Optimal scenario balance of reduction in costs and greenhouse gas emissions for municipal solid waste management

To reduce carbon intensity, an improved management method balancing the reduction in costs and greenhouse gas(GHG)emissions is required for Tianjin's waste management system. Firstly, six objective functions, namely, cost minimization, GHG minimization, eco-efficiency minimization, cost maximization, GHG maximization and eco-efficiency maximization, are built and subjected to the same constraints with each objective function corresponding to one scenario. Secondly, GHG emissions and costs are derived from the waste flow of each scenario. Thirdly, the range of GHG emissions and costs of other potential scenarios are obtained and plotted through adjusting waste flow with infinitely possible step sizes according to the correlation among the above six scenarios. And the optimal scenario is determined based on this range. The results suggest the following conclusions. 1) The scenarios located on the border between scenario cost minimization and GHG minimization create an optimum curve, and scenario GHG minimization has the smallest eco-efficiency on the curve; 2) Simple pursuit of eco-efficiency minimization using fractional programming may be unreasonable; 3) Balancing GHG emissions from incineration and landfills benefits Tianjin's waste management system as it reduces GHG emissions and costs.

Implementation of a greenhouse gas reduction roadmap for steel producing companies

This paper shall show an economic feasible approach to implement greenhouse gas(GHG) reduction measures into steel companies. The goal to improve energy consumption is directly linked to the reduction of GHG emissions and therefore directly in correlation with the economic viability. A baseline scenario of the considered reference system and of the respective reference year has to be defined, mapped and analysed. In a second step an analysis of the same operation using available and prospected best available technology (BAT) processes is carried out to generate a basis for a benchmark system. The identified reduction potentials are reported and the GHG emission reductions are put into relation to the investment cost of the new process technologies/process adaption to be implemented.This economic feasibility calculation is necessary to realise a cost efficient GHG reduction roadmap implementation into the company's business operations. The GHG reduction roadmap is developed using the abatement curve concept to get an indication of ' low hanging fruits' and for establishing a sequence for implementing carbon emission reductions measures. The scope of that approach can be extended by including further important environmental parameters like NOx, SO_2,CO,dust,heavy metal emissions in air as well as production residues.That gives in the end a broader picture and more starting points to improve the overall environmental performance of steel producing companies beyond the GHG emissions and energy consumption.

Mitigation of greenhouse gases released from mining activities:A review

Climate changes that occur as a result of global warming caused by increasing amounts of greenhouse gases(GHGs)released into the atmosphere are an alarming issue.Controlling greenhouse gas emissions is critically important for the current and future status of mining activities.The mining industry is one of the significant contributors of greenhouse gases.In essence,anthropogenic greenhouse gases are emitted directly during the actual mining and indirectly released by the energy-intensive activities associated with mining equipment,ore transport,and the processing industry.Therefore,we reviewed both direct and indirect GHG emissions to analyze how mining contributes to climate change.In addition,we showed how climate change impacts mineral production.This assessment was performed using a GHG inventory model for the gases released from mines undergoing different product life cycles.We also elucidate the key issues and various research outcomes to demonstrate how the mining industry and policymakers can mitigate GHG emission from the mining sector.The review concludes with an overview of GHG release reduction and mitigation strategies.

对农业温室气体(GHG)减排潜力的几点看法

[目的]探讨农业温室气体（GHG）减排潜能与可持续发展。[方法]通过引用联合国政府间气候变化委员会评估报告相关数据,从减排技术潜能和减排经济潜能2个方面对农业GHG（主要包括CO2、CH4、N2O）的减排潜力及其影响因素进行分析与评价,并对农业GHG减排技术与前景进行评价与展望。[结果]农业GHG减排大约89%的潜能将来自土壤碳鏊合作用;农业GHG减排成本大约是0~27美元/t CO2-EQ;多数减排方案强调对现有技术的再利用,使其在不同领域得到广泛推广,同时注意加强可行的新型技术的研究与开发。[结论]即使农业GHG的排放与日俱增,但从长远角度看,农业GHG减排的潜力巨大。当前需要关注是,要确定气候变化、可持续性发展、改善环境质量三者的协同作用。

