上海市交通碳排放量与城市发展的关系研究

随着社会经济快速发展,上海市交通需求量逐年增长,导致交通运输行业的能源消费量以及碳排放量不断增加。研究了1998—2012年上海市交通碳排放量与城市发展的关系,并对该市的交通碳排放量进行了预测与情景分析。结果表明,上海市交通碳排放量与人均GDP、人均消费支出、城市化率均呈显著的正相关关系。协整检验显示,上海市交通碳排放量与上海市城市发展存在协整关系。对交通碳排放量影响最显著的是城市化率,其次是人均GDP,再次是人均消费支出。在正常、低碳、强化低碳情景下,2050年上海市的交通碳排放量分别为46 599.24万、28 196.70万、9 575.47万t。通过转变发展方式,有望科学合理地减少交通碳排放量。     

基于主成分分析法的城市客运交通碳排放影响因素研究

以广东省城市客运交通为研究对象,基于2005—2015年私人交通(私人载客汽车和摩托车)碳排放测算数据和公共交通(公共汽电车、出租车和轨道交通)碳排放公布数据,应用主成分分析法对其影响因素进行分析。结果表明:2005—2015年广东省城市客运交通碳排放总量呈上升趋势,年均增长率达14.69%;其中私人交通碳排放增长显著,是广东省城市客运交通碳排放主要来源;而公共交通碳排放年增长率有所下降,表明广东省公共交通领域新能源汽车推广政策成效明显。影响广东省城市客运交通碳排放的主要因素是经济水平、城市交通规模及运输能力,其次为居民出行习惯和环境质量。因此,广东省未来城市客运交通低碳发展模式应削弱个体交通,构建以公共交通为导向的交通发展模式。     

天津市滨海新区家庭直接能源消费碳减排分析

以天津市滨海新区家庭直接能源消费碳排放量为基础数据,运用统计类比分析的方法分析了居民家庭通过有意识改变直接能源消费方式所能带来的碳减排空间及碳减排结构。分析表明,5、6月平均户均碳减排量为27.75kg(以CO2减排当量计,下同),平均人均碳减排量为9.20kg,平均减排比为8.92%。家庭用电的碳排放量具有最大的减排空间;燃气的碳排放量相对于用电和交通较小,但燃气节约比相对最高,因此居民燃气的碳减排空间也相当可观;私家车是影响家庭交通出行碳排放量的最重要因素。家庭人口与住宅面积不是影响家庭碳减排量的主导因素,居民的环保意识及行为在家庭碳减排中起重要作用。因此,提高居民的低碳环保意识,改善居民的生活方式,对于国家碳减排意义重大。     

基于对数平均迪氏指数法的天津市能源消费碳排放分解分析

根据联合国政府间气候变化专门委员会(IPCC)2006年版碳排放计算指南中的计算公式和碳排放系数缺省值计算了天津市2000-2008年能源消费的碳排放量,然后对人均GDP、人口和能源强度与碳排放量作相关性分析,运用对数平均迪氏指数(LMDI)法对天津市能源消费碳排放量和碳排放强度进行分解分析,最后探讨了其主要影响因素的...     

碳排放约束下的天津市能源区域分配研究——基于碳夹点模型分析

能源的供需及碳排放约束是中国各省市在经济快速发展过程中必须考虑的问题。在能源供需和碳排放约束下,对区域的能源利用进行合理分配具有实际意义。利用碳夹点分析方法,对天津市的能源分配问题进行研究,建立分析模型,在考虑整体和区域的能源需求和碳排放约束条件下,分别确定各种化石能源和清洁能源的使用量,以实现最优的能源结构和能源供需平衡,为地方政府制定合理的能源供应量和碳排放约束指标提供科学依据。研究表明,若只考虑天津市总体的碳排放约束(1 570.6×105 t)和能源需求(223.0×1013 kJ),需要减少24.9×1013 kJ的煤能源使用,同时增加31.7×1013 kJ的清洁能源;若天津市能提供50.0×1013 kJ的清洁能源,在达到能源总需求的同时,总的碳排放为1 378.5×105 t,因此能源部门在规划天津市的总体碳排放约束时不应低于此值;考虑各个区域的碳排放约束的条件下,规划得到的排放总量为1 434.1×105 t,能够满足当前的碳排放限值。     

