In-situ measurement and distribution of flue gas mercury for a utility PC boiler system

The in-situ instrumentation technique for measuring mercury and itsspeciation downstream a utility 100 MW pulverized coal (PC) fired boiler system was developed andconducted by the use of the Ontario hydro method (OHM) consistent with American standard test methodtogether with the semi-continuous emissions monitoring (SCEM) system as well as a mobile laboratoryfor mercury monitoring. The mercury and its speciation concentrations including participate mercuryat three locations of before air preheater, before electrostatic precipitator (ESP) and after ESPwere measured using the OHM and SCEM methods under normal operation conditions of the boiler systemas a result of firing a bituminous coal. The vapor-phase total mercury Hg(VT) concentration declinedwith the decrease of flue gas temperature because of mercury species transformation from oxidizedmercury to particulate mercury as the flue gas moved downstream from the air preheater to the ESPand after the ESP. A good agreement for Hg°, Hg^(2+) and Hg( VT) was obtained between the twomethods in the ash-free area. But in the dense particle-laden flue gas area, there appeared to be abig bias for mercury speciation owing to dust cake formed in the filter of OHM sampling probe. Theparticulateaffinity to the flue gas mercury and the impacts of sampling condition to accuracy ofmeasure were discussed.

The Selection and Application of Anticorrosive Materials for Flue Gas Desulfurization (FGD) System in Cement Plant

This paper combined with the actual case of flue gas desulfurization (FGD) system in cement Plant, analyzes the corrosion environment in each area of the FGD system, and selects appropriate anticorrosive materials for different corrosion environment, so as to provide operating experience and reference for the safe, stable and efficient operation of the FGD system.

Flue Gas Monitoring System With Empirically-Trained Dictionary

The monitoring of flue gas of the thermal power plants is of great significance in energy conservation and environmental protection.Spectral technique has been widely used in the gas monitoring system for predicting the concentrations of specific gas components.This paper proposes flue gas monitoring system with empirically-trained dictionary(ETD)to deal with the complexity and biases brought by the uninformative spectral data.Firstly,ETD is extracted from the raw spectral data by an alternative optimization between the sparse coding stage and the dictionary update stage to minimize the error of sparse representation.D1,D2 and D3 are three types of ETD obtained by different methods.Then,the predictive model of component concentration is constructed on the ETD.In the experiments,two real flue gas spectral datasets are collected and the proposed method combined with the partial least squares,the background propagation neural network and the support vector machines are performed.Moreover,the optimal parameters are chosen according to the 10-fold root-mean-square error of cross validation.The experimental results demonstrate that the proposed method can be used for quantitative analysis effectively and ETD can be applied to the gas monitoring systems.

基于在线监测数据的催化再生烟气污染综合评价

为综合评估催化裂化装置废气排放对环境大气的污染状况,以28套典型催化裂化装置的催化剂再生烟气为研究对象,统计分析2022年1—12月上述装置排放的3种大气污染物(SO^(2)、NO_(x)和颗粒物)的质量浓度和废气流量的连续小时级在线监测数据。SO2、NO_(x)和颗粒物排放质量浓度均值分别为5.95 mg/m^(3)、39.32 mg/m^(3)和6.30 mg/m^(3),污染物达标排放率达到99.99%,仅通过达标排放率难以判别装置间的污染排放水平。因此,本文通过层次分析(Analytic Hierarchy Process,AHP)主观赋权法与指标相关性权重(Criteria Importance Through Intercriteria Correlation,CRITIC)客观赋权法相结合的方式构建了催化再生烟气污染评价指数(Exhaust Pollution Evaluation Index,Iepe),并结合聚类分析结果和废气污染评价指数计算数据,确定了适用于评估催化再生烟气污染排放等级的Iepe。通过对废气污染评价指数的综合分析发现,催化再生烟气处于超低污染水平的催化裂化装置有3套,处于低强度污染水平的催化裂化装置有20套,处于中等强度污染水平的催化裂化装置有5套。氮氧化物和颗粒物质量浓度对催化再生烟气污染评价指数的贡献较大,建议炼化企业将催化再生烟气的氮氧化物和颗粒物质量浓度作为废气污染管控的重点,以进一步提升催化裂化装置的绿色低碳水平。

