Reducing greenhouse gas emissions of a heterogeneous vehicle fleet

Recent research on the vehicle routing problem attempts to integrate so-called “green” aspects into classical planning models. The minimization of transport-related emissions (especially CO₂) instead of driving distances is an important integration approach. Within this paper, we propose an approach which is focusing on the reduction of CO₂ emissions caused by transportation. Based on the observation that vehicles with different maximal payload values have different payload-dependent fuel consumption characteristics, we integrate into Dantzig’s classical vehicle routing model the option of choosing vehicles of different size for route fulfillment. Then, the Emission Minimization Vehicle Routing Problem with Vehicle Categories (EVRP-VC) is introduced. It aims at minimizing the fuel consumption, respectively CO₂ emissions instead of the driving distances. Comprehensive computational experiments with CPLEX are conducted to evaluate the EVRP-VC. A major finding is that the quantity of fuel needed to serve a given request portfolio can be reduced tremendously by using an inhomogeneous fleet with vehicles of different size.     

Well-to-wheel analysis on greenhouse gas emission and energy use with natural gas in Korea

Purpose

In Korea, natural gas is widely used as city gas, fuel for electricity generation, and fuel for transportation (e.g., city bus). However, the environmental impact associated with the use of natural gas in Korea has not been paid much attention to. In this study, well-to-wheel (WTW) analysis on the greenhouse gas (GHG) emissions and energy uses associated with natural gas in Korea was performed by considering every step from feedstock recovery to final use in the vehicle operation.

Methods

The raw data used in the analysis were mainly provided by Korean natural gas industry and related associations. The additional information, especially for the processes in foreign countries, was also collected by literature survey. We adopted the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model as a base WTW analysis tool, which was developed by the U.S. Argonne National Laboratory. However, the WTW analysis on natural gas in Korea is far different from that of the U.S, because ~99 % of natural gas used in Korea is imported from the oversea countries in the form of liquefied natural gas (LNG). For this reason, detailed parameters in GREET were changed for Korean situation, and especially, significant modifications were made on liquefaction, LNG transportation and storage, and re-gasification processes.

Results and discussion

As a result of the analysis, the well-to-pump GHG emissions of city gas and compressed natural gas are calculated as 25,717–30,178 and 28,903–33,422 g CO₂ eq./GJ_{Fianl_fuel}, respectively. The WTW GHG emission of compressed-natural-gas-fueled city bus is calculated as 1,348–1,417 g CO₂ eq./km. These values are relatively larger than those of the U.S., because most of the natural gas used in the U.S. is transported by pipeline in a gaseous state, which typically takes less energy and associated GHG emissions, as compared to the import of LNG in Korea. Finally, sensitivity analysis is performed on the parameters, which have either range of values among various sources or uncertainties due to lack of accurate information.

Conclusions

The results show that further investigation on three parameters, i.e., CO₂ venting during natural gas processing, CH₄ leakage in Korea, and CH₄ leakage during recovery process, would be helpful to further improve overall accuracy of the analysis.     

Evaluating the reduction in green house gas emissions achieved by the implementation of the household appliance recycling in Japan

