The Experts below are selected from a list of 2475 Experts worldwide ranked by ideXlab platform
Fang-hei Tsau - One of the best experts on this subject based on the ideXlab platform.
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trimethyl borate regenerated from spent sodium borohydride after hydrogen production
Industrial & Engineering Chemistry Research, 2010Co-Authors: Binghung Chen, Jie Ren Ku, Fang-hei TsauAbstract:Sodium metaborate (NaBO2) is the hydrolysate of sodium borohydride (NaBH4) for hydrogen production. Trimethyl borate (B(OCH3)3), the major reactant for producing sodium borohydride via the Brown−Schlesinger process, is successfully regenerated from sodium metaborate (NaBO2) via a sequential process including reacting with sulfuric acid, cooling crystallization, and reactive esterification distillation. The metaborate is first converted to boric acid (H3BO3) by reacting with sulfuric acid, bypassing formation of Borax (na2b4o7·10H2O) required in a conventional process. Cooling crystallization is utilized to separate and purify boric acid from coexisting sodium sulfate (Na2SO4). Subsequently, trimethyl borate is formed via esterification of boric acid with methanol, in which reactive esterification distillation is adopted to facilitate the esterification and purify the product. Formation of boric acid and trimethyl borate is confirmed with X-ray diffraction (XRD) analysis, Fourier transform infrared spectro...
Yao Hui Huang - One of the best experts on this subject based on the ideXlab platform.
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ruthenium immobilized on al2o3 pellets as a catalyst for hydrogen generation from hydrolysis and methanolysis of sodium borohydride
RSC Advances, 2012Co-Authors: Chia Chi Su, Ming Chun Lu, Shu Ling Wang, Yao Hui HuangAbstract:Ru immobilized Al2O3 pellets were synthesized as a catalyst for hydrogen generation in NaBH4 solutions. Under the Ru/Al2O3 catalysis, the hydrogen generation rate from the hydrolysis and methanolysis of NaBH4 in alkaline solution was explored as a function of NaBH4 concentration and temperature. Meanwhile, the borate byproducts derived from the NaBH4 hydrolysis were characterized by XRD and NMR. The results showed that the hydrogen generation rate depended on NaBH4 concentration for the hydrolysis, but did not for the methanolysis. 10 wt% NaBH4 hydrolysis containing 1 wt% NaOH catalyzed with 0.5 g Ru/Al2O3 could generate hydrogen with a rate of about 65.5 ml min−1 g−1. The productivity and activation energy of hydrogen generation from the NaBH4 hydrolysis were 93% and 41.8 kJ mol−1, and from the NaBH4 methanolysis were 97% and 51.0 kJ mol−1, respectively. The XRD and NMR analyses showed that the species from the hydrolysis byproducts varied with the NaBH4 concentration could be the Borax (na2b4o7·H2O) and sodium borate hydrate (NaBO2·H2O).
Shihua Sang - One of the best experts on this subject based on the ideXlab platform.
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liquid solid equilibrium for quaternary system na2so4 k2so4 na2b4o7 k2b4o7 h2o at 288 k
Journal of Chemical & Engineering Data, 2005Co-Authors: Ying Zeng, Shihua SangAbstract:An experimental study on phase equilibria at 288 K in the quaternary system Na2SO4 + K2SO4 + na2b4o7 + K2B4O7 + H2O was done by the isothermal evaporation method. Equilibrium solubilities and properties such as density, electrical conductivity, and pH of the solution were measured, and the equilibrium phase diagram was constructed in which there were two invariant points, six univariant curves, and four crystallization fields corresponding to Borax (na2b4o7·10H2O), sodium sulfate, potassium sulfate, and potassium borate quahydrate (K2B4O7·4H2O). No solid solutions or double salts were found.
Ting-yu Liu - One of the best experts on this subject based on the ideXlab platform.
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Selection of Fluxing Agent for Coal Ash and Investigation of Fusion Mechanism: A First-Principles Study
Energy & Fuels, 2009Co-Authors: Zhongxiao Zhang, Rong-qing Guan, Yu-shuang Chen, Ting-yu LiuAbstract:An approach based on the ab initio quantum chemical modeling [CASTEP, generalized gradient approximation (GGA), and density functional theory (DFT)] was first employed to guide the selection of the appropriate fluxing agent to reduce the coal ash melting temperature. Two kinds of typical Chinese coal ash A and B with a high-melting temperature were chosen as the investigated subjects. Result of the calculation shows that mullite mineral, which is the main component of coal ash, is easier to combine with an electron acceptor than with an electron donor. Because the cations of Borax (na2b4o7·10H2O) and limestone can act as electron acceptors, Borax and limestone were selected as the fluxing agents in our experiment. Results of the experiment show that the melting temperatures of coal ash A and B are both decreased by Borax and limestone, respectively. Moreover, Borax has a better fluxing effect than limestone under the same conditions. The further numerical study on the coal ash fusing mechanism indicates t...
Binghung Chen - One of the best experts on this subject based on the ideXlab platform.
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trimethyl borate regenerated from spent sodium borohydride after hydrogen production
Industrial & Engineering Chemistry Research, 2010Co-Authors: Binghung Chen, Jie Ren Ku, Fang-hei TsauAbstract:Sodium metaborate (NaBO2) is the hydrolysate of sodium borohydride (NaBH4) for hydrogen production. Trimethyl borate (B(OCH3)3), the major reactant for producing sodium borohydride via the Brown−Schlesinger process, is successfully regenerated from sodium metaborate (NaBO2) via a sequential process including reacting with sulfuric acid, cooling crystallization, and reactive esterification distillation. The metaborate is first converted to boric acid (H3BO3) by reacting with sulfuric acid, bypassing formation of Borax (na2b4o7·10H2O) required in a conventional process. Cooling crystallization is utilized to separate and purify boric acid from coexisting sodium sulfate (Na2SO4). Subsequently, trimethyl borate is formed via esterification of boric acid with methanol, in which reactive esterification distillation is adopted to facilitate the esterification and purify the product. Formation of boric acid and trimethyl borate is confirmed with X-ray diffraction (XRD) analysis, Fourier transform infrared spectro...