减排计划新技术的烦恼——碳捕获与封存技术发展受到质疑

任何一项创新的新能源技术都会遇到诸多的挑战、争议以及发展瓶颈。作为控制温室气体排放的热门技术,二氧化碳碳捕获与封存正经历这一发展过程。     

碳捕获领域的发展现状和未来挑战

目前,国内外大量研究围绕如何降低CO2捕获成本展开,研究规模逐年扩大,发展势头强劲,前景广阔。特别是以膜分离法为代表的新型分离技术,在降低捕获成本上表现出了极大的潜力,是CO2捕获技术发展的重要方向之一。CO2捕获和封存是一种能稳定大气中温室气体浓度的选择方案。CO2捕获和封存是指将CO2从工业或能源相关的排放源中分离出来,输送到一个封存地点,并且长期与大气隔绝。CO2捕获过程是产     

氢动力汽车和电动汽车在中国的应用前景分析

为了分析电动汽车和氢动力汽车在中国的应用前景,使用从油井到车轮的生命周期评价方法,对以煤基原料提供动力的电动汽车和氢动力汽车的循环的生命周期化石能消耗和温室气体排放进行了对比。结果表明:从全生命周期的角度看,未采用CO2捕集与封存技术时,电动汽车在生命周期化石能消费和温室气体排放方面优势明显。随着CCS技术的大规模商业化,氢动力汽车的全生命周期温室气体排放将优于电动汽车,但这需要以生命周期化石能消费的增加为代价,中国政府有必要加大对电动汽车的关注。     

燃煤电厂CO_2捕集与封存技术分析

国家"十三五"控制温室气体排放工作方案对大型发电集团供电CO_2排放强度提出了明确要求,即到2020年,单位供电二氧化碳排放控制在550gCO_2/kWh以内。该文对3种燃煤发电CCS技术即燃烧后、燃烧前和氧燃料CCS在国内外研发和应用现状进行了详细综述,并提出我国以煤为主的能源结构禀赋和电力生产以煤电为主导的格局,决定了在近中期未来燃煤电厂应用CCS技术不可避免,燃煤发电企业应针对市场变化,提出应对碳减排形式的可行性方案。     

CO_2减排技术研究进展

因燃烧化石燃料而排放的温室气体所导致的环境问题已经成为全球性问题。在这些温室气体中,CO2所占的比例最高。与此同时,CO2在化学工业中有很大的用途。因此,从烟气中分离CO2并将其资源化利用具有十分重要的意义。本文从燃料的前期处理、CO2的分离和捕集、后期封存及其资源化利用三个方面介绍了CO2减排及其资源化利用的途径和方法,并对各减排方法进行了分析和比较,总结了各方法的优劣性及其适用范围,对CO2减排技术的发展前景和面临的挑战进行了展望。     

城市温室气体排放清单研究 ——以浙江省浦江县为例

在双碳工作中,温室气体清单编制是非常重要的一环.本文以浙江省金华市浦江县2010—2019年度温室气体清单为研究对象,明确了温室气体排放清单体系和数据来源,分析了温室气体排放总量、结构特征及变化趋势,同时提出低碳发展建议.浦江县2010—2019年温室气体总排放量呈先下降、后上升的趋势.温室气体排放清单报告包括二氧化碳、甲烷、氧化亚氮、含氟气体的排放源和吸收汇,主要分布在能源活动、工业生产过程、农业活动、废弃物处理及土地利用变化和林业五个领域.低碳发展建议主要为强化能源双控、大力推进绿色产业发展、重点行业提升整治、推进清洁生产、深入推进生态示范创建、尝试开展近零碳试点、推进林业降碳增汇工作等.     