Background, Aim and Scope The Home Appliance Recycling Law (hereunder referred to as the Law) for used cathode ray tube (CRT) TVs, air conditioners, refrigerators and washing machines was enacted in April 2001 in Japan. The Law requires that retailers reclaim, and manufacturers and importers recycle such home appliances. Consumers are required to pay collection and recycling fees incurred in disposing of any of the four home appliances. Home appliances must, as a general rule, be managed in accordance with the Law. In reality, other routes exist, such as via local authorities, scrap processors, illegal dumping and exporting. At about the time the Law was enacted, the refrigerant used for air conditioners and refrigerators was replaced by more environmentally friendly substances such as isobutene. Local authorities had the responsibility of disposing of the appliances of households before the enactment of the Law. It was general practice for local authorities to dispose of home appliances in landfills after breaking them up and recovering valuable resources such as iron, copper and aluminum. Although they made efforts to recover refrigerant fluorocarbons, there were not required to do so. Materials and Methods This study analyzed the material flow resulting from the Law and other processing flows to quantify the global warming effect caused by home appliance recycling using the life cycle assessment (LCA) method. To evaluate the Law and to develop policy planning, the challenges of future efforts will be considered using time series data. For these reasons, we have assessed the Project Scenario, which corresponded to the present reality; the Baseline Scenario, which assumed that measures such as the Law were not implemented after 2000, and the Ideal Scenario, where all used products were recycled as prescribed by the Law. The environmental impacts for each scenario were estimated using value, which was obtained from multiplying the amount of reproduction and waste treatment by each inventory data. Results It is estimated that emission reductions of 4.7E+4 t CO₂e, subtracted the Project Scenario from the Baseline Scenario, were reduced for TVs in 2001 through recycling. The impact from recycling glass from cathode ray tube (CRT) televisions is significant. An improvement of 2.3E+4 t CO₂e could be anticipated by upgrading to the Ideal Scenario in 2001. It was estimated that there was a reduction of 9.2E+5 t CO₂e in 2001 for air conditioners. Although the effect of the recovery for refrigerants contributed greatly, some fluorocarbons that are still discharged have had a considerable impact on greenhouse gas emissions. Hypothetically, a reduction of 3.2E+6 t CO₂e could be anticipated with the Ideal Scenario in 2001. A reduction of 2.6E+6 t CO₂e was achieved for refrigerators in 2001. Although a further reduction can be anticipated through the Ideal Scenario, there will not be much difference with the Project Scenario by 2010. It was estimated that 3.8E+4 t CO₂e were reduced for washing machines in 2001. Only a small improvement can be expected through the Ideal Scenario. Discussion Since many assumptions were used in this study, a sensitivity analysis was carried out in order to grasp their impact. The findings of the sensitivity analysis are that the uncertainties are large, but the number of the greenhouse gas (GHG) reductions is still clear except for the difference between the Project Scenario and the Ideal Scenario for TVs. This analysis gives authenticity to the findings. Conclusions Establishing a system for liquid crystal display and plasma display panel TVs is desirable because the absolute amount of used LCD/PDP TVs will rapidly increase as the usage of CRT TVs rapidly decreases from 2007. With regard to refrigerant recovery from air conditioners, a significant decrease in GHG emissions has been recorded. There is, however, still ample room for improvement. It will be necessary to switch to refrigerants with low global warming potentials (GWPs) or work more on improving the recovery rate in the future. Alternatives and recovery of fluorocarbons from refrigerators contributed greatly to GHG reductions. The GHG emissions from refrigerator recycling will be minimal whether used refrigerator will be processed legally or not because most used refrigerators will contain natural refrigerants in the near future. The improvement for washing machines was low because it was assumed that their main constituent steel has been previously recycled, and that the plastic recycling rate will not change significantly in the future. An improvement in the recycling technology itself is required. This study was carried out on four home appliance products, and it was found that the Home Appliance Recycling Law has brought significant reductions in GHG emissions. There is also room to make GHG reductions through improving the processing methods further. Recommendations and Perspectives The impact on GHG emissions by fluorocarbons of air conditioners and refrigerators is the greatest. Adequate measures are particularly required for air conditioners that may continue to discharge GHGs in the future. ESS-Submission Editor: Dr. Lindita Bushi (lindita.bushi@ghgm.com)     

Development and use of a vaccinia virus neutralization assay based on flow cytometric detection of green fluorescent protein

A rapid and sensitive neutralization assay is required to evaluate alternative smallpox vaccines. Here we describe the development and use of a 96-well plate, semi-automated, flow cytometric assay that uses a recombinant vaccinia virus expressing enhanced green fluorescent protein and which would be applicable to other viruses.     

