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.

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.

The Influence of Rice Husk Ash on Mechanical Properties of the Mortar and Concrete: A Critical Review

Increasing the population and infrastructure in both emerging and developed countries requires a considerable amount of cement, which significantly affects the environment. The primary materials of concrete (‘cement’) production emit a large quantity of CO2 into the environment. Also, the cost of conventional building materials like cement gives motivation to find geopolymer waste materials for concrete. To reduce harmful effects on the environment and cost of traditional concrete substance, alternative waste materials like rice husk ash (RHA), ground granulated blast-furnace (GGBS), fly ash (FA), and metakaolin (MK) can be used due to their pozzolanic behavior. RHA waste material with a high silica concentration obtained from burning rice husks can possibly be used as a supplementary cementitious material (SCM) in the manufacturing of concrete, and its strong pozzolanic properties can contribute to the strength and impermeability of concrete. This review paper highlights a summary of the positive effect of using RHA as a partial substitute for cement in building construction, as well as its optimal inclusion of enhanced mechanical properties like compressive strength, flexural strength, and split tensile strength of mortar and concrete.

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.

The Clean Development Mechanism and Sustainable Development in China's Electricity Sector

The Clean Development Mechanism,a flexibility mechanism contained in the KyotoProtocol, offers China an important tool to attractinvestment in clean energy technology and processesinto its electricity sector. The Chinese electricitysector places centrally in the country’s economy andenvironment, being a significant contributor to theacid rain and air pollution problems that plague manyof China’s cities and regions, and therefore a focusof many related energy and environmental policies.China’s electricity sector has also been the subjectof a number of economic analyses that have showedthat it contains the highest potential for clean energyinvestment through the Clean DevelopmentMechanism of any economic sector in China. Thismechanism, through the active participation frominvestors in more industrialized countries, can helpalleviate the environmental problems attributable toelectricity generation in China through advancingsuch technology as wind electricity generation, cleancoal technology, high efficient natural gas electricitygeneration, or utilization of coal mine methane. Inthis context, the Clean Development Mechanismalso compliments a range of environmental and energypolicies which are strategizing to encourage thesustainable development of China’s economy.

N_2O emission factors of nitric acid production in China from CDM projects

Industrial production process including nitric acid production is an important greenhouse gas emission source. Although IPCC guidelines have given calculation methods and emission factors for N2O emission from nitric acid production, emission factors of nitric acid production in China are not given. And it can be seen from the comparison of the guidelines and registered CDM projects in China that the N2O emission factors given in the IPCC guidelines and actual N2O emission from nitric acid production in China differ greatly while measured N2O emission data is not available, so determination of emission factors for N2O emission from nitric acid production is an important basic research for N2O emission calculation in China. The method that calculate N2O emission factors from nitric acid production in China is studied with baseline emission factors based on actual measurement of registered CDM projects and the calculated emission factor is compared with that given in the IPCC guidelines in the text.

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.

Shortened Duration of Global Warming Slowdowns with Elevated Greenhouse Gas Emissions

Continuous emissions of anthropogenic greenhouse gases(GHGs)and aerosols in the last 160 years have resulted in an increasing trend of global mean surface temperatures(GMSTs).Due to interactions with natural variability,rates of the combined anthropogenically and naturally induced warming trends are characterized by significant slowdowns and speedups on decadal timescales.Here,by analyzing observed and model-simulated data,we investigate how the duration of these episodes will change with different strengths of GHG and aerosol forcing.We found that the duration of warming slowdowns can be more than 30 yr with a slower rate of anthropogenic emissions but would shorten to about 5 yr with a higher one.This duration reduction depends on both the magnitude of the climate response to anthropogenic forcing and the strength of the internal variability.Moreover,the warming slowdowns can still occur even towards the end of this century under high emissions scenarios but with significantly shortened duration.

Spatiotemporal evolution and driving factors for GHG emissions of aluminum industry in China

China’s aluminum(Al)production has released a huge amount of greenhouse gas(GHG)emissions.As one of the biggest country of primary Al production,China must mitigate its overall GHG emission from its Al industry so that the national carbon neutrality target can be achieved.Under such a background,the study described in this paper conducts a dynamic material flow analysis to reveal the spatiotemporal evolution features of Al flows in China from 2000 to 2020.Decomposition analysis is also performed to uncover the driving factors of GHG emission generated from the Al industry.The major findings include the fact that China’s primary Al production center has transferred to the western region;the primary Al smelting and carbon anode consumption are the most carbonintensive processes in the Al life cycle;the accumulative GHG emission from electricity accounts for 78.14% of the total GHG emission generated from the Al industry;China’s current Al recycling ratio is low although the corresponding GHG emission can be reduced by 93.73% if all the primary Al can be replaced by secondary Al;and the total GHG emission can be reduced by 88.58% if major primary Al manufacturing firms are transferred from Inner Mongolia to Yunnan.Based upon these findings and considering regional disparity,several policy implications are proposed,including promotion of secondary Al production,support of clean electricity penetration,and relocation of the Al industry.

