聚乙烯醇脱水—氧化脱氢制备线型碳

报道了以聚乙烯醇(PVA)为起始物制备线型碳的研究结果。制备过程类似于炭纤维制备过程中的预氧化工艺,在氧和惰性气体比例适当的条件下,聚乙烯醇在反应釜中梯度升温,以便逐步脱水、氧化脱氢,并保持其原来的晶型。研究了聚乙烯醇在加压下脱水、氧化脱氢制备线型碳的反应条件。产品用红外光谱、激光拉曼光谱和X 射线衍射表征,并与已报道的结果比较,表明产品为β型(累积双键型)线型碳。产品的X 射线衍射结果与原料聚乙烯醇几乎一样,证明产品保持了原料的晶体构型。本合成法可能成为适用的线型碳合成的新途径,并提出了一个可能的反应机理。

对甲苯磺酸催化—氧化钙脱水法合成富马酸二甲酯

在对甲苯磺酸催化作用下,用氧化钙作脱水剂,采用索氏提取器来合成富马酸二甲酯(DMF),酯化反应仅需3h,收率可达到92％～93％,纯度在97％以上,同时探讨了影响酯化率的各种因素,确定了反应的最佳条件。

长网造纸机氧化铝陶瓷脱水元件的制备与应用

讨论了内嵌式氧化铝陶瓷脱水元件的制备及其在3150mm长网新闻纸机运行情况和存在的问题。将氧化铝陶瓷嵌条置于超高分子聚乙烯脱水板磨损最严重的位置,其耐磨性保证了脱水板有较长的使用寿命,而其低摩擦的光滑面降低了成形网磨损和动力消耗。这种结构形式的脱水板因能维持稳定的外形尺寸而可以始终维持脱水效果并使纸张质量处于最佳状态。嵌条和成形网磨损分析结果表明:细晶结构和粗晶结构的氧化铝陶瓷可满足网部不同位置对脱水元件的要求,但都要求这两种结构的氧化铝陶瓷尽可能少地含有耐磨、耐蚀性较差的晶界玻璃相和显气孔率。

氟烷磺酰氟和邻位二醇化合物的脱水环氧化反应

在二氯甲烷中和在1,8-二氮杂双环[5.4.0]十一-7-烯(DBU)存在下,氟烷磺酰氟和4个赤式邻位二醇及3个末端邻位二醇之间的脱水环氧化反应,结果以中等到优秀的收率(45%～90%)生成了相应的顺式环氧化合物和末端环氧化合物。实验结果进一步拓展了氟烷磺酰氟在有机合成化学中的应用范围。

微晶氧化锆整体脱水元件在压榨部的应用

压榨部脱水元件的选用 光华纸业。5机为2640长网多缸造纸机，主要生产双胶纸和中高档静电复印纸。2010年3月之前，纸机实际运行车速仅为200-230m／min，压榨部毛布真空吸水筘面板使用的脱水元件为超高分子聚乙烯材质。该材质面板在使用半个月后就会因不耐磨出现严重的凹凸不平现象，侄此状况下，毛布所受到的摩擦力不均匀，凸出部他磨损异常严重，

生物质副产物粗甘油制备丙烯酸

以粗甘油为原料,采用新型负载型杂多酸催化剂和氧化物催化剂,通过两段反应制备丙烯酸。利用BET、NH_3-TPD、FTIR和原子吸收光谱分析等方法分析了粗甘油中不同杂质的影响。实验结果表明,粗甘油中的无机盐离子是造成粗甘油脱水产物丙烯酸收率降低、乙酸收率增加的主要原因。Na^+和K^+等碱金属杂质沉积在HPW/Cs-SBA催化剂表面,导致催化剂的比表面积和孔体积显著降低,平均孔径增大,催化剂上大量的中强酸性位点转化成弱酸性位点,酸性位点的总量也有所下降。只需对粗甘油进行脱盐处理,而不需要脱除其他有机物杂质即可用于脱水制备丙烯酸,反应70 h内丙烯酸收率稳定在86%左右,与使用精制甘油时的效果相当。

氟烷基磺酰氟和(2S,3R)-2,3-二羟基-3-苯基丙酸甲酯的脱水环氧化反应的研究

考察了(2S,3R)-2,3-二羟基-3-苯基丙酸甲酯和几种常用的氟烷基磺酰氟试剂在有机碱存在下的脱水环氧化反应.实验结果表明,氟烷基磺酰氟能够诱导(2S,3R)-2,3-二羟基-3-苯基丙酸甲酯发生脱水环氧化反应而生成(2R,3R)-2,3-环氧-3-苯基丙酸甲酯,得率80%～92%,且产物的不对映过量(ee)值大于97%.该方法具有工业化应用前景.