Domestic water versus imported virtual blue water for agricultural production: A comparison based on energy consumption and related greenhouse gas emissions

The supply of water, food, and energy in our global economy is highly interlinked. Virtual blue water embedded into internationally traded food crops has therefore been extensively researched in recent years. This study focuses on the often neglected energy needed to supply this blue irrigation water. It provides a globally applicable and spatially explicit approach to the watershed level for water source specific quantification of energy consumption and related greenhouse gas (GHG) emissions of irrigation water supply. The approach is applied to Israel's total domestic and imported food crop supply of 105 crops by additionally including import-related transportation energy and emissions. Total energy use and related emissions of domestic crop production were much lower (551 GWh/422 kt CO₂-equivalents [CO₂e]) than those embedded into crop imports (1639 GWh/649 kt CO₂e). Domestic energy and emissions were mainly attributable to the irrigation water supply with artificial water sources (treated domestic wastewater and desalinated water, 84%). Transport accounted for 79% and 66% of virtually imported energy and emissions, respectively. Despite transport, specific GHG emissions (CO₂e per ton of crop) were significantly lower for several crops (e.g., olives, almonds, chickpeas) compared to domestic production. This could be attributed to the high share of energy-intensive artificial water supply in combination with higher irrigation water demands in Israel. In the course of an increasing demand for artificial water supply in arid and semi-arid regions, our findings point to the importance of including “energy for water” into comparative environmental assessment of crop supply to support decision-making related to the water–energy–food nexus.     

基于MSIASM和能源消费碳排放的中国四大直辖市社会代谢分析

通过社会代谢多尺度综合评估(Multi-Scale Integrated Assessment of Societal Metabolism,MSIASM)方法,采用生物-经济压力和不同组织尺度下的体外能代谢率、能源密度指标,并将能源消费碳排放融入评估框架,评价了中国四大直辖市2004年至2010年的社会代谢及其综合发展状况。研究中能源消费碳排放的加入较好补充了MSIASM在生态评估方面的弱势。研究结果显示,四大直辖市整体社会代谢发展良好,体外能代谢率和生物-经济压力稳步上升,能源密度和单位能耗碳排放不断降低,总体呈现良性发展态势。从各个直辖市的社会经济系统各部门表现来看,各城市体现了自己的突出特点。在深入到行业尺度研究体外能代谢率、能源密度后,整体显示出控制工业部门和交通运输部门的能耗增长对于提高经济生产能源效率的突出作用,同时应继续加大金融和计算机等低能耗高经济生产率行业的发展力度。     

Pharmacophore based 3D-QSAR modeling and free energy analysis of VEGFR-2 inhibitors

VEGFR-2, a transmembrane tyrosine kinase receptor is responsible for angiogenesis and has been an attractive target in treating cancers. The inhibition mechanism of structurally diverse urea derivatives, reported as VEGFR-2 inhibitors, was explored by pharmacophore modeling, QSAR, and molecular dynamics based free energy analysis.The pharmacophore hypothesis AADRR, resulted in a highly significant atom based 3D-QSAR model (r² = 0.94 and q² = 0.84). Binding free energy analysis of the docked complexes of highly active and inactive compounds, after 7 ns MD simulation, revealed the importance of van der Waals interaction in VEGFR-2 inhibition. The decomposition of binding free energy on a per residue basis disclosed that the residues in hinge region and hydrophobic pocket play a role in discriminating the active and inactive inhibitors. Thus, the present study proposes a pharmacophore hypothesis representing the identified interactions pattern and its further application as a template in screening databases to identify novel VEGFR-2 inhibitor scaffolds.     