基于灰色关联分析的天津市碳排放驱动因素研究

天津市拥有中国重要老工业基地和低碳城市试点的“双重身份”,当前面临城市化工业化阶段的能源刚性需求巨大和减排压力日渐增大的双重压力,因此制定适宜天津市现阶段发展特征的碳排放政策追在眉睫.采用政府间气候变化专门委员会(IPCC)推荐的碳排放核算方法对天津市2001-2010年的CO2排放进行了估算,结合低碳城市试点指标剖析了天津市面临的减排困境;为找出解决办法,采用灰色关联分析法对天津市碳排放的驱动因素进行了识别.结果表明,能源消耗总量、人口指标、经济增长速度和产业结构指标等是CO2排放的关键因素,并由此得出结论,天津市碳减排的工作重心应集中于优化产业结构和能源利用结构、提高能效、倡导低碳消费等方面.     

上海市交通环境空气质量监测路边站发展探索

近年来,随着上海市机动车数量的增加,越来越多的市民开始关注机动车尾气污染.上海市计划在“十二五”期间加强交通污染的监测和评估,在机动车尾气污染敏感区域建立交通环境空气质量监测路边站.通过分析上海市目前的交通污染现状和该市的交通环境空气质量监测开展情况,提出了该市交通环境空气质量监测路边站的发展思路和路边站建设中需关注的问题.     

中国2010年上海世界博览会碳排放核算体系研究

在《温室气体盘查议定书》(GHG Protocol)方法学的基础上,根据中国2010年上海世界博览会(简称上海世博会)碳排放特征,探索建立了上海世博会碳排放核算体系,包括碳排放报告原则、测算边界、排放源界定以及相应计算方法,以期为国际大型赛事或活动碳排放核算方法学的建立提供一定参考。基于跟踪评估测算结果,上海世博会碳排放总量(以二氧化碳当量计)为492.151万t,范围3(交通运输、其他类型间接排放)引起的碳排放占比最高(92.5%),其中游客出行是最关键的排放源,其碳排放占碳排放总量的64.8%。因此,引导游客的绿色出行是"低碳世博"的关键。     

天津市煤炭消费的行业结构和影响因素分析

分析了天津市煤炭消费的行业结构和影响因素,旨在为天津市削减煤炭消费总量提供参考依据。由于煤炭大部分用于生产二次能源,计算了天津市生产各行业消费的二次能源所需的煤炭量,将其与各行业的煤炭终端消费量综合考虑。结果显示,天津市煤炭消费的行业集中度较高,工业占大部分比例,其中又以钢铁、化工行业最突出,同时生活消费和第三产业的煤炭消费量也不容忽视。与全市煤炭消费总量灰色关联度最高的指标为城市建设用地数量和人均生活能源消费量。     

天津市典型道路机动车实际活动水平特征研究

采用实地监测的方法,对天津市典型区域(中心城区、远郊区)、典型道路(快速路、主干路、次干路、支路、集疏港公路)机动车实际活动水平特征进行调查和统计分析。各道路的车流量和车速小时变化趋势均分别呈现出较明显的"M"型和"W"型特征,与人们日常出行规律相符。中心城区同类型道路车流量高于远郊区,同类型道路车速与远郊区基本相当。不同类型道路车队构成存在较大差异,但小型客车仍为各类型道路主流车型,均占80%以上,远郊区货车比例相对较高。集疏港公路具有显著的"潮汐交通"特点,"客货混行"造成"港城交通矛盾"突出。     

Soil carbon dynamics and potential carbon sequestration by rangelands

The USA has about 336 Mha of grazing lands of which rangelands account for 48%. Changes in rangeland soil C can occur in response to a wide range of management and environmental factors. Grazing, fire, and fertilization have been shown to affect soil C storage in rangelands, as has converting marginal croplands into grasslands. Carbon losses due to soil erosion can influence soil C storage on rangelands both by reducing soil productivity in source areas and potentially increasing it in depositional areas, and by redistributing the C to areas where soil organic matter mineralization rates are different. Proper grazing management has been estimated to increase soil C storage on US rangelands from 0.1 to 0.3 Mg C ha(-1)year(-1) and new grasslands have been shown to store as much as 0.6 Mg C ha(-1)year(-1). Grazing lands are estimated to contain 10-30% of the world's soil organic carbon. Given the size of the C pool in grazing lands we need to better understand the current and potential effects of management on soil C storage.     

