采用汽提燃烧方法处理甲醇生产废水

以大庆油田化工有限公司甲醇分公司10万t/a甲醇装置的精馏生产废水的分析数据为基础,通过对甲醇废水中主要组成物的物理性质分析和各种污水处理方法的研究,探讨了利用中压汽提塔采用汽提焚烧法处理甲醇生产废水的可行性,并提出了甲醇精馏废水处理的新途经和方法.     

固体超强酸SO4^2—／ZrO2—TiO2催化合成丙烯酸异丁酯

采用浸渍法制备了固体超强酸SO4^2-/ZrO2-TiO2多相催化剂,用于催化丙烯酸与异丁醇反应合成丙烯酸异丁酯（IBA）。研究了催化剂制备及IBA合成的适宜工艺条件：H2SO4浓度为0．6mol/L,焙烧温度550℃,焙烧时间4h,丙烯酸与异丁醇的摩尔比为1：1．20,催化剂和阻聚剂用量分别为丙烯酸质量的4％和0．05％,反应温度125℃,反应时间2．5h。实验结果表明,催化剂有良好的催化活性,丙烯酸的酯化率可达84．6％。     

Detailed Structure–Function Correlations of Bacillus subtilis Acetolactate Synthase

Isobutanol is deemed to be a next‐generation biofuel and a renewable platform chemical. 1 Non‐natural biosynthetic pathways for isobutanol production have been implemented in cell‐based and in vitro systems with Bacillus subtilis acetolactate synthase (AlsS) as key biocatalyst. 2 – 6 AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg²⁺ as cofactors. AlsS also catalyzes the conversion of 2‐ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol. Our phylogenetic analysis suggests that the ALS enzyme family forms a distinct subgroup of ThDP‐dependent enzymes. To unravel catalytically relevant structure‐function relationships, we solved the AlsS crystal structure at 2.3 Å in the presence of ThDP, Mg²⁺ and in a transition state with a 2‐lactyl moiety bound to ThDP. We supplemented our structural data by point mutations in the active site to identify catalytically important residues.     

毛细管气相色谱法测定丙烯腈中微量杂质

以异丁醇为内标溶液,使用HP-1 0.53 mm×30μm×120 m毛细管柱和氢火焰离子化检测器,测定丙烯腈中微量有机物丙烯醛、乙腈、丙酮、噁唑、丙腈的含量,标准偏差均低于0.15,平均回收率分别为98%,100%,99%,100%,99%。     

Recovery of isobutanol from esterified wastewater by PDMS composite membrane

The esterification reaction of acetic acid and isobutanol produces isobutyl acetate, which generates a large amount of wastewater containing isobutanol. The conventional biochemical treatment is heavy and wastes resources. The effects of isobutanol concentration on the swelling degree and separation performance of polydimethylsiloxane (PDMS) membrane, the operating parameters of the pervaporation process and the effect of isobutyl acetate on the recovery of isobutanol by PDMS membrane were studied. The results show that with the isobutanol concentration increases from 1%(mass) to 3%(mass), the swelling degree of the PDMS membrane increases first and then stabilizes, the flux of isobutanol increases, and the separation factor is about 15. When the operating temperature increases from 30℃ to 60℃, the flux increases, the separation factor of isobutanol decreases, and the total apparent activation energy is 33.87 kJ/mol. With increase of the flow rate, the isobutanol flux is stability while the separation factor increases slightly. The trace amounts of isobutyl acetate can promote the recovery of isobutanol by the membrane. The recovery rate of isobutanol by PDMS membrane is greater than 94.0%, and the concentration of isobutanol in the retentate can be reduced to 0.1%(mass). The research results can provide a basis for PDMS composite membrane to treat low-concentration organic solvent wastewater.     