Accounting greenhouse gas emissions of food consumption between urban and rural residents in China: a whole production perspective

Food consumption is necessary for human survival.On a global scale,the greenhouse gas(GHG)emission related to food consumption accounts for 19%–29%of the total GHG emission.China has the largest population in the world,which is experiencing a rapid development.Under the background of urbanization and the adjustment of the diet structure of Chinese residents,it is critical to mitigate the overall GHG emission caused by food consumption.This study aims to employ a single-region input-output(SRIO)model and a multi-regional input-output(MRIO)model to measure GHG emission generated from food consumption in China and compare the contributions of different industrial sectors,uncovering the differences between urban and rural residents and among different provinces(autonomous regions/municipalities),as well as identifying the driving forces of GHG emission from food consumption at a national level.The results indicate that the total GHG emission generated from food consumption in China tripled from 157 Mt CO_(2)e in 2002 to 452 Mt CO_(2)e in 2017.The fastest growing GHG emission is from the consumption of other processed food and meat products.Although GHG emissions from both urban and rural residents increased,the gap between them is increasing.Agriculture,processing and manufacture of food,manufacture of chemical and transportation,storage and post services sectors are key sectors inducing food consumption related GHG emissions.From a regional perspective,the top five emission provinces(autonomous regions/municipalities)include Shandong,Hubei,Guangdong,Zhejiang,and Jiangsu.Based on such results,policy recommendations are proposed to mitigate the overall GHG emission from food consumption.

农田土壤温室气体排放机理与影响因素研究进展

根据近几年国内外相关文献 ,对农田土壤中二氧化碳、甲烷与氧化亚氮排放相关机理及影响因子进行了归纳 ,并介绍了动物废弃物施用于农田土壤所导致的温室气体排放的变化情况 ;同时还对一些与土壤温室气体排放影响因素有关的定量模拟方程进行了介绍。

碳排放权交易机制下提升企业温室气体排放监测报告能力研究

温室气体排放监测、报告与核证(MRV)制度不仅是获取真实准确温室气体排放数据的重要途径,更是进行温室气体减排政策创新、构建基于市场机制的碳排放权交易体系的核心内容。企业作为市场参与的主体,需要不断提升其在温室气体排放监测报告上的能力,以适应市场发展和政策要求。本文在对监测报告制度的理论基础、内涵要求及运行机理进行全面阐述的基础上,分析了我国企业温室气体排放监测报告能力和管理水平建设的现状及面临的主要问题,并提出若干对策建议。

Abating transport GHG emissions by hydrogen fuel cell vehicles： Chances for the developing world

Fuel cell vehicles, as the most promising clean vehicle technology for the future, represent the major chances for the developing world to avoid high-carbon lock-in in the transportation sector. In this paper, by taking China as an example, the unique advantages for China to deploy fuel cell vehicles are reviewed. Subsequently, this paper analyzes the greenhouse gas （GHG） emissions from 19 fuel cell vehicle utilization pathways by using the life cycle assessment approach. The results show that with the current grid mix in China, hydrogen from water electro- lysis has the highest GHG emissions, at 3.10 kgCO2/km, while by-product hydrogen from the chlor-alkali industry has the lowest level, at 0.08 kgCO2/krn. Regarding hydrogen storage and transportation, a combination of gas-hydrogen road transportation and single compression in the refueling station has the lowest GHG emissions. Regarding vehicle operation, GHG emissions from indirect methanol fuel cell are proved to be lower than those from direct hydrogen fuel cells. It is recommended that although fuel cell vehicles are promising for the developing world in reducing GHG emissions, the vehicle technology and hydrogen production issues should be well addressed to ensure the life-cycle low-carbon performance.

土壤碳氮循环综合研究支撑农业可持续发展

常熟农业生态实验站(以下简称“常熟站”)成立于1987年,是中国科学院设在长江三角洲地区的唯一从事农业、资源与生态环境多学科综合观测、研究与示范基地。建站以来,常熟站在全国率先开展土壤氮素循环、农田固碳减排、农业面源污染等颇具特色的系统研究工作。近5年来,围绕我国农业可持续发展的优化施氮、碳减排与面源污染治理三大科技问题,创建了以经济和环境经济指标为依据的全国水稻适宜施氮量分区确定方法,提出了生物炭施用结合氮肥优化管理与生物炭生产过程生物油/气资源化利用实现我国粮食生产碳中和的技术路径,构建了耦合景观格局和生态过程的南方稻作区面源污染本土化模型,为我国持续推动农业减污降碳增效协同提供了重要科技支撑。

Dietary mitigation of enteric methane emissions from ruminants:A review of plant tannin mitigation options

Methane gas from livestock production activities is a significant source of greenhouse gas(GHG)emissions which have been shown to influence climate change.New technologies offer a potential to manipulate the rumen biome through genetic selection reducing CH4 production.Methane production may also be mitigated to varying degrees by various dietary intervention strategies.Strategies to reduce GHG emissions need to be developed which increase ruminant production efficiency whereas reducing production of CH4 from cattle,sheep,and goats.Methane emissions may be efficiently mitigated by manipulation of natural ruminal microbiota with various dietary interventions and animal production efficiency improved.Although some CH4 abatement strategies have shown efficacy in vivo,more research is required to make any of these approaches pertinent to modern animal production systems.The objective of this review is to explain how anti-methanogenic compounds(e.g.,plant tannins)affect ruminal microbiota,reduce CH4 emission,and the effects on host responses.Thus,this review provides information relevant to understanding the impact of tannins on methanogenesis,which may provide a cost-effective means to reduce enteric CH4 production and the influence of ruminant animals on global GHG emissions.