Sensitivity of carbon sequestration costs to soil carbon rates

Modifying current agricultural management practices as a means of sequestering carbon has been shown to be a relatively low cost way to offset greenhouse gas emissions. In this paper we examine the sensitivity of the estimates of the amount of soil carbon sequestered and the implied costs of sequestering a tonne of carbon to changes in the rates of soil carbon sequestered for alternative production practices. An application is made to the dryland grain production systems of the US Northern Plains where the marginal costs of soil C range from $20 to $100 per MT. We show that the resulting changes in the marginal costs quantities of C sequestered are not a monotonic transformation of the changes in the soil carbon rates. These results underscore the importance of using a linked economic and biophysical simulation model to assess the economic potential for sequestering carbon in agricultural soils.     

活性炭纤维脱除二氧化碳的实验研究

采用活性炭纤维(ACF)作为吸附材料,研究了ACF对CO_2和N_2的吸、脱分离特性。结果表明,粘胶基活性炭纤维(V-ACF)和聚丙烯腈基活性炭纤维(PAN-ACF)对CO_2和N_2都表现出较好的吸附效果,其中V-ACF对CO_2和N_2的吸附系数高达9,说明ACF是很好的吸附分离材料。ACF对不同烟气浓度和温度下对CO_2吸附的结果说明,ACF对于高浓度CO_2更易于脱除;讨论了ACF在不同解析温度或时间对吸附的影响和ACF的热稳定性,结果表明,在较高解析温度或者较长解析时间下更加容易脱除CO_2,且再生时间短,最佳的解析时间为15 min。经过相同的多次实验,ACF的性能稳定,再生效率稳定在86%。     

含碳气溶胶研究进展：有机碳和元素碳

含碳气溶胶是我国大气区域性复合型污染的重要物种,对全球气候变化、辐射强迫、能见度、环境质量、人类健康等会产生重要影响.主要从含碳气溶胶来源及成因、环境影响、样品采集及测试等方面对国内外相关研究进行了评述,讨论了有机碳和元素碳研究中存在的关键和难点问题,并对其发展前景进行了展望.     

Hydrodehalogenation of chlorobenzene on activated carbon and activated carbon supported catalysts

Chlorinated aromatic compounds in (waste) gases can be removed and/or dehalogenated by passing over a bed of activated carbon (AC) in a hydrogen containing atmosphere. Dehalogenation of the model compound chlorobenzene (PhCl) to HCl is complete at 490 degrees C--rather than the approximately 900 degrees C needed for the mere gas-phase reaction--but part of the benzene moieties is retained on the AC, resulting in its rather rapid deactivation, apparently due to a large decrease in surface area. Therefore, <1 mmol PhCl per gram of 'catalyst' could be processed. At 600 degrees C chlorobenzene yields 100% of both HCl and benzene, but still the AC lost most of its activity in time. Performances are compared of three different commercial ACs. As a HCl-washed AC is just as active, metals are not involved. This acid-washed AC was used as a support for 10 wt% Ni or Fe catalysts. While Fe did not show appreciable activity, results with Ni are promising. The yields of HCl and benzene from PhCl are approximately 100% already at T<400 degrees C, and T(50%) congruent with 260 degrees C, over 200 degrees C lower than with AC alone. There is no appreciable decrease of activity after having injected >20 mmol PhCl per gram of catalyst at partial conversion.     

The impacts of carbon emissions and voluntary carbon disclosure on firm value

Investors and other stakeholders are starting to pay attention to firms’ carbon emissions and carbon disclosure. This study investigated the effects of voluntary carbon disclosure information and carbon emissions on firm value from listed companies in the Shanghai and Shenzhen 300 (CSI 300) Index. We also apply the Probit model to predict the probability of voluntary carbon disclosure information. The results indicate that the increase in carbon emissions has a negative impact on firm value. The action that companies select to disclose carbon emissions has a positive impact on firm value. The effect of leverage ratio on VCDI is increasing year by year. What is more, the probability of the average size firm carbon disclosure was 30.73% in 2020. Company management needs to pay attention to the risks caused by carbon emissions and ensure the quality of carbon disclosure information, especially the authenticity and reliability of the information.

