Chemical vapor deposition(CVD) of SiC from methyltrichlorosilane(MTS) was studied at two different molar ratios of H2 to MTS(n(H2) /n(MTS) ) . The total pressure was kept as 100 kPa and the temperature was varied from...Chemical vapor deposition(CVD) of SiC from methyltrichlorosilane(MTS) was studied at two different molar ratios of H2 to MTS(n(H2) /n(MTS) ) . The total pressure was kept as 100 kPa and the temperature was varied from 850 to 1 100 ℃ at a total residence time of 1 s. Steady-state deposition rates as functions of reactor length and of temperature,investigated at different n(H2) /n(MTS) values,show that hydrogen exhibits strongly influences on the deposition rate. Especially,the deposition of Si co-deposit can be obtained in broader substrate length and at higher temperatures with increasing hydrogen partial pressure. Influence of hydrogen on the deposition process was also studied using gas phase composition and deposit composition analysis at various n(H2) /n(MTS) . SEM micrographs directly show the variation of surface morphologies at various n(H2) /n(MTS) . It can be found that the crystal grain of the deposit at 1 100 ℃ is better developed and the crystallization is also improved with increasing n(H2) /n(MTS) .展开更多
Municipal solid wastes from industrial plants were pyrolyzed in a fixed bed reactor to evaluate the influence of paper/plastic ratio and reaction time both on product quantity and quality. Raw materials have been pyro...Municipal solid wastes from industrial plants were pyrolyzed in a fixed bed reactor to evaluate the influence of paper/plastic ratio and reaction time both on product quantity and quality. Raw materials have been pyrolyzed under nitrogen in a 3.0 dm^3 autoclave. Results show considerable differences in yields and quality of products obtained by pyrolysis of wastes with different paper content. Light and heavy oils were mixtures of organic compounds containing valuable hydrocarbons and oxygenated chemicals, while chars were rather composed of inorganic compounds from the raw materials. Longer reaction time of pyrolysis had produced higher non-condensable gas, water and light oil. Gases contained CO, CO2 and hydrocarbons, but the concentrations were very function of reaction time and paper/plastic ratio. Light and heavy oils showed similarities with middle distillates and heavy oils in refinery, the high paper content of the raw materials was unfavourable for longer storage of waste derived oils.展开更多
基金Project supported by the One Hundred Talents Program of Chinese Academy of Sciences
文摘Chemical vapor deposition(CVD) of SiC from methyltrichlorosilane(MTS) was studied at two different molar ratios of H2 to MTS(n(H2) /n(MTS) ) . The total pressure was kept as 100 kPa and the temperature was varied from 850 to 1 100 ℃ at a total residence time of 1 s. Steady-state deposition rates as functions of reactor length and of temperature,investigated at different n(H2) /n(MTS) values,show that hydrogen exhibits strongly influences on the deposition rate. Especially,the deposition of Si co-deposit can be obtained in broader substrate length and at higher temperatures with increasing hydrogen partial pressure. Influence of hydrogen on the deposition process was also studied using gas phase composition and deposit composition analysis at various n(H2) /n(MTS) . SEM micrographs directly show the variation of surface morphologies at various n(H2) /n(MTS) . It can be found that the crystal grain of the deposit at 1 100 ℃ is better developed and the crystallization is also improved with increasing n(H2) /n(MTS) .
文摘Municipal solid wastes from industrial plants were pyrolyzed in a fixed bed reactor to evaluate the influence of paper/plastic ratio and reaction time both on product quantity and quality. Raw materials have been pyrolyzed under nitrogen in a 3.0 dm^3 autoclave. Results show considerable differences in yields and quality of products obtained by pyrolysis of wastes with different paper content. Light and heavy oils were mixtures of organic compounds containing valuable hydrocarbons and oxygenated chemicals, while chars were rather composed of inorganic compounds from the raw materials. Longer reaction time of pyrolysis had produced higher non-condensable gas, water and light oil. Gases contained CO, CO2 and hydrocarbons, but the concentrations were very function of reaction time and paper/plastic ratio. Light and heavy oils showed similarities with middle distillates and heavy oils in refinery, the high paper content of the raw materials was unfavourable for longer storage of waste derived oils.
