Angle Scattering Method for Soot Concentration Measurement under Ultra-Low Emissions Condition

Aiming at the problem of soot concentration measurement under ultra-low emission conditions,a forward small angle soot concentration measurement method is proposed.Taking a typical boiler emission of 0.1μm-3.0μm bimodal distribution soot as an object,the particle scatter simulation calculation under different parameters is carried out,and the influence of detection angle and particle size on the angular scatteringmeasurement of ultra-low emission soot is analyzed.The influence of detection angle and particle size on the angular scatteringmeasurement of ultra-lowemission soot is analyzed.Preferably,thewavelength of incident light is 650 nm,and the forward detection angle parameter is 15◦for the design of forward small angle soot concentration measurement system.An experimental system for measuring soot with standard concentration is built.Experiments of particle concentration measurement of 1.0μm and 3.0μm under ultra-low emission conditions are carried out.The results show that the average deviation of soot concentration measurement is less than 0.10 mg/m3 under the condition of ultra-low emission by using 15◦of forward detection,which provides an effective way for monitoring ultra-low emission soot concentration in coal-fired power plants.

Localization Reform of Carbon Emissions Trading Mechanism in China

Based on the practical experiences of Guangdong carbon emissions trading pilot, the key issues such as cap setting, allowance alloca- tion, system defects, regulatory integration and MRV mechanisms were analyzed in this paper from the localization perspective. A number of solu- tions and policy recommendations were also proposed in this study in order to solve these barriers.

Re-understanding and Thinking about Environmental Impact of Coal-fired Power Plants under Ultra-low Emission

From the perspective of development background,concepts and related policies of ultra-low emission,according to work practice,some issues and difficulties that need to be paid attention to in the environmental impact assessment of ultra-low-emission thermal power projects were discussed from the aspects of evaluation criteria,evaluation grade and scope,pollution control technical lines,environmental benefit accounting,and total emission control,and corresponding recommendations were put forward.

Distribution and bioavailability of mercury in size-fractioned atmospheric particles around an ultra-low emission power plant in Southwest China

Ultra-low emission(ULE)technology retrofits significantly impact the particulate-bound mercury(Hg)emissions from coal-fired power plants(CFPPs);however,the distribution and bioavailability of Hg in size-fractioned particulate matter(PM)around the ULE-retrofitted CF-PPs are less understood.Here,total Hg and its chemical speciation in TSP(total suspended particles),PM_(10)(aerodynamic particle diameter≤10μm)and PM_(2.5)(aerodynamic particle diameter≤2.5μm)around a ULE-retrofitted CFPP in Guizhou Province were quantified.Atmospheric PM_(2.5)concentration was higher around this ULE-retrofitted CFPP than that in the intra-regional urban cities,and it had higher mass Hg concentration than other sizefractioned PM.Total Hg concentrations in PM had multifarious sources including CFPP,vehicle exhaust and biomass combustion,while they were significantly higher in autumn and winter than those in other seasons(P<0.05).Regardless of particulate size,atmospheric PM-bound Hg had lower residual fractions(<21%)while higher HCl-soluble fractions(>40%).Mass concentrations of exchangeable,HCl-soluble,elemental,and residual Hg in PM_(2.5)were higher than those in other size-fractioned PM,and were markedly elevated in autumn and winter(P<0.05).In PM_(2.5),HCl-soluble Hg presented a significantly positive relationship with elemental Hg(P<0.05),while residual Hg showed the significantly positive relationships with HCl-soluble Hg and elemental Hg(P<0.01).Overall,these results suggested that atmospheric PM-bound Hg around the ULE-retrofitted CFPP tends to accumulate in finer PM,and has higher bioavailable fractions,while has potential transformation between chemical speciation.

Development and Commercial Application of Ultra-Low Pressure Naphtha Reforming Technology with Continuous Catalyst Regeneration

The development history and major technological innovations of the ultra-low pressure naphtha reforming technology with continuous catalyst regeneration in China were introduced.This technology had been adopted by the 1.0 Mt/a CCR unit at the Guangzhou Company.The appropriate catalyst was selected to meet the demand of the unit capacity,the feedstock,and the product slate.The design parameters,including the reaction pressure,the octane number of C5+liquid product,the reaction temperature,the space velocity,the hydrogen/oil molar ratio,and the catalyst circulating rate,were chosen based on the study of process conditions and parameters.The commercial test results showed that the research octane number of C5+product reached 104 when the capacity of the CCR unit was 100%and 115%of the design value.The other technical targets attained or exceeded the expected value.