基于生命周期分析的风电场GHGs减排效益

风电设备生产及风电场建设产生的环境影响备受关注.本研究以中国东南沿海城市某100 MW陆上风电场为例,基于生命周期评价方法,对其风机产品生产制造、运输、风电配套设施建设和运营维护等阶段的环境影响(以温室气体为归一化度量指标)进行了量化分析.研究结果表明,该风电场生命周期温室气体排放总量约为90000 t(以CO2当量计,排放强度为17.8 g/(kW·h)).其中,生产制造阶段占比最大(67.8%),其次为建设施工阶段(19.2%).与其他能源发电方式对比表明,风电温室气体排放强度明显高于水电(以CO2当量计,约3.5 g/(kW·h)),但与光伏发电(以CO2当量计,约50 g/(kW·h))、生物质(以CO2当量计,约200 g/(kW·h))和火力(以CO2当量计,约800 g/(kW·h))等能源方式相比,减排效益显著.

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.

Thermodynamic Analysis of Alternative Marine Fuels for Marine Gas Turbine Power Plants

The marine shipping industry faces challenges to reduce engine exhaust emissions and greenhouse gases （GHGs） from ships, and in particular, carbon dioxide. International regulatory bodies such as the International Maritime Organization and National Environmental Agencies of many countries have issued rules and regulations to drastically reduce GHG and emissions emanating from marine sources. This study investigates the possibility of using natural gas and hydrogen as alternative fuels to diesel oil for marine gas turbines and uses a mathematical model to assess the effect of these alternative fuels on gas turbine thermodynamic performance. Results show that since natural gas is categorized as a hydrocarbon fuel, the thermodynamic performance of the gas turbine cycle using natural gas was close to that of the diesel case. However, the gas turbine thermal efficiency was found to be slightly lower for natural gas and hydrogen fuels compared to diesel fuel.

Transformation of methane to synthesis gas over metal oxides without using catalyst

This article reviews a new developing method in the field of metal oxide reduction in chemical and metallurgical processes, which uses methane as a reducing agent. Commonly, coal is used as the reducing agent in the reduction of metal oxide and other inorganic materials; Metal producing factories are among the most intensive and concentrated source of greenhouse gases and other pollutants such as heavy metals, sulfur dioxide and fly ash. Thermodynamically, methane has a great reducing capability and can be activated to produce synthesis gas over a metal oxide as an oxygen donor. Metal oxide reduction and methane activation, two concurrent thermochemical processes, can be combined as an efficient and energy-saving process; nowadays this kind of technologies is of great importance. This new reduction process could improve energy efficiencies and significantly decrease greenhouse gas emission compared to the conventional process; furthermore, the produced gases are synthesis gas that is more valuable than methane. In this paper, thermodynamic studies and advantages of this promising method were discussed. The major aim of this article is to introduce methane as a best and environmentally friendly reducing agent at low temperature.

Effective goaf gas capture design at Ravensworth Underground Mine

This paper highlights a reliable goaf gas capture system developed and used at Ravensworth Under-ground Mine since its trial in 2009. The method utilises horizontal holes drilled from underground sites and connected to an underground gas pipeline. This system incorporates a gas suction and flaring plant designed specifically for this method. The current method has captured effectively a total longwall, and adjacent goaf gas accounts for over 85%. The design of the holes drilled has been the success of the gas flow reliability. The flow is extraordinarily consistent and predictable. The management of the under-ground pipeline determines the overall reliability of flow. The design has resulted in Ravensworth Man-agement being confident to remove a gas bearing bleeder roadway and still manage the existing tailgate roadway for allowing access as required. The reduction of CO2 equivalent emissions recorded is approx-imately 0.35 ？ 106 tons annually. This design has further improvements to be added to allow use at any other site with gas in the overlying strata.

Analysis of Potential for HFC-23 Emission Reduction in China's Fluorine Chemical Industry

China is one of the major producers of chlorodifluoromethane(HCFC-22)in the world.A large amount of fluoroform(HFC-23)is emitted during the production of HCFC-22.Emission factors of HFC-23 were calculated in accordance with the monitoring reports of eleven HFC-23 clean development mechanism(CDM)projects in China and the HFC-23emissions in 2000–2010 as well as that in 2011–2020 were estimated and projected,respectively.It is expected that,by the end of 2020,emissions of HFC-23 in China will be as much as 230 Mt CO2-eq.If HCFC-22 producers voluntarily reduced HFC-23 emissions,it would contribute 3.2%–3.6%to the national CO2emission reduction target for 2020.