一种基于BIOLOG代谢指纹分析的油气微生物勘探新方法

【目的】建立基于土壤微生物群落生理功能代谢的油气微生物勘探新方法。【方法】采集新疆玛北油气藏区浅层地表土壤样品45份,非油气藏区样品25份,利用BIOLOG微平板,测定微生物群落代谢活性,采用判别分析模型判断油气藏区微生物异常。【结果】从95种碳源中,筛选到10种能够体现油气藏区与非油气藏区土壤微生物群落结构差异的典型碳源,利用判别函数对试验及对照区进行回判,油气藏区判别正确率为97.8%,非油藏区判别正确率为100%,总判别正确率为98.6%。【结论】BIOLOG技术能高效准确的用于油气藏初步勘测。     

Development of new microsatellite primers for green and white sturgeon

Sixty-eight primer sets for microsatellite loci were developed from microsatellite motif enriched genomic libraries of pooled DNA from the polyploid green and white sturgeon (Acipenser medirostris and A. transmontanus). Four individuals from each species were screened for polymorphism at these loci. Forty-eight loci amplified in both species, and some exhibited species-specific amplification for white or green sturgeon (8 and 12 loci, respectively). The number of alleles per locus ranged from one to 12. At least 68% of the green and 65% of the white sturgeon loci we developed are polysomic.     

基于LEAP的厦门市节能与温室气体减排潜力情景分析

城市是人类社会经济活动的中心,聚集了世界一半以上的人口。在城市发生的温室气体排放量占全球排放总量的75%左右,因此在城市这个尺度上研究温室气体减排意义重大。从城市这个尺度出发,以厦门市为实际研究案例,应用LEAP模型进行节能减排政策情景分析,定量分析评价城市节能减排潜力,并详细分析各种控制情景和各部门的节能减排贡献率。研究结果显示:在综合控制情景下,厦门能源消费总量年均增长率、万元地区生产总值能耗和温室气体排放总量年均增长率都有所下降;清洁燃料替代措施节能减排效果最好,工业部门节能减排潜力最大;优化能源使用结构蕴藏巨大减排潜力。     

电-氢-糖循环的新能源体系研究进展

发展绿色低碳的可再生能源体系已经成为重要的国际共识和方向,也是我国践行“双碳”目标、保障能源安全、走社会可持续发展的必要路径。本文聚焦电-氢-糖(electricity-hydrogen-carbohydrate, EHC)循环的新能源理论体系,重点综述了中国科学院天津工业生物技术研究所10余年来在基于体外多酶催化系统(in vitro synthetic enzymatic biosystem, ivSEB)的糖与水反应制氢、糖完全氧化产电,以及氢或电能固定CO₂到糖的生物转化方面所做的工作,阐述体外多酶催化系统的设计原则、分子基础,并从电-氢-糖循环进一步延伸出以糖(淀粉)为核心的体外合成生物制造,结合最新相关研究进展,分析讨论体外多酶催化体系的特色和优缺点,并展望未来发展方向,促进经济和社会的绿色低碳可持续发展。     

Localising livestock protein feed production and the impact on land use and greenhouse gas emissions

Livestock farmers in Sweden usually grow feed grains for livestock but import protein feed from outside Sweden. Aside from the economic implications, some environmental issues are associated with this practice. We used life cycle assessment to evaluate the impact of local protein feed production on land use and greenhouse gas emissions, compared with the use of imported protein feed, for pig meat and dairy milk produced in Sweden. Our results showed that local production reduced greenhouse gas emissions by 4.5% and 12%, respectively, for pigs and dairy cows. Land use for feed production in Sweden increased by 11% for pigs and 25% for dairy cows, but total land use decreased for pig production and increased for dairy milk production. Increased protein feed cultivation in Sweden decreased inputs needed for animal production and improved some ecological processes (e.g. nutrient recycling) of the farm systems. However, the differences in results between scenarios are relatively small and influenced to an extent by methodological choices such as co-product allocation. Moreover, it was difficult to assess the contribution of greenhouse emissions from land use change. The available accounting methods we applied did not adequately account for the potential land use changes and in some cases provided conflicting results. We conclude that local protein feed production presents an opportunity to reduce greenhouse gas emissions but at a cost of increasing land occupation in Sweden for feed production.     