Changes in Violaxanthin Deepoxidase Activity and Unsaturation of Thylakoid Membrane Lipids in Indica and Japonica Rice Under Chilling Condition and Strong Light

To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under chilling condition and strong light. The contents of unsaturated fatty acids of thylakoid membrane lipids decreased and that of the saturated ones increased with the time of chilling and strong light treatment, resulting in the reduction of the index of unsaturation of fatty acids (IUFA). The activity of violaxanthin deepoxidase (VDE), a key enzyme of xanthophyll cycle, also reduced. The content of violaxanthin (V) increased, and the contents of antheraxanthin (A) and zeaxanthin M decreased, the ratio of (A+Z)/ (A+Z+V) decreased correspondingly. Arrhenius analysis showed that VDE was sensitive to both chilling and unsaturation level of thylakoid membrane lipids. Correlation analysis showed that there was distinctly positive relationships between IUFA of thylakoid membrane lipids and the activity of VDE, Fv/Fm, and D, protein content. Lower IUFA values, less fluidity and stability of thylakoid membrane lipids, lower VDE activity and (A+Z)/(A+Z+V) ratio were found in indica rice cv. Shanyou 63 than in japonica rice cv. 9516 under chilling and strong light.

Photosynthesis of Resurrection Angiosperms

Resurrection plants which are able to quickly reactivate after falling into a period of anabiosis caused by dehydration have been very rare among angiosperms, especially among dicotyledons whose chlorophyll content and chloroplast structure little changed in the course of desiccation, therefore has been called homoiochlorophyllous desiccation-tolerant plants (HDTs). Another type of resurrection angiosperms that lost its chlorophyll dining desiccation is called poikilochlorophyllous desiccation-tolerant plants (PDTs). HDTs have been received more attention because of simplicity of protection mechanism which is much easy to the study and utilization of the desiccation tolerance of resurrection angiosperms. Recent advances in studies of photosynthesis of resurrection angiosperms indicate that photochemical activities are sensitive indicators for the study of physiological state of resurrection angiosperms during desiccation and rehydration. Photochemical activities of resurrection angiosperms are inhibited with loss of water similar to those of general plants, however, the magic thing is that they could reactivate rapidly during rehydration even losing more than 95% water. Up-regulations in xanthophyll cycle and antioxidative systems as well as preservation in integrity and stability of photosynthetic membranes during desiccation may be very important to desiccation tolerance of resurrection angiosperms. The fact that phosphate treatment in rehydration stage also strongly influences resurrection indicated importance of studies on rehydration stages of resurrection angiosperms.

Kinetics of Fe_3O_4 formation by air oxidation

The kinetics of Fe3O4 formation by air oxidation of slightly acidic suspension of Fe（OH）2 was studied. The effects of initial concentration of Fe（Ⅱ）, temperature, partial pressure of oxygen, air flow rate and stirring rate on the oxidation rate were investigated. The results show that Fe3O4 formation is composed of two-step reaction, the first step is the formation of Fe（OH）+2 by oxidation of Fe（OH）+ complex ions, the second step is the formation of magnetite by dehydration and deprotonation of Fe（OH）+ and Fe（OH）+2. The oxidation reaction is zero-order with respect to the concentration of Fe（Ⅱ） and around 0.5-order with respect to partial pressure of oxygen, and oxygen transfer process is rate-limiting step of oxidation reaction with apparent activation energy of 2.74 kJ·mol-1.

Model and Design of Cogeneration System for Different Demands of Desalination Water, Heat and Power Production

In order to improve the energy efficiency, reduce the CO2 emission and decrease the cost, a cogenera- tion system for desalination water, heat and power production was studied in this paper. The superstructure of the cogeneration system consisted of a coal-based thermal power plant （TPP）, a multi-stage flash desalination （MSF） module and reverse osmosis desalination （RO） module. For different demands of water, heat and power production, the corresponding optimal production structure was different. After reasonable simplification, the process model ot each unit was built. The economical model, including the unit investment, and operation and maintenance cost, was presented. By solving this non-linear programming （NLP） model, whose objective is to minimize the annual cost, an optimal cogeneration system can be obtained. Compared to separate production systems, the optimal system can reduce 16.1%-21.7% of the total annual cost. showing this design method was effective.

