Risk assessment in a hypothetical network pipeline in UK transporting carbon dioxide

With the advent of Carbon Capture and Storage technology (CCS) the scale and extent of its handling is set to increase. Carbon dioxide (CO₂) capture plants are expected to be situated near to power plants and other large industrial sources. Afterward CO₂ is to be transported to storage site using one or a combination of transport media: truck, train, ship or pipeline. Transport by pipeline is considered the preferred option for large quantities of CO₂ over long distances. The hazard connected with this kind of transportation can be considered an emerging risk and is the subject of this paper.The paper describes the Quantitative Risk Assessment of a hypothetical network pipeline located in UK, in particular the study of consequences due to a CO₂ release from pipeline.The risk analysis highlighted that some sections of pipeline network cross densely populated areas. For this reason, some changes in the original path of the network have been proposed in order to achieve a significant reduction in the societal risk.     

Modeling the impacts of temperature and precipitation changes on soil CO2 fluxes from a Switchgrass stand recently converted from cropland

Switchgrass(Panicum virgatum L.) is a perennial C_4 grass native to North America and successfully adapted to diverse environmental conditions. It offers the potential to reduce soil surface carbon dioxide(CO_2) fluxes and mitigate climate change. However, information on how these CO_2 fluxes respond to changing climate is still lacking. In this study, CO_2 fluxes were monitored continuously from 2011 through 2014 using high frequency measurements from Switchgrass land seeded in 2008 on an experimental site that has been previously used for soybean(Glycine max L.) in South Dakota, USA. DAYCENT, a process-based model, was used to simulate CO_2 fluxes. An improved methodology CPTE[Combining Parameter estimation(PEST) with "Trial and Error" method] was used to calibrate DAYCENT. The calibrated DAYCENT model was used for simulating future CO_2 emissions based on different climate change scenarios. This study showed that:(i) the measured soil CO_2 fluxes from Switchgrass land were higher for 2012 which was a drought year, and these fluxes when simulated using DAYCENT for long-term(2015–2070) provided a pattern of polynomial curve;(ii) the simulated CO_2 fluxes provided different patterns with temperature and precipitation changes in a long-term,(iii) the future CO_2 fluxes from Switchgrass land under different changing climate scenarios were not significantly different, therefore, it can be concluded that Switchgrass grown for longer durations could reduce changes in CO_2 fluxes from soil as a result of temperature and precipitation changes to some extent.     

The effects of temperature and resource availability on denitrification and relative N2O production in boreal lake sediments

Anthropogenic environmental stressors(like atmospheric deposition,land use change,and climate warming) are predicted to increase inorganic nitrogen and organic carbon loading to northern boreal lakes,with potential consequences for denitrification in lakes.However,our ability to predict effects of these changes is currently limited as northern boreal lakes have been largely neglected in denitrification studies.The aim of this study was therefore to assess how maximum potential denitrification and N_2O production rates,and the relationship between the two(relative N_2O production),is controlled by availability of nitrate(NO_3~-),carbon(C),phosphorus(P),and temperature.Experiments were performed using the acetylene inhibition technique on sediments from a small,nutrient poor boreal lake in northern Sweden in 2014.Maximum potential denitrification and N_2O production rates at 4°C were reached already at NO_3~-additions of 106–120 μg NO_3~-–N/L,and remained unchanged with higher NO_3 amendments.Higher incubation temperatures increased maximum potential denitrification and N_2O production rates,and Q10 was somewhat higher for N_2O production(1.77) than for denitrification(1.69).The relative N_2O production ranged between 13% and 64%,and was not related to NO_3~-concentration,but the ratio increased when incubations were amended with C and P(from a median of 16% to 27%).Combined,our results suggests that unproductive northern boreal lakes currently have low potential for denitrification but are susceptible to small changes in NO_3 loading especially if these are accompanied by enhanced C and P availability,likely promoting higher N_2O production relative to N_2.     

CO2 capture performance of bi-functional activated bleaching earth modified with basic-alcoholic solution and functionalization with monoethanolamine: isotherms, kinetics and thermodynamics

CO_2 capture performance of bifunctional activated bleaching earth(ABE) was investigated at atmospheric pressure. The sorbents were characterized by means of X-ray diffraction(XRD), Brunauer–Emmett–Teller(BET), Caron-Hydrogen-Nitrogen analysis(CHN), Fourier transform infrared(FT-IR) and thermal gravimetric analysis(TGA). The CO_2 capacity was enhanced via basic-modification and monoethanolamine(MEA) loading of the ABE sorbent to obtain a bifunctional surface property. Here, basic-modified calcined ABE with a 30 wt.%MEA loading(SAB-30) showed the highest CO_2 capture capacity, but this was decreased with excess MEA loading( 30 wt.%). At a 10%(V/V) initial CO_2 concentration feed, the maximum capacity of SAB-30 increased from 2.71 mmol/g at 30℃(without adding moisture to the feed) to 3.3 mmol/g at 50℃ when adding 10%(V/V) moisture to the feed. Increasing the moisture concentration further reduced the maximum CO_2 capacity due to the blocking effect of the excess moisture on the sorbent surface. However, SAB-30 could completely capture CO_2 even in a 100%(V/V) initial CO_2 concentration feed. A maximum CO_2 capacity of5.7 mmol/g for SAB-30 was achieved at 30℃. Varying the ratio of sorbent weight to total flow rate of the gas stream had no discernible effect on the equilibrium CO_2 capture capacity. Avrami's equation and Toth's isotherm model provided a good fitting for the data and suggested the presence of more than one reaction pathway in the CO_2 capture process and the heterogeneous adsorption surface of SAB-30. Thermodynamics studies revealed that CO_2 capture on the bifunctional SAB-30 is feasible, spontaneous and exothermic in nature.     