Natural Gas and Indoor Air Pollution: A Comparison With Coal Gas and Liquefied Petroleum Gas

Objective The study was designed to compare the combustion products of coal gas, liquefied petroleum gas and natural gas in relation to indoor air pollution. Methods Regular pollutants including B(a)P were monitored and 1-hydroxy pyrene were tested in urine of the enrolled subjects. Radon concentrations and their changes in four seasons were also monitored in the city natural gas from its source plant and transfer stations to final users. To analyze organic components of coal gas, liquefied petroleum gas and natural gas, a high-flow sampling device specially designed was used to collect their combustion products, and semi-volatile organic compounds contained in the particles were detected by gas chromatograph-mass spectrograph (GC/MS). Results Findings in the study showed that the regular indoor air pollutants particles and CO were all above the standard in winter when heating facilities were operated in the city, but they were lowest in kitchens using natural gas; furthermore, although NO2 and CO2 were slightly higher in natural gas, B(a)P concentration was lower in this group and 1-hydroxy pyrene was lowest in urine of the subjects exposed to natural gas. Organic compounds were more complicated in coal gas and liquefied petroleum gas than in natural gas. The concentration of radon in natural gas accounted for less than 1‰ of its effective dose contributing to indoor air pollution in Beijing households. Conclusion Compared to traditional fuels, gases are deemed as clean ones, and natural gas is shown to be cleaner than the other two gases.

激光分析仪测量湿烟气氨逃逸的应用实践

在工业产业生产期间,氨气的使用和排放不可规避,但其过量排放将会严重影响周围环境。为了对氨气排放作出有效控制,实时监测氨逃逸成为了一项关键任务。激光分析仪作为一种高精度、非接触的测量技术,正逐渐成为氨逃逸监测的首选工具。基于此,概述了激光分析仪的工作原理,思考湿烟气氨逃逸测量的重要性,重点探究激光分析仪在湿烟气氨逃逸测量中的应用,旨在提供有效的监测解决方案,以降低环境污染风险并提高工业生产效率。

Progress in Global Gas Hydrate Development and Production as a New Energy Resource

Natural gas hydrates have been hailed as a new and promising unconventional alternative energy,especially as fossil fuels approach depletion,energy consumption soars,and fossil fuel prices rise,owing to their extensive distribution,abundance,and high fuel efficiency.Gas hydrate reservoirs are similar to a storage cupboard in the global carbon cycle,containing most of the world's methane and accounting for a third of Earth's mobile organic carbon.We investigated gas hydrate stability zone burial depths from the viewpoint of conditions associated with stable existence of gas hydrates,such as temperature,pressure,and heat flow,based on related data collected by the global drilling programs.Hydrate-related areas are estimated using various biological,geochemical and geophysical tools.Based on a series of previous investigations,we cover the history and status of gas hydrate exploration in the USA,Japan,South Korea,India,Germany,the polar areas,and China.Then,we review the current techniques for hydrate exploration in a global scale.Additionally,we briefly review existing techniques for recovering methane from gas hydrates,including thermal stimulation,depressurization,chemical injection,and CH4-CO2 exchange,as well as corresponding global field trials in Russia,Japan,United States,Canada and China.In particular,unlike diagenetic gas hydrates in coarse sandy sediments in Japan and gravel sediments in the United States and Canada,most gas hydrates in the northem South China Sea are non-diagenetic and exist in fine-grained sediments with a vein-like morphology.Therefore,especially in terms of the offshore production test in gas hydrate reservoirs in the Shenhu area in the north slope of the South China Sea,Chinese scientists have proposed two unprecedented techniques that have been verified during the field trials:solid fluidization and formation fluid extraction.Herein,we introduce the two production techniques,as well as the so-called"fbur-in-one"environmental monitoring system employed during the Shenhu production test.Methane is not currently commercially produced from gas hydrates anywhere in the world;therefore,the objective of field trials is to prove whether existing techniques could be applied as feasible and economic production methods for gas hydrates in deep-water sediments and permafrost zones.Before achieving commercial methane recovery from gas hydrates,it should be necessary to measure the geologic properties of gas hydrate reservoirs to optimize and improve existing production techniques.Herein,we propose horizontal wells,multilateral wells,and cluster wells improved by the vertical and in dividual wells applied during existing field trials.It is noteworthy that relatively pure gas hydrates occur in seafloor mounds,within near-surface sediments,and in gas migration conduits.Their extensive distribution,high saturation,and easy access mean that these types of gas hydrate may attract considerable attention from academia and industry in the future.Herein,we also review the occurrence and development of concentrated shallow hydrate accumulations and briefly introduce exploration and production techniques.In the closing section,we discuss future research needs,key issues,and major challenges related to gas hydrate exploration and production.We believe this review article provides insight on past,present,and future gas hydrate exploration and production to provide guidelines and stimulate new work into the field of gas hydrates.

