水蒸气作为催化剂处理H_2S气体的试验研究

目前国内外对较高浓度的H2S的治理主要是使用克劳斯法,但该方法虽几经改进,反应也要在200~400℃的条件下才能进行,治理费用较高。本研究采用水蒸气作催化剂,改变了SO2+2H2S=3S+2H2O的反应历程,使该反应在常温下就有显著的反应速度,在反应温度为50~60℃时,硫的转化率可达到90%左右,使H2S的污染治理技术取得了历史性突破。     

Variations in stable hydrogen and oxygen isotopes in atmospheric water vapor in the marine boundary layer across a wide latitude range

The newly-developed cavity ring-down laser absorption spectroscopy analyzer with special calibration protocols has enabled the direct measurement of atmospheric vapor isotopes at high spatial and temporal resolution. This paper presents real-time hydrogen and oxygen stable isotope data for atmospheric water vapor above the sea surface, over a wide range of latitudes spanning from 38°N to 69°S. Our results showed relatively higher values of 8180 and 82H in the subtropical regions than those in the tropical and high latitude regions, and also a notable decreasing trend in the Antarctic coastal region. By combining the hydrogen and oxygen isotope data with meteoric water line and backward trajectory model analysis, we explored the kinetic fractionation caused by subsiding air masses and related saturated vapor pressure in the subtropics, and the evaporation-driven kinetic fractionation in the Antarctic region. Simultaneous observations of meteorological and marine variables were used to interpret the isotopic composition characteristics and influential factors, indicating that d-excess is negatively correlated with humidity across a wide range of latitudes and weather conditions worldwide. Coincident with previous studies, d-excess is also positively correlated with sea surface temperature and air temperature （Tair）, with greater sensitivity to Tair. Thus, atmospheric vapor isotopes measured with high accuracy and good spatial- temporal resolution could act as informative tracers for exploring the water cycle at different regional scales. Such monitoring efforts should be undertaken over a longer time period and in different regions of the world.     

淡水测验

淡水对人类生活是必需的,你对其实际储量了解多少?1、在地球的水储量中淡水所占的百分比是多少?25%10%30.5%52%答案:2.5%。地球水量中的淡水只占2.5%。其中2/3是冰块,只有不足1%才能用于生长谷物、提供饮用、洗涤家什、制冷取暖等。2、绝大部分的水用于何处?工业农场与牧场饮用发电答案:用于农场与牧场。全世界64%的水这一昂贵的自然资源,用于灌溉生产世     

炼油厂含苯系物污水处理工艺模拟研究

为了实现炼油厂含苯系物污水的回收利用,提出了液液萃取-汽提联合处理工艺。应用Aspen Plus对该工艺流程进行模拟,采用UNIQUAC物性方法,分析了抽余油用量、汽提蒸汽量等主要工艺参数对污水处理效果的影响。模拟结果表明,含苯系物污水经联合工艺处理后,净化水主要污染物含量低于饮用水标准限值,可作为新鲜水供炼厂回用;抽余油萃取了污水中的油和苯系物之后,依然满足该炼油厂对抽余油的质量要求,可按原计划送往下游装置。本工艺过程未产生二次污染,达到零排放的环保目标。     

水蒸气法制备污泥质活性炭的实验研究

以污泥和木屑为原料,采用管式炉水蒸气活化法,对流化床热解炉制得的热解炭进行制备活性炭的研究,分析了活化因素对活化效果的影响、亚甲基蓝在活性炭上的吸附平衡和动力学、污泥活性炭浸出液中重金属的含量及其孔结构等性能.实验结果表明:随着活化温度的升高、活化时间的延长和水蒸气流量的增加,活性炭的得率不断降低,亚甲基蓝的吸附值先升高后降低;污泥中添加20%木屑时制得的活性炭的吸附性能是纯污泥质活性炭的一倍多; Langmuir吸附等温线模型、准二级反应模型能够比较准确地描述亚甲基蓝在污泥活性炭上的吸附相平衡及吸附过程,平衡时活性炭对亚甲基蓝单层最大吸附量为71.43mg/g;污泥质活性炭的孔结构以过渡孔为主;浸出液中只有少量的重金属.     