温室气体管控纳入化工园区规划环评的技术方法探索和实证研究

《中共中央国务院关于深入打好污染防治攻坚战的意见》中明确提出“将温室气体管控纳入环评管理”,温室气体管控纳入环评已成为深入推进碳达峰行动的重要举措。产业园区是控制污染物和温室气体排放增量的重要载体,是推进减污降碳源头防控的重要抓手。该研究重点围绕协同减污降碳优化规划方案这一关键问题,探索产业园区规划环评中开展温室气体评价的技术方法,并以某石化园区为例开展了实践探索。为了在环评中科学、合理地分析和评价温室气体减排潜力,从两方面探索评价技术方法:一是温室气体与大气耦合评价方法,开展温室气体评价重点排放设施能效分析,结合大气评价中空气质量目标改善要求和初步模拟预测结果,联合提出淘汰高耗低效热源设施、分阶段推进清洁能源替代的规划调整建议;二是研究创新温室气体评价和循环经济分析紧密结合的环评方法,遵循化工园区协同、合作、共享的一体化设计理念和循环经济理念,以资源循环降碳、能效提升降碳为目标,充分发挥化工园区碳固定、碳消纳的天然优势,促进园区内产业链协同。实证研究表明:①通过全面识别园区减污和降碳的关键环节,以“提效-控煤”为主线,温室气体评价与大气评价联合提出热源点整合方案;聚焦园区CO_(2)资源化利用、能源梯级利用,推动两家企业6套装置实施CO_(2)回收,并实施聚碳酸酯、碳酸乙烯酯等CO_(2)产业链利用项目,将零散企业余热资源统一纳网,实现余热余压利用,很好地验证了前述技术方法的可行性,以及温室气体评价对能源规划方案和产业循环经济方案的优化调整作用。②基于现行产业园区环评的评价技术流程,采用全过程纳入模式,提出了温室气体全过程评价技术框架,即现状评价“挖潜力”、规划分析“融理念”、影响识别“定目标”、影响评价“评趋势”、方案论证“明措施”、调整建议“优方案”。此外,对未来研究提出展望,一是增强污染防治与气候治理的协同性,二是关注难以量化的新排放源和非二氧化碳温室气体,三是结合不同园区面临的能源转型和环境目标压力,形成差异化的温室气体减排方案。该研究提出的技术框架和评价方法为优化化工园区环评源头管控作用起到有力支撑,具有重要的现实意义。

Ecological Footprint of Hydropower Development in China and the Associated Reductions of Greenhouse Gas Emission

Hydropower, next to coal, is the second most important source of electric power supply in China. It amounted to 20.4% of the nation＇s total installed capacity of electricity generation in 2011. To provide a comprehensive picture of the development of hydropower in China and its potential environmental impacts, this study calculates the ecological footprint and greenhouse gas emission reduction of hydropower development in China over the past 60 years. The ecological footprints include the energy ecological footprint and arable land occupation footprint. The energy ecological footprint is calculated in terms of the area of the land which would be used for reforestation in order to assimilate CQ emissions from fossil energy consumption for hydropower development. The arable land occupation footprint is calculated in terms of the area of the land to be inundated by hydropower development. The calculated energy ecological footprint was 502 422 ha in 2010 or about 0.3% of total arable land in China and the calculated inundated land was about 1.42×10 6 ha or about 1.2% of total arable land in China. The regional power grid baseline method was used to calculate the greenhouse gas emission reduction. Results indicated that CQ emission reduction from hydropower development was increasing rapidly since 1949 and reached 5.02×108 tons of COe emission in 2010, with an accumulative total of 6.221×109 tons of CQ emission during the period 1949-2010.

