排放、减排措施与对策*

根据《中华人民共和国气候变化初始国家信息通报》,1994年中国温室气体排放总量约为3650×10⁶t的CO₂当量,其中CO₂,CH₄和N₂O分别占73.1 ％ ,19.7 ％ 和7.2 ％ 。CO₂排放主要来自能源活动,CH₄排放主要来自农业活动和能源活动,N₂O排放主要来自农业活动。在过去的20余年里,中国为减缓全球温室气体排放的增长速度做出了重要的贡献。对文献资料和大量研究结果的分析表明,中国可通过采取相关措施和制订相应政策进一步减少温室气体的排放。减少CO₂排放的主要措施和对策包括:调整能源结构(降低煤炭消费比例、适度提高天然气比例和发展核能);提高能源生产、转化、分配和使用过程中的效率;开发利用水能、风能、太阳能和生物能等可再生能源;通过植树造林,推广秸秆还田、平衡施肥和少(免)耕等增加陆地生态系统的碳吸收。减少CH₄排放的主要措施和对策包括:回收利用煤层气;改造生活垃圾填埋场地和筛选环境适应性强的CH₄氧化菌并接种于填埋场;改善反刍动物的营养成分;稻田合理灌溉、提高水稻的收获指数、选育和种植CH₄排放低的水稻品种等。减少农田N₂O排放的主要措施和对策包括:提高氮肥利用率;推广施用长效肥和控释肥;施用生物抑制剂和实施微生物工程等。     

Hydrogen from coal: Production and utilisation technologies

Although coal may be viewed as a dirty fuel due to its high greenhouse emissions when combusted, a strong case can be made for coal to be a major world source of clean H₂ energy. Apart from the fact that resources of coal will outlast oil and natural gas by centuries, there is a shift towards developing environmentally benign coal technologies, which can lead to high energy conversion efficiencies and low air pollution emissions as compared to conventional coal fired power generation plant. There are currently several world research and industrial development projects in the areas of Integrated Gasification Combined Cycles (IGCC) and Integrated Gasification Fuel Cell (IGFC) systems. In such systems, there is a need to integrate complex unit operations including gasifiers, gas separation and cleaning units, water gas shift reactors, turbines, heat exchangers, steam generators and fuel cells. IGFC systems tested in the USA, Europe and Japan employing gasifiers (Texaco, Lurgi and Eagle) and fuel cells have resulted in energy conversions at efficiency of 47.5% (HHV) which is much higher than the 30–35% efficiency of conventional coal fired power generation. Solid oxide fuel cells (SOFC) and molten carbonate fuel cells (MCFC) are the front runners in energy production from coal gases. These fuel cells can operate at high temperatures and are robust to gas poisoning impurities. IGCC and IGFC technologies are expensive and currently economically uncompetitive as compared to established and mature power generation technology. However, further efficiency and technology improvements coupled with world pressures on limitation of greenhouse gases and other gaseous pollutants could make IGCC/IGFC technically and economically viable for hydrogen production and utilisation in clean and environmentally benign energy systems.     

Life Cycle Assessment of Energy Balance and Emissions of a Wind Energy Plant

Life cycle analysis (LCA) methodology was used to perform a quantitative, comparative analysis and rating of the construction and operation of a wind energy plant. For this case study, the Glacier Hills Wind Park (90 1.8-MW turbines in south-central Wisconsin) was evaluated. Significant environmental and economic benefits are often advertised with the installation of new wind energy facilities, although independent and comprehensive LCA and sustainable energy science are typically not implemented. Hence, a quantitative demonstration with LCA methodology of the life cycle emissions and environmental impact, from construction through operations, can greatly assist in highlighting significant areas of energy consumption and emissions during manufacturing, transportation, and construction of a wind farm. Results portray the amount of greenhouse gas emissions and energy consumption/generation over the life cycle of the wind park. Transportation of large components from overseas led to the consumption of considerable quantities of fossil fuel, responsible for up to 22 % of the total greenhouse gas emissions due to transportation. The energy payback ratio (25.5), energy payback time (12.3 months) and the total grams of equivalent CO_2(eq) per kWh of energy (16.9) produced were calculated over the life time of this onshore wind farm.     