NOx Emission Reduction Using Hydrous Ethanol-Gasoline Blend with Syngas in SI Engine

This paper presents a comparatively experimental study of nitrogen oxide (NOx) emissions from an internal combustion engine fed by gasoline available in the Saudi Arabian market rating octane number (RON 91 and RON 95) with admixtures of syngas with 0% E0, 5% E5 and 10% E10—by volume of pure ethanol—and HE5 and HE10 with water concentrations of 5%, 10%, 30% and 40%—by volume of hydrous ethanol—at stoichio-metric mixtures. An on-board plasma system used to produce syngas through the partial oxidation of gasoline with air in a plasma-assisted fuel reformer. The syngas injected in a gasoline engine with a fuel injection system modified for operation with addition of some amount of syngas. The experimental results demonstrated a significant total reduction in NOx emissions and slightly increased in fuel consumption when mixing gasoline (RON 91 and RON 95), ethanol (E5 and E10) and hydrous ethanol (HE5 and HE10) with syngas. For the use of hydrous ethanol (HE5 and HE10) along with the addition of syngas, for both RON 91 and RON 95, the lowest NOx emissions are found 72% with a water concentration of 40%.

绿色金融改革创新试验区的碳减排效应——基于空间溢出效应与城市异质性的视角

实施绿色金融试点政策是我国自下而上完善绿色金融体系的重要举措,对于地区产业低碳转型和发展新质生产力具有重要意义。本文利用2010—2019年283个地级市的平衡面板数据,以绿色金融试点政策为切入点,采用双重差分模型和空间计量方法系统评估了实施绿色金融试点政策的碳减排效应。研究发现,绿色金融试点政策的实施显著降低了试点城市的工业碳排放总量和工业碳强度,且政策效果具有持续性和稳健性。绿色金融试点政策具有显著的空间溢出效应,即本地绿色金融试点政策的实施会对空间关联地区的碳减排产生积极影响,但施策过程中需防范污染产业转移风险。进一步研究发现,绿色金融试点政策的碳减排效应在不同区域和不同试点城市中呈现异质性。影响机制分析结果表明,绿色金融试点政策主要通过发展绿色信贷、优化能源消费结构和提升能源利用效率等方式促进地区碳减排。本文研究为我国完善绿色金融体系和实现“双碳”目标提供了实证参考。

稀燃条件下掺烧乙醇重整气对直喷汽油机燃烧及碳烟排放影响的仿真研究

为解决直喷汽油机稀薄气体的燃烧及排放问题,采用掺烧乙醇重整气改善直喷汽油机的性能,并利用CONVERGE三维仿真技术从微观角度解释发动机的性能表现。结果表明,引入乙醇重整气可以改善缸内当量比分布,促进H基、OH基的生成,有助于燃烧的良好进行;随重整气掺混比的升高,HO_(2)和H_(2)O_(2)分布范围更广、浓度更高,在燃烧室内分层现象更加明显;随着重整气掺混比增加到20%,缸内碳烟的生成质量和数量密度峰值分别降低了90%和56.25%,直喷汽油机碳烟排放得到有效改善。

基于5E模型的创新实践课程教学设计与实施

传统“教师讲授,学生聆听”的教学模式不利于激发学生自主创造性,无法有效提升学生的问题解决能力,因而不能较好地实现创新实践类课程的教学目标。对此,该文提出基于5E模型的课程设计,并将其运用于能源动力类本科专业节能减排创新实践课程。该教学设计下,学生需要开展小组合作学习,自主探索并提出问题,而后通过所学知识及相关信息的搜集、整合、运用使问题得到创造性的解决。实施过程中强调以学生为主体,教师在旁起辅助和引导作用。结果表明,该设计模型的实施能引导学生实现对知识的自主建构,有助于强化学生的自主学习能力及创新实践能力,并有效培育学生的科研精神,能够较好地实现创新实践课程的教学目标。

