影响氯丙醇收率的因素与优化控制

根据反应原理并结合生产实践,定性分析、探讨了氯醇法生产环氧丙烷的关键工序———氯醇化工序中影响氯丙醇收率的因素,提出了提高氯丙醇收率的优化控制措施。     

丙烯氧化制环氧丙烷研究进展

环氧丙烷 (PO)是重要的有机化工原料和中间体 ,目前工业采用氯醇法和间接氧化法生产。这两种方法均存在严重缺陷 ,有待于改进。本文主要介绍丙烯直接氧化法制取PO的近期进展 ,指出了丙烯直接氧化法研究的难点和今后研究的方向。     

Polymerization of some oxiranes using the diphenylzinc-butanone system in benzene at 60°C

The diphenylzinc-butanone system was used as polymerization catalyst for some oxiranes in benzene solution at 60°C. This system is greatly influenced by the molar ratio of butanone to diphenylzinc, and the maximum catalytic activity for propylene oxide and ethylene oxide was found for a ratio of unity. GPC results strongly suggest the presence of more than one active species for the system. ¹³C NMR analysis indicates that the resulting poly(propylene oxide) has a head-to-tail arrangement. For the polymerization of propylene oxide with butanone/diphenylzinc = 1, after an initial induction period, the reaction was first-order with respect to monomer with k = 2·51 × 10^?5 s^?1. Ethylene oxide polymerizations using butanone/diphenylzinc = 1 and 5 were also first-order with respect to monomer after an initial induction period with k = 7·80 × 10^?6 s^?1 and k