利用二萘酚副产亚钠生产焦亚硫酸钠的研究

二萘酚副产亚硫酸钠主含量低,杂质成分复杂,产品附加值低,只能用在低端行业。根据二萘酚副产亚硫酸钠中杂质的性质,利用二萘酚在酸性、常温条件下不溶于水的特性,向副产亚硫酸钠溶液中通入二氧化硫进行酸化,过滤回收副产亚钠中的二萘酚,向回收二萘酚后的滤液中加入生石灰,再次向溶液中通入二氧化硫,使生石灰转化为易溶于水的亚硫酸氢钙,亚硫酸氢钙与溶液中的硫酸钠反应生成不溶于水的硫酸钙沉淀,通过过滤的方式除去,除去二萘酚和硫酸钠的亚硫酸氢钠溶液经过高真空低温蒸发、离心过滤干燥,得到质量分数96.5%以上的优等品焦亚硫酸钠,具有明显的经济效益。

Ultra-deep oxidative desulfurization of fuel with H_2O_2 catalyzed by phosphomolybdic acid supported on silica

A highly active catalyst of phosphomolybdic acid ~HPMo） was prepared and applied in the catalytic oxidative desulfurization （CODS） system. The catalyst was characterized by FT-IR, XRD, XPS and superconducting NMR. The influences of rn（catalyst）/m（oil）, V（H202）fV（oil）, reaction temperature and reaction time on the fractional conversion of benzothiophene （BT） and dibenzothiophene （DBT） were investigated. GC-MS and micra-coulometric methods were employed to investigate the reaction. The catalyst has high desulfurization activity in the removal of BT and DBT under mild conditions. The recycling experiments indicated that DBT and BT removal could still reach 95.2% and 95.7% after 10 cycles.

The Future Programming of Acid Rain and SO_2 Control in China

This paper describes a programme for controlling acld rain and SO2 pollutions in the coming years in China. It embraces the control targets in some respects, such as precipitation acidity, urban SO2 pollution, SO2 emission sources and its total emission, and various control measures, such as limiting the exploitation of high sulfur coal, promoting steam coal washing, strengthening SO2 emission sources control and readjusting their special layout, enhancing total SO2 emission control, implementing the licence system of pollution discharge and the exchange system of SO2 emission and revising the SO2 emission standards.

Preparation of chemical manganese dioxide from manganese sulfate

Chemical Manganese Dioxide （CMD） was prepared by an alkali-oxidation method. There are several virtues to this environmental friendly and clean process, including the nontoxic and harmless reagents and products, easy operations, no pollutants, easily obtained raw materials and moderate reaction conditions. The synthesized manganese dioxide was characterized by XRD and SEM. The particles were small, consisting primarily of α-MnO2 and γ-MnO2. Experimental results showed that the optimum conditions were： MnSOa.H20 to NaOH ratio, 1.0：2.4; catalyst concentration （catalyst TF-2）, 6% of the MnSO4; initial solution pH, 11; reaction time and temperature, 20 min and 80 ℃; air flow, 0.20 m3/h; and, agitation rate, 700 r/rain. The conversion of MnSO4 can exceed 80% under these optimum conditions.

Conversion of glycerol to acrolein by mesoporous sulfated zirconia-silica catalyst

A mesoporous sulfated zirconia-silica catalyst bearing only Br？nsted acid sites converted glycerol to acrolein in 81%yield with 82% selectivity.Space time yield as high as 9.0 mmol h^（-1） g_（cat）^（-1） was achieved even at a low reaction temperature of 523 K.The catalytic activity and selectivity were higher than those of typical sulfated zirconia.It is proposed that the milder acidity due to dilution of zirconium species by silica and large pore size for faster diffusion contributed towards the better catalytic performance.

Effective photocatalytic conversion of formic acid using iron,copper and sulphate doped TiO_(2)

In this paper,the combined addition of copper or iron and sulphate ions onto TiO_(2) prepared by a simple sol-gel method is studied for formic acid photocatalytic conversion.A wide structural and morphological characterization of the different photocatalysts was performed by X-ray diffraction(XRD),N_(2)-physisorption for BET surface area measurements,scanning and transmission electronic microscopies(SEM and TEM),UV-Vis diffuse spectroscopy(DRS)and X-ray photoelectron spectroscopy(XPS),in order to correlate the physico-chemical properties of the materials to their photocatalytic efficiencies for formic acid oxidation.Results have shown important differences among the catalysts depending on the metal added.Sulphated TiO_(2)/Cu(1%Cu)was the best photocatalyst obtaining about 100% formic acid conversion in only 5 min.The appropriate physico-chemical features of this photocatalyst,given by the addition of combined copper and sulphate ions,explain its excellence in photocatalytic reaction.