Smart gas sensor arrays powered by artificial intelligence

Mobile robots behaving as humans should possess multifunctional flexible sensing systems including vision,hearing,touch,smell,and taste.A gas sensor array(GSA),also known as electronic nose,is a possible solution for a robotic olfactory system that can detect and discriminate a wide variety of gas molecules.Artificial intelligence(AI)applied to an electronic nose involves a diverse set of machine learning algorithms which can generate a smell print by analyzing the signal pattern from the GSA.A combination of GSA and AI algorithms can empower intelligent robots with great capabilities in many areas such as environmental monitoring,gas leakage detection,food and beverage production and storage,and especially disease diagnosis through detection of different types and concentrations of target gases with the advantages of portability,low-powerconsumption and ease-of-operation.It is exciting to envisage robots equipped with a"nose"acting as family doctor who will guard every family member's health and keep their home safe.In this review,we give a summary of the state-of the-art research progress in the fabrication techniques for GSAs and typical algorithms employed in artificial olfactory systems,exploring their potential applications in disease diagnosis,environmental monitoring,and explosive detection.We also discuss the key limitations of gas sensor units and their possible solutions.Finally,we present the outlook of GSAs over the horizon of smart homes and cities.

The Experimental WSN Network for Underground Monitoring H2 Abundance in the Mine Atmosphere Karnasurt Mine Lovozero Layered Alkaline Intrusion

We have developed specialized equipment based on hydrogen mini-MDM sensors and the WSN telecommunication technology for long-term monitoring of hydrogen content in the environment.Unlike existing methods,the developed equipment makes it possible to carry out measurements directly in the explosion zone with high discreteness in time.This equipment was tested at a large rare-earth deposit of the Lovozero alkaline pluton Karnasurt in the underground mining tunnel.We observed a short time impulse very high concentration of hydrogen in the atmosphere(more than 3 orders of normal atmosphere concentration).This discovery is very important because at the time of the explosion one can create abnormally high concentrations of explosive mixtures of hydrocarbon gases that can leaded to accidents.The high resolving power of the our measurement equipment makes it possible in the first time in practical to determine the shape of the anomaly hydrogen of such a concentration and to calculate the volumes of hydrogen released from the rocks,at first time in the practice.The shape of the anomaly usually consists of 2-3 additional peaks of the shape-“dragon-head”like.We make an first attempt is made to explain this form of anomaly in the article.The aim of the work the estimate hydrogen emission in mining ore deposit of rare earth elements.

