Nitrogen oxide emission calculation for post-Panamax container ships by using engine operation power probability as weighting factor: A slow-steaming case

In this study, the nitrogen oxide (NO_x) emission factors and total NO_x emissions of two groups of post-Panamax container ships operating on a long-term slow-steaming basis along Euro–Asian routes were calculated using both the probability density function of engine power levels and the NO_x emission function. The main engines of the five sister ships in Group I satisfied the Tier I emission limit stipulated in MARPOL (International Convention for the Prevention of Pollution from Ships) Annex VI, and those in Group II satisfied the Tier II limit. The calculated NO_x emission factors of the Group I and Group II ships were 14.73 and 17.85 g/kWhr, respectively. The total NO_x emissions of the Group II ships were determined to be 4.4% greater than those of the Group I ships. When the Tier II certification value was used to calculate the average total NO_x emissions of Group II engines, the result was lower than the actual value by 21.9%. Although fuel consumption and carbon dioxide (CO₂) emissions were increased by 1.76% because of slow steaming, the NO_x emissions were markedly reduced by 17.2%. The proposed method is more effective and accurate than the NO_x Technical Code 2008. Furthermore, it can be more appropriately applied to determine the NO_x emissions of international shipping inventory.

Implications: The usage of operating power probability density function of diesel engines as the weighting factor and the NO_x emission function obtained from test bed for calculating NO_x emissions is more accurate and practical. The proposed method is suitable for all types and purposes of diesel engines, irrespective of their operating power level. The method can be used to effectively determine the NO_x emissions of international shipping and inventory applications and should be considered in determining the carbon tax to be imposed in the future.     

SCR脱硝在燃煤电厂超低排放中的适用性分析

通过流场模拟、化学动力学计算、并结合物理实验,全过程研究SCR反应器内烟气组分的动量/能量/质量传递及脱硝还原反应,计算在不同入口NOx浓度下SCR出口NOx和氨逃逸的排放量及空间分布,确定SCR在NOx超低排放要求下的适用范围。研究结果表明,为实现NOx-3并同时满足NH3-3的要求,2层SCR催化剂可处理的入口烟气NO浓度上限为240 mg·Nm-3,而3层SCR催化剂则可对NO浓度-3的烟气实施超低排放治理,为合理选择SCR超低排放设计方案提供了数据支撑。     

Research on a China 6b heavy-duty diesel vehicle real-world engine out NOx emission deterioration and ambient correction using big data approach

Environmental Science and Pollution Research - China VI standard proposed higher requirements for durability of heavy-duty diesel vehicles emissions. Previous research which took advantages of both...     

Combustion,performance, and emission characteristics of diesel engine using oxyhydrogen gas as a fuel additive

Environmental Science and Pollution Research - A lot of research is being carried out to reduce the environmental pollution resulting from compression ignition engines. For this, various gaseous...     

Establishment of a database of emission factors for atmospheric pollutants from Chinese coal-fired power plants

Field measurements and data investigations were conducted for developing an emission factor database for inventories of atmospheric pollutants from Chinese coal-fired power plants. Gaseous pollutants and particulate matter (PM) of different size fractions were measured using a gas analyzer and an electric low-pressure impactor (ELPI), respectively, for ten units in eight coal-fired power plants across the country. Combining results of field tests and literature surveys, emission factors with 95% confidence intervals (CIs) were calculated by boiler type, fuel quality, and emission control devices using bootstrap and Monte Carlo simulations. The emission factor of uncontrolled SO₂ from pulverized combustion (PC) boilers burning bituminous or anthracite coal was estimated to be 18.0S kg t^?1 (i.e., 18.0 × the percentage sulfur content of coal, S) with a 95% CI of 17.2S–18.5S. NO_X emission factors for pulverized-coal boilers ranged from 4.0 to 11.2 kg t^?1, with uncertainties of 14–45% for different unit types. The emission factors of uncontrolled PM_2.5, PM₁₀, and total PM emitted by PC boilers were estimated to be 0.4A (where A is the percentage ash content of coal), 1.5A and 6.9A kg t^?1, respectively, with 95% CIs of 0.3A–0.5A, 1.1A–1.9A and 5.8A–7.9A. The analogous PM values for emissions with electrostatic precipitator (ESP) controls were 0.032A (95% CI: 0.021A–0.046A), 0.065A (0.039A–0.092A) and 0.094A (0.0656A–0.132A) kg t^?1, and 0.0147A (0.0092–0.0225A), 0.0210A (0.0129A–0.0317A), and 0.0231A (0.0142A–0.0348A) for those with both ESP and wet flue-gas desulfurization (wet-FGD). SO₂ and NO_X emission factors for Chinese power plants were smaller than those of U.S. EPA AP-42 database, due mainly to lower heating values of coals in China. PM emission factors for units with ESP, however, were generally larger than AP-42 values, because of poorer removal efficiencies of Chinese dust collectors. For units with advanced emission control technologies, more field measurements are needed to reduce emission factor uncertainties.     