挑战全球气候变化——二氧化碳捕集与封存

全球极端气候事件频发,全球气候变暖日益显著,已成为各国政府和公众关注的焦点问题.减少二氧化碳(CO2)等温室气体的排放,对于应对全球气候变化十分必要、非常迫切.在人类活动排放的CO2中,火电厂是最大的集中排放源.同样,火力发电行业也是我国CO2的主要排放源,将是未来减排CO2的主要对象.本文对可实现火力发电过程大规模减排的CO2捕集与封存技术进行了综述,包括主要的技术原理、工艺路线等内容,还涉及了其中的一些关键问题,如不同捕集技术的优缺点、封存技术的可靠性等.     

欧盟电力行业碳捕获及储存技术的研发趋势

目前,欧盟碳捕获及储存技术（CCS）的研发创新活动主要集中在两大行业：电力生产行业和石油天然气工业,以及与两大行业相关的燃料、设备和服务供应商。石油天然气工业利用二氧化碳（CO2）注入石油或天然气田,可提高油气的开采率（EOR）,因此CCS技术的研发活动较早,     

CO_2捕集回收再利用工艺在燃煤电厂应用探讨

大量使用矿物燃料是全球变暖的主要原因,而火力发电厂燃煤是温室气体的主要来源之一。因此,火电厂二氧化碳的捕集再利用再一次成为全球关注的主要问题。该文主要介绍了燃煤电厂CO2捕集工艺技术,主要包括CO2分离、工艺流程、吸收液和吸附剂的选择等,并介绍了碳捕集回收再利用工艺。     

经济危机减少二氧化碳排放量

2008年，经济危机令德国企业界大伤脑筋，对于环保人士却是出奇地好。过去的一年中，德国排放的温室气体总量竟为自1990年以来最少的一年。日前，这一调查结果由联邦环境部公布，据统计，德国在2008年各种温室气体的总排放量为9.45亿吨二氧化碳。比国际公认的二氧化碳排放的标准年份1990年少了将近23％。     

Production of dimethylfuran for liquid fuels from biomass-derived carbohydrates

Diminishing fossil fuel reserves and growing concerns about global warming indicate that sustainable sources of energy are needed in the near future. For fuels to be useful in the transportation sector, they must have specific physical properties that allow for efficient distribution, storage and combustion; these properties are currently fulfilled by non-renewable petroleum-derived liquid fuels. Ethanol, the only renewable liquid fuel currently produced in large quantities, suffers from several limitations, including low energy density, high volatility, and contamination by the absorption of water from the atmosphere. Here we present a catalytic strategy for the production of 2,5-dimethylfuran from fructose (a carbohydrate obtained directly from biomass or by the isomerization of glucose) for use as a liquid transportation fuel. Compared to ethanol, 2,5-dimethylfuran has a higher energy density (by 40 per cent), a higher boiling point (by 20 K), and is not soluble in water. This catalytic strategy creates a route for transforming abundant renewable biomass resources into a liquid fuel suitable for the transportation sector, and may diminish our reliance on petroleum.     

Non-CO2 greenhouse gases and climate change

Earth's climate is warming as a result of anthropogenic emissions of greenhouse gases, particularly carbon dioxide (CO(2)) from fossil fuel combustion. Anthropogenic emissions of non-CO(2) greenhouse gases, such as methane, nitrous oxide and ozone-depleting substances (largely from sources other than fossil fuels), also contribute significantly to warming. Some non-CO(2) greenhouse gases have much shorter lifetimes than CO(2), so reducing their emissions offers an additional opportunity to lessen future climate change. Although it is clear that sustainably reducing the warming influence of greenhouse gases will be possible only with substantial cuts in emissions of CO(2), reducing non-CO(2) greenhouse gas emissions would be a relatively quick way of contributing to this goal.     

