The increment of hydrogen demand in oil refineries motivates the industries to optimize the hydrogen network and rationally use hydrogen resources for energy conservation and cost reduction. In the hydrogen distribution networks，in addition to the consumption of hydrogen，the foremost consumption of energy is compression power. In order to unify and optimize the consumption of hydrogen and compression power，“exergy standard” is proposed to design and optimize the hydrogen distribution network. The consumption of hydrogen utility and compression power are converted to exergy and the total exergy consumption is utilized to evaluate the hydrogen network. In addition，a network evolution strategy is also utilized to reduce the number of compressors effectively，which can guarantee the optimal energy performance and economical benefit. A literature case is solved to illustrate the applicability and effectiveness of the proposed methodology.

In order to improve energy consumption efficiency of alumina evaporation process(AEP)，an optimization model is built to maximize exergy utilization ratio.  The objective is to minimize exergy loss rate and maximize target exergy efficiency. The constraints of the optimization model are handled by a type of robust function combined with a basin hopping based infeasible solution modification method. This decreases the influence of infeasible solutions，that is，those with a big degree of constraint violation，and preserves the information provided by infeasible solutions. A particle swarm optimization(PSO)algorithm with vortex topology is used to optimize the objective function effectively. Optimal results of a practical AEP show that the optimization model takes into account both exergy loss rate and system thermodynamic perfect degree,and optimization operation can improve energy efficiency and ensure the quality of solution.

A mechanical vapor compression(MVC)based desalination system for oilfield waste water is proposed to combat the difficulties resulted from complicated and strongly polluting pollutants of the waste water in using membrane methods. The complete mathematical model for process simulation and design is developed for the MVC-based oilfield waste water desalination system and the influences of the heat transfer temperature difference of falling-film evaporators，waste water temperature and evaporation temperature on the system performance are analyzed. The results show that the temperature difference is the controlling factor that determines the specific heat transfer area and the specific compression work of the system. Reducing this temperature difference will directly decrease the specific compression work and increase the specific heat transfer area. Higher waste water temperature results in a slight decrease in the specific heat transfer area，which demonstrates that the system is highly perfect in thermodynamics. The results also show that increasing evaporation temperature may significantly improve the performance of the system.

In order to evaluate the design schemes for heat exchanger and other mechanical equipment，based on the extension theory，a multilevel assessing index system for heat exchanger design schemes was proposed，a multilevel matter-element model for the design scheme was established，and a multilevel assessing method for the design scheme was proposed. A comprehensive evaluation of shell and tube heat exchanger was realized，the objectivity and validity of the result were confirmed，and the result shows that the method is effective and reliable.

The failure process of fluorocarbon coating in 3.5% NaCl solution under wet-dry cyclic condition was studied with electrochemical impedance technique，Fourier transform infrared spectrometry(FTIR)and scanning electronic microscope(SEM).The results showed that the failure rate of coating under wet-dry environment was faster than that under complete immersion condition. The wet-dry condition promoted formation of micro-pores in the coating and resulted in decreased coating resistance and increased water absorption. The failure mechanism for fluorocarbon coating under wet-dry environment was suggested. The coating volume experienced swelling and contraction during the wet-dry cycle，which resulted in increased micro-pores and cracks in the coating. Electrolyte entered the coating defects under the action of osmotic pressure，leading to blisters and reduced adhesion of the coating to the substrate.

Sugar can bagasse(SCB)was mechanically activated by a self-made stirring-type ball mill. The effects of dosage of aluminate ester and activation time on the activation grade, contact angle of modified SCB and viscosity of SCB/paraffin oil system were investigated. In addition, the crystal structure and functional groups of bagasse were characterized by X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR).The results showed that after modification with aluminate ester, the activation grade and contact angle of SCB increased, while viscosity of SCB/paraffin oil system decreased.  The optimal effect was achieved when the dosage of aluminate ester was 3% of SCB. It was found that the reaction of SCB and aluminate ester was strengthened obviously by mechanical activation. The activation grade and contact angle of mechanically activated SCB increased obviously, and the viscosity of activated SCB/paraffin oil system decreased greatly after modification with aluminate ester. The optimal mechanical activation time was 120 min. After modification with aluminate ester, the dispersion of SCB in organic phase increased greatly, and the effect of mechanically activated SCB modified with aluminate ester became more remarkable. XRD analysis showed  that mechanical activation decreased the degree of crystallinity of cellulose, made it more accessible to aluminate ester, and improved the reactivity of cellulose. FTIR analysis showed that chemical reaction of the hydroxy group on the surface of SCB and the alkoxyl group of aluminate ester took place during the modification, forming a new chemical bond Al—O—C, and a molecule layer of aluminate ester was also formed on the surface of SCB.

