Applied Mechanics and Materials Vols. 291-294

Abstract: In order to obtain the pressure drop of the horizontal liquid-solid circulation fluidization bed with Kenics static mixers, experiments were carried out in four Kenics static mixers with different aspect ratio of mixing element(AR) over a range of 30000 to 51000 to get pressure drop data. Dimension analysis revealed that the pressure drop characteristic of the Kenics static mixer can be described by three dimensionless parameters, such as the friction factor, Reynolds number, and aspect ratio of mixing element. According to the experiment data, a new dimensionless pressure drop correlation was developed. The results indicate that the value of Cf becomes constant and has no correlation with the value of Re in fixed AR. The value of Cf was increased with the increase of AR.

Abstract: A mechanism of CO₂-CH₄ reforming over supported transition metal catalysts (platinum, rhodium, ruthenium) under a supercritical condition (304.13K, 72.90atm) was investigated using the B3LYP density functional method and MP2 method. Results obtained show that there are two channels in this reaction. The oxidized material is the most important catalyst in each reaction channel. For Pt, Rh and Ru, the rate-determining step of the reaction is the same - the step of CO₂ activation. Because of the large activation energies, the oxide reforming on Rh and Ru catalysts can't proceed under the supercritical condition. For Pt, the CO₂ activation reaction proceeds easier than the other two kinds of catalysts. According to the energy calculation results, specific activities of three kinds of the transition metals follow in the order: Pt ＞ Rh ＞ Ru.

Abstract: The adsorption process of Cr (VI) in aqueous solution on activated carbon prepared by discarded disposable chopsticks was investigated to study the effect factors on adsorption properties. adsorption mechanism was discussed. The results showed that the adsorption performance was influenced by partical size, dosage, pH of medium, initial concentration and adsorption time. Adsorption reached equilibrium after 60min at temperature 25°C, pH=3, 80 mesh of adsorbent particle size. The highest removal efficiency can reach 92%. The results indicated that activated carbon as adsorbent can effectively deal with waste water containing (VI).

Abstract: The investigation on application of oxygen-enriched combustion in cement rotary kiln shows that flame temperature in rotary kiln can be increased, which improves the utilization of coal and thermal efficiency of rotary kiln. And the fuel consumption and the cost of production can be reduced. In this situation, the objective of increasing production, improving quality and saving energy can be achieved. In the meanwhile, the requirement of air can be reduced in oxygen-enriched combustion. Thus the generation of flue gas and the products of incomplete combustion, which usually are CO, can be reduced. And then the exhaust gas loss and the generation and emission of CO2 and NOx can be accordingly reduced, which enhances to achieve the objective of reduction of pollutants and promote the environmental benefit greatly.

Abstract: Energy is the foundation of regional economy sustainable development. it is more and more serious of regional energy security problem with the rapid economic growth, industrialization and city development. The concept of regional energy security is defined. According to the characteristic of regional energy security problem, a cluster ensemble structure with system energy theory and an algorithm, called F-ETMC, are put forward to analysis regional energy security problem. The experiment shows that the method not only effectively analysis the regional energy security, but also provides the reference for energy development strategy and policy making.

Abstract: A newly constrained multi-objective differential evolution optimization technique (CMODE) for security constrained economic/environmental dispatch (EED) was proposed. The proposed CMODE evolved a constrained multi-objective version of differential evolution (DE) by employing the traditional multi-objective differential evolution (DEMO) and constrain handle technique to balance the search between feasible region and infeasible region. The proposed CMODE method had been applied to solve the security constrained EED problem. Experiments had been carried on a standard test system. The results demonstrate the high efficiency of the proposed method to solve security constrained EED problem, and the necessary of taking security constrains into consideration.

Abstract: 400 MW IGCC power plants were modeled by using commercial software GT PRO. The high pressure unsaturated water extracted from heat recovery steam generator (HRSG) was used to heat clean syngas to various temperatures. The influences of clean syngas preheating temperature on plant performances were investigated. Results showed that net power output and coal consumption both reduced with the increase of syngas preheating temperature, and coal consumption reduced to a larger extent. Moreover, when syngas preheating temperature increased, the net electric efficiency increased and the net heat rate decreased gradually. It was concluded that preheating clean syngas in a reasonable way was beneficial to improve the performances of IGCC power plant.

Abstract: At the pyrolysis temperature range of 460°C to 560°C, the pyrolysis of Wulagai lignite and the acid-washed lignite is completed on the fixed-bed reactor. The phenols are detected by GC. Study shows that the minerals in coal may influence the decomposition of the phenols intermediates or suppress the producing of final phenols, acid-washing helps improving the yield of phenols. The minerals in lignite have no effect on the generation of low boiling-point phenols in the lower pyrolysis temperature, but have significant effect on the yield of high boiling-point phenols. The minerals in Wulagai lignite have a significant effect on the distribution of the fixed bed low temperature pyrolysis phenols.

Abstract: The petroleum coke (refered to as PC) with the addition of FeSO4 was obtained by impregnation method, and the reactivity of PC with CO2 are analysed by TG.PC samples were heated from room temperature to 1300 °C with heating rate of 20 °C / min at the atmosphere of CO2 (40 ml/min) and N2 (60 ml/min).At the same time, FTIR spectral of the gasflowing was obtained every 30 seconds. The results show that the TG curve of raw petroleum coke begin to decline, and the CO peak in its 3D infrared spectrogram plot has appeared at the temperature of 1100°C, which proved that the raw petroluem coke (refered to as RPC) has reacted with CO2 at 1100°C. And as the FeSO4 added amount increased,the gasification beginning temperature and initial release time of CO are all in advance,which prove that FeSO4 can enhance the reactivity of PC carbon dioxide gasification.

Abstract: The study of relationship between PAHs(Polycyclic Aromatic Hydrocarbons) and macerals contributes to understand the occurrence and distribution of PAHs in coal. Ten coal samples were collected and then tested macerals and 15 PAHs quantitatively. The concentration of total PAHs, single PAH and every-ring of PAHs tend to increase with and reduce with the increasing inertinite, vitrinite and liptinite contents. The higher the PAHs ring number is, the more obvious the effect of macerals exert on them. Higher H/C, O/C atomic ratios and higher aromaticity in inertinite groups are the main reasons for the positive relationship between inertinite and PAHs. Degree of coalification had a significant effect on the relationship between PAHs and maceral groups in coal.