沥青废气燃烧处理技术

在不同温度、不同沥青废气与天然气混合比及不同催化剂的条件下,用燃烧法对沥青熔化中产生的废气进行处理,研究其最佳处理效果,降低沥青废气排放浓度和废气中有害物质的浓度,解决了沥青废气严重污染环境的问题。     

Open burning of household waste: Effect of experimental condition on combustion quality and emission of PCDD, PCDF and PCB

Open burning for waste disposal is, in many countries, the dominant source of polychlorinated dibenzodioxins, dibenzofurans and biphenyls (PCDD/PCDF/PCB) release to the environment. To generate emission factors for open burning, experimental pile burns of about 100 kg of household waste were conducted with emissions sampling. From these experiments and others conducted by the same authors it is found that less compaction of waste or active mixing during the fire - “stirring” - promotes better combustion (as evidenced by lower CO/CO₂ ratio) and reduces emissions of PCDD/PCDF/PCB; an intuitive but previously undemonstrated result. These experiments also support previous results suggesting PCDD/PCDF/PCB generation in open burning - while still highly variable - tends to be greater in the later (smoldering) phases of burning when the CO/CO₂ ratio increases.     

钢铁行业碳减排情景仿真分析及评价研究

我国钢铁行业碳排放量约为全国碳排放总量的15%。因此完成钢铁行业碳减排目标是实现我国碳减排总量目标的重要环节。研究为求解未来钢铁行业的碳排放总量与碳减排潜力,提出一种基于技术进步与碳减排外部性的情景仿真模型。在不同的技术进步与碳减排外部性情境下,模型综合考虑节能减排技术对行业/地区碳排放的影响,设计锁定、成长和促进三种碳减排情景。最后采用该模型对重庆市钢铁行业的碳排放总量,碳减排潜力与节能技改投资成本变化进行了情景仿真分析与评价。研究表明,为更好地实现行业的碳减排目标,在现有的节能减排政策环境下,重庆市钢铁行业,需要进一步加强对节能减排技术的推广;加大技术推广投资,用于更多的节能减排技术的研发与推广,加快节能减排技术扩散速度,增强行业碳减排成效;有选择性的进行投入与推广,提高资金的利用效率,以有限的资金实现行业/地区碳减排成效的最大化。     

水煤浆在节能减排中的应用及发展前景

水煤浆是由60%~68%的煤和32%~40%的水或废水经研磨混合,在0.5%添加剂作用下形成的一种均匀稳定的流体洁净燃料,以流态雾化喷燃方式燃烧。水煤浆技术基本成熟,已被广泛应用于工业锅炉和窑炉。在同等条件下,水煤浆与燃煤相比可节煤32%,减排SO2和烟尘分别达到77%和82%以上;燃自制水煤浆时可节省燃料费20%以上。将水煤浆技术应用于治理棉浆粕黑液时,不仅投资比碱回收工程少1/2,而且实现了零排放。自"十五"以来,国家一直十分重视水煤浆产业,其发展前景十分广阔。     

Mercury (Hg) emissions from domestic biomass combustion for space heating

Three mercury (Hg) species (gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and fine particulate-bound mercury (PBM_2.5)) were measured in the stack of a small scale wood combustion chamber at 400 °C, in the stack of an advanced wood boiler, and in two areas influenced by wood combustion. The low temperature process (lab-scale) emitted mostly GEM (∼99% when burning wood pellets and ∼95% when burning unprocessed wood). The high temperature wood boiler emitted a greater proportion of oxidized Hg (approximately 65%) than the low temperature system. In field measurements, mean PBM_2.5 concentrations at the rural and urban sites in winter were statistically significantly higher than in warmer seasons and were well correlated with Delta-C concentrations, a wood combustion indictor measured by an aethalometer (UV-absorbable carbon minus black carbon). Overall the results suggest that wood combustion may be an important source of oxidized mercury (mostly in the particulate phase) in northern climates in winter.     