Anaerobic co-digestion of sewage and brewery sludge for biogas production and land application

In Thailand, sewage sludge production from the Bangkok metropolitan area can reach up to 63,000 ton/y by 2010. The Beer-Thai Company, Thailand, produces beer and generates lots of sludge as waste. Sewage sludge and brewery sludge can be used to generate energy which could be saved on the fossil fuels conventionally used as a source of energy. The possibility was explored to mix brewery sludge with sewage sludge at different mixing ratios for anaerobic digestion so that the energy can be generated as biogas and at the same time, digested sewage sludge can be used as fertilizer for agricultural applications. A batch anaerobic reactor under mesophilic condition for a digestion period of 40 days was used in the laboratory. The acrylic reactor was cylindrical with a working weight of 12 kg. The diameter was 23.7 cm and the height was 34.5 cm. Sludge mixtures at different ratios were fed into the reactors and the optimum mixing ratio was determined. Experimental results showed that the sludge mixture at ratio of 25:75 % by weight (sewage:brewery) yielded higher biogas production. A reduction in heavy metals and pathogens was observed at this ratio after the digestion indicating its safe use as fertilizer. Nitrogen content was about 4.95 % which is well above the commercial fertilizers. At optimum mixing ratio of 25:75, the amount of the generated biogas is 1.15×10⁶ m³/y. This large amount of biogas is equivalent to 1.44 million kWh/y of electricity, 561,000 L/y of diesel oil and 936,000 L/y of vehicle gasoline.     

水利工程对岩溶水体碳循环的影响

为认识水利工程建设对岩溶库区温室气体排放的影响,本文对岩溶区水利工程破坏岩溶水体DIC的稳定性、增加温室气体排放以及水利工程建设所带来的水体富营养化问题进行了初步总结。结果表明,水利工程不仅打破了岩溶水体DIC的自身稳定性,加速水体无机CO2逸出过程,导致CaCO3发生沉淀,而且还通过改变岩溶水动力条件、加速温室气体排放等途径来提高岩溶水体的碳储存、转移、形成与分解过程。与此同时作者还建议:(1)尽快开展岩溶水体温室气体排放的定性分析与定量计算工作,并与不同排放源的温室气体释放效应进行对比;(2)温室气体排放的估算须建立在岩溶碳循环研究基础上,从时间和空间尺度上分析影响岩溶水体温室气体排放过程的关键因素,并把岩溶水体温室气体排放纳入整个岩溶生态系统的生命周期中进行考虑。      

Potentiel des méthodes de séparation et stockage du CO2 dans la lutte contre l'effet de serre

Increasing atmospheric level of greenhouse gases are causing global warming and putting at risk the global climate system. The main anthropogenic greenhouse gas is CO₂. Technical solutions exist to reduce CO₂ emission and stabilise atmospheric CO₂ concentration, including energy saving and energy efficiency, switch to lower carbon content fuels like natural gas and to energy sources that operate with zero CO₂ emissions such as renewable or nuclear energy, enhance the natural sinks for CO₂ (forests, soils, etc.), and last but not least, sequester CO₂ from fossil fuels combustion. The purpose of this paper is to provide an overview of the technology and cost for capture and storage of CO₂. Some of the factors that will influence application, including environmental impact, cost and efficiency, are also discussed. Capturing CO₂ and storing it in underground geological reservoirs appears as the best environmentally acceptable option. It can be done with existing technology; however, substantial R&D is needed to improve available technology and to lower the cost. Applicable to large CO₂ emitting industrial facilities such as power plants, cement factories, steel industry, etc., which amount to more than 30% of the global anthropogenic CO₂ emission, it represents a valuable tool in the battle against global warming. To cite this article: P. Jean-Baptiste, R. Ducroux, C. R. Geoscience 335 (2003).     

