The process window for diamond deposition from the vapor phase with sulfur in the C–H–O feed gas mixtures

Theoretical predictions using a modified radical species ternary diagram for C–H–O system indicate that addition of sulfur expands the C–H–O gas phase compositional window for diamond deposition. Sulfur addition to no-growth domain increases the carbon super-saturation by binding the oxygen and the addition of sulfur to the non-diamond domain reduces the heavy carbon super-saturation by decreasing C_nH_m species concentration in the gas phase. The overall effect of sulfur addition to gas phase mixtures is characterized as that of oxygen addition to the C–H system, i.e. expansion of the compositional window over which diamond can be deposited from the gas phase. In addition, the increasing sulfur concentration to diamond domain feed gases beyond 2000 ppm did not affect the steady state gas phase composition but the quality of diamond was reduced.     

Mathematical analysis and experimental results of applying enhanced-surface-area packed-bed electrodes in electrogenerative sulfur dioxide oxidation

The results of applying enhanced-surface-area packed-bed (ESAP) electrodes in electrogenerative SO₂/O₂ cells are reported to illustrate their utility and potential applications. Mathematical analysis with parameters pertinent to the experimental conditions shows that all electrocatalyst sites in these electrodes are expected to be uniformly utilized for electrochemical SO₂ oxidation. Experimental results showed that ESAP electrodes (1 mg Pt/cm²) could provide at least 5 times higher SO₂ conversion at given cell voltages than graphite sheet electrodes (1.5 mg Pt/cm²).     

Adsorption and decomposition of H2S on Pd(1 1 1) surface: a first-principles study

Gradient-corrected density functional theory was used to investigate the adsorption of H₂S on Pd(1 1 1) surface. Molecular adsorption was found to be stable with H₂S binding preferentially at top sites. In addition, the adsorption of other S moieties (SH and S) was investigated. SH and S were found to be preferentially bind at the bridge and fcc sites, respectively. The reaction pathways and energy profiles for H₂S decomposition giving rise to adsorbed S and H were determined. Both H₂S_(ad) → SH_(ad) + H_(ad) and SH_(ad) → S_(ad) + H_(ad) reactions were found to have low barriers and high exothermicities. This reveals that the decomposition of H₂S on Pd(1 1 1) surface is a facile process.     

浅析硫磺回收装置中的自动控制设计

大规模高含硫原油的炼制工艺必须配套设置脱硫和硫磺回收装置。笔者针对硫磺回收装置的特点,为确保装置的安全平稳运行,提出了该装置自动控制设计中需要严格监控的工艺参数及重点部位,叙述了仪表选型原则和精确测量与控制的原理和方法。     

Laboratory simulated slipstream testing of novel sulfur removal processes for gasification application

The Wabash River Integrated Methanol and Power Production from Clean Coal Technologies (IMPPCCT) project is investigating an Early Entrance Coproduction Plant (EECP) concept to evaluate integrated electrical power generation and methanol production from coal and other carbonaceous feedstocks. Research, development and testing (RD&T) that is currently being conducted under the project is evaluating cost effective process systems for removing contaminants, particularly sulfur species, from the generated gas which contains mainly synthesis gas (syngas), CO₂ and steam at concentrations acceptable for the methanol synthesis catalyst. The RD&T includes laboratory testing followed by bench-scale and field testing at the SG Solutions Gasification Plant located in West Terre Haute, Indiana. Actual synthesis gas produced by the plant was utilized at system pressure and temperature for bench-scale field testing.     

横向光泵获得S_2紫外激光

用ＸｅＣｌ准分于激光器（３０８．１ｎｍ）横向泵浦Ｓ２激光器，又成功地实现了Ｓ２Ｂ－Ｘ态近ＵＶ波段的激光振荡。在波长３３０．９～３９０．０ｎｍ范围内观测到６条近ＵＶ激光输出。测量了有关的激光参数。     

Sulfur in chromia

The solubility of sulfur in chromia has been studied in H₂-H₂O-H₂S tagged with³⁵S at 973 and 1173 K at low oxygen and sulfur partial pressures typical for coal gasification-systems. For monocrystalline samples, it has been shown that sulfur-containing species are only present adsorbed on the surface of the specimens and can be removed by ultrasonic cleaning in acetone. The surface coverage after 4 weeks of exposure to H₂-H₂O-H₂S was between 2.8 and 19.3% of a monolayer. In polycrystalline chromia, sulfur was located only in pores and cracks of the sample. In dense, compact areas of the specimens the solubility of sulfur was below the detection limit of autoradiography, which was estimated to be better than 0.17 ppm.     

炼厂硫腐蚀的典型案例分析及解决措施

通过硫在不同温度与环境下对金属材料腐蚀的典型案例分析，简述其腐蚀机理与解决,工对今后炼厂高硫油加工提出进一步建议。     

A MECHANISTICALLY BASED MATHEMATICAL MODEL OF SULFUR DIOXIDE ABSORPTION INTO A CALCIUM HYDROXIDE SLURRY IN A SPRAY DRYER

A mathematical model has been developed to predict So₂ absorption and removal during the constant rate drying period of a spray dryer. The model, based on film theory, treats the atomized slurry droplets as spheres containing discrete sorbent particles of slaked lime with the fluid uniformly distributed around the individual particles. The model includes gas and liquid phase mass transfer coefficients as well as resistance to Ca(OH)₂ dissolution. A sensitivity analysis has been conducted and a comparison was made between pilot-scale experimental data and model-predicted values of S0₂ removal efficiency.