以磺酸阳离子交换树脂为原料合成含硫水不溶性杀菌剂

设计了一个新的以磺酸阳离子交换树脂为原料制备含硫水不溶性杀菌剂的合成路线，通过聚苯乙烯磺酸吡啶盐中间体合成磺酰氯树脂，在磺酰氯树脂上固载二乙胺，再用带有叔胺基的树脂与卤代烷作用合在含硫的铵盐型聚合物杀菌剂，使用所研制的水不溶性杀菌剂用量2mg/mL时杀菌率达到90％以上。     

Optimizing emission inventory for chemical transport models by using genetic algorithm

Air pollutant emission inventory is an important input parameter for chemical transport models (CTMs). Since great uncertainties exist in the emission inventory, further improvements and refinements are required. In this paper, genetic algorithm (GA), a global search and optimization method, was applied to optimize the emission inventory for the Models-3/Community Multiscale Air Quality (CMAQ) model. An emission optimizing system based on GA was developed and embedded to the CMAQ through the design of several core modules, which implemented the basic functions such as emission adjusting, GA population initializing, CMAQ results evaluating and GA operating. Hypothetical and real-data experiments were respectively performed to examine the validity of GA for emission calibrating. GA showed good performance in both experiments and was always able to find the global minimum. The emission optimizing system was then used to calibrate seasonal PM₁₀ emission inventories of Beijing. Results revealed that PM₁₀ emission in Beijing was underestimated in 2002, an average of 62.74% higher adjustment factor should be imposed on the original emission in target months of different seasons. With the calibrated emission inventories, CMAQ model errors were decreased by 6.46% on average in different seasons. It was concluded that GA was a promising search technique in calibrating emission inputs for CTMs.     

Derivation of new emission factors for quantification of mass emissions when using optical gas imaging for detecting leaks

This paper describes the development of new "leak/no-leak" emission factors that are suitable for estimating facilities' fugitive emissions when using an alternative work practice (AWP) that is based on optical gas imaging technology for detecting leaking piping system components. These emission factors were derived for valves, pumps, and connectors/flanges for instrument leak detection thresholds ranging from 3 to 60 g/hr using a combination of field data and Monte Carlo statistical simulation techniques. These newly derived leak/no-leak emission factors are designed to replace the U.S. Environment Protection Agency (EPA) 1995 Protocol factors, which were based on Method 21 monitoring of leaks at "uncontrolled" facilities. The emission factors published in the 1995 Protocol have not been updated since the 1970s. This derivation is based on results where the authors document the use of a Monte Carlo simulation technique to quantify the required leak detection thresholds that provide equal--or better--environmental benefits for an AWP. The use of these newly derived emission factors is demonstrated for different methods of computing fugitive emissions from a hypothetical model refinery. The resulting facility emissions calculated by using these new emission factors is compared with the existing emission estimation methods provided in the EPA 1995 Protocol. The results demonstrate that the new emission factors provide an emission estimate that is the closest to that obtained from the direct determination of total emissions by Monte Carlo simulations.     

Mercury emission trend influenced by stringent air pollutants regulation for coal-fired power plants in Korea