绿色金融改革创新减污降碳效应研究

减污降碳是开展绿色金融的重要目标。本文以绿色金融改革创新试验区的设立作为准自然实验,运用双重差分模型分析绿色金融改革创新试验区对二氧化碳、二氧化硫、氮氧化物的减排效果。结果表明,试验区试点政策对二氧化碳、二氧化硫具有显著的减排效果,但对氮氧化物的减排效果不明显。机制分析表明,试验区试点政策未能通过促进技术创新实现二氧化碳、二氧化硫、氮氧化物的减排,但是能通过降低能耗总量与优化用能结构实现二氧化碳、二氧化硫的减排。异质性分析表明,试验区试点政策的减污降碳效果在东部地区、环境治理力度弱的地区、产业结构高级的地区以及金融发展水平高的地区更加明显。本文为如何优化试验区试点政策效果提供了一定的启示。

高焦混合煤气重整制备高品质高炉喷吹还原气研究

文章从热力学角度对甲烷—二氧化碳重整过程进行了探究,分析了涉及相关化学反应的吉布斯自由能变及化学平衡常数。研究了温度、压力、进料配比、水蒸气的加入量对CH_(4)转化率、CO_(2)转化率、积碳率的影响。结果表明:随着温度升高,CH_(4)与CO_(2)转化率增加,积碳率减少;随着压力增加,CH_(4)与CO_(2)转化率降低,积碳率增加;加入一定量的水蒸气可降低积碳率,此时CH_(4)与CO_(2)转化率仍然很高。重整过程的最佳反应条件为900℃、105 Pa、n(CH_(4))∶n(CO_(2))∶n(H 2O(g))=1∶1∶0.7,此时CH_(4)转化率为99%,CO_(2)转化率为96%,积碳率为0%。

城市绿色金融改革对减污降碳协同增效的影响研究——基于双重机器学习的因果推断

减污降碳协同增效是中国建设社会主义现代化强国的必然选择。2017年绿色金融改革创新试验区试点政策的落地标志着中国进入绿色金融改革新阶段。基于此,以绿色金融改革创新试验区为准自然实验,选取2012—2020年中国279个城市的面板数据为研究样本,采用双重机器学习模型实证分析城市绿色金融改革对减污降碳协同增效的影响。研究发现,城市绿色金融改革可以实现减污降碳协同增效,同时可以降低工业生产过程和交通与建筑的碳排放。作用机制分析发现,城市绿色金融改革可以通过加大研发投入、提高绿色创新水平和促进数字普惠金融发展,进而实现减污降碳协同增效。根据功能定位、发展基础和资源禀赋进行异质性分析发现,“一带一路”城市和资源型城市绿色金融改革可以实现减污降碳协同增效,而从发展基础异质性来看,只有以经济发展和产业结构升级相结合为发展主线的城市绿色金融改革才能实现减污降碳协同增效的耦合协调发展。研究内容有助于为地方政府探寻绿色金融改革减污降碳协同增效的新路径、新模式、新实践提供理论支持。

Multi-process and multi-pollutant control technology for ultra-low emissions in the iron and steel industry

The iron and steel industry is not only an important foundation of the national economy,but also the largest source of industrial air pollution.Due to the current status of emissions in the iron and steel industry,ultra-low pollutant emission control technology has been researched and developed.Liquid-phase proportion control technology has been developed for magnesian fluxed pellets,and a blast furnace smelting demonstration project has been established to use a high proportion of fluxed pellets(80%)for the first time in China to realize source emission reduction of SO_(2)and NO_(x).Based on the characteristics of high NO_(x)concentrations and the coexistence of multiple pollutants in coke oven flue gas,low-NO_(x)combustion coupled with multi-pollutant cooperative control technology with activated carbon was developed to achieve efficient removal of multiple pollutants and resource utilization of sulfur.Based on the characteristics of co-existing multiple pollutants in pellet flue gas,selective non-catalytic reduction(SNCR)coupled with ozone oxidation and spray drying adsorption(SDA)was developed,which significantly reduces the operating cost of the system.In the light of the high humidity and high alkalinity in flue gas,filter materials with high humidity resistance and corrosion resistance were manufactured,and an integrated pre-charged bag dust collector device was developed,which realized ultralow emission of fine particles and reduced filtration resistance and energy consumption in the system.Through source emission reduction,process control and end-treatment technologies,five demonstration projects were built,providing a full set of technical solutions for ultra-low emissions of dust,SO_(2),NO_(x),SO_(3),mercury and other pollutants,and offering technical support for the green development of the iron and steel industry.