The effects of gas entry route and blow tank pressure on characteristic of dense-phase pneumatic conveying of pulverized coal were studied in top discharge blow tank conveying system. Additionally，a comparison was made on solid mass flow rate，solid-gas ratio and conveying stability between top and bottom discharge blow tank conveying system. It was found that in top blow tank conveying system，solid mass flow rate and solid-gas ratio first increased and then decreased with the fluidizing gas in the conical section; decreased with the supplementary gas and fluidizing gas in the bottom section; while for the blow tank pressure increasing，solid mass flow rate and solid-gas ratio first increased obviously and then the increasing degree weakened. In the same total conveying pressure drop，there are higher solid mass flow rate and gas-solid ratio for the bottom than the top discharge blow tank conveying systems，but there was little difference in conveying stability between the two systems.

An explosion accident is possible for process of oil recovery using air injection because of the existence of flammable mixture. So it is necessary to measure the explosion limits and the critical oxygen content of crude oil vapor at different temperatures from 15℃ to 150℃. The measurement result indicated that the explosion limit of crude oil vapor is 4.62%—14.01% at 15℃ and 4.24%—15.62% at 150℃，while the critical oxygen is 13.15% at 15℃ and 12.47% at 150℃. The range of explosion limit widens and the critical oxygen content decreases with temperature increasing. The correlations between explosion limits as well as critical oxygen content and temperature are founded through numerical analysis，which could be used for forecasting the explosion limits and the critical oxygen content of crude oil at different temperatures.

In order to activate indigenous microorganisms in reservoirs to enhance oil recovery，the compositions of indigenous microbial community in Zhan 3 block were interpreted with the methods of MPN(most probable number)and DGGE(denatured gradient gel electrophoresis).To get more information，the ionic compositions of the water from oil field were also analyzed by means of ion chromatography and inductively coupled plasma emission spectrometry. In order to evaluate effectively the effect of the activation system，the microflora dynamics of bacteria and SRB in the water sample，the effect of emulsification of crude oil were taken as evaluation indexes. The compositions and concentration ranges of the activation system were selected by means of single-factor test. Based on the single-factor test，the mathematical regression model was established about the dependent variable［corn steep powder,(NH₄)₂HPO₄，NaNO₃］and independent variables(the absorption value at 650 nm of the activated water sample)through Box-Benhnken center composite design and response surface methodology. As the final composition of the activation system were corn steep powder 0.33 g·（100 ml）^-1,(NH₄)₂HPO₄ 0.312 g·（

A hydrocarbon-degrading facultative strain WJ-1 was isolated from the formation water of Menggulin oil reservoir and identified as Pseudomonas aeruginosa by the physiological-biochemical tests and 16S rDNA technology. In order to investigate the biodegradation characteristics of this strain with crude oil as sole carbon source，four different crude oils gathered from Xinjiang，Zhongchakou，Daqing-Jiangqiao，Menggulin oil reservoirs were used. The biodegradation effect on four fractions(saturated hydrocarbons，non-hydrocarbons，aromatics，asphaltene and resin)of oil were analyzed by rod thin layer chromatography and the results showed that the relative contents of non-hydrocarbons，asphaltene and resin decreased in average by above 10% after WJ-1 strain metabolism. Gas chromatography experiments indicated that the light components of saturated hydrocarbons increased，the heavy components of saturated hydrocarbons and phenanthrene of aromatics decreased. The viscosity and solidification point of four crude oils in average reduced by about 45% and 6℃. Physical simulation studies using four different crude oils in porous media showed that the strain WJ-1 could enhance oil recovery by 4.78%，5.15%

Degradation of phenol in water by microwave-assisted chlorine dioxide oxidation

ZHAO Deming，ZHANG Tan，ZHANG Jianting，XU Xinhua

2011, 62(7):  2020-2025. 

Abstract ( 1192 )   PDF (460KB) ( 551 )  

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The degradation of phenol in aqueous solution by microwave-assisted chlorine dioxide(MW/ClO₂)oxidation was studied with laboratory-scale experiments. The affecting factors such as initial ClO₂ concentration，MW power，pH value，initial phenol concentration and reaction temperature，and reaction kinetics were investigated. For all oxidation processes by alone MW radiation or ClO₂ oxidation as well as combined MW/ClO₂，phenol degradation followed pseudo-first-order kinetics. The overall reaction rates were significantly enhanced in the combined MW/ClO₂ system，mainly because microwave could accelerate chlorine dioxide to generate chlorine radical(·Cl)and other reactive oxygen intermediates. The observed synergetic effects in MW/ClO₂ process resulted in an increased in the net reaction rate by a factor of 1.4. The results also showed that the effect of initial ClO₂ concentration，MW power，pH value and initial phenol concentration on reaction rate is significant，