Energy return on investment, energy payback time, and greenhouse gas emissions of coal seam gas(CSG) production in China: a case of the Fanzhuang CSG project

The studies and development of coal seam gas（CSG） have been conducted for more than 30 years in China, but few of China＇s CSG projects have achieved large-scale commercial success; faced with the boom of shale gas, some investors are beginning to lose patience and confidence in CSG. China currently faces the following question： Should the government continue to vigorously support the development of the CSG industry？ To provide a reference for policy makers and investors, this paper calculates the EROI_（stnd）[a standardized energy return on investment（EROI） method], EROI_（ide）（the maximum theoretical EROI）, EROI_（3,i）（EROI considering the energy investment in transport）, and EROI_（3,1＋e）（EROI with environmental inputs） of a single vertical CSG well in the Fanzhuang CSG project in the Qinshui Basin. The energy payback time（EPT） and the greenhouse gas（GHG） emissions of the CSG systems are also calculated. The results show that over a 15-year lifetime, EROI_（stnd）, EROI_（ide）, EROI_（3,1）, and EROI_（3,1＋e）are expected to deliver EROIs of approximately11：1, 20：1, 7：1, and 6：1, respectively. The EPT within different boundaries is no more than 2 years, and the life-cycle GHG emissions are approximately 18.8 million kg CO_2 equivalent. The relatively high EROI and short EPT indicate that the government should take more positive measures to promote the development of the CSG industry.

Evaluation of the Effect of Agricultural Management on Energy Yield and Greenhouse Gas Emission Reduction of Bioenergy Production Chains

The role of energy crops in reducing fossil energy use and greenhouse gas emission is much debated. To improve decision making on the use of crops for producing bioenergy, a tool (Energy Crop Simulation Model or E-CROP) has been developed to calculate 1) sustainable crop dry matter yield levels as function of agricultural inputs, and 2) gross and net energy yield and greenhouse gas emission reduction, covering the entire bioenergy production chain from sowing to distribution of bioenergy. E-CROP can be applied to a wide range of crops, soils, climatic conditions, management choices, and conversion technologies. This paper describes E-CROP and focuses on its application on four arable crops, as cultivated on two contrasting sites in the Netherlands (potato and sugar beet for bioethanol, winter oilseed rape for biodiesel and silage maize for bioelectricity) and on the effect of crop management (viz. irrigation and nitrogen fertilisation). In all situations, gross energy output exceeded total energy input. Calculated for an average situation, net energy yield ranged from 45 to 140 GJ.ha-1. Lowering irrigation and/or fertilisation input levels generally resulted in a reduction of net energy yields. The net reduction of greenhouse gas emissions in the average situation ranged from 0.60 to 6.5 t CO2-eq.ha-1. In general, N2O emission from nitrogen fertiliser caused large variations in the net reduction of greenhouse gas emission, which even became negative in some situations. Lowering nitrogen fertilisation to levels that are suboptimal for net energy yields enhanced the net reduction in greenhouse gas emission, implicating that both goals cannot be optimised simultaneously. Agricultural knowledge is important for optimising the outputs of bioenergy production chains.

Energy Emissions Profile and Floating Solar Mitigation Potential for a Malaysia’s State

