Gas–liquid membrane contactors for carbon dioxide capture from gaseous streams

Membrane technology is characterized by high efficiency, compatibility and flexibility of various membrane processes in integrated systems, low power consumption, high stability and environmental safety of processes, comparative ease and simplicity of controlling and scaling-up, as well as a unique functional flexibility of the membrane processes. This is why the membrane technology is considered as a promising way to reduce anthropogenic emissions of carbon dioxide into the atmosphere. Gas–liquid membrane contactors are a prime example of high-performance hybrid processes using membrane technologies. Integrating several separation methods in one device (membrane contactor) makes it possible to retain benefits of membrane technology, such as small size and flexibility, complementing them with high separation selectivity typical of CO₂ absorption. This review presents the basic principles of operation and design of membrane contactors, and a wide range of materials, membranes, and liquid absorbents for membrane CO₂ absorption/stripping are considered. Particular attention has been paid to current studies on CO₂ removal from thermal power plant flue gas, natural gas, biogas, and syngas. The examples of pilot-scale and semi-commercial implementation of CO₂ absorption/stripping in membrane contactors have been given.     

Study of a plugging microbial consortium using crude oil as sole carbon source

A microbial consortium named Y4 capable of producing biopolymers was isolated from petroleum-contaminated soil in the Dagang Oilfield, China. It includes four bacterial strains： Y4-1 （Paenibacillus sp.）, Y4-2 （Actinomadura sp.）, Y4-3 （Uncultured bacterium clone） and Y4-4 （Brevibacillus sp.）. The optimal conditions for the growth of the consortium Y4 were as follows： temperature about 46 ℃, pH about 7.0 and salinity about 20.0 g/L. The major metabolites were analyzed with gas chromatographymass spectrometry （GC-MS）. A comparison was made between individual strains and the microbial consortium for biopolymer production in different treatment processes. The experimental results showed that the microbial consortium Y4 could produce more biopolymers than individual strains, and the reason might be attributed to the synergetic action of strains. The biopolymers were observed with optical and electron microscopes and analyzed by paper chromatography. It was found that the biopolymers produced by the microbial consortium Y4 were insoluble in water and were of reticular structure, and it was concluded that the biopolymers were cellulose. Through a series of simulation experiments with sand cores, it was found that the microbial consortium Y4 could reduce the permeability of reservoir beds, and improve the efficiency of water flooding by growing biomass and producing biopolymers. The oil recovery was enhanced by 3.5% on average. The results indicated that the consortium Y4 could be used in microbial enhanced oil recovery and play an important role in bioremediation of oil polluted environments.     

Environmental-friendly shrimp waste protein corrosion inhibitor for carbon steel in 1 M HCl solution

Recovery shrimp waste protein (RSWP) was extracted, characterized and tested their inhibition effects as a corrosion inhibitor for carbon steel in 1?M HCl solution using different electrochemical techniques. The results have been shown that the corrosion rate decreases with increasing inhibitor concentration. To verify the morphology of RSWP film formed on the carbon steel surface, scanning electron microscopy (SEM) was used. The inhibition mechanism of the extracted RSWP is discussed in terms of adsorption on the carbon steel surface. The results of the energy adsorption were showed chemisorption effect for RSWP on the carbon steel surface.     

Co-optimization of carbon dioxide storage and enhanced oil recovery in oil reservoirs using a multi-objective genetic algorithm （NSGA-II）

Climate researchers have observed that the carbon dioxide （CO2） concentration in the atmosphere have been growing significantly over the past century. CO2 from energy represents about 75% of the greenhouse gas （GHG） emissions for Annex B （Developed） countries, and over 60% of global emissions. Because of impermeable cap rocks hydrocarbon reservoirs are able to sequester CO〉 In addition, due to high-demand for oil worldwide, injection of CO2 is a useful way to enhance oil production. Hence, applying an efficient method to co-optimize CO2 storage and oil production is vital. Lack of suitable optimization techniques in the past led most multi-objective optimization problems to be tackled in the same way as a single objective optimization issue. However, there are some basic differences between the multi and single objective optimization methods. In this study, by using a non- dominated sorting genetic algorithm （NSGA-II） for an oil reservoir, some appropriate scenarios are proposed based on simultaneous gas storage and enhanced oil recovery optimization. The advantages of this method allow us to amend production scenarios after implementing the optimization process, by regarding the variation of economic parameters such as oil price and CO2 tax. This leads to reduced risks and time duration of making new decisions based on upcoming situations.     