Urbanization and carbon emissions in China:Analysis of dynamic relationships from 1978 to 2020

Since China's reform and opening-up in 1978,rapid urbanization has coincided with a surge in carbon emissions.Statistical,geospatial,and time-series analysis methods were utilized to examine the dynamic relationship between urbanization and carbon emissions over the past 43 years;elucidate the mechanisms through which dimensions of urbanization,such as population,land,economy,and green development,impact carbon emissions at various stages;and further explore the heterogeneity among cities of different scales.The analysis reveals that 2001 and 2011 represent significant turning points in China's carbon emission growth“S”curve.The phase of rapid carbon emissions growth is associated with an increase in the urbanization rate from 40% to 50%,a shift in industrial structure from being dominated by secondary industry to tertiary industry,and a decrease in urban population density from 19,600 to 16,000 people per square kilometer of built-up area.Regions northeast of the“Bayannur-Ningde Line”have experienced rapid increases in carbon emissions,with large and medium-sized cities being the primary contributors nationwide.The TVP-VAR results indicate that higher urbanization rates have short-term carbon and mid-to long-term carbon-reducing effects.Population concentration in large cities facilitates short-to mid-term carbon reduction,whereas intensive urban development,industrial upgrading,and the promotion of clean energy use have sustained carbon-reducing effects.Carbon emissions exhibit path dependence.Increased urbanization rates in mega-cities and super-cities result in carbon-increasing effects,whereas the optimization of industrial structures exerts an inhibitory effect on carbon emissions in medium-sized and large cities.The changes in impulse response values of various variables are influenced by the developmental trajectory of Chinese cities from“small to large and then to agglomerations.”These recommendations indicate the necessity for differentiated emission reduction strategies contingent on the specific regions and types of cities in question.

基于DRM的天然气制氢减排与甲醇联产方案及关键参数优化

基于甲烷CO_(2)重整(DRM)建立了天然气制氢减排与甲醇联产耦合系统,利用DRM反应处理天然气制氢工艺废气并生产甲醇,实现天然气制氢系统的碳减排和资源化利用。基于反应平衡和甲醇合成反应经验模型建立了耦合系统的Aspen Plus模拟模型和高效分析优化数学模型,并对关键参数进行了优化。模拟结果表明,DRM的最佳温度范围为805~825℃;在甲烷水蒸气重整(MSR)温度为850℃时,甲烷补充量、水蒸气补充量和DRM温度的最佳值分别为14.0 mol/s、8.0 mol/s和805℃,耦合系统的碳排放较传统天燃气制氢工艺降低38%;MSR和DRM的甲烷进料配比可用于产品结构调整,在甲醇与H2的市场价格比大于3.0时,提高DRM反应甲烷补充量可提高经济效益。

甲醇水蒸气重整制氢过程的能耗和经济性分析

以工业甲醇制氢装置的工艺参数为基础,利用Aspen Plus软件建立了甲醇水蒸气重整制氢工艺模型,对甲醇制氢过程的反应热力学进行探讨,分析各主要工艺参数对制氢过程中能耗、物耗、成本和碳排放强度的影响。结果表明:反应温度升高有利于甲醇转化率的提升,但会导致CO选择性上升而氢气产率下降;在温度为240℃、压力为1.5 MPa、水醇摩尔比为1.8、变压吸附(PSA)单元氢气收率为90%的优化工况条件下,甲醇水蒸气重整制氢过程的甲醇单耗、综合能耗、碳排放强度和氢气成本分别为5.96 kg kg、1185.98 kgOE t(1 kgOE=41.8 MJ)、10.45 kg kg和17.46元kg;较高的反应压力和PSA单元氢气收率、较低的水醇摩尔比和反应温度有利于甲醇制氢过程的节能减排;而从氢气成本的角度出发,对甲醇水蒸气重整制氢过程影响由强到弱的顺序为:PSA单元氢气收率>水醇摩尔比>反应压力>反应温度。