The establishment of the National Low Carbon City Master Plan(NLCCM)by Malaysia’s government presents a significant opportunity to minimize carbon emissions at the subnational or local scales,while simultaneously fostering remarkable economic potential.However,the lack of data management and understanding of emissions at the subnational level are hindering effective climate policies and planning to achieve the nationally determined contribution and carbon neutrality goal.There is an urgent need for a subnational emission inventory to understand and manage subnational emissions,particularly that of the energy sector which contribute the biggest to Malaysia’s emission.This research aims to estimate carbon emissions for Selangor state in accordance with the Global Protocol for Community-Scale Greenhouse Gas Emission Inventories(GPC),for stationary energy activities.The study also evaluates the mitigation potential of Floating Solar Photovoltaic(FSPV)proposed for Selangor.It was found that the total stationary energy emission for Selangor for the year 2019 was 18,070.16 ktCO2e,contributed the most by the Manufacturing sub-sector(40%),followed by the Commercial and Institutional sub-sector;with 82%contribution coming from the Scope 2 emission.The highest sub-sector of Scope 1 emissions was contributed by Manufacturing while Scope 2 emissions from the Commercial and Institutional.Additionally,the highest fuel consumed was natural gas,which amounted to 1404.32 ktCO2e(44%)of total emissions.The FSPV assessment showed the potential generation of 2.213 TWh per year,by only utilizing 10%of the identified available ponds and dams in Selangor,equivalent to an emission reduction of 1726.02 ktCO2e,offsetting 11.6%Scope 2 electricity emission.The results from the study can be used to better evaluate existing policies at the sub-national level,discover mitigation opportunities,and guide the creation of future policies.

Inventory Research of Greenhouse Gas about Energy Sector Activities in Jiangsu Province and Analysis on Relevant Problems

The emission of greenhouse gas generated by energy activity had the maximum influence on total emission. We introduced research content and method of inventory for greenhouse gas generated by energy activity in Jiangsu in 2005 and 2010, and obtained finial results. According to the sum of green gas emission from various parts, greenhouse gas emission of energy activity in Jiangsu occupied 76% -79% of total emission in 2005 and 2010. Meanwhile, the problems encountering in preparation process of inventory were summed and deeply analyzed, such as data ob- taining and processing, inconsistent statistical channel and actual measurement of emission factor. Finally, some suggestions about carrying out provincial greenhouse gas inventory work of energy activity in the future were put forward.

A comprehensive investigation of loading variance influence on fuel consumption and gas emissions in mine haulage operation

The data collected from haul truck payload management systems at various surface mines show that the payload variance is significant and must be considered in analysing the mine productivity, diesel energy consumption, greenhouse gas emissions and associated costs. The aim of this study is to determine the energy and cost saving opportunities for truck haulage operations associated with the payload variance in surface mines. The results indicate that there is a non-linear relationship between the payload variance and the fuel consumption, greenhouse gas emissions and associated costs. A correlation model, which is independent of haul road conditions, has been developed between the payload variance and the cost saving using the data from an Australian surface coal mine. The results of analysis for this particular mine show that a significant saving of fuel and greenhouse gas emissions costs is possible if the standard deviation of payload is reduced from the maximum to minimum value.

Decoupling of greenhouse gas emissions from economic growth in Cameroon

Knowledge of decoupling indicators and its determinants is useful for formulating targeted policy recommendations. To this end, the Log-Mean Divisia Index and Tapio models were applied in this paper to study the decoupling relationship among economic growth and GHG emissions in Cameroon over the period 1971-2014. The analyzes were conducted according to the three major periods that marked Cameroon after independence and the decoupling indicators were broken down into seven factors while considering the three main GHGs emitted in this country (i.e. CO2, CH4, and N2O). The results showed that weak decoupling, strong decoupling, and strong negative decoupling occurred in Cameroon during the periods 1971-1984 and 1994-2014 which represent the periods before and after the economic crisis, respectively. In addition to these three decoupling statuses, recessive decoupling only appeared during the economic crisis period (1984-1994). From 1971 to 1984 and between 1994 and 2014, carbon intensity, economic activity, population, and emission factor not only contributed to the increase of Cameroon’s GHG (particularly CO2) emissions but also prevented decoupling. Unlike the period 1984-1994, energy intensity contributed to reducing environmental pollution while promoting decoupling during the periods 1971-1984 and 1994-2014. Although all played an important role in decoupling, we found that after the introduction of natural gas into the country’s energy mix from 2007, the effect of renewable energies on the mitigation of Cameroon’s CO2 emissions remained higher than the substitution of fossil fuels. However, to develop a cleaner economy, Cameroon should maintain modest economic growth and continuously transform economic development pathways, while encouraging the use of renewable energy to further reduce energy intensity per unit of GDP per capita.