Ammonia and greenhouse gas distribution in a dairy barn during warm periods

This research aimed to quantify concentrations of ammonia(NH3),carbon dioxide(CO_(2))and methane(CH_(4)),estimate emissions,and analyze the factors influencing them during warm periods in an open dairy barn equipped with two cooling systems in a Mediterranean climate zone.Gas distribution within the barn was observed to vary both vertically and horizontally,with the highest gas concentrations observed in the central area of the barn.NH_(3),CH_(4)and CO_(2)ranged in 1.7–7.4,7–18,560–724μg·g^(–1),respectively.Natural ventilation through openings and the operation of cooling systems induced changes in indoor microclimate conditions,influencing cow behavior and,consequently,gas production.Gas concentrations were the highest at air velocities below 0.5 m·s^(–1).The highest concentration of NH_(3)was observed when the temperature-humidity index(THI)was>72 and≤78;and CO_(2)and CH_(4)concentrations were the highest with THI≥72 and decreased with THI≤72.NH_(3)concentrations when barn management included three daily milkings were higher than those measured when barn management was based on two daily milkings,and lower for CH_(4)and CO_(2).NH_(3)and CH_(4)emissions were the highest during barn cleaning,while the lowest NH_(3)emissions occurred during activity of the cows(i.e.,feeding,walking).

基于在线监测数据的石化企业CFB锅炉大气污染物排放综合评价

为评估CFB锅炉现有工艺的清洁生产水平及大气污染治理效果,收集了2021年1112家典型石化企业循环流化床(CFB)锅炉的3种常规大气污染物(SO_(2)、NO_(x)以及颗粒物)质量浓度和废气流量的连续小时级在线监测数据,并对污染物排放质量浓度的月均值进行了统计分析。3种污染物排放质量浓度均值分别为22.83 mg/m^(3)、5.68 mg/m^(3)和3.02 mg/m^(3),大气污染达标排放率已经达到100%。单因素方差分析表明CFB锅炉间的污染物排放质量浓度存在显著性差异。基于系统聚类分析可将12台CFB锅炉分为两类:一类污染物排放质量浓度较高,而废气流量较低,占比74.54%;另一类污染物排放质量浓度较低,而废气流量较高,占比25.46%。通过CRITIC客观赋权法构建废气排放综合指数以比较各CFB锅炉的污染排放状况,发现处于超低污染水平的CFB锅炉有2个;处于低污染排放的最多,共有7个;处于中等强度排放的有3个。废气流量对综合指数贡献大,今后在线监测达标排放仍应将污染物总量控制作为重点工作,建议结合企业废气排放口污染物排放总量数据提出企业总量管理目标。

基于DOAS方法烟道污染气体在线监测系统的设计

基于紫外差分吸收光谱法,研制了烟气在线连续监测系统.阐述了系统的工作原理和数据处理方法.仪器实现了高灵敏探测器和低噪声放大器的关键技术,解决了脉冲光源关键问题,因而具有良好的稳定性和可靠性.仪器工作波段在200-500nm,可以对烟气中SO2和NO2含量进行定量测量.实验结果表明:测得的SO2和NO2浓度在满量程范围内相对误差≤±5%,可满足烟气排放污染物连续在线监测的要求.

垃圾焚烧炉飞灰和烟气中多氯化萘的分布特征

分析深圳市生活垃圾、医疗废弃物和危险废弃物焚烧炉排放飞灰及烟道气中多氯化萘（polychlorinated naphthalene,PCN）的污染特征.结果发现,垃圾焚烧炉排放飞灰和烟道气中PCN的质量分数为0.18~3.30 ng/g（平均0.73 ng/g;干质量（dry weight,dw））和质量浓度0.33~1.70 ng/m3（平均0.87 ng/m3,dw）.医疗废弃物和工业废弃物焚烧炉中的PCN含量普遍高于生活垃圾焚烧炉,飞灰和烟道气中排放的PCN主要以3-氯取代化合物—5-氯取代化合物为主,其中,CN23、CN28/CN43、CN35、CN38/CN40、CN46、CN61、CN57、CN62和CN59是最主要的化合物.