Ozonation of Sulfur Dioxide in Sulphuric Acid Solution

In this study, the oxidation rates of sulfur dioxide （SO2） in sulphuric acid solution by ozone and oxygen were compared, and the oxidation mechanism of ozone on SO2 was investigated. The results showed that the oxidation-reduction potential of the acidic solution was enhanced, the transformation rate of sulfuric acid to sulphuric acid was increased and the absorption driving force was improved in the presence of ozone. By comparing the amount of sulfate ions measured in the experiments and the theoretical amount of sulfate ions calculated from the amount of ozone consumed in the reaction, it can be confirmed that oxygen free radicals from dissociation of ozone are reactive as an efficient oxidant and oxygen from ozone generator participates in the reaction with SO2. 0.602 mol of effective oxygen was introduced into the reaction by one mole of ozone in 10.15 rain at sulphuric acid concentration of 3% （by mass）, SO2 concentration of 1.33% （by volume） and oxygen flow rate of 1.5 L.min^-1 from ozone generator.

Quantum Chemical Study of Potential Energy Surface in the Formation of Atmospheric Sulfuric Acid

A new potential energy surface （PES） for the atmospheric formation of sulfuric acid from OH＋SO2 is investigated using density functional theory and high-level ab initio molecular orbital theory. A pathway focused on the new PES assumes the reaction to take place between the radical complex SO3.HO2 and H2O. The unusual stability of SO3.HO2 is the principal basis of the new pathway, which has the same final outcome as the current reaction mechanism in the literature but it avoids the production and complete release of SO3. The entire reaction pathway is composed of three consecutive elementary steps： （1） HOSO2＋O2-＋SO3.HO2, （2） SO3.HO2＋H20-＋SO3·H2O·HO2, （3） SO3.H20.HO2-＋H2SO4＋HO2. All three steps have small energy barriers, under 10 kcal/rnol, and are exotherrnic, and the new pathway is there- fore favorable both kinetically and therrnodynarnically. As a key step of the reactions, step （3）, HO2 serves as a bridge molecule for low-barrier hydrogen transfer in the hydrolysis of SO3. Two significant atmospheric implications are expected frorn the present study. First, SO3 is not released from the oxidation of SO2 by OH radical in the atmosphere. Second, the conversion of SO2 into sulfuric acid is weakly dependent on the humidity of air.

A comparative effect of 3 disinfectants on heterotrophic bacteria, iron bacteria and sulfate-reducing bacteria

The disinfection effect of chlorine dioxide, chlorine and their mixture on heterotrophic bacteria, iron bacteria and sulfate-reducing bacteria in circulating cooling water was studied. The results of the test indicated that high purity chlorine dioxide was the most effective biocide in the 3 disinfectants, and with a dosage of 0.5 mg/L, chlorine dioxide could obtain perfect effect. High purity chloride dioxide could have the excellent effect with the pH value of 6 to 10, and could keep it within 72 h. Chlorine and their mixture couldn’t reach the effect of chlorine dioxide.

Kinetic study on hydrolysis and oxidation of formamidine disulfide in acidic solutions

Hydrolysis and oxidation of formamidine disulfide in acidic medium were investigated using high-performance liquid chro- matography （HPLC） and mass spectrometry （MS） at 25 ~C. By controlling the slow reaction rate and choosing appropriate mobile phase, HPLC provides the unique advantages over other methods （UV-Vis, chemical separation） in species tracking and kinetic study. In addition to thiourea and formamidine sulfinic acid, two unreported products were also detected in the hy- drolysis reaction. Mass spectrometry measurement indicates these two products to be formamidine sulfenic acid and thiocyan- ogen with mass weights of 92.28 and 116,36, respectively. In the oxidation of formamidine disulfide by hydrogen peroxide, besides thiourea, formamidine sulfenic acid, formamidine sulfinic acid, thiocyanogen and urea, formamidine sulfonic acid and sulfate could be detected. The oxidation reaction was found to be first order in both forrnamidine disulfide and hydrogen per- oxide. The rate constants of hydrolysis and oxidation reactions were determined in the pH range of 1.5-3.0. It was found both rate constants are increased with the increasing of pH. Experimental curves of different species can be effectively simulated via a mechanism scheme for formamidine disulfide oxidation, including hydrolysis equilibrium of formamidine disulfide and irre- versible hydrolysis of formamidine sulfenic acid.