Comparative lifecycle greenhouse gas emissions and their reduction potential for typical petrochemical enterprises in China

Petrochemical enterprises have become a major source of global greenhouse gas(GHG)emissions.Yet,due to the unavailability of basic data,there is still a lack of case studies to quantify GHG emissions and provide petrochemical enterprises with guidelines for implementing energy conservation and emission reduction strategies.Therefore,this study conducted a life cycle assessment(LCA)analysis to estimate the GHG emissions of four typical petrochemical enterprises in China,using first-hand data,to determine possible emission reduction measures.The analytical data revealed that Dushanzi Petrochemical(DSP)has the highest GHG emission intensity(1.17 tons CO_(2)e/ton),followed by Urumqi Petrochemical(UP)(1.08 tons CO_(2)e/ton),Dalian Petrochemical(DLP)(average 0.58 tons CO_(2)e/ton)and Karamay Petrochemical(KP)(average 0.50 tons CO_(2)e/ton)over the whole life cycle.At the same time,GHG emissions during fossil fuel combustion were the largest contributor to the whole life cycle,accounting for about 77.31%–94.27% of the total emissions.In the fossil-fuel combustion phase,DSP had the highest unit GHG emissions(1.20 tons CO_(2)e),followed by UP(0.89 tons CO_(2)e).In the industrial production phase,DLP had the highest unit GHG emissions(average 0.13 tons CO_(2)e/ton),followed by UP(0.10 tons CO_(2)e/ton).During the torch burning phase,torch burning under accident conditions was the main source of GHG emissions.It is worth noting that the CO_(2) recovery stage has"negative value,"indicating that it will bring some environmental benefits.Further scenario analysis shows that effective policies and advanced technologies can further reduce GHG emissions.

A cross-cultural study of sustainable nutrition and its environmental impact in Asia and Europe:A comparison of China and Germany

Global challenges such as climate change,biodiversity loss,and health crises necessitate a shift towards sustainable diets.Incorporating sustainability into food-based dietary guidelines(FBDGs)is essential for this shift,and cultural considerations also play a vital role,as food culture significantly influences dietary habits.Considering that Asia and Europe exhibit distinct food cultures,tailored approaches are necessary.Additionally,countries face diverse nutritional challenges,ranging from malnutrition to diet-related diseases,and regional variation in environmental impact necessitates context-specific strategies.Achieving sustainable nutrition depends on understanding cultural influences and regional dynamics.This paper compares China’s and Germany’s dietary guidelines and dietary patterns and their impact on sustainability.It shows that Chinese and German FBDGs only slightly differ,despite the different eating cultures and habits of each country.Alone the recommended amounts for eggs and fish are considerably higher in China than in Germany.However,in both China and Germany,actual dietary patterns deviate from the dietary guidelines.In China,concomitant with economic growth and urbanization,a dietary shift towards increased consumption of animal products and decreased consumption of vegetables and cereals has been observed in the last decades,which has led to a decline in nutritional deficiencies but an increase in obesity and overweight.Obesity and overweight are also on the rise in Germany.A dietary shift could therefore also be beneficial for public health.While following the respective national guidelines would benefit the environment,alternative diets such as a plant-based diet offer even lower environmental footprint.Revising guidelines to prioritize sustainability in addition to health aspects while considering regional contexts and cultural preferences is recommended to foster sustainable eating habits globally.This approach is pivotal for promoting dietary shift towards sustainability on a global scale.

Charging Ahead with E-Buses: Benefits, Costs, and Transition Roadmap

This paper reaches a recommendation for the 10-year e-bus transition roadmap for New York City. The lifecycle model of emission reduction demonstrates the ecological and financial impacts of a complete transition from the current diesel bus fleet to an all-electric bus fleet in New York City by 2033. This study focuses on the NOx pollution, which is the highest among all major cities by Environmental Protection Agency (EPA) and greenhouse gases (GHG) with annual emissions of over five million tons. Our model predicts that switching to an all-electric bus fleet will cut GHG emissions by over 390,000 tons and NOx emissions by over 1300 tons annually, in addition to other pollutants such as VOCs and PM 2.5. yielding an annual economic benefit of over 75.94 million USD. This aligns with the city mayor office’s initiative of achieving total carbon neutrality. We further model an optimized transition roadmap that balances ecological and long-term benefits against the costs of the transition, emphasizing feasibility and alignment with the natural replacement cycle of existing buses, ensuring a steady budgeting pattern to minimize interruptions and resistance. Finally, we advocate for collaboration between government agencies, public transportation authorities, and private sectors, including electric buses and charging facility manufacturers, which is essential for fostering innovation and reducing the costs associated with the transition to e-buses.

