Greenhouse gas emissions from production and use of used cooking oil methyl ester as transport fuel in Thailand

Biodiesel, produced from various vegetable and/or animal oils, is one of the most promising alternative fuels for transportation in Thailand. Currently, the waste oils after use in cooking are not disposed adequately. Such oils could serve as a feedstock for biodiesel which would also address the waste disposal issue. This study compares the life cycle greenhouse gas (GHG) emissions from used cooking oil methyl ester (UCOME) and conventional diesel used in transport. The functional unit (FU) is 100 km transportation by light duty diesel vehicle (LDDV) under identical driving conditions. Life cycle GHG emissions from conventional diesel are about 32.57 kg CO₂-eq/FU whereas those from UCOME are 2.35 kg CO₂-eq/FU. The GHG emissions from the life cycle of UCOME are 93% less than those of conventional diesel production and use. Hence, a fuel switch from conventional diesel to UCOME will contribute greatly to a reduction in global warming potential. This will also support the Thai Government's policy to promote the use of indigenous and renewable sources for transportation fuels.     

Pledges for climate mitigation: the effects of the Copenhagen accord on CO2 emissions and mitigation costs

The UN Framework Convention of Climate Change 15th Conference of the Parties Copenhagen Accord has been followed up by national pledges of greenhouse gas emissions reductions in the year 2020 without specifying measures to enforce actions. As a consequence, the capacity of parties to fulfil their obligations is of basic interest. This article outlines the effects of full compliance with pledges on greenhouse gas emissions, economic growth, and trade. The study is based on the global computable general equilibrium model global responses to anthropogenic changes in the environment (GRACE) distinguishing between fossil and non-fossil energy use. Global emissions from fossil fuels in 2020 turn out to be 15 % lower than in a business as usual scenario and 3 % below the global emissions from fossil fuels in 2005. China and India increase their emissions to 1 % and 5 % above business as usual levels in 2020. India and Russia increase their net export of steel corresponding to around 30 and 45 % of their production levels in 2020. In spite of some leakage of energy intensive production also to China, we find that structural change remains the dominant factor behind the rapid reduction of CO₂ emission intensity in China towards 2020.     

Stepwise multiple regression method of greenhouse gas emission modeling in the energy sector in Poland

The energy sector in Poland is the source of 81% of greenhouse gas (GHG) emissions. Poland, among other European Union countries, occupies a leading position with regard to coal consumption. Polish energy sector actively participates in efforts to reduce GHG emissions to the atmosphere, through a gradual decrease of the share of coal in the fuel mix and development of renewable energy sources. All evidence which completes the knowledge about issues related to GHG emissions is a valuable source of information. The article presents the results of modeling of GHG emissions which are generated by the energy sector in Poland. For a better understanding of the quantitative relationship between total consumption of primary energy and greenhouse gas emission, multiple stepwise regression model was applied. The modeling results of CO₂ emissions demonstrate a high relationship (0.97) with the hard coal consumption variable. Adjustment coefficient of the model to actual data is high and equal to 95%. The backward step regression model, in the case of CH₄ emission, indicated the presence of hard coal (0.66), peat and fuel wood (0.34), solid waste fuels, as well as other sources (− 0.64) as the most important variables. The adjusted coefficient is suitable and equals R² = 0.90. For N₂O emission modeling the obtained coefficient of determination is low and equal to 43%. A significant variable influencing the amount of N₂O emission is the peat and wood fuel consumption.     

Stepwise multiple regression method of greenhouse gas emission modeling in the energy sector in Poland

The energy sector in Poland is the source of 81% of greenhouse gas (GHG) emissions. Poland, among other European Union countries, occupies a leading position with regard to coal consumption. Polish energy sector actively participates in efforts to reduce GHG emissions to the atmosphere, through a gradual decrease of the share of coal in the fuel mix and development of renewable energy sources. All evidence which completes the knowledge about issues related to GHG emissions is a valuable source of information. The article presents the results of modeling of GHG emissions which are generated by the energy sector in Poland. For a better understanding of the quantitative relationship between total consumption of primary energy and greenhouse gas emission, multiple stepwise regression model was applied. The modeling results of CO₂ emissions demonstrate a high relationship (0.97) with the hard coal consumption variable. Adjustment coefficient of the model to actual data is high and equal to 95%. The backward step regression model, in the case of CH₄ emission, indicated the presence of hard coal (0.66), peat and fuel wood (0.34), solid waste fuels, as well as other sources (-0.64) as the most important variables. The adjusted coefficient is suitable and equals R² = 0.90. For N₂O emission modeling the obtained coefficient of determination is low and equal to 43%. A significant variable influencing the amount of N₂O emission is the peat and wood fuel consumption.     

