Advanced Materials Research Vols. 396-398

Abstract: Sugarcane bagasse microcrystalline cellulose (SBMC) was first prepared under subcritical Water/CO₂ by degradation of sugarcane bagasse cellulose (SBC). The obtained products were characterized by FT-IR, XRD and TGA and the results showed that the amorphous parts of SBC was easily decomposed, and yet the crystal parts kept a good form all along during the degradation, which demonstrated SBMC had good thermal stability. Furthermore, the reaction temperature, reaction time, reaction pressure and liquid-solid ratio were systematically investigated during the work. The optimum reaction conditions are as follows: the reaction temperature was 200°C; the reaction time was 60 min; the reaction pressure was 2 MPa and the liquid-solid ratio was 40:1.

Abstract: A ferrate solution about 236.87mM was obtained under the optimum conditions: 16MNaOH, J=100mAcm-2, 35°C, electrolysis duration (1h), The optimal current efficiency was 45.86%. The cyclic voltammogram of iron with 3.3% Si revealed a new anodic wave between -0.2V and 0.1V versus HgO/Hg corresponding to Fe(V) production.

Abstract: Various corrosion media were prepared by dual-cells experimental setup, including fresh sterilized culture medium, culture medium with sulfate-reducing bacteria (SRB), and culture medium containing only SRB metabolites. Corrosion exposure tests of Q235 carbon steel were conducted in these media, and effects of SRB on the corrosion behavior of Q235 were studied by electrochemical methods and surface analyses. As the results, Q235 was uniformly corroded in the fresh sterilized culture medium in a mode of active dissolution; in the culture medium of SRB, Q235 was protected by the iron sulfides layer to some extent in the early stage of exposure, but severely localized corrosion subsequently occurred resulting from the localized breakdown of iron sulfides layer in presence of SRB and SRB biofilm; while in the culture medium containing only SRB metabolites, Q235 was well protected over the whole exposure period, suggesting that a uniform and stable layer of iron sulfides was formed in this medium.

Abstract: A series of new green metallurgical processes have been proposed and developed to improve the recovery of vanadium and chromium in vanadium slag, and solve the environmental problems occurred in the traditional production process. The reactivity of three reaction media including sub-molten potassium hydroxide, sub-molten sodium hydroxide, and NaOH-NaNO₃ binary molten salt medium has been examined and compared. In comparison with the traditional sodium salt roasting technology, which operates at 850 °C, the operation temperature in the new media can drop to 200~450°C, significantly decreasing the energy consumption. Chemical conversion ratio of vanadium and chromium using the new reaction media could reach to above 95% and 80%, respectively, superior to the traditional technology. For in the latter technology the data is 80% for vanadium and only 10% for chromium. Thus, the application of such reaction media in the processing of vanadium slag has been proven to be feasible and attractive, and the processes developed based on such media are expected to replace the traditional roasting process in the near future.

Abstract: The electrochemical interaction between bacteria and electrode should be further strengthened at the present stage in order to develop microbial fuel cells (MFCs) to practical power sources. Developing effective anode materials is an alternative to achieving this goal. In this study, the redox activity of polyaniline (PAn) in neutral pH solution was improved by doping ionic liquid (IL) into the synthesized PAn; and the current output of MFC could be enhanced by using IL doped polyaniline (PAnIL) film as anode material. Both cyclic voltermmeter (CV) measurement and MFC operation showed that PAnIL electrochemically synthesized in solution with 30%(v/v) IL addition exhibited the best performance.

Abstract: This paper makes some research on designing and manufacturing a nanosecond pulse power supply of electrochemical micromachining, including DC power supply, waveform generation circuit, rectifier and filter circuit，power amplification and rapid protection circuit. This power supply can generate 5MHz maximum frequency and square wave of 100ns pulse width, stably. The voltage ranges from 0V to 10V, and duty ratio ranges from 0.1 to 0.5, continuously.

Abstract: The constructed Sb-doped SnO2 electrode was obtained for electrochemical degradation of RDX. The influences of current density and initial concentration of RDX on electrochemical degradation of RDX were studied. Kinetics analysis shows that the electrochemical degradation of RDX follows the pseudo first-order reaction. The mechanism of electrochemical degradation of RDX was also discussed.

Abstract: The ideal adsorbed solution (IAS) theory has an advantage that no restriction exists for the type of pure component isotherm. One can choose the isotherm that fits the experimental data best. However, the theory requires a lot of numerical calculation, including numerical integration. This study shows that IAS needs very accurate values of numerical integration when the D-R equation is used as a single component isotherm. The error of numerical integration should be set to be no larger than 10-7. Otherwise the error of numerical calculation will occur, which may increase prediction deviation.

Abstract: Evaluation and optimization of coalbed methane favorable blocks is a very important basic work in the process of coalbed methane exploration and development, and the study results directly decide the success or failure of coalbed methane development. Firstly the thesis took Jiaozuo mining area as an example and set up an evaluation index system on favorable block of coal-bed methane development based on fuzzy mathematics theory, secondly a quantitative and comprehensive evaluation program were proposed, and made a comprehensive evaluation of coalbed methane favorable blocks of Jiaozuo mining area lastly. Evaluation results direct that the exploration and development of coalbed methane in Jiaozuo mining area are better and also have some reference value for the evaluation of favorable blocks in other similar areas.

Abstract: Granular activated carbon is used in adsorption of low concentration ethanol in water, and the saturated carbon is desorbed by microwave irradiation under N2 condition for recovery of the ethanol and regeneration of the activated carbon. Through the study on microwave desorption of ethanol-loaded activated carbon under N2 condition, the following conclusions can be drawn. The highest value of the ethanol concentration appears quicker and higher when the microwave power is stronger. For example, the highest value appears before 80s when the microwave power is 320W; the ethanol-loaded activated carbon can be desorbed nearly completely after 120s when the microwave power is not weaker than 320W; the microwave power has an important effect on the outlet concentration curve of ethanol, and it is an important factor that affects the results of microwave desorption; After three processes of activated carbon adsorption and microwave desorption under N2 condition, the concentration of ethanol can come up to over than 94%～95% from 4%～8%. This paper sets forth the process and principle for microwave desorption of ethanol-loaded activated carbon under N2 condition.