A study on carbon dioxide emissions from bituminous coal in Korea

Consumption of primary energy in Korea increased 5.25 % per year over a 10 years span starting in 1990. Korea ranked 8th in primary energy consumption in 2011; coal consumption increased 35 % from 87,827 million tons in 2006–119,321 tons in 2010. Heavy energy-consuming countries consistently conduct research to develop an emission factor of Tier 2 level, reflecting the characteristics of the fuel that they use. To calculate the emission factor of bituminous coal for fuel, this study developed emission factor and calculated emission amount by implementing fuel analysis on bituminous coal consumed in Korea between 2007 and 2009. CO₂ emission factor calculated by fuel analysis method is 95,315 kg/TJ, which is 0.75 % higher than the default value suggested by IPCC. The emission amount calculated by using the CO₂ emission factor in this study is 231.881 million tons, which has a difference of 1.739 million tons compared to the IPCC default value.     

Strategies for addressing climate change on the industrial level: affecting factors to CO<Subscript>2</Subscript> emissions of energy-intensive industries in China

This paper explores China’s strategies for addressing climate change on the industrial level. Focusing on six energy-intensive industries, this paper applies gray relational analysis theory to the affecting factors to CO₂ emissions of each industry after calculating each industry’s CO₂ emissions during 2001–2010. Further research based on GM(1, 1) model is conducted to forecast the trend of the factors, the energy consumption and each industry’s CO₂ emissions during the 12th Five-Year Plan period. As a breakthrough in previous conclusions, energy consumption structure was divided into the respective proportion of coal, oil, natural gas and electricity in the primary energy consumption, with which industrial output and energy intensity are combined to analyze each of their impacts on the energy-intensive industries. It turns out that all the factors’ impacts on emissions of the six major energy-intensive industries are significant, despite their differentiated extents. It is worth noting that, contrary to previous findings, industrial output is not the leading affecting factor to CO₂ emissions of the energy-intensive industries compared with the proportion of coal and electricity in the primary energy consumption. The GM(1, 1) forecast results of energy consumption and CO₂ emissions by the end of 2015 show that coal and electricity will remain a large proportion in primary energy consumption. This research may shed some light on China’s adjustment of energy structure under the pressure of addressing climate change and hence provide decision support for the acceleration of renewable energy utilization in the industrial departments.     

Measuring global energy-related sulfur oxides emissions embodied in trade: a multi-regional and multi-sectoral analysis

Sulfur oxides (SO_X) emissions embodied in trade (SEET) may play an important role in affecting national responsibilities toward pollutant emission reduction within the context of global greenhouse gas emission policy. This paper analyzes the change of the SEET associated with energy consumption from the perspective of a country and a sector between 1995 and 2011, exploring the evolution characteristic of the sources and flows of the SEET for 39 countries, as well as measuring the production-based and consumption-based global SO_X emissions’ inventory and investigating the impact of international trade on the allocation of national pollutant emissions’ reduction obligations. One important finding is that the volume of SO_X emissions embodied in global trade increased dramatically from 1995 to 2011, and the global SO_X emissions stemming from anthropogenic energy consumption are mostly from China and the USA. Another important finding is that, referring to specific sectors, whether seen from the total SEET or from the sources of SEET or from the total SO_X emissions occurring from economic consumption and production, energy sectors, like electricity, gas, and water supply and coke, refined petroleum, and nuclear fuel, are the main contributors to the increase in the global SO_X emissions. Notably, however, our results show that the sector of agriculture, hunting, forestry, and fishing should be allocated more SO_X emission reduction responsibilities under a consumption-based emissions’ accounting inventory.