Energy use efficiency and greenhouse gas emissions(GHG)analysis of garlic cultivation in Turkey

This study has been conducted with the purpose of determining energy use efficiency and greenhouse gas emissions of garlic cultivation during the 2020-2021 cultivation season in Adıyaman province of Turkey.Questionnaires,observations and field works were performed in 134 garlic farms in the region through simple random method.In garlic cultivation,energy input was calculated as 32103.20 MJ/hm^(2)and energy output was calculated as 30096 MJ/hm^(2).With regards to the three highest inputs in garlic production,46.66%of the energy inputs consisted of chemical fertilizers energy(14979.26 MJ/hm^(2)),11.29%consisted of farmyard manure energy(3625.71 MJ/hm^(2))and 10.48%consisted of human labour energy(3363.36 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy in garlic cultivation were calculated as 0.94,1.71 MJ/kg,0.59 kg/MJ,and−2007.20 MJ/hm^(2),respectively.The total energy input consumed in garlic cultivation was classified as 27.19%direct energy,72.81%indirect energy,35.17%renewable energy and 64.87%nonrenewable energy.Total GHG emissions and GHG ratio were calculated as 8636.60 kg CO_(2)-eq/hm^(2)and 0.46 kg CO_(2)-eq/kg,respectively.

Effects of Reduced Nitrogen Fertilization and Biochar Application on CO_2 and N_2O Emissions from a Summer Maize-Winter Wheat Rotation Field in North China

This experiment was conducted in Xinxiang, Henan from June 2013 to June 2014. Total four treatments were designed including farmers ’ common practice （F, 250 kg/hm^2）, 80% F （LF, 200 kg/hm^2）, 80% F＋biochar （LFC） and no fertilizer （CK） to measure the dynamic emissions of CO2 and N2O from a summer maize-winter wheat field by static chamber-gas chromatography method. The results showed that the soil CO2 emission was 21.8-1 022.7 mg/（m^2·h）, and was mainly influenced by soil temperature and moisture content. During the growth of summer maize, the soil CO2 emission was more significantly affected by soil moisture con-tent; and in winter wheat growing season, it was more significantly affected by soil temperature in the top 5 cm. The LF and LFC treatments significantly reduced the soil cumulative CO2 emission, especial y during the growth of winter wheat. Fertiliza-tion and irrigation were the main factors influencing the soil N2O emission. The soil N2O emission during the fertilization period accounted for 73.9%-74.5% and 40.5%-43.6% of the soil cumulative N2O emission during the summer maize-and winter wheat-growing season, respectively. The peak of emission fluxes was determined by fertilization amount, while the occurrence time of emission peak and emission re-duction effect were influenced by irrigation. The LF treatment reduced the soil cu-mulative N2O emission by 15.7%-16.8% and 18.1%-18.5% during the growth period of summer maize and winter wheat, respectively. Reduced nitrogen fertilization is an effective way for reducing N2O emission in intensive high-yielding farmland. Under a suitable nitrogen level （200 kg/hm^2）, the application of biochar showed no significant effect on the soil N2O emission in a short term. The N2O emission factors of the L and LF treatments were 0.60% and 0.56%, respectively. ln the intensive high-yield-ing farmland of North China, reducing the nitrogen application amount is an appro-priate measure to mitigate greenhouse gas emissions without crop yield loss.