Mitigation of greenhouse gas emissions in European conventional and organic dairy farming

Dairy farming is the largest agricultural source of the greenhouse gases methane (CH₄) and nitrous oxide (N₂O) in Europe. A whole-farm modeling approach was used to investigate promising mitigation measures. The effects of potential mitigation measures were modeled to obtain estimates of net greenhouse gas (GHG) emissions from representative dairy model farms in five European regions. The potential to reduce farm GHG emissions was calculated per kg milk to compare organic and conventional production systems and to investigate region and system specific differences. An optimized lifetime efficiency of dairy cows reduced GHG emissions by up to 13% compared to baseline model farms. The evaluation of frequent removal of manure from animal housing into outside covered storage reduced farm GHG emissions by up to 7.1%. Scraping of fouled surfaces per se was not an effective option since the reduction in GHG emissions from animal housing was more than out-weighed by increased emissions from the storage and after field application. Manure application by trail hose and injection, respectively, was found to reduce farm GHG emissions on average by 0.7 and 3.2% compared to broadcasting. The calculated model scenarios for anaerobic digestion demonstrated that biogas production could be a very efficient and cost-effective option to reduce GHG emissions. The efficiency of this mitigation measure depends on the amount and quality of organic matter used for co-digestion, and how much of the thermal energy produced is exploited. A reduction of GHG emissions by up to 96% was observed when all thermal energy produced was used to substitute fossil fuels. Potential measures and strategies were scaled up to the level of European regions to estimate their overall mitigation potential. The mitigation potential of different strategies based on a combination of measures ranged from −25 up to −105% compared to baseline model farms. A full implementation of the most effective strategy could result in a total GHG emission reduction of about 50 Mt of carbon dioxide (CO₂) equivalents per year for conventional dairy farms of EU(15) comparable to the defined model farms.     

Quantification of carbon dioxide and methane emissions in urban areas: source apportionment based on atmospheric observations

Anthropogenic emissions of carbon dioxide (CO₂) and methane (CH₄) in the atmosphere constitute an important component of the related carbon budget. The main source of anthropogenic CO₂ is burning of fossil fuels, especially in densely populated areas. Similar emissions of CH₄ are associated with the agricultural sector, coal mining, and other human activities, such as waste management and storage and natural gas networks supplying methane to large urban, industrial centers. We discuss several methods aimed at characterizing and quantifying atmospheric loads and fluxes of CO₂ and CH₄ in Krakow, the second largest city in Poland. The methods are based on atmospheric observations of mixing ratios as well as isotopic composition of the investigated gases. Atmospheric mixing ratios of CO₂ and CH₄ were measured using gas chromatography (GC) and cavity ring-down spectroscopy (CRDS). The isotopic composition of CO₂ and CH₄ was analyzed using isotope ratio mass spectrometry (IRMS), accelerator mass spectrometry (AMS), and CRDS techniques. These data, combined with auxiliary information characterizing the intensity of vertical mixing in the lower atmosphere (height of the nocturnal boundary layer [NBL] and atmospheric ²²²Rn concentration), were further used to quantify emission rates of CO₂ and CH₄ in the urban atmosphere of Krakow. These methods provide an efficient way of quantifying surface emissions of major greenhouse gases originating from distributed sources, thus complementing the widely used bottom-up methodology based on emission statistics.