     

对我国油气资源潜力与对策的思考

随着中国经济的高速发展,油气资源的消费量逐年增加,我国现已成为世界上第二位石油消费大国,石油对外依存度高达40%,石油资源储量和生产量很难保证现代化需求.因此,21世纪我国挖掘油气资源潜力的对策是:必须采取大力开发天然气生产业,开拓国际原油市场,分享世界石油资源,扩大老油田的资源与提高能源效率并重的方针.     

准噶尔盆地西北缘克百地区天然气成因与潜力分析

通过准噶尔盆地西北缘克拉玛依-百口泉百地区天然气赋存特征、组成、类型与来源的分析,明确了佳木河组与石 炭系烃源岩对气藏气的贡献,指出应加强烃源岩地质与地化特征、成气潜力的研究。天然气既有原油溶解气,也有较纯的 气藏气。原油溶解气在二叠系和中生界油藏中均有分布,来源于风城组烃源岩,与原油同源同期运移聚集而成,属于油型 气。气藏气主要分布在五八区的佳木河组和直接覆盖于佳木河组之上的上乌尔禾组,为佳木河组烃源岩高成熟阶段以独立 气相运移聚集成藏的天然气,属于煤型气,佳木河组气源岩对佳木河组内部及其上覆紧邻地层气藏的分布有重要控制作用。 石炭系烃源岩对深部位煤型气有贡献。已发现气藏的构造下倾部位或更深部位应该有一定的天然气勘探潜力,是下一步的 重要勘探方向。     

Optimized scheduling for electric lift trucks in a sugarcane agro-industry based on thermal,biomass and solar resources

Resource scheduling for both cost and pollution minimization in the power system is so crucial. To reduce the greenhouse gas emission, employing renewable energy resources, especially solar and wind energy, and beside them plug-in hybrid electric vehicles are effective solutions. In industrial factories, using biomass resources for power generation is both economic and environmental approach. In sugarcane company, bagasse is plant fiber residue which is used as fuel. Electric lift trucks, capable of being connected to power grid, could decrease the pollution in industrial transportations. In this paper, scheduling problem for a large-scale sugarcane factory including solar resources, a thermal unit, and electric lift trucks is presented and solved by CPLEX solver in GAMS software. In order to consider uncertainties, different scenarios are noticed. To contribute better understanding of optimization problem, cost, pollution, and charging regime of electric lift trucks are carefully analyzed. The results show that implementation of the biomass electric power generation is effective for reducing cost and amount of emission.     

Alternative refrigerants in vapour compression refrigeration cycle for sustainable environment: a review of recent research

Vapour compression refrigeration is used in almost 80 % of the refrigeration industries in the world for refrigeration, heating, ventilating and air conditioning. The high-grade energy consumption of these devices is very high and the working substance creates environmental problems due to environmental unfriendly refrigerants such as chloroflurocarbons, hydrochloroflurocarbons and hydroflurocarbons. Heating, ventilating, air conditioning and refrigeration industries are searching for ways to increase performance, durability of equipments and energy efficiency in a sustainable way while reducing the cost of manufacturing. With the present refrigerants, environmental problems such as ozone layer depletion, global warming potential, green house gases and carbon emission are increasing day by day. In this paper, the popular refrigerant is thoroughly studied experimentally and recommendations are given for alternatives such as carbon dioxide, ammonia and hydrocarbons and new artificially created fluid, Hydro-Fluoro-Olefin 1234yf by DuPont and Honeywell which exhibit good thermo-physical and environmental properties and will be commercialized in the near future.     

减缓全球变暖与温室气体吸收汇研究进展

对减缓全球气候变化与温室气体“汇”的最新研究进展作了较为详尽的综述。针对目前温室气体汇研究中的主要前沿科学问题进行了深入分析：包括汇的定义、种类及方法学问题,土地利用变化和森林以及农业土壤汇的种类及计算中存在的一些问题,人类活动对自然生态系统源汇状况的影响等;对还估算各种温室气体源汇的不确定性作了分析总结;在列举了一些气候变化框架公约缔约国及发展中国家对《京都议定书》中引入温室气体“汇”的看法及态