锅炉余热回收实用性的改进

以天然气为燃料的锅炉,排烟温度高（150-250℃）,并含有约15-19％的水蒸气（容积成分）,是烟气热量的主要携带者。如果将锅炉的排烟温度降到水蒸汽露点以下,烟气中的水蒸汽就会凝结而放出汽化潜热,将其回收利用的锅炉称为冷凝式锅炉。     

CaO对城市生活垃圾原位水蒸气气化制备富氢燃气的影响

为高效资源化利用城市生活垃圾,提出了一种城市生活垃圾原位水蒸气气化制备富氢燃气方法. 在城市生活垃圾原位水蒸气气化过程中添加CaO,对CO₂进行高温吸收,促进H₂产生. 考察了n(Ca)/n(C)(CaO与垃圾原料中碳元素的摩尔比)、反应温度及垃圾含水率等因素对H₂产率以及气化特性的影响. 结果表明:随着n(Ca)/n(C)由0增至1.5,φ(H₂)和H₂产率(以w计)分别由25.89%、10.86g/kg增至45.90%、31.56g/kg;水蒸气的引入提高了CaO的碳酸化反应活性,促进了H₂的产生,但当含水率高于39.45%时,则会降低产气品质;反应温度高于750℃时,虽能强化城市生活垃圾、焦油的热分解等反应产生更多的H₂,但不利于CaO的碳酸化反应,最佳的操作温度为700～750℃;对固体残留物进行XRD和SEM分析可知,反应温度高于750℃会降低CaO的活性,不利于CaO对CO₂的吸收. 以CaO为添加剂的城市生活垃圾原位水蒸气气化制备富氢燃气是一种有效的城市生活垃圾资源化利用方式.      

城市生活垃圾水蒸气催化热解的实验研究

采用自行设计的外热式催化热解实验装置,以城市生活垃圾为原料,对温度(600℃～900℃)、物料的组分、加热方式、水蒸气以及白云石催化剂等影响垃圾热解的因素进行了分析。结果表明,气化温度、水蒸气、催化剂对垃圾热解性能影相显著。随热解温度的升高,产气量不断上升,H2和CO的含量增加,当温度为900℃时,产气量达到0.96m3/kg,H2和CO含量分别达35.1%和31.8%;催化剂使用、水蒸汽通入显著改善产品气质量,特别是H2含量,可达45%左右;挥发分含量较高的物料热解性相对较好;快加热方式有利于提高产品气质量。     

Automatic and continuous measurement of aerosol properties in Dunhuang, China

Ground-based simultaneous observations of sun direct and scattering radiation were carded out in Dunhuang for nearly 2 years.Aerosol optical depth, Angstrom wavelength exponent and size distribution were obtained from solar extinction and sky radiation. Water vapor content was obtained from sun direct radiation measurement at 940 nm. Relationship between aerosol properties and water vapor was discussed. Results showed that distinct seasonality of aerosol optical depth and Angstrom wavelength exponent was corresponding to seasonal variation of dust activity. Aerosol relative size distribution kept stable and volume concentration change was the reason resulting in variation of aerosol optical depth. Water vapor had minor effects on aerosol optical and physical properties.     

低温吸附工艺处理化工生产车间VOCs

采用由颗粒活性炭吸附和水蒸汽解吸组成的两级"吸附-解吸"工艺处理化工生产车间的有机废气,分析处理效果并探讨了可行性。结果表明:在甲醇和甲酸甲酯的浓度分别为4 071～7 456 mg/m~3、6 165～10 914 mg/m~3、一级吸附床温度为5～15℃,二级吸附床温度为0～5℃条件下,两级"吸附-解吸"工艺对甲醇和甲酸甲酯的平均去除率分别为98.15%和91.51%,出口甲醇和甲酸甲酯浓度平均值分别为85 mg/m~3和569 mg/m~3;该工艺具有投资及运行成本低、有机物去除率较高、产品回收价值高等优点,可用于处理并回收化工生产车间的废气。