Long-term decline of global atmospheric ethane concentrations and implications for methane

After methane, ethane is the most abundant hydrocarbon in the remote atmosphere. It is a precursor to tropospheric ozone and it influences the atmosphere's oxidative capacity through its reaction with the hydroxyl radical, ethane's primary atmospheric sink. Here we present the longest continuous record of global atmospheric ethane levels. We show that global ethane emission rates decreased from 14.3 to 11.3 teragrams per year, or by 21 per cent, from 1984 to 2010. We attribute this to decreasing fugitive emissions from ethane's fossil fuel source--most probably decreased venting and flaring of natural gas in oil fields--rather than a decline in its other major sources, biofuel use and biomass burning. Ethane's major emission sources are shared with methane, and recent studies have disagreed on whether reduced fossil fuel or microbial emissions have caused methane's atmospheric growth rate to slow. Our findings suggest that reduced fugitive fossil fuel emissions account for at least 10-21 teragrams per year (30-70 per cent) of the decrease in methane's global emissions, significantly contributing to methane's slowing atmospheric growth rate since the mid-1980s.     

太阳能材料国际发展态势分析

随着全球气候变暖、化石燃料价格高涨、民众环保意识增强,以太阳能为主的可再生能源的开发与
应用日益得到各个国家和国际组织的认同与支持,这一领域的研究也得以快速发展。太阳能的充分开发和利
用,离不开太阳能材料和技术的发展。本报告主要从国际相关战略计划和路线图、研究热点领域及关键技
术、文献计量学、我国研发现状等几个方面对太阳能材料国际发展态势进行分析,最后提出了我国太阳能材
料与技术的发展对策与建议。     

Strong radiative heating due to the mixing state of black carbon in atmospheric aerosols

Aerosols affect the Earth's temperature and climate by altering the radiative properties of the atmosphere. A large positive component of this radiative forcing from aerosols is due to black carbon--soot--that is released from the burning of fossil fuel and biomass, and, to a lesser extent, natural fires, but the exact forcing is affected by how black carbon is mixed with other aerosol constituents. From studies of aerosol radiative forcing, it is known that black carbon can exist in one of several possible mixing states; distinct from other aerosol particles (externally mixed) or incorporated within them (internally mixed), or a black-carbon core could be surrounded by a well mixed shell. But so far it has been assumed that aerosols exist predominantly as an external mixture. Here I simulate the evolution of the chemical composition of aerosols, finding that the mixing state and direct forcing of the black-carbon component approach those of an internal mixture, largely due to coagulation and growth of aerosol particles. This finding implies a higher positive forcing from black carbon than previously thought, suggesting that the warming effect from black carbon may nearly balance the net cooling effect of other anthropogenic aerosol constituents. The magnitude of the direct radiative forcing from black carbon itself exceeds that due to CH4, suggesting that black carbon may be the second most important component of global warming after CO2 in terms of direct forcing.     

CO2 and the end-Triassic mass extinction.

The end of the Triassic period was marked by one of the largest and most enigmatic mass-extinction events in Earth's history and, with few reliable marine geochemical records, terrestrial sediments offer an important means of deciphering environmental changes at this time. Tanner et al. describe an isotopic study of Mesozoic fossil soils which suggests that the atmospheric concentration of carbon dioxide (pCO2) across the Triassic-Jurassic boundary was relatively constant (within 250 p.p.m.v.), but this is inconsistent with high-resolution evidence from the stomatal characters of fossil leaves. Here I show that the temporal resolution of the fossil-soil samples may have been inadequate for detecting a transient rise in pCO2. I also show that the fossil-soil data are consistent with a large increase in pCO2 across the Triassic-Jurassic boundary when variations in the stable carbon isotope (denoted as delta13C) in terrestrial plant leaves are taken into account. These factors suggest that the linkage between pCO2, global warming and the end-Triassic mass extinction remains intact.     