基于声发射技术的连续重整反应器故障诊断

重整反应器是连续重整装置的关键设备,反应器内气固相错流接触,当气体流速足够大时会出现空腔和贴壁的非正常现象,限制反应器的操作弹性,影响装置的安全稳定运行。采用声发射技术对冷态操作下的反应器进行检测,对比分析反应器不同运行状态的声发射信号,以便及时判断是否出现了上述非正常现象。试验结果显示:反应器正常运行时信号波形平稳,平均信号电平20 dB、幅值35~45 dB;异常时波形中出现脉冲形状,其中,空腔时平均信号电平20~35 dB、幅值35~55 dB,特征频率25~150 kHz,贴壁时平均信号电平30~60 dB、幅值35~75 dB,特征频率25~250 kHz。催化剂流动状态改变时信号的波形、特征参数和功率谱会出现明显变化。使用多个传感器可以实现对故障的定位并可识别故障类型。上述结果表明,声发射技术作为一种非侵入式的测量技术,能够有效检测连续重整反应器的运行状态,可为装置长期安全稳定运行提供技术保障。

高分子科学实验中玻璃化转变可视化的教学改革探索

在高分子专业相关的课程中,玻璃化转变是重要的组成部分。玻璃化转变发生于温度高于玻璃化转变温度(Tg)后分子链段运动的一系列变化,具有很强的理论性特点。设计科学严谨又通俗易懂的教学方法和手段展开教学是该课程的难点。聚集诱导发光(AIE)分子所表现出的内运动受限发光特点为可视化研究玻璃化转变过程提供了条件。本文通过在高分子材料中掺杂AIE分子的方式设计了一种实验教学样品,其可通过简单的紫外灯照射实现玻璃化转变的可视化,更好地帮助教师阐述分子链段运动特点,达到了很好的教学效果。

合成氨装置转化炉烟气中氮氧化物达标排放技术改造

分析了一段转化炉烟气中氮氧化物的形成机理,确定该装置一段转化炉烟气中氮氧化物主要由燃料气中弛放气部分夹带的氨燃烧所形成。通过对氨回收系统再生塔进行技术改造,将停用的氨回收系统的再生塔改造成水洗塔,采取下段循环洗涤、上段清水洗涤的两段洗涤方式除去弛放气中的氨,洗涤后产生的氨水通过管线送至尿素装置水解系统氨水槽中回收,洗涤后的弛放气与燃料天然气混合后送至转化炉燃烧,从而成功将一段转化炉烟气中氮氧化物由380 mg/m^(3)降至180 mg/m^(3)以下,实现了一段转化炉烟气中氮氧化物达标排放。

国家级金融改革试验区能否促进低碳转型发展——来自准实验的考察

实现碳达峰、碳中和目标是推动我国经济高质量发展的内在要求,低碳转型发展无疑是实现这一重要目标的必由之路。而通过金融改革有效促进碳排放绩效提升,已经成为低碳转型发展的必然选择。本文以国家级金融改革试验区政策作为准实验,采用考虑环境非期望产出的包含总体环境技术的DEA模型,对城市的碳排放绩效进行准确核算,以此对低碳转型发展水平进行衡量,进而采用DID方法系统地研究了金融改革试验区对低碳转型发展的影响及内在作用机制。研究发现:金融改革政策的实施显著地促进了城市低碳转型发展,在经过一系列稳健性检验后该结论依然成立;机制分析表明,金融改革政策能够有效改善金融资源配置,并促进绿色技术进步,从而加速城市低碳转型发展;异质性分析表明,金融改革政策对低碳转型发展的促进效应在资源型城市、东部地区、二线和三线城市更为明显。本文的研究为准确理解国家级金融改革试验区推动我国低碳转型发展的效应及机制提供了有力的经验证据。