Emissions of unintentional persistent organic pollutants from open burning of municipal solid waste from developing countries

Open burning of waste is the most significant source of polychlorinated dibenzo-para-dioxins and dibenzofurans (PCDD/PCDF) in many national inventories prepared pursuant to the Stockholm Convention on Persistent Organic Pollutants. This is particularly true for developing countries. Emission factors for POPs such as PCDD/PCDF, dioxin-like polychlorinated biphenyls (dl-PCB) and penta- and hexachlorobenzenes (PeCBz/HCB) from open burning of municipal solid waste in China and Mexico are reported herein. Six different waste sources were studied varying from urban-industrial to semi-urban to rural. For PCDD/PCDF, the emission factors to air ranged from 3.0 to 650 ng TEQ kg⁻¹ waste and for dl-PCB from 0.092 to 54 ng TEQ kg⁻¹ waste. Emission factors for PeCBz (17-1200 ng kg⁻¹ waste) and HCB (24-1300 ng kg⁻¹ waste) spanned a wide but similar range. Within the datasets there is no indication of significant waste composition effect on emission factor with the exception of significantly higher Mexico rural samples.     

Historical estimation of carbonaceous aerosol emissions from biomass open burning in China for the period 1990-2005

Multi-year inventories of carbonaceous aerosol emissions from biomass open burning at a high spatial resolution of 0.5° × 0.5° have been constructed in China using GIS methodology for the period 1990-2005. Black carbon (BC) emissions have increased by 383.03% at an annual average rate of 25.54% from 14.05 Gg in 1990 to 67.87 Gg in 2005; while organic carbon (OC) emissions have increased by 365.43% from 57.37 Gg in 1990 to 267.00 Gg in 2005. Through the estimation period, OC/BC ratio for biomass burning was averagely 4.09, suggesting that it was not the preferred control source from a climatic perspective. Spatial distribution of BC and OC emissions were similar, mainly concentrated in three northeastern provinces, central provinces of Shandong, Jiangsu, Anhui and Henan, and southern provinces of Guangxi, Guangdong, Hunan and Sichuan basin, covering 24.89% of China’s territory, but were responsible for 63.38% and 67.55% of national BC and OC emissions, respectively.     

Comparisons of two serious air pollution episodes in winter and summer in Beijing

Characteristics of two serious air pollution episodes(9–15 January, as the winter case; and30 June to 1 July, as the summer case), which occurred in Beijing in 2013 were investigated and compared using multi-method observations and numerical simulations. During these two air pollution episodes, PM_(2.5) concentrations varied significantly within Beijing, with PM_(2.5) concentrations in southern parts of Beijing being significantly higher than in northern areas. Typically, heavy air pollution episodes begin in the southern parts and disperse towards the northern parts of Beijing. Clearly, synoptic patterns and the stability of atmospheric circulation patterns were the main factors controlling air pollution in Beijing.During the winter case, a warm center above 900 h Pa occurred over Beijing. Meanwhile, in the summer case, although there was only a weak inversion, the convective inhibition energy was strong(over 200 J/k G). This clearly influenced the duration of the air pollution event. Except for the local accumulation and secondary atmospheric reactions in both cases, regional straw burnings contributed a lot to the PM_(2.5) concentrations in summer case.Using the CAMxmodel, we established that regional transport contributed almost 59% to the PM_(2.5) averaged concentration in Beijing in the winter case, but only 31% in the summer case. Thus, the winter case was a typical regional air pollution episode, while the summer case resulted from local accumulation straw burnings transportation and strong secondary atmospheric reactions. Given that air pollution is a regional problem in China, consistent and simultaneous implementation of regional prevention and control strategies is necessary to improve regional air quality.     

Ecological assessment of the environmental impacts of the kerosene burning in jet turbines and its improvement assessment

The burning of kerosene in jet turbines is investigated for two reference flights with a Boeing 747-400 and an Airbus A320-200, representing the typical Lufthansa planes for long and middle distance. The ecological evaluation is performed by Life Cycle Assessment (LCA). Formation of condensation trails, which is a specific environmental impact caused by air traffic, has to be considered in addition to established LCA impact categories. Based on the ecological assessment, an improvement assessment is performed. Environmental performance of diesel fuel during the combustion in car engines is analysed based on available publications. The relevant parameters for the environmental impact of the combustion of diesel (aromatics content, reduction of sulphur content, the reduction of the density and raising of the cetane number) are discussed with regard to improvements of the exhaust qualities of kerosene. A reduction of the aromatics content promises to improve the emission of soot which should be further investigated.