Indirect radiative forcing of climate change through ozone effects on the land-carbon sink

The evolution of the Earth's climate over the twenty-first century depends on the rate at which anthropogenic carbon dioxide emissions are removed from the atmosphere by the ocean and land carbon cycles. Coupled climate-carbon cycle models suggest that global warming will act to limit the land-carbon sink, but these first generation models neglected the impacts of changing atmospheric chemistry. Emissions associated with fossil fuel and biomass burning have acted to approximately double the global mean tropospheric ozone concentration, and further increases are expected over the twenty-first century. Tropospheric ozone is known to damage plants, reducing plant primary productivity and crop yields, yet increasing atmospheric carbon dioxide concentrations are thought to stimulate plant primary productivity. Increased carbon dioxide and ozone levels can both lead to stomatal closure, which reduces the uptake of either gas, and in turn limits the damaging effect of ozone and the carbon dioxide fertilization of photosynthesis. Here we estimate the impact of projected changes in ozone levels on the land-carbon sink, using a global land carbon cycle model modified to include the effect of ozone deposition on photosynthesis and to account for interactions between ozone and carbon dioxide through stomatal closure. For a range of sensitivity parameters based on manipulative field experiments, we find a significant suppression of the global land-carbon sink as increases in ozone concentrations affect plant productivity. In consequence, more carbon dioxide accumulates in the atmosphere. We suggest that the resulting indirect radiative forcing by ozone effects on plants could contribute more to global warming than the direct radiative forcing due to tropospheric ozone increases.     

Warming trends in Asia amplified by brown cloud solar absorption

Atmospheric brown clouds are mostly the result of biomass burning and fossil fuel consumption. They consist of a mixture of light-absorbing and light-scattering aerosols and therefore contribute to atmospheric solar heating and surface cooling. The sum of the two climate forcing terms-the net aerosol forcing effect-is thought to be negative and may have masked as much as half of the global warming attributed to the recent rapid rise in greenhouse gases. There is, however, at least a fourfold uncertainty in the aerosol forcing effect. Atmospheric solar heating is a significant source of the uncertainty, because current estimates are largely derived from model studies. Here we use three lightweight unmanned aerial vehicles that were vertically stacked between 0.5 and 3 km over the polluted Indian Ocean. These unmanned aerial vehicles deployed miniaturized instruments measuring aerosol concentrations, soot amount and solar fluxes. During 18 flight missions the three unmanned aerial vehicles were flown with a horizontal separation of tens of metres or less and a temporal separation of less than ten seconds, which made it possible to measure the atmospheric solar heating rates directly. We found that atmospheric brown clouds enhanced lower atmospheric solar heating by about 50 per cent. Our general circulation model simulations, which take into account the recently observed widespread occurrence of vertically extended atmospheric brown clouds over the Indian Ocean and Asia, suggest that atmospheric brown clouds contribute as much as the recent increase in anthropogenic greenhouse gases to regional lower atmospheric warming trends. We propose that the combined warming trend of 0.25 K per decade may be sufficient to account for the observed retreat of the Himalayan glaciers.     

海洋酸化的生态危害研究进展

工业革命以来,人类活动产生的巨量CO2进入大气层,不仅产生严重的温室效应,也使得全球海洋出现酸化现象。海洋中氢离子浓度在最近200年里已经上升了30%,21世纪内将再增加3倍,到22世纪海洋将处于极端酸性环境。已有的报道显示,酸化将对石灰化型生物造成非常严重的损害,但海洋酸化对生态系统稳定和人类健康的影响需要长时间的观察和研究。本文总结了近年来有关海洋酸化研究的最新成果,介绍了海洋中不同生态系统所受海洋酸化的影响方式和影响程度,展望了未来研究的方向思路和对策。     

试论气候变化对中国生态、经济发展的影响

随着社会经济的发展和科学技术的进步,气候变暖的现实已对人类社会和自然生态系统构成了严重的威胁。世界经济的迅速发展和社会的进步,向大气排放的有害物质及化石能源消耗与日俱增,带来了日益严重的环境问题,导致全球平均气温逐年升高。中国是一个发展中国家,从能源方面入手采取减缓全球气候变化的措施,促进我国的能源利用水平,推进我国能源优质化的进程,加快我国实现经济增长方式从粗放型向集约型的根本性转变。