杭州市城市生活垃圾处理主要温室气体及VOCs排放特征

为了解城市生活垃圾处理过程中主要温室气体及VOCs排放的变化特征,基于《2006年IPCC国家温室气体清单指南》《浙江省市县温室气体清单编制指南》和《大气挥发性有机物源排放清单编制技术指南》推荐的方法,估算了2005—2016年杭州市生活垃圾处理主要温室气体及VOCs排放量.结果表明:2005—2016年杭州市生活垃圾处理过程中温室气体排放占绝对主导地位,VOCs排放只占极少一部分.杭州市生活垃圾处理主要温室气体和VOCs排放量总体上呈上升趋势,与2005年相比,2016年杭州市生活垃圾处理主要温室气体排放量增长了68. 8%,VOCs排放量增长了134. 0%.从生活垃圾处理方式来看,杭州市生活垃圾填埋处理的温室气体排放量远高于焚烧处理方式,但填埋处理的VOCs排放量却低于焚烧处理方式(2007年和2008年除外).杭州市生活垃圾填埋处理和焚烧处理的温室气体排放强度分别为0. 72～0. 86、0. 18～0. 23.从排放贡献和排放强度来看,采用填埋处理方式有利于减少垃圾处理过程中VOCs的排放,而采用焚烧处理方式更有利于温室气体的减排.随着人均生活垃圾产生量的上升,无论是温室气体还是VOCs,杭州市人均垃圾处理排放量总体呈现稳步上升的态势.研究显示,深入垃圾分类回收、控制人均生活垃圾产生量、优化垃圾焚烧处理方式,可以实现生活垃圾处理主要温室气体和VOCs的协同减排.

温室气体减排项目评价方法研究

阐述了温室气体减排技术选择的准则与优先领域，以及温室气体减排项目评价应包括的主要内容；对３类主要的温室气体减排项目———节能技术改造项目、新建提高能源转换或利用效率项目及能源替代项目，分别探讨了基准线的确定方法、减排量和增量减排成本的计算方法在这３个项目评价中的难点；介绍了温室气体间接减排项目评价方法；最后以张北风电场二期风电项目为例对全球环境效益进行评价。

城市污水处理厂温室气体的排放及减排对策

近年来,我国污水处理事业得到了大力的发展,污水处理厂污染物减排能力逐年提升。然而,污水及剩余污泥处理处置过程中温室气体的排放问题却没有得到应有的重视。本文系统阐述了城市污水处理厂温室气体的来源,并从污水处理工艺的选择、工艺运行参数的科学调控、剩余污泥的处理处置和资源化、处理水的回用等方面提出了温室气体的减排对策,从而为开展污水处理厂温室气体减排的研究及低碳运行的实践提供借鉴。

船舶温室气体减排措施及对我国的影响分析

气候变暖是人类面临的最为严重的环境问题之一。由于行业特殊性,《联合国气候变化框架公约》及其《京都议定书》要求国际航行船舶通过国际海事组织(IMO)实现其温室气体减排。回顾了国际社会关于船舶温室气体减排的谈判进程,介绍了国际海运业温室气体减排的现状和特征及技术性、营运性与基于市场的减排措施,在分析IMO对船舶温室气体减排的立法进展及其可能对我国造船业、航运业、人才需求等方面造成的影响基础上提出了参考建议。

黄花和脱水污泥厌氧消化的温室气体减排研究

采用联合国政府间气候委员会(IPCC)推荐的方法,对植物加拿大一枝黄花和污泥生物质厌氧消化产沼气的环境和能量影响进行了评估.环境影响评估重点关注温室气体(GHG)减排,将加拿大一枝黄花和脱水污泥的中温小试厌氧消化的甲烷产率数据运用于GHG减排潜质的计算;能量评估包括污泥贮存及传播、消化液的沼气逃逸,及化学肥料和化学药剂的投加几个过程中的直接和间接的能量输入.结果表明,一枝黄花和脱水污泥联合厌氧消化净GHG排放量随着SRT的缩短和黄花添加比例的增加而逐渐下降,在二者以挥发性固体(VS)比例1:1混合,停留时间为20d时的能量效率较高,GHG减排量较大,与基础方案相比,添加黄花可以实现78%的净GHG减排.