     

Early atmospheric detection of carbon dioxide from carbon capture and storage sites

The early atmospheric detection of carbon dioxide (CO₂) leaks from carbon capture and storage (CCS) sites is important both to inform remediation efforts and to build and maintain public support for CCS in mitigating greenhouse gas emissions. A gas analysis system was developed to assess the origin of plumes of air enriched in CO₂, as to whether CO₂ is from a CCS site or from the oxidation of carbon compounds. The system measured CO₂ and O₂ concentrations for different plume samples relative to background air and calculated the gas differential concentration ratio (GDCR = ?ΔO₂/ΔCO₂). The experimental results were in good agreement with theoretical calculations that placed GDCR values for a CO₂ leak at 0.21, compared with GDCR values of 1–1.8 for the combustion of carbon compounds. Although some combustion plume samples deviated in GDCR from theoretical, the very low GDCR values associated with plumes from CO₂ leaks provided confidence that this technology holds promise in providing a tool for the early detection of CO₂ leaks from CCS sites. Implications: This work contributes to the development of a cost-effective technology for the early detection of leaks from sites where CO₂ has been injected into the subsurface to enhance oil recovery or to permanently store the gas as a strategy for mitigating climate change. Such technology will be important in building public confidence regarding the safety and security of carbon capture and storage sites.     

Net carbon flux from agricultural ecosystems: methodology for full carbon cycle analyses

Agricultural ecosystems have the potential to sequester carbon in soils by altering agricultural management practices (i.e. tillage practice, cover crops, and crop rotation) and using agricultural inputs (i.e. fertilizers and irrigation) more efficiently. Changes in agricultural practices can also cause changes in CO2 emissions associated with these practices. In order to account for changes in net CO2 emissions, and thereby estimate the overall impact of carbon sequestration initiatives on the atmospheric CO2 pool, we use a methodology for full carbon cycle analysis of agricultural ecosystems. The analysis accounts for changes in carbon sequestration and emission rates with time, and results in values representing a change in net carbon flux. Comparison among values of net carbon flux for two or more systems, using the initial system as a baseline value, results in a value for relative net carbon flux. Some results from using the full carbon cycle methodology, along with US national average values for agricultural inputs, indicate that the net carbon flux averaged over all crops following conversion from conventional tillage to no-till is -189 kg C ha(-1) year(-1) (a negative value indicates net transfer of carbon from the atmosphere). The relative net carbon flux, using conventional tillage as the baseline, is -371 kg C ha(-1) year(-1), which represents the total atmospheric CO2 reduction caused by changing tillage practices. The methodology used here illustrates the importance of (1) delineating system boundaries, (2) including CO2 emissions associated with sequestration initiatives in the accounting process, and (3) comparing the new management practices associated with sequestration initiatives with the original management practices to obtain the true impact of sequestration projects on the atmospheric CO2 pool.     

Fate of biodegradable dissolved organic carbon produced by ozonation on biological activated carbon

The adsorption and desorption characteristics of BDOC produced by ozonation and the replacement of BDOC by non-BDOC on BAC was studied. The fate of BDOC produced by ozonation in the BAC column was also evaluated by comparative experiment between the BAC supplied with the mixture of BDOC and non-BDOC and the BAC supplied only with non-BDOC. Fulvic acids extracted from two river sediments and one forest soil were used. BDOC produced by ozonation showed the same or lower adsorption capacity than non-BDOC after biodegradation. The adsorption rate of BDOC on GAC was lower than that of non-BDOC. BDOC produced by ozonation had low desorbability and majority of BDOC produced were not replaced by non-BDOC. BDOC in the ozonated fulvic acid did not affect the breakthrough of the ozonated fulvic acid on GAC in the early stage of adsorption, suggesting that most of BDOC were biodegraded on the surface of GAC before adsorption. Therefore, the production of BDOC by ozonation before the GAC treatment is very effective for the extension of GAC service life and the reduction of DOC loading to GAC.