KnowledgeEditor: a new tool for interactive modeling and analyzing biological pathways based on microarray data

KnowledgeEditor is a graphical workbench for biological experts to model biomolecular network graphs. The modeled network data are represented by SRML, and can be published via the internet with the help of plug-in module 'GSCope'. KnowledgeEditor helps us to model and analyze biological pathways based on microarray data. It is possible to analyze the drawn networks by simulating up-down regulatory cascade in molecular interactions. AVAILABILITY: KnowledgeEditor is available at http://gscope.gsc.riken.go.jp/.     

Compartmentalized energy transfer in cardiomyocytes: use of mathematical modeling for analysis of in vivo regulation of respiration.

The mathematical model of the compartmentalized energy transfer system in cardiac myocytes presented includes mitochondrial synthesis of ATP by ATP synthase, phosphocreatine production in the coupled mitochondrial creatine kinase reaction, the myofibrillar and cytoplasmic creatine kinase reactions, ATP utilization by actomyosin ATPase during the contraction cycle, and diffusional exchange of metabolites between different compartments. The model was used to calculate the changes in metabolite profiles during the cardiac cycle, metabolite and energy fluxes in different cellular compartments at high workload (corresponding to the rate of oxygen consumption of 46 mu atoms of O.(g wet mass)-1.min-1) under varying conditions of restricted ADP diffusion across mitochondrial outer membrane and creatine kinase isoenzyme "switchoff." In the complete system, restricted diffusion of ADP across the outer mitochondrial membrane stabilizes phosphocreatine production in cardiac mitochondria and increases the role of the phosphocreatine shuttle in energy transport and respiration regulation. Selective inhibition of myoplasmic or mitochondrial creatine kinase (modeling the experiments with transgenic animals) results in "takeover" of their function by another, active creatine kinase isoenzyme. This mathematical modeling also shows that assumption of the creatine kinase equilibrium in the cell may only be a very rough approximation to the reality at increased workload. The mathematical model developed can be used as a basis for further quantitative analyses of energy fluxes in the cell and their regulation, particularly by adding modules for adenylate kinase, the glycolytic system, and other reactions of energy metabolism of the cell.     

A methodology for separating uncertainty and variability in the life cycle greenhouse gas emissions of coal-fueled power generation in the USA

Purpose

Results of life cycle assessments (LCAs) of power generation technologies are increasingly reported in terms of typical values and possible ranges. Extents of these ranges result from both variability and uncertainty. Uncertainty may be reduced via additional research. However, variability is a characteristic of supply chains as they exist; as such, it cannot be reduced without modifying existing systems. The goal of this study is to separately quantify uncertainty and variability in LCA.

Methods

In this paper, we present a novel method for differentiating uncertainty from variability in life cycle assessments of coal-fueled power generation, with a specific focus on greenhouse gas emissions. Individual coal supply chains were analyzed for 364 US coal power plants. Uncertainty in CO₂ and CH₄ emissions throughout these supply chains was quantified via Monte Carlo simulation. The method may be used to identify key factors that drive the range of life cycle emissions as well as the limits of precision of an LCA.

Results and discussion

Using this method, we statistically characterized the carbon footprint of coal power in the USA in 2009. Our method reveals that the average carbon footprint of coal power (100 year time horizon) ranges from 0.97 to 1.69 kg CO₂eq/kWh of generated electricity (95 % confidence interval), primarily due to variability in plant efficiency. Uncertainty in the carbon footprints of individual plants spans a factor of 1.04 for the least uncertain plant footprint to a factor of 1.2 for the most uncertain plant footprint (95 % uncertainty intervals). The uncertainty in the total carbon footprint of all US coal power plants spans a factor of 1.05.

Conclusions

We have developed and successfully implemented a framework for separating uncertainty and variability in the carbon footprint of coal-fired power plants. Reduction of uncertainty will not substantially reduce the range of predicted emissions. The range can only be reduced via substantial changes to the US coal power infrastructure. The finding that variability is larger than uncertainty can obviously not be generalized to other product systems and impact categories. Our framework can, however, be used to assess the relative influence of uncertainty and variability for a whole range of product systems and environmental impacts.