Regulatory control of mercury emission from anthropogenic sources has become a global concern in the recent past. Coal-fired power plants are one of the largest sources of anthropogenic mercury emission into the atmosphere. This paper summarizes the current reducing trend of mercury emission as co-beneficial effect by more stringent regulation changes to control primary air pollutants with introducing test results from the commercial coal-fired facilities and suggesting a guideline for future regulatory development in Korea. On average, mercury emission concentrations ranged 16.3–2.7 μg Sm^?3, 2.4–1.1 μg Sm^?3, 3.1–0.7 μg Sm^?3 from anthracite coal-fired power plants equipped with electrostatic precipitator (ESP), bituminous coal-fired power plants with ESP + flue gas desulphurization (FGD) and bituminous coal-fired power plants with selective catalytic reactor (SCR) + cold side (CS) ? ESP + wet FGD, respectively. Among the existing air pollution control devices, the best configuration for mercury removal in coal-fired power plants was SCR + CS ? ESP + wet FGD, which were installed due to the stringent regulation changes to control primary air pollutants emission such as SO₂, NOx and dust. It was estimated that uncontrolled and controlled mercury emission from coal-fired power plants as 10.3 ton yr^?1 and 3.2 ton yr^?1 respectively. After the installation of ESP, FGD and SCR system, following the enforcement of the stringent regulation, 7.1 ton yr^?1 of mercury emission has been reduced (nearly 69%) from coal-fired power plants as a co-benefit control. Based on the overall study, a sample guideline including emission limits were suggested which will be applied to develop a countermeasure for controlling mercury emission from coal-fired power plants.     

电力行业SO_2排污权有偿使用和排污交易探讨

面对日益严格的环境总量控制制度以及有限的环境容量资源,电力行业需要寻求高效的环境管理手段,以解决未来发展的环境约束.针对电力行业SO2排放现状,分析了电力行业建立SO2排污权有偿使用机制的必要性、可行性以及与现有政策的兼容性,从中揭示了排污权有偿使用机制对电力行业健康发展所起的积极作用.     

Enhancement in combustion,performance, and emission characteristics of a diesel engine fueled with diesel,biodiesel, and its blends by using nanoadditive

This article presents the results of investigations carried out to evaluate the improvement in combustion, performance, and emission characteristics of a diesel engine fueled with neat petro-diesel (PD), soybean biodiesel (SB), and 50% SB blended PD (PD50SB) by using carbon nanotube (CNT) as an additive. The acid–alkaline-based transesterification process with sodium hydroxide (NaOH) as a catalyst was applied to derive the methyl ester of SB. A mass fraction of 100 ppm CNT nanoparticle was blended with base fuels by using an ultrasonicator and the physiochemical properties were measured based on EN standards. The measured physiochemical properties are in good agreement with standard limits. The experimental evaluations were carried out under varying brake mean effective pressure (BMEP) conditions in a single-cylinder, four-stroke, and natural aspirated research diesel engine at a constant speed of 1500 rpm. The results reveal that the SB and its blend promote shorter ignition delay period (IDP) that is resulting in lower in-cylinder pressure (ICP) and net heat release rate (NHR) compared to PD. The SB and its blend increase the brake specific fuel consumption (BSFC), and reduce the brake specific energy consumption (BSEC) and exhaust gas temperature (EGT), due to lower heating value, and efficient combustion, respectively. As far as the emission characteristics are concerned, the SB and its blend promote lower magnitude of hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO₂), and smoke emissions compared to PD except for oxides of nitrogen (NO_x) emission. The CNT nanoparticle inclusion with base fuels significantly improves the combustion, performance, and emissions level irrespective of engine load conditions.

     

A study on the evaluations of emission factors and uncertainty ranges for methane and nitrous oxide from combined-cycle power plant in Korea

In this research, in order to develop technology/country-specific emission factors of methane (CH₄) and nitrous oxide (N₂O), a total of 585 samples from eight gas-fired turbine combined cycle (GTCC) power plants were measured and analyzed. The research found that the emission factor for CH₄ stood at “0.82 kg/TJ”, which was an 18 % lower than the emission factor for liquefied natural gas (LNG) GTCC “1 kg/TJ” presented by Intergovernmental Panel on Climate Change (IPCC). The result was 8 % up when compared with the emission factor of Japan which stands at “0.75 kg/TJ”. The emission factor for N₂O was “0.65 kg/TJ”, which is significantly lower than “3 kg/TJ” of the emission factor for LNG GTCC presented by IPCC, but over six times higher than the default N₂O emission factor of LNG. The evaluation of uncertainty was conducted based on the estimated non-CO₂ emission factors, and the ranges of uncertainty for CH₄ and N₂O were between ?12.96 and +13.89 %, and ?11.43 and +12.86 %, respectively, which is significantly lower than uncertainties presented by IPCC. These differences proved that non-CO₂ emissions can change depending on combustion technologies; therefore, it is vital to establish country/technology-specific emission factors.     