轧钢工业蓄热式加热炉烟气测试过程应注意的若干问题

分析了轧钢工业蓄热式加热炉原理,提出在蓄热式加热炉烟气监测过程中应随时观测工况、压力、温度、氧量的变化,准确掌握蓄热式加热炉在生产时所产生的污染物的浓度、排放量,以保证监测数据的真实性、代表性。

双向活塞式精密气体采样计量泵的研制

文章介绍了双向活塞式精密气体采样计量泵的研制及其特性和应用 .

Evaluation of Volatile Organic Compounds and Polyaromatic Hydrocarbons in Barker Reservoir in Houston, Texas after the 2017 Hurricane Harvey

Analysis of volatile organic compounds (VOCs) and polyaromatic hydrocarbons (PAHs) in the Barker Reservoir in Houston, Texas, United States is reported. Samples were collected within one week after the August 2017 Hurricane Harvey. Using a gas chromatograph equipped with a mass spectrometer, 4 VOCs and 13 PAHs were found in the Barker Reservoir. Concentrations of acetone, benzene, chloroform, and toluene were 1500, 380, 830, and 290 parts per million (ppm), respectively. Benzene and chloroform are classified as probable human carcinogens by the U.S. Environmental Protection Agency (EPA). Six PAHs including benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, chrysene, and dibenz[a,h]anthracene are probable human carcinogens. The most concentrated PAH was acenaphthylene at 0.068 ppm, while the least one was fluoranthene at 0.00046 ppm. Results revealed water contaminants in Houston and its vicinities during the flooding season and served as references for water monitoring purposes in the future.

HG-HC智能烟尘粉尘在线监测仪

本文详细介绍了自主开发的HG-HC型烟尘粉尘在线监测仪的监测原理、技术特点及应用情况。

烟塔合一的环境影响实证研究

为跟踪了解烟塔合一对区域大气环境和理论下洗区污染物浓度的影响,分别于采暖期和非采暖期在华能陕西秦岭电厂周边400 km^2范围内对SO_2和NO_2进行连续15天采样分析,在电厂排烟冷却塔理论下洗区域内布置环境空气自动站进行一年以上逐时监测,并结合气象资料对烟塔合一的环境影响进行实证研究。结果表明:采暖期和非采暖期SO_2、NO_2环境空气质量监测结果均满足《环境空气质量标准》(GB3095—2012)的要求,电厂对区域环境的影响可以接受;环境空气自动站长时间连续监测期间未观测到因烟气下洗而产生的局部污染物浓度高的现象,主导风向西风条件下理论下洗区内的污染物浓度与东风时无显著差异(P>0.05),西风条件下大风时的污染物浓度水平显著低于小风时的浓度(P<0.01),监测结果表明烟塔合一模式下理论下洗区域不会出现地面污染物浓度高的问题。

数字化分析技术在环保监测中的应用

火力发电厂发电过程中,烟气流量在线监测的准确性一直是困扰环保部门的一大问题。采用基于计算流体力学的数字化分析技术和工况标定的方法,对某电厂烟气在线监测装置实施了技术升级,提高了环保部门对烟气监测的准确度。结果表明,采用数字化分析技术,能够显著减小烟气的在线监测误差,真实反映工业企业的烟气排放情况,有助于更好地处理和控制烟气内有害物质,使排除烟气达到国家规定的环保排放要求。

石化企业环保监测系统的应用与管理

针对石油化工企业生产废水和烟气排放的在线监测与管理问题,介绍了在线环保监测系统的工作原理和选型设置。环保在线监测系统通过现场在线分析和测量仪表对各装置废水和锅炉烟气的各项监测参数进行在线动态检测,将检测数据连续、实时地传输到监控平台,实现了对外排放监测点的自动连续数据监控和报警,达到规范和加强石化企业环保在线监测系统的依法运行和监管目的。