A statistical analysis of the carbon dioxide capture process

Post combustion carbon dioxide (CO₂) capture is one of the most commonly adopted technologies for reducing industrial CO₂ emissions, which is now an important goal given the widespread concern over global warming. Research on amine-based CO₂ capture has mainly focused on improving effectiveness and efficiency of the CO₂ capture process. Our research work focuses on studying the relationships among the significant parameters influencing CO₂ production because an enhanced understanding of the intricate relationships among the parameters involved in the process is critical for improving efficiency of the CO₂ capture process. This paper presents a statistical study that explores the relationships among parameters involved in the amine-based post combustion CO₂ capture process at the International Centre for CO₂ Capture (ITC) located in Regina, Saskatchewan of Canada. A multiple regression technique has been applied for analysis of data collected at the CO₂ capture pilot plant at ITC. The parameters have been carefully selected to avoid issues of multicollinearity, and four mathematical models among the key parameters identified have been developed. The models have been tested, and accuracy of the models is found to be satisfactory. The models developed in this study describe part of the CO₂ capture process and can help to predict performance of the CO₂ capture process at ITC under different conditions. Some results from a preliminary validation process will also be presented.     

Power generation with CO2 capture: Technology for CO2 purification

The goal of this paper is to find methodologies for removing a selection of impurities (H₂O, O₂, Ar, N₂, SO_x and NO_x) from CO₂ present in the flue gas of two oxy-combustion power plants fired with either natural gas (467 MW) or pulverized fuel (596 MW). The resulting purified stream, containing mainly CO₂, is assumed to be stored in an aquifer or utilized for enhanced oil recovery (EOR) purposes. Focus has been given to power cycle efficiency i.e.: work and heat requirements for the purification process, CO₂ purity and recovery factor (kg of CO₂ that is sent to storage per kg of CO₂ in the flue gas). Two different methodologies (here called Case I and Case II) for flue gas purification have been developed, both based on phase separation using simple flash units (Case I) or a distillation column (Case II). In both cases purified flue gas is liquefied and its pressure brought to 110 atm prior to storage.Case I: A simple flue gas separation takes place by means of two flash units integrated in the CO₂ compression process. Heat in the process is removed by evaporating the purified liquid CO₂ streams coming out from both flashes. Case I shows a good performance when dealing with flue gases with low concentration of impurities. CO₂ fraction after purification is over 96% with a CO₂ recovery factor of 96.2% for the NG-fired flue gas and 88.1% for the PF-fired flue gas. Impurities removal together with flue gas compression and liquefaction reduces power plant output of 4.8% for the NG-fired flue gas and 11.6% for the PF-fired flue gas. The total amount of work requirement per kg stored CO₂ is 453 kJ for the NG-fired flue gas and 586 kJ for the PF-fired flue gas.Case II: Impurities are removed from the flue gas in a distillation column. Two refrigeration loops (ethane and propane) have been used in order to partially liquefy the flue gas and for heat removal from a partial condenser. Case II can remove higher amounts of impurities than Case I. CO₂ purity prior to storage is over 99%; CO₂ recovery factor is somewhat lower than in Case I: 95.4% for the NG-fired flue gas and 86.9% for the PF-fired flue gas, reduction in the power plant output is similar to Case I.Due to the lower CO₂ recovery factor the total amount of work per kg stored CO₂ is somewhat higher for Case II: 457 kJ for the NG-fired flue gas and 603 kJ for the PF-fired flue gas.     

Model prediction on the rise of pCO2 in uniform flows by leakage of CO2 purposefully stored under the seabed

A numerical study was conducted to predict pCO₂ change in the ocean on a continental shelf by the leakage of CO₂, which is originally stored in the aquifer under the seabed, in the case that a large fault connects the CO₂ reservoir and the seabed by an earthquake or other diastrophism. The leakage rate was set to be 6.025 × 10⁻⁴ kg/m²/sec from 2 m × 100 m fault band, which corresponds to 3800 t-CO₂/year, referring to the monitored seepage rate from an existing EOR field. The target space in this study was limited to the ocean above the seabed, the depth of which was 200 or 500 m. The computational domain was idealistically rectangular with the seabed fault-band perpendicular to the uniform flow. The CO₂ takes a form of bubbles or droplets, depending on the depth of water, and their behaviour and dissolution were numerically simulated during their rise in seawater flow. The advection–diffusion of dissolved CO₂ was also simulated. As a result, it was suggested that the leaked CO₂ droplets/bubbles all dissolve in the seawater before spouting up to the atmosphere, and that the increase in pCO₂ in the seawater was smaller than 500 μ atm.     