煤炭生产的水足迹评价研究

水足迹是水资源占用的综合评价指标,能够量化人类活动对水资源和水环境的影响,为水资源的高效利用与可持续管理提供科学参考.本文在WFN水足迹评价方法和国际标准水足迹评价方法的基础上,提出了基于生命周期的包含蓝水足迹、灰水足迹和间接水足迹的能源系统水足迹评价模型.将此模型应用到煤炭生产,计算了我国单位煤炭生产的水足迹.研究结果表明,我国1 GJ煤炭生产的水足迹为0.19 m~3,水足迹的80%来源于采掘过程,从水足迹类型来看,灰水足迹占到了87%的比例.本研究为能源系统水足迹评价提供了方法理论,并可为以煤炭为原料或燃料的下游产品水足迹评价提供数据支撑.     

2005年-2014年新疆生态足迹的计算及分析

随着社会经济的发展和人口密度不断增加的双重压力下,新疆维吾尔自治区的生态环境质量问题也日益突出,这就妨碍了区域经济的可持续发展.生态足迹是评估生态环境质量的重要指标,文章根据新疆维吾尔自治区2005年-2014年自然资源、能源消费、人口等数据,计算得出的生态足迹、生态环境承载能力和生态赤字结果显示,新疆维吾尔自治区自然资源供应和需求之间的关系不均衡,新疆生态足迹和生态承载力并不是处于最佳可持续性状态.     

Land Area Eligible for Afforestation and Reforestation within the Clean Development Mechanism: A Global Analysis of the Impact of Forest Definition

Within the United Nations Framework Convention on Climate Change (UNFCCC) Kyoto Protocol, countries have significant latitude to define a forest. The most important parameter affecting area designated as forest is the minimum crown cover which can be set between 10 and 30%. The choice will have implications for the amount of land available in a country for afforestation and reforestation activities within the Clean Development Mechanism (CDM-AR). In this paper, we present an analysis of the regional differences in land availability for CDM-AR projects. We then examine how the choice of a high or low threshold value for crown cover will affect the area available for CDM activities and how the limitations imposed by this element of the definition compares to other factors that are likely to limit CDM activities. Results represent a global analysis that included all countries not included in Annex I of the Kyoto Protocol, and examined the effect on land availability of a range of crown cover thresholds ranging from 10–30%. Of the 140 Non-Annex One countries, 107 countries were found to have a potential for CDM-AR projects. Asia had the largest amount of combined area suitable for CDM-AR at the 10% crown cover threshold level. However, at 30%, South America had the greatest amount of land available, and a large change in available land area, which increased by almost five times compared to what was available at the 10% threshold. The area available in Africa increased by a factor of 5.5. Central America showed the largest increase, to almost 10 times more at the 30% threshold. By contrast, within Asia, the area increase was comparatively less, but still the area nearly doubled. Globally, a low threshold of 10% crown cover excluded almost 2/3 of the land identified that was eligible at 30%, over 5 million km². The spatial analyses showed not only the effects of the choice of the crown cover criterion, but also where the land was available for CDM activities within each country at different thresholds. Protected areas account for 10–20% of the CDM-AR eligible area in most countries.     

基于生态足迹模型的土地利用生态环境分析方法研究

随着经济和社会的发展,生态环境问题正日益受到各国政府和社会的关注。而作为人类一切活动载体的土地,其生态环境显得愈加重要。生态足迹法是一种定量度量生态经济发展协调状况及发展能力的有效方法。本文是基于Bicknell的投入产出模型探讨了对土地利用生态环境进行动态分析的方法,进一步研究了一定区域在进行对外贸易时,对土地资源的开发利用和消费,为衡量土地生态环境和可持续发展状况,作出科学的决策提供定量工具。并从土地利用角度出发,提出了减少生态赤字一些对策。     

Urban hinterlands—the case of an Israeli town ecological footprint

Modern urban life is characterized by the consumption of materials and energy, which are imported from all over the world and discharge waste that in many cases has a negative impact on ecosystems far from the cities in which they consumed. Indeed, cities cannot survive without worldwide hinterlands for resources and emissions sequestration. The ecological footprint (EF) concept provides valuable insights into the human appropriation of resources relative to earth’s carrying capacity, and therefore it enables us to compare human demands with nature’s supply and provides an indicator of human ecological sustainability. An attempt was made to calculate the EF of Ra’anana, Israel as a case study, to compare the EF-value with the expected for ecological sustainability and to emphasize the dependence on overseas ecosystems. Ra’anana, a town of 67,300 inhabitants in the year 2002, is considered a ‘dormitory town’ with a high quality of life. The EF was calculated using mainly the component method. The calculated EF for Ra’anana is 4.0 ha/resident which means that the required hinterland, located all over the world, is nearly 180 times the size of the town. The town’s EF is twice the value expected for sustainability on a global scale. We draw several scenarios in order to reduce the EF. On a national basis as well as with the town case study, electric energy, food and waste can be reduced and in turn would have a dramatic impact on the EF.