臭氧/活性炭/真空紫外光联用处理甲基肼废水的影响因素

研究比较了臭氧氧化（O3）、臭氧/活性炭氧化（O3/AC）、真空紫外/臭氧（VUV/O3）、真空紫外/臭氧/活性炭氧化（VUV/O3/AC）对甲基肼废水的处理效果,以甲基肼和COD去除率为指标,其中VUV/O3/AC最为有效。考察了活性炭投加量、臭氧投加量、初始pH值和活性炭使用次数等因素的影响。结果表明,反应最佳工艺条件为臭氧投加4.2 mg·min-1、pH值为9.60、活性炭投加量为6 g·L-1。反应60 min,甲基肼去除率可达99.3%,COD去除率可达75.7%。同时,探究了活性炭的重复使用效果,分析了反应过程的中间产物。     

Predicting low biota to sediment accumulation factors of PAHs by using infinite-sink and equilibrium extraction methods as well as BC-inclusive modeling

Sequestration of polycyclic aromatic hydrocarbons (PAHs) results in the slow release of PAHs from sediment to the aqueous environment, thus limiting bioavailability. Three methods to account for the limited bioavailability of native PAHs to the gastropod Hinia reticulata were therefore investigated: (i) infinite-sink extractions that measure desorption; (ii) equilibrium extractions that measure freely dissolved pore water concentrations and (iii) black carbon-inclusive modeling. The rapidly desorbing fraction was estimated based on the amount desorbed by Tenax. Relatively small amounts of PAHs (<9%) were present in F(rapid) and the observed solid-water distribution ratios (K(d,obs)) were approximately 1-2 orders of magnitude higher than literature K(oc) values. Biota to sediment accumulation factors (BSAFs) measured in the gastropod H. reticulata ranged from 0.02 to 0.07, 10-140 times lower than the theoretical value of approximately 1-2. The BSAFs calculated using the rapidly desorbing fraction or freely dissolved aqueous concentrations were also much lower than the theoretical value, and median values differed from the measured BSAFs by only a factor of 1.5-9. Furthermore, the result of using a BC-inclusive BSAF model could explain the deviation from the theoretical BSAF value and account for the low bioavailability of these native PAHs to H. reticulata. Risk assessment strategies of in situ contamination should therefore include a combination of chemical methods accounting for bioavailability, as well as bioaccumulation studies.     

PM10 emission factors for non-exhaust particles generated by road traffic in an urban street canyon and along a freeway in Switzerland

Recent studies have shown clear contributions of non-exhaust emissions to the traffic related PM10 load of the ambient air. These emissions consist of particles produced by abrasion from brakes, road wear, tire wear, as well as vehicle induced resuspension of deposited road dust. The main scope of the presented work was to identify and quantify the non-exhaust fraction of traffic related PM10 for two roadside locations in Switzerland with different traffic regimes. The two investigated locations, an urban street canyon with heavily congested traffic and an interurban freeway, are considered as being typical for Central Europe. Mass-relevant contributions from abrasion particles and resuspended road dust mainly originated from particles in the size range 1–10 μm. The results showed a major influence of vehicle induced resuspension of road dust. In the street canyon, the traffic related PM10 emissions (LDV: 24 ± 8 mg km^?1 vehicle^?1, HDV: 498 ± 86 mg km^?1 vehicle^?1) were assigned to 21% brake wear, 38% resuspended road dust and 41% exhaust emissions. Along the freeway (LDV: 50 ± 13 mg km^?1 vehicle^?1, HDV: 288 ± 72 mg km^?1 vehicle^?1), respective contributions were 3% brake wear, 56% resuspended road dust and 41% exhaust emissions. There was no indication for relevant contributions from tire wear and abrasion from undamaged pavements.     

Environmental impact assessments of different auxiliary power units used for commercial aircraft by using global warming potential approach

Environmental Science and Pollution Research - In this paper, environmental impact analysis is applied to the various auxiliary power units (APUs) used for commercial aircraft in air transportation...     

The application of forward osmosis for simulated surface water treatment by using trisodium citrate as draw solute

Environmental Science and Pollution Research - In this study, trisodium citrate was used as draw solute in forward osmosis (FO) due to its biodegradability and easy reuse after FO dilution. The...     

Liquid chromatographic methods coupled to chemometrics: a short review to present the key workflow for the investigation of wine phenolic composition as it is affected by environmental factors

Environmental Science and Pollution Research - The guarantee of wine authenticity arises great concern because of its nutritional and economic importance. Phenolic fingerprints have been used as a...