Wet Oxidation of PVA-Containing Desizing Wastewater

Polyvinyl alcohol (PVA)-containing desizing wastewater was treated by various wet oxidation methods.Parameters such as reaction temperature, initial solution pH, and the dosage of H2O2 were investigated in terms of chemical oxygen demand (CODcr) and total organic carbon (TOC) removal rate. Up to 90% of the initial CODcr was removed by wet air oxidation(WAO) at 270℃ with stoichiometric oxygen supply, while at temperature of 200℃, the CODcr removal rate was found to be 80%. Similar results were obtained by Promoted WAO (PWAO) and wet peroxide oxidation(WPO) at a lower temperature of 150℃. Reaction temperature was found to have a significant effect on the oxidation performance for all the methods. Initial solution pH was observed to play a significant role in PWAO and WPO where H2O2 was employed. Comparison of WAO, CWAO(catalytic wet air oxidation), PWAO and WPO shows that the rate of CODcr removal increases in the order: WAO, CWAO, PWAO and WPO.

Preparative Parameter Effects on Synthesis of Birnessite by O_2 Oxidation

Birnessite occurs in a wide variety of natural environments, and plays animportant role in soil chemistry. A modified Staehli procedure was used to synthesize sodiumbirnessite in an alkali medium by O_2 oxidation. The effects of preparative parameters on thesynthesis of birnessite, such as pretreatment on solutions with N2, reaction temperature, O_2 flowrate, fluxion velocity of the reaction suspension, and dehydration conditions were investigated. Thefluxion velocity of the reactive suspension and O_2 flow rate significantly influenced thesynthesis of birnessite. Vigorous stirring raised the fluxion velocity of the reaction suspensionand easily allowed synthesis of pure crystalline birnessite. However pretreatment of the reactingsolutions with N_2 and the reaction temperature had little effect on the synthesis. Diffusion of O_2was the controlling step during the course of oxidation. The optimum synthetic conditions for purebirnessite were: a NaOH to Mn molar ratio of 13.7, an O_2 flow rate of 2 L min^(-1), and oxidationfor 5 hours with vigorous stirring at normal temperatures. The chemical composition of thesynthesized pure birnessite was Na_(0.25)MnO_(2.07)·0.66H_2O.

Influence of dehydrating agents on the oxidative carbonylation of methanol for dimethyl carbonate synthesis over a Cu/Y-zeolite catalyst

The influence of the dehydration by metal oxides on the synthesis of dimethyl carbonate （DMC） via oxidative carbonylation of methanol was studied. A Cu/Y-zeolite catalyst was prepared by the ion exchange method from CuCl2.2H2O and the commercial NH4-form of the Y type zeolite, The catalyst was characterized by X-ray fluorescence （XRF）, N2 adsorption （BET method）, X-ray diffraction （XRD）, and temperature-programmed de- sorption of ammonia （NH3-TPD） to evaluate its Cu and Cl content, surface area, structure, and acidity. Reaction tests were carried out using an autoclave （batch reactor） for 18 h at 403 K and 5.5 MPa （2CH3OH ＋ 1/2O2 ＋ CO （CH3O）2CO ＋ H2O）. The influence of various dehydrating agents （ZnO, MgO, and CaO） was examined with the aim of increasing the methanol conversion （XMeOH, MeOH conversion）. The MeOH conversion increased upon addition of metal oxides in the order CaO 〉〉 MgO 〉 ZnO, with the DMC selectivity （SDMC） following the order MgO 〉 CaO 〉 ZnO. The catalysts and dehydrating agents were characterized before and after the oxidative carbonylation of methanol by thermogravimetric and differential thermogravimetric （TG/DTG）, and XRD to con- firm that the dehydration reaction occurred via the metal oxide （MO ＋ H2O →M（OH）2）. The MeOH conversion increased from 8.7% to 14.6% and DMC selectivity increased from 39.0% to 53.1%, when using the dehydrating azent CaO.

Performance of Wuxi WWTP in China

In Wuxi Wastewater Treatment Plant, the Anaerobic, anoxic and oxic (A2/O) process was employed to remove the nitrogen and phosphorus, which exhibited the positive results of the high removal efficiency for phosphorus with a range of 67.7% to 89.9% and an average value of 78.0. The effluent of phosphorus met the national discharge standard. The removal of TN was effected by both BOD variation of influent and wastewater temperature. TN removal was in the range of 28.5% to 55.8% with an average value of 39.4%. The energy cost was 0.15 kWh(m3d)-1 or 1.35 kWh(kgBOD@d)-1. The annual average sludge production was 46.3 m3d-1, the annual average dosage for the dewatering was 40 kg d-1 .