N2O emission in partial nitritation-anammox process

Nitrous oxide(N2O)is one of the significant greenhouse gases,and partial nitritation-anammox(PNA)process emits higher N2O than traditional nitrogen removal processes.N2O production in PNA mainly occurs in three different pathways,i.e.,the ammonia oxidizing bacteria(AOB)denitrification,the hydroxylamine(NH2 OH)oxidation and heterotrophic denitrifiers denitrification.N2O emission data vary significantly because of the different operational conditions,bioreactor configurations,monitoring systems and quantitative methods.Under the common operational parameter scopes of PNA,N2O emission via NH2 OH oxidation dominates at relatively low dissolved oxygen(DO),low inorganic carbon(IC),high pH or low N02-concentration,while N2O emission via AOB denitrification dominates at relative higher DO,higher IC.lower pH or higher N2O-concentration.AOB are highly enriched while nitriteoxidizing bacteria(NOB)are rarely found in partial nitritation process,and the order Nitrosomonadales of AOB is the dominant group and N2O producer.Anammox bacteria,AOB and certain amount of heterotrophic denitrifying bacteria are observed in the anammox process,the genus Denitratisoma and the heterotrophic denitrifying bacteria in the deep layer of anammox granules are the dominant N2O generation bacteria.In one-stage PNA reactors,anammox bacteria account for a large fraction of the biomass,AOB account for small portion,and NOB account for even less.The microbial community,diversity and N2O producers in one-stage PNA reactors are similar with those in two-stage PNA reactors.The dominant anammox bacteria,AOB and NOB in PNA are the species Candidatus Brocadia,the genera of Nitrotoga,Nitrospira and Nitrobacter,and the genus Nitrosomonas,respectively.The relations between N2O emission pathways and microbial communities need further study in the future.

Development of a stationary ca,-bon emission inventory for Shanghai using pollution source census data

This study utilizes 521,631 activity data points from the 2007 Shanghai Pollution Source Census to compile a stationary carbon emission inventory for Shanghai. The inventory generated from our dataset shows that a large portion of Shanghai＇s total energy use consists of coal-oriented energy consumption. The elec- tricity and heat production industries, iron and steel mills, and the petroleum refining industry are the main carbon emitters. In addition, most of these industries are located in Baoshan District, which is Shanghai＇s largest contributor of carbon emissions. Policy makers can use the enterprise- level carbon emission inventory and the method designed in this study to construct sound carbon emission reduction policies. The carbon trading scheme to be established in Shanghai based on the developed carbon inventory is also introduced in this paper with the aim of promoting the monitoring, reporting and verification of carbon trading. Moreover, we believe that it might be useful to consider the participation of industries, such as those for food processing, beverage, and tobacco, in Shanghai＇s carbon trading scheme. Based on the results contained herein, we recommend establishing a comprehensive carbon emission inventory by inputting data from the pollution source census used in this study.

Resource and waste quantification scenarios for wind turbine decommissioning in the United Kingdom

Wind power produces more electricity than any other form of renewable energy in the United Kingdom(UK)and plays a key role in decarbonisation of the grid.Although wind energy is seen as a sustainable alternative to fossil fuels,there are still several environmental impacts associated with all stages of the lifecycle of a wind farm.This study determined the material composition for wind turbines for various sizes and designs and the prevalence of such turbines over time,to accurately quantify waste generation following wind turbine decommissioning in the UK.The end of life stage is becoming increasingly important as a rapid rise in installation rates suggests an equally rapid rise in decommissioning rates can be expected as wind turbines reach the end of their 20-25-year operational lifetime.Waste data analytics were applied in this study for the UK in 5-year intervals,stemming from 2000 to 2039.Current practices for end of life waste management procedures have been analysed to create baseline scenarios.These scenarios have been used to explore potential waste management mitigation options for various materials and components such as reuse,remanufacture,recycling,and heat recovery from incineration.Six scenarios were then developed based on these waste management options,which have demonstrated the significant environmental benefits of such practices through quantification of waste reduction and greenhouse gas(GHG)emissions savings.For the 2015-2019 time period,over 35 kilotonnes of waste are expected to be generated annually.Overall waste is expected to increase over time to more than 1200 kilotonnes annually by 2039.Concrete is expected to account for the majority of waste associated with wind turbine decommissioning initially due to foundations for onshore turbines accounting for approximately 80%of their total weight.By 2035-2039,steel waste is expected to account for almost 50%of overall waste due to the emergence of offshore turbines,the foundations of which are predominantly made of steel.