Determination of energy use efficiency and greenhouse gas emissions in peach production

The purpose of this study was to determine the energy use efficiency and greenhouse gas(GHG)emissions in peach production that took place in Kırklareli province of Turkey during the 2020-2021 production season.This study included calculations of energy input,energy output,energy use efficiency,specific energy,energy productivity,net energy,energy input types,GHG emissions and GHG ratio.Survey,observation and data calculations are related to the 2020-2021 production season.The data obtained from the study were collected from 16 different farms(reachable)through face-to-face surveys with full count method.Energy input and energy output were calculated as 19570.58 MJ/hm^(2) and 19471.94 MJ/hm^(2),respectively.With regards to production inputs,55.70% of the energy inputs consisted of chemical fertilizers energy(10900.03 MJ/hm^(2)),9.46% consisted of chemicals energy(1852.10 MJ/hm^(2)),9.32% consisted of human labour energy(1823.13 MJ/hm^(2)),7.65% consisted of electricity energy(1497.28 MJ/hm^(2)),6.91% consisted of diesel fuel energy(1351.52 MJ/hm^(2)),4.73% consisted of irrigation water energy(926.10 MJ/hm^(2)),3.43% consisted of machinery energy(671.98 MJ/hm^(2)),1.88% consisted of transportation energy(367.72 MJ/hm^(2)),0.88% consisted of farmyard manure energy(171.80 MJ/hm^(2))and 0.05%consisted of lime energy(8.94 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy were calculated as 0.99,1.91 MJ/kg,0.52 kg/MJ and-98.64 MJ/hm^(2),respectively.The consumed total energy input in production was classified as 28.60% direct energy,71.40% indirect energy,14.93% renewable energy and 85.07% non-renewable.Total GHG emissions and GHG ratio were calculated as 1683.24 kgCO_(2)-eq/hm^(2) and 0.16 kg CO_(2)-eq/kg,respectively.

Net energy yield and carbon footprint of summer corn under different N fertilizer rates in the North China Plain

Excessive use of N fertilizer in intensive agriculture can increase crop yield and at the same time cause high carbon（C） emissions.This study was conducted to determine optimized N fertilizer application for high grain yield and lower C emissions in summer corn（Zea mays L.）.A field experiment, including 0（N0）, 75（N75）, 150（N150）, 225（N225）, and 300（N300） kg N ha–1 treatments, was carried out during 2010–2012 in the North China Plain（NCP）.The results showed that grain yield, input energy, greenhouse gas（GHG） emissions, and carbon footprint（CF） were all increased with the increase of N rate, except net energy yield（NEY）.The treatment of N225 had the highest grain yield（10 364.7 kg ha–1） and NEY（6.8%）, but the CF（0.25） was lower than that of N300, which indicates that a rate of 225 kg N ha–1 can be optimal for summer corn in NCP.Comparing GHG emision compontents, N fertilizer（0–51.1%） was the highest and followed by electricity for irrigation（19.73–49.35%）.We conclude that optimazing N fertilizer application rate and reducing electricity for irrigation are the two key measures to increase crop yield, improve energy efficiency and decrease GHG emissions in corn production.

Comparative evaluation of energy and resource consumption for vacuum carbothermal reduction and Pidgeon process used in magnesium production

With the fast development of the application of magnesium based alloys,the demand for primary magnesium is increasing dramatically all over the world.The Pidgeon process is the most widely used process for producing magnesium in China,but suffers from problems such as high energy,resource consumption and environmental pollution.While the process of vacuum carbothermal reduction to produce magnesium(VCTRM)has attracted more and more attention as its advantages,but it has not been well-practiced in industrial applications and there also is no comprehensive and quantitative analysis of this process.This study quantified the flows of resource and energy for the Pidgeon process and the VCTRM process,then compared and analyzed these two processes with each other from three aspects.The VCTRM process results in 63.14%and 69.16%lower of non-renewable mineral resources and energy consumptions when compared to the Pidgeon process,respectively.Moreover,the low energy consumption(2.675 tce vs.8.681 tce)and material to magnesium ratio(2.953:1 vs.6.429:1)of the VCTRM process,which lead to lower greenhouse gas(GHG)emissions(8.777 t vs.26.337 t)and solid waste generation(0.522 t vs.5.465 t)with a decrease of 66.67%and 90.45%,respectively.Results indicate that the VCTRM process is a more environmentally friendly process for magnesium production with high efficiency but low cost and low pollution,and it shows a good potential to be industrialized in the future after solving the bottleneck problem of the reverse reaction.