沉淀剂对ZnCr氧化物催化剂合成异丁醇性能的影响

为开发高选择性和稳定性的异丁醇合成催化剂,选用了不同的沉淀剂,通过共沉淀法制备了系列ZnCr基氧化物催化剂。采用N_2吸附-脱附、X射线衍射(XRD)、程序升温还原(H_2-TPR)等手段对催化剂织构参数、体相结构、还原性能等进行表征,并研究了其CO加氢制异丁醇的催化性能。表征数据表明:使用碱性较弱的沉淀剂时,制得的催化剂比表面积较大,ZnO和Cr_2O_3形成非计量比尖晶石Zn_xCr_(2/3(1-x))O结构,且颗粒分散度较好,被还原能力较强。使用强碱性沉淀剂时,制得的催化剂比表面积较小,出现相分离现象,且被还原能力较差。研究结果表明,使用(NH_4)_2CO_3沉淀剂制备的ZnCr催化剂表现出了最佳的催化性能。该催化剂在390℃,10000h~(-1),12MPa时,CO单程转化率可达15.3%,醇选择性90.3%,异丁醇选择性33.5%。     

An efficient catalyst for the production of isobutanol and methanol from syngas. XI. K‐ and Pd‐promoted Zn/Cr/Mn spinel (excess ZnO)

A 2.25 wt% K‐ and 6.0 wt% Pd‐promoted Zn/Cr/Mn spinel (excess ZnO) higher alcohol synthesis (HAS) catalyst has been tested for the production of isobutanol and methanol at 440°C and 1500 psig. An isobutanol production rate of 179 g kg⁻¹ h⁻¹, a methanol‐to‐isobutanol mole ratio of 1.3 and a total alcohol rate of 304 g kg⁻¹ h⁻ are attained. This ratio is slightly higher than the desired value of 1.0 for MTBE production. These results are superior to others presented in the literature thus far. Surface characterization data indicate that the near‐surface region of the catalyst consists primarily of ZnO and K. Pretreating the catalyst in a reductive environment similar to that given to the catalyst before reaction tests, causes an enrichment of the K promoter at the surface. The product stream composition does not significantly change during five days of testing. This revised version was published online in July 2006 with corrections to the Cover Date.     

Study of cold start air–fuel mixture parameters for spark ignition engines fueled with gasoline–isobutanol blends

Biofuels are set to play an important role in the future strategy of automotive fuel suppliers, and therefore the study of using alcohols in spark ignition engines has become a necessity. A simple thermodynamic model was developed for calculating air–fuel mixture parameters for port injection engines fueled with gasoline–isobutanol blends, and theoretical results were compared to experimental values. For simulating the evaporation process, gasoline was considered a mixture of four components, with isobutanol added in different proportions. As all engine components are at ambient temperature during cold starts, mixture formation was considered an adiabatic process, with the fuel breaking up into droplets and evaporating, thus resulting in a temperature drop. A port injection engine fitted to a passenger car was used to validate the model for calculating air–fuel mixture parameters.     

PDMS复合膜回收酯化反应废水中的异丁醇

乙酸与异丁醇酯化反应生产乙酸异丁酯,产生大量含异丁醇的废水,常规生化处理负荷重,浪费资源。采用PDMS复合膜分离回收酯化废水中的异丁醇,考察了异丁醇浓度对PDMS复合膜溶胀度及分离性能的影响,优化渗透汽化过程操作参数,研究了乙酸异丁酯对PDMS复合膜回收异丁醇效果的影响。结果表明,随着异丁醇浓度从1%增大到3%(质量),PDMS复合膜溶胀度先增大后趋于平稳,异丁醇的渗透通量呈增大趋势,分离因子保持在15左右;操作温度从30℃升至60℃时,渗透通量增大,异丁醇的分离因子下降,总表观活化能为33.87kJ/mol;流速增加,Reynolds数增大,异丁醇渗透通量变化不大,但分离因子略有增大;微量乙酸异丁酯的存在可促进渗透汽化膜回收异丁醇。采用PDMS复合膜分离酯化废水中的异丁醇,回收率大于94.0%,渗余液中异丁醇浓度可降至0.1%(质量)左右。研究结果可为PDMS复合膜处理低浓度有机溶剂废水提供依据。