MSBR法处理焦化废水

焦化废水成分复杂,是一种较难处理的工业废水.试验采用MSBR法对其进行处理,考察了5组水力停留时问(66h,39h,28 h,20 h,17 h)下不同反应阶段(厌氧池、缺氧池、好氧池、SBR出水)对水样的处理效果.结果显示,HRT总为66h条件下.CODCr去除率为82%,效果相对最好,并且每组HRT下焦化废水中的CODCr均是在 MSBR系统前置的厌/缺氧池(A2)已得到大幅度去除.但硝化作用受到抑制,NH3-N的去除效果并不明显.     

地下饮用水中痕量NO2-的催化动力学法测定

报道了一种新的测定NO2-的高选择性和高灵敏度的催化光度分析法.基于H3PO4介质中,碘绿与溴酸钾的氧化还原反应受亚硝酸盐的催化使碘绿褪色.据此建立了测定NO2-的新方法.本方法检出限为0.29μg/L,该方法用于地下饮用水、环境标样的测定,相对标准偏差为1.05%～4.80%,加标回收率为95%～117%.     

空气和废气监测中H2S标液的选择

有2种不同方法制备的H2S标准溶液进行测定,结果表明,所得标准曲线斜率一致,因此,在实际工作中可对其灵活运用。     

5—(4—磺酸基苯偶氮)8—(2,4—二硝基苯氨基)喹啉测定食品中铜的研究应用

在弱碱性介质中 ,5— (4—磺酸基苯偶氮 ) 8— (2 ,4—二硝基苯氨基 )喹啉 (SPDNPAQ)与铜反应生成 2∶ 1紫红色络合物 ,体系 λmax=56 0 nm,ε=1.2 3× 10 5L· mol-1· cm-1。铜含量在 0～ 0 .4 mg/ L内符合比耳定律 ,方法用于一些生物样品和水样中铜的测定。     

Using the polychaete Arenicola marina to determine toxicity and bioaccumulation of PAHS bound to sediments

Transportation system has contributed significantly to the development of human civilization; on the other hand it has an enormous impact on the ambient air quality in several ways. In this paper the air and noise pollution at selected sites along three sections of National Highway was monitored. Pakistan National Highway Authority has started a Highway Improvement program for rehabilitations and maintenance of National highways to improve the traffic flows, and would ultimately improve the air quality along highways. The ambient air quality and noise level was monitored at nine different locations along these sections of highways to quantify the air pollution. The duration of monitoring at individual location was 72 h. The most of the sampling points were near the urban or village population, schools or hospitals, in order to quantify the air pollution at most affected locations along these roads. A database consisting of information regarding the source of emission, local metrology and air quality may be created to assess the profile of air quality in the area.     

Coupling upland watershed and downstream waterbody hydrodynamic and water quality models (SWAT and CE-QUAL-W2) for better water resources management in complex river basins

Effective water resources management programs have always incorporated detailed analyses of hydrological and water quality processes in the upland watershed and downstream waterbody. We have integrated two powerful hydrological and water quality models (SWAT and CE-QUAL-W2) to simulate the combined processes of water quantity and quality both in the upland watershed and downstream waterbody. Whereas the SWAT model outputs water quality variables in its entirety, the CE-QUAL-W2 model requires inputs in various pools of organic matter contents. An intermediate program was developed to extract outputs from SWAT at required subbasin and reach outlets and converts them into acceptable CE-QUAL-W2 inputs. The CE-QUAL-W2 model was later calibrated for various hydrodynamic and water quality simulations in the Cedar Creek Reservoir, TX, USA. The results indicate that the two models are compatible and can be used to assess and manage water resources in complex watersheds comprised of upland watershed and downstream waterbodies.     

高效液相色谱-串连四极杆质谱联用测定水样和气样中的1-甲基-2-吡咯烷酮

建立了水和气样中1-甲基-2-吡咯烷酮的高效液相色谱-串连四极杆质谱测定方法。水样经0.45μm滤膜可直接进样,气样中的1-甲基-2-吡咯烷酮经活性炭吸附后,经30%乙腈水溶液洗脱后进样,最低检出质量达0.012ng;线性范围在0.001~2mg/L;方法灵敏度高,干扰小,定性能力强,快速简单,回收率良好。