     

Energy modeling on cleaner vehicles for reducing CO2 emissions in Japan

This study is to evaluate the impact of cleaner vehicles on energy systems and CO₂ emissions in the transportation sector in Japan. The transportation sector has the characteristic of spending petroleum. Even when the cost of petroleum rises, conventional vehicles cannot switch fuels to alternative energy right away. Cleaner vehicles, such as fuel cell vehicles, would be one of the alternative technologies in the transportation sector. It is supposed to have excellent performance in fuel efficiency and has strong possibility to reduce CO₂ drastically. This paper uses a multi-period market equilibrium model to explore the impacts of cleaner vehicles on the passenger transportation sector in Japanese energy system out to the year 2040. A Btu tax is tentatively imposed to evaluate the effect of fuel cost on energy consumption in the transportation sector. Financial parameters such as capital cost and operating cost are considered to summarize the profit in taxation case. The result of this study shows that fuel cell vehicles have a great effect on reducing CO₂ emissions especially when Btu taxes are imposed, which in turn has the advantage of encouraging a more diverse set of technologies and fuels. The analysis that petroleum consumption can be reduced using fuel cell vehicles will have effects on perspectives on energy systems in Japan.     

Attributional life cycle assessment of woodchips for bioethanol production

Besides the apparent need to reduce greenhouse gas emissions, other important factors contributing to the renewed interest in biofuels are energy security concerns and the need of sustainable transportation fuel. Nearly 30% of the annual CO₂ emissions in the U.S. come from the transportation sector and more than half of the fuel is imported. Biofuels appear to be a promising option to reduce carbon dioxide emissions, and the reliance on imported oil concomitantly. The interest on (ligno) cellulosic ethanol is gaining momentum as corn-based ethanol is criticized for using agricultural outputs for fuel production. Among many lignocellulosic feedstocks, woodchips is viewed as one of the most promising feedstocks for producing liquid transportation fuels. The renewable and carbon neutral nature of the feedstocks, similar chemical and physical properties to gasoline, and the low infrastructure cost due to the availability of fuel flex vehicles and transportation networks make (ligno) cellulosic bioethanol an attractive option. An in-depth LCA of woodchips shows that harvesting and woodchips processing stage and transportation to the facility stage emit large amount of environmental pollutants compared to other life cycle stages of ethanol production. Our analysis also found that fossil fuel consumption and respiratory inorganic effects are the two most critical environmental impact categories in woodchips production. We have used Eco-indicator 99 based cradle-to-gate LCA method with a functional unit of 4 m³ of dry hardwood chips production.     

Does the Swedish consumer's choice of food influence greenhouse gas emissions?

Consumer's choice of food can influence the environment. In Sweden, in common with many other countries, consumers need to be given information so they can make environmentally informed shopping choices. However, what is the most advantageous dietary choice to lower greenhouse emissions? This study investigates the greenhouse gas emissions associated with food production for food consumed in Sweden annually. Specifically, this study compares greenhouse gas emissions associated with a nutritionally and environmentally sustainable diet with the average consumption of food in Sweden 1999. The study concludes that the change in energy use and greenhouse gas emission associated with this change of diet is negligible. Lowering greenhouse gas emissions by changing food production processes results in more profound changes than teaching consumers to make environmentally correct choices. There is a basic need for a reduction or a replacement of the use of fossil fuels to produce and distribute our food in order to reach any significant reduction in the emission of greenhouse gases. Swedish agricultural policy does not provide ways to reduce greenhouse gas emissions. In Sweden therefore there is an immediate need to design policy instruments with the primary aim of reducing the greenhouse effect.     

A Greenhouse Gas Balance of two Existing International Biomass Import Chains

Various utility companies are considering or already initiated the import of biomass from abroad for electricity generation, especially via co-firing in coal-fired power plants. This results in international logistic biomass supply chains, which raise questions on the environmental performance of such chains. In this study, a life cycle inventory has been performed on two existing biomass import chains to evaluate the greenhouse gas balance of biomass import for co-firing. We considered production, transport and co-firing of wood pellets from Canada and palm kernel shells from Malaysia in a 600 MW _e coal-fired power plant in the Netherlands. Those chains are compared with various reference systems for energy production and the alternative use of biomass. Primary energy savings of these import and co-firing chains are between 70% and 100% of the biomass energy content. Net avoided greenhouse gas emissions are in the range of 340–2100 g/kWh. In the most optimistic scenario, pellet co-firing avoids methane emissions that would have occurred if the pellets were decomposed at landfills when not applied for energy production. In the most pessimistic scenario, palm kernel shell co-firing competes with the application as resource for animal feed production, which requires production and transport of an alternative resource. As the energy reference systems of the importing and exporting country and the alternative application of biomass have a significant impact on the net avoided greenhouse gas emissions, these factors should be considered explicitly when studying biomass trade for energy purposes.     