Developing China's National Emission Trading Scheme:Experiences from Existing Global Schemes and China's Pilot Programs

Market-based emission trading schemes(ETSs) are widely used in the developed world to reduce greenhouse gas(GHG) emissions which are perceived as the source of global climate change. China, as the largest GHG emitter in the world, is committed to introducing an ETS to reduce emissions. Here we reviewed existing ETSs and sustainable energy policies worldwide as well as China's pilot programs. These studies were conducted in order to propose recommendations for national initiatives and strategies to be implemented in China in relation to climate change adaptation and mitigation. It has been shown that setting emission caps in the context of a national emission intensity target is difficult. However, implementing reliable systems for measurement, reporting, and verification of emissions are essential. A two-level management system(by central and provincial governments) for carbon trading is beneficial to ensure uniform standards and compliance while maintaining flexibility. Persistent political support from, and effective coordination of, policies by the government are crucial. In addition, strengthening of institutional innovation, and the establishment of a national GHG emissions information system, are of equal importance. This vital information could provide a great opportunity for China to re-define its economic growth and take global leadership in combatting climate change.

北京公交集团绿色低碳转型经验及未来发展路径研究

在全球气候变暖的背景下,绿色低碳转型已成为公共交通行业实现可持续发展的核心战略。本文深入探讨了北京公交集团在绿色低碳转型过程中的实践经验,分析了其在推动新能源公交车应用、优化能源结构、提升运营效率等方面的具体做法和取得的成效。同时,指出了在转型过程中存在的技术挑战、基础设施配套不足、实现碳中和难等问题。基于此,提出了未来北京公交集团绿色低碳转型的主要路径,包括进一步调整车辆能源结构、提升车辆使用效率、利用数据手段赋能、开展绿电绿证交易、做好能耗精细管控和提高全体员工节能意识等措施。这些措施旨在为地面公交企业的绿色低碳转型提供参考,助力实现碳达峰碳中和目标。

Comparative analysis of greenhouse gas emission inventory for Pakistan:Part I energy and industrial processes and product use

In order to further improve the accuracy and reliability and reduce uncertainties in the national GHG inventories for Pakistan,this study call for using 2006 IPCC Guidelines,to help to identify the national targets for GHG mitigation with respect to the nationally determined contributions(NDCs).GHG(CO2,CH4,and N20)inventories for Pakistan have been developed by conducting a detailed sectoral assessment of IPCC source sectors,energy,industrial processes and product use(IPPU),agriculture,forestry and other land use(AFOLU),and the waste sector.Further,sector wise comparative analysis of GHG inventories(1994-2017)based on the 2006 and 1996 IPCC Guidelines have also been presented.Results indicated an average relative difference of 4%in total GHG emissions(CO2 equivalent)from energy sector between 2006 and 1996 IPCC Guidelines.With 3.6%average annual growth rate based on 2006 IPCC Guidelines,CO2 from energy sector remained the most abundant GHG emitted,followed by CH4 and N2O.While the average absolute difference in emissions of CH4 and N20 from the energy sector is notable,the total estimated GHG emissions by 2006 IPCC Guidelines duplicate those by 1996 IPCC Guidelines.In the mineral industry with 2006 IPCC Guidelines,an average annual growth rate of 6.7%is observed,contributing 64%of total IPPU sector CO2 emissions.Nevertheless,the relative difference between the two Guidelines in overall IPPU sector emissions remained negligible.There might be a need for switching to 2006 IPCC Guidelines to consider more parameters such as additional source sectors and new default emission factors that fit into national circumstances.