催化裂化烟气除尘脱硫项目的污染减排应用

由于日益严格的环保要求,国家环境保护部多次在会议上提出改善环境效益。炼油部催化裂化装置在引进先进的脱硫技术后,与多方合作采用烟气排放连续监测系统(CEMS)对炼油部催化裂化装置的污染源排放进行实时监测,实现了污染物减排的控制。

Ru nanoparticles supported on hydrophilic mesoporous carbon catalyzed low-temperature hydrodeoxygenation of microalgae oil to alkanes at aqueous-phase

The processing of an energy carrier such as microalgae oil into valuable fuels and chemicals is quite promising.Aqueous-phase processing is suitable for this purpose because the separation of intrinsic water from the algae cell is difficult.In this study,we synthesized ruthenium(Ru)nanoparticles supported on highly hydrophilic mesoporous carbon to catalyze the quantitative hydrodeoxygenation(HDO)of microalgae oil to alkanes in a one-pot process at a low temperature(140℃)in the aqueous phase.The mesoporous carbon was obtained by single-step calcination of starch and zinc chloride in nitrogen.The as-obtained carbon showed high surface areas and pore volumes,allowing high dispersion of Ru nanoparticles.The surface of the carbon material was rich in hydroxyl groups,as evidenced by X-ray photoelectron spectroscopy(XPS),infrared(IR)spectroscopy,and thermogravimetric analysis(TGA)measurements.As a result,the carbon material contacted preferably with the water phase versus the organic phase,improving the accessibility of substrates.On the other hand,the contact angle test results speculated the superior hydrophilic nature of mesoporous Ru/C(ZnCl2,starch)than commercial Ru/C.Both kinetics modeling and in situ IR monitoring in water revealed the superior performance of the hydrophilic mesoporous and hydrophilic Ru/C compared to a commercial Ru/C for the tandem hydrogenation of stearic acid and decarbonylation of stearyl alcohol.The herein designed hydrothermal carbon material was highly active,environmentally benign,sustainable,and recyclable material,and could be potentially used for other hydrogenation reactions in the aqueous phase.

Removal of mercaptans from light oils using ionic liquid–NaOH aqueous solution as extractants

The application of ionic liquids as alternatives to conventional organic solvents in the extraction process has been investigated. In the present study, fourteen species of imidazolium-based ionic liquids were added into the NaOH （aq） to remove the mercaptans. The influences of anion species and cation alkyl chain length of the imidazolium-based ionic liquids on the performance of mercaptan removal from light oils have been discussed. The efficiency of extraction for mercaptans exhibited the order of [Ac]- 〉 [OH]- [Br]- 〉 [BF4]-. The longer alkyl chain imidazolium-based ionic liquids contributed to enhance desulfurization rate of l-butyl mercaptan. 100% desulfurization rate of l-butyl mercaptan was achieved by the anion of Ac- ionic liquids and NaOH （aq） at a volume ratio of 40：1 （V（oil]：Vfionic liouid）） and a short eouilibrium time within 10 min.

油热固相反应制备纳米Ni_(0.6)Zn_(0.4)Fe_2O_4铁氧体

将在气泡液膜中进行共沉淀反应制得的Ni-Zn-Fe氢氧化物的螺旋状分子簇前驱体,在白油中于240℃进行油热反应,大量制得尖晶石型晶体结构的纳米Ni0.6Zn0.4Fe2O4铁氧体。在油热反应过程中没有观察到溶解-结晶现象,提出了氢氧化物脱水,氧化物分子自组装的油热固相反应。

Kinetics of Wet Air Oxidation of Wastewater from Natural Fiber Web Desizing

This work described the application of wet air oxidation (WAO) to the treatment of desizing wastewater from natural fiber processing. A two-liter autoclave batch reactor was used for the experiments. The range of operating temperature examined was between 150 and 290℃, and partial pressure of oxygen ranged from 0.375 to 2.25 MPa standardized at 25℃. Variations in Chemical Oxygen Demand(COD) and Total Organic Carbon(TOC) were monitored during each experiment and used to assess the performance of the process. Experimental results showed that WAO can be an efficient method for the treatment of desizing wastewater. Furthermore, Catalytic Wet Air Oxidation (CWAO) was applied to reduce the reaction temperature and pressure in WAO process. A higher COD removal ratio was achieved under more mild reaction condition with the aid of CWAO. A mathematical model was also proposed to simulate the WAO process of desizing wastewater, in which three distinct kinetics steps were considered to describe the degradation of starch. The model simulations were in well agreement with the experimental data.