中国油气系统甲烷逸散排放估算

为实现碳达峰碳中和目标,中国正致力于推动能源低碳化转型,这促进能源由煤炭向油气资源的转变.因此,中国石油和天然气系统（油气系统）的甲烷（CH₄）排放日益受到关注.逸散排放包括设备泄漏、排空和火炬燃烧,涉及油气资源的开发、生产、运输、储存和分配等过程.但目前油气系统CH₄逸散排放缺乏统一的核算方法,逸散排放量亦未被纳入国家温室气体清单统计之中.基于相关方法,评估了1980~2020年中国油气系统的CH₄逸散排放.结果表明,油气系统的CH₄逸散排放随着油气资源的生产和消费增长而快速增加,由1980年不足60万t增长至2020年的超过260万t.石油系统和天然气系统在2020年的CH₄逸散排放分别达到约60万t和200万t,是1980年的1.38倍和16.6倍.油气系统的CH₄逸散主要源于天然气生产、石油生产、天然气分配、天然气运输和储存,分别占总排放的41%、20%、18%和13%.天然气管道是主要的逸散设施.相比于常规油气资源开发,非常规油气资源开发的排放强度更高.研究完善了CH₄逸散排放清单,可为CH₄减排提供重要科学数据支持.     

The role of biotic carbon stocks in stabilizing greenhouse gas concentrations at safe levels

The goal of the Climate Convention and its Kyoto Protocol is to stabilize greenhouse gas concentrations in the atmosphere at a safe level. This requires both strict limits on emissions from fossil fuels and effective management of biotic carbon stocks. If fossil fuel emissions from 1990 to 2100 are limited to 600 PgC, biotic carbon stocks must increase by 120 PgC to stabilize CO₂ concentrations at 450 ppmv. Establishing an appropriate policy regime to accomplish this goal is complicated by a factor of six discrepancy between estimates of the current biotic sink based on national emissions inventories compared with global carbon cycle model calculations. Appropriate policies must also be designed to create incentives for technological innovation in the energy sector and minimize the risk of granting emission credits for biotic carbon sequestration that proves to be temporary.     

四川盆地气矿天然气开发过程中温室气体的排放特征

天然气开发过程是化石能源系统重要的排放源之一. 包括我国在内的发展中国家对于油气系统温室气体排放的研究尚处于起步阶段,并且也无统一的计算方法. 为研究我国天然气开发过程中温室气体排放情况,以四川盆地某较大规模(年产气量约16×108 m3)的天然气气矿为研究对象. 利用甲烷泄漏浓度检测仪对该气矿井口、集气站、配气站等场站的所有元件的潜在泄漏点进行了逐一检测,同时采集油田水和天然气样品,在实验室对油田水露天放置过程和天然气火炬燃烧过程的温室气体排放进行了模拟研究,计算了该矿2011年天然气开发过程中温室气体排放量. 结果表明:2011年研究气矿CH₄和CO₂排放量分别为1 033.32和1 295.56 t,折合CO₂当量为27 128.56 t. 与采用IPCC(政府间气候变化专门委员会)《2006年国家温室气体清单指南》第一层次方法计算的结果对比发现,IPCC方法计算结果(CH₄和CO₂排放量分别为20 287.39、12 479.74 t,折合CO₂当量为519 664.74 t)远高于实测法计算结果,因此,IPCC方法总体上严重高估了我国温室气体排放量.      