“光火储”一体化发电系统的季节适应性分析

为探索基于压缩空气储能的“光火储”一体化发电系统的季节适应性,选取一年内4个典型日分别代表春夏秋冬4个季节,研究季节特性对一体化发电系统5种运行模式的影响。结果表明:季节变化时,一体化发电系统性能变化较大,其中模式2、3性能受季节变化影响最大,模式4不受季节影响但性能较差,模式5季节适应性最好。此外,一体化发电系统可依据实际运行条件灵活选择运行模式,避免能源浪费。

基于调研数据的河北平原农村温室气体核算

将农村温室气体排放途径划分为农业生产、畜牧养殖、垃圾污水处理和能源消耗4类,基于《省级温室气体排放清单指南》和IPCC碳排放清单编制方法提出各途径温室气体排放量计算方法,并针对河北省平原地区316个行政村进行核算.借助K均值聚类算法,根据各途径排放的CO_(2)当量将全部村落划分为3类,并对各类型村落温室气体排放特征进行分析.结果表明:调研农村CO_(2)排放主要来源于能源消耗,占比在70.9%-75.5%;CH4排放主要来源于畜牧养殖和垃圾污水处理,合计占比在73.2%-94.7%;N_(2)O排放主要来源于农业生产,占比在52.3%-84.7%;能源消耗是农村CO_(2)当量排放的主要来源,其次是农业生产和畜牧养殖;节能仍是目前农村地区降低碳排放的有效途径,同时应当注意农田和养殖动物的科学管理,提高垃圾和污水的收集与规范化处理水平.

油气田现场甲烷逸散检测装置设计的研究

油田温室气体排放源主要包括燃料燃烧、火炬、工艺放空及甲烷逸散排放等。甲烷逸散源自设备泄漏,如阀门、法兰等,其排放广泛且检测复杂,带来较大的不确定性。当前,油气田对甲烷逸散的监测不足,核算缺乏现场数据。因此,研制开发一款油气田甲烷逸散监测装置,增强检测能力并对测量装置相关参数进行测试。得到的测试结果甲烷逸散率检测精度满足实际现场测试需求,该设计可适用于多种检测环境且系统性能良好的油气田现场甲烷逸散检测,为油气田温室气体排控提供有利的硬件保障。

煤电升级改造背景下烟气余热利用节能效益对比评估

对火电企业进行节能减排改造,能够降低火电供电煤耗,进而有效减少二氧化碳排放量的增长,对实现碳达峰、碳中和目标具有重要意义。以某630 MW机组为例,对比4种余热利用方案(低温省煤器方案、二级低温省煤器方案、旁路烟道方案和机炉耦合方案)的系统机组,进行了关键技术参数与节电效果比较分析,结果表明:排烟温度降为90℃,供电煤耗率低温省煤器方案降低1.88 g/(kW·h),二级低温省煤器方案降低2.16 g/(kW·h),旁路烟道方案降低2.29 g/(kW·h),而机炉耦合方案降低2.66 g/(kW·h),节能效果最为显著。

冶金精细化工过程中的节能减排技术与应用研究

冶金精细化工过程中的节能减排技术与应用研究随着环保意识日益增强,节能减排技术在冶金精细化工过程中的应用越来越受到重视。优化现有生产工艺,提高生产效率,减少能源消耗和排放物排放,包括优化炼铸工艺、精炼工艺和炉火相结合工艺等。采用高效节能设备,如高效燃烧设备、高效余热回收设备、高效除尘设备等,降低能耗和排放物排放。开发新型环保材料或添加剂,改善生产工艺,实现节能减排。对生产过程中产生的废弃物进行有效处理和综合利用,降低环境污染,实现资源的再生利用。

涡流管在二氧化碳生产中的节能应用

涡流管结构简单、易维修,其在工业领域中应用非常广泛。为了实现二氧化碳生产过程中的节能,从涡流管的能力分离效应出发,就工业化二氧化碳生产过程如何实现能量消耗降低进行了探讨,希望为推进节能减排提供支持。