Positive carbon isotope excursions: global correlation and genesis in the Middle–Upper Ordovician in the northern Tarim Basin, Northwest China

Stable carbon isotope ratio(δ~(13) C_(carb)) analysis has been widely applied to the study of the inter-continental or global marine carbonate correlation.Large-scale Cambrian-Ordovician carbonate platforms were developed in the Tarim Basin.But research on fluctuation characteristics and global correlation of(δ~(13) C_(carb)) is still weak.Based on conodont biostratigraphy and whole-rock 8(δ~(13) C_(carb)) data in the Tahe oil-gas field of the northern Tarim Basin,the global correlation and genesis of positive carbon isotope excursions in the Darriwilian—Early Katian was examined.Three positive excursions were identified in the Tahe oil-gas field including the middle Darriwilian carbon isotope excursion(MDICE),the Guttenberg carbon isotope excursion(GICE).and a positive excursion within the Pygodus anserinus conodont zone which is named the Early Sandbian carbon isotope excursion(ESICE) in this paper.Furthermore,these positive excursions had no direct relation with sea level lluctuations.MDICE and GICE could be globally correlated.The Middle-Upper Ordovician Saergan Formation source rocks of the Kalpin outcrops were in accordance with the geological time of MDICE and ESICE.GICE had close relationship with the source rock of the Lianglitag Formation in the basin.Massive organic carbon burial was an important factor controlling the genesis of these positive excursions.     

Issues Triggered by Carbon Dioxide Emission Worldwide and Countermoves——Geological burial of carbon dioxide is effective method to avoid global warming

Large quantities of fossil fuel （coal, petroleum and natural gas） is used in the industrial production and people＇s livelihood, leading to a continuous rise in greenhouse gas emission. As a result, the air pollution and greenhouse effect have posed a severe threat to the environment on which the survival of the humanity is based. The UK released a comprehensive report on the climate changes in 2006. The sea level will rise in the middle of this century if no actions are taken. More disastrous flooding and draughts will force 200 million people to leave their homeland. In a milestone report released in Paris in March 2007,     

Evaluation of a novel cationic surfactant based on 2-(2 (dimethylamino)ethoxy)ethanol as a corrosion inhibitor for carbon steel 1018 in 1.0 M HCl solution

Corrosion inhibition of a novel cationic surfactant namely, N-(2-(2-hydroxyethoxy)ethyl)-N,N-dimethyldodecan-1-aminium bromide (HEDDB) was evaluated as a corrosion inhibitor for carbon steel in 1.0 M HCl by electrochemical frequency modulation (EFM), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. Results of Tafel polarization exhibit that the synthesized surfactant HEDDB behaves as mixed-type inhibitor. The effectiveness of temperature on the corrosion rate which evaluated by chemical technique (weight loss) was investigated and assessed. Langmuir’s adsorption isotherm was the preferable fitted isotherm. The results of weight loss clarified that the efficiency of the synthesized surfactant increases with raising both the concentration of the surfactant and the temperature. HEDDB effectiveness on the morphology of metal surface was monitored by Atomic Force Microscopy (AFM) and Scanning Electron Microscope (SEM) techniques. Quantum chemical technique has been employed to discuss the inhibition efficiency by effectiveness of molecular structure of the synthesized inhibitor. The various techniques which used in this research have inhibition efficiency (IE) with the same direction.     

Foil-supported Rh/γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> and Pt/γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> catalysts for carbon dioxide methane reforming

Rh/γ-Al₂O₃ and Pt/γ-Al₂O₃ catalysts supported on a metal foil surface have been studied in the carbon dioxide reforming of methane. The stability and activity of platinum and rhodium catalysts with different compositions have been determined. The kinetic function parameters have been found by solving the inverse problem. It has been shown that the 0.06% rhodium catalyst is the most active; its activity is more than two orders of magnitude higher than that of the nickel-chromium catalyst studied earlier.