Discrete event simulation to aid decision-making and mitigation in solid waste management

This article aims to evaluate municipal solid waste (MSW) management schemes in order to promote sustainability and eco-efficiency, core elements in global mitigation strategies in both public and private policies. A discrete event simulation (DES) approach was used to integrate the economic, environmental, and social aspects related to aseptic carton packages (ACP) in Itajuba, Brazil. The simulated scenarios consider three alternatives for disposing ACP: landfills, recycling, and incineration with energy recovery. According to our findings, incineration alternatives are preferred from an eco-efficiency perspective, given the potential greenhouse gas (GHG) emissions reductions and due to the possibility of energy recover, which reinforces the contribution of this technology to promote sustainability as largely found in the international literature. Given the context of MSW management in Brazil, this represents a significant opportunity to increase the effectiveness of mitigation strategies adopted in the country. Taking into account that this is by far the least applied technology, the authors strongly advocate that global strategies for mitigation consider different approaches to integrate carbon dioxide (CO₂) emission reductions related to the entire MSW management system and its alternatives, thus advancing from a waste disposal-oriented system to a life cycle–oriented system.

     

Energy efficiency and reduction of Co2 emissions through 2015: The Brazilian cement industry

The cement industry is characterisedby intensive energy consumption throughout itsproduction stages which, together with the calcinationof its raw materials, accounts for significant amountsof greenhouse gases (GHG) emissions. In 1996, theBrazilian cement industry consumed 4.3% of the energyrequired by the industrial sector, contributing over22 Tg (Teragrams) of CO₂. The prospects forgrowth in this sector in Brazil indicate risingdemands for fossil fuels, with a consequent upsurge inemissions. This article aims to present the prospectsfor energy conservation in the Brazilian cementindustry through to 2015, taking into account: theintroduction of new production technologies in thissector, the use of waste and low-grade fuels,cogeneration, the use of cementitious materials, andother measures, based on a technical and economicenergy demand simulation model. In all scenarios, wefound that is possible to significantly reduce energyconsumption and CO₂ emissions for BrazilianCement Industry. Under the market potential scenarios,energy savings vary between 1562.0 to 1900.6 PJ(PetaJoules), with use of cementitious materialsaccounting for around 31% of this total. Fortechnical potential scenarios, use of cementitiousmaterials could represent 51% to 52% of totalachieved energy savings, between 2374.6 to 2803.4 PJ.     

我国近10年城市生活垃圾处置单元温室气体排放时空变化及减排潜能分析

生活垃圾处置单元是重要的温室气体（GHG）排放源,明确其排放变化趋势及特征,是制定生活垃圾单元GHG减排的前提.采用IPCC清单模型,对中国2010~2020年城市生活垃圾（MSW）处置单元的GHG排放进行了估算.结果表明,GHG排放量（以CO₂-eq计,下同）从2010年的42.5 Mt增长至2019年的75.3 Mt,2020年降低到72.1 Mt;生活垃圾填埋场是GHG排放的主要来源,随着生活垃圾焚烧比例的增加,焚烧GHG排放占比从2010年的16.5%快速增加到2020年的60.1%;在区域分布上,华东和华南地区是排放量最高的区域,广东、山东、江苏和浙江是最主要的排放省.实行生活垃圾分类,转变生活垃圾处置方式（垃圾填埋向焚烧的转变）,提高填埋场填埋气体（LFG）收集效率,利用生物覆盖功能材料强化覆盖层甲烷（CH₄）氧化效率,是实现固废处置单元GHG减排的主要措施.     

2015年中国地区大气甲烷排放估计及空间分布

CH₄是仅次于CO₂的重要温室气体,也是重要的化学活性气体.定量估算我国甲烷的排放量及分析其空间分布特征,对于控制温室气体排放,减缓温室效应具有重要意义.本文以2015年中国官方统计年鉴资料为基础,利用IPCC排放清单指南、国内外排放因子研究结果及动力学模型方法,从能源活动（煤炭开采和油气系统）、农业活动（反刍动物、稻田排放和秸秆露天燃烧）、自然源排放（自然湿地和植被排放）、废弃物处理（固体废弃物、工业污水和生活污水）和人工湿地等几个主要方面,对中国地区的CH₄排放进行定量估计.结果表明：中国地区2015年CH₄排放总量为61.59 Tg,其中以农业活动和能源活动为主要排放源,排放量分别达到20.42 Tg和20.39 Tg,占总排放量比例分别约为33.2%和33.1%.CH₄自然源考虑了植被和自然湿地排放,排放量为11.77 Tg,占比为19.1%;废弃物处理产生的CH₄排放量为8.64 Tg,占比为14.0%;人工湿地排放量为0.37 Tg,占比为0.6%.从空间分布来看,CH₄排放具有较明显的不均匀性,大值区主要集中在华北、西南及东南地区,而西北地区的排放量则相对较低,主要与各地的资源环境、人口密度和经济情况密切相关.     

The analysis of greenhouse gas emissions/reductions in waste sector in Vietnam

The global waste sector produces, on average, 2–5 % of global anthropogenic greenhouse gas (GHG) emissions. The amount of GHG emissions has grown steadily and is predicted to increase considerable in the forthcoming decades because of the increases in population and gross domestic product (GDP). However, the GHG mitigation opportunities for the sector are still fully not exploited, in particularly in developing countries. A series of initiatives were highly successful and showed that large reductions in emissions are possible. This study aims to propose a holistic quantification model, which can be used for estimation of waste generation and evaluation of the potential reduction of GHG emissions in waste sector for developing countries with a particular application to Vietnam. The two scenarios set for the study were business as usual (BaU) which waste management is assumed to follow past and current trends and CounterMeasure (CM) which alternative waste treatment and management are assessed. Total emissions in the BaU scenario are projected to increase from 29.47 MtCO₂eq in 2010 to 85.60 MtCO₂eq by 2030 and 176.32 MtCO₂eq by 2050. The highest emissions are due to methane (CH₄) released by disposal sites, accounting for about 60 % of the GHG emissions from waste in Vietnam in 2030. This emission is projected to increase significantly (67 % in 2050), unless more of the methane is captured and used for energy generation. The CM scenario gives emission reductions from 25.7 % (2020), 40.5 % (2030) to 56.6 % (2050) compared to the BaU scenario. The highest GHG reduction is achieved through recycling, followed by methane recovery to optimize the co-benefit for climate change mitigation.     

The environmental effect of reusing and recycling a plastic-based packaging system

This Australian study presents the findings of a life-cycle assessment (LCA) that examined whether a re-use and recycle strategy for a plastic-based packaging that substantially reduces the quantity of waste to landfill would also reduce the overall environmental burden. The resources and environmental effects assessed over the life of each of the packagings included fossil fuel consumption, greenhouse gas emissions and photochemical oxidant precursors. The results demonstrate that recycle and reuse strategies for plastic-based products can yield significant environmental benefits. The study also includes some interesting findings regarding the relative contributions of transportation and construction energy, and the potential benefits of adjusting the impact assessment results to take into account the spatial variation in the significance of some environmental effects.     

中国氢燃料电池车燃料生命周期的化石能源消耗和CO2排放

氢燃料电池车(FCV)具有运行阶段高能效和零排放的优点,近年来得到快速的商业化发展.氢能生产具有多种技术路径,不同路径的能源和环境效益存在显著差异.本研究采用生命周期评价方法,运用GREET模型对不同氢燃料路径下的FCV燃料周期(WTW)的化石能源消耗和CO_2排放进行了全面评价.选取了多种制氢路径作为评价对象,建立了中国本地化的FCV燃料生命周期数据库,在此基础上分析了FCV相对传统汽油车的WTW节能减排效益,并和混合动力车和纯电动车进行比较.结果表明,使用可再生电力和生物质等绿色能源制氢供应FCV能取得显著的WTW节能减排效益,可削减约90%的化石能耗和CO_2排放.在发展相对成熟的传统能源制氢路径中,以焦炉煤气制得氢气为原料的FCV,能产生显著的节能减排效益,其化石能耗低于混合动力车,CO_2排放低于混合动力车和纯电动车.结合对资源储备和技术成熟度的考虑,我国在发展氢能及FCV过程中,近期可考虑利用焦炉煤气等工业副产物制氢,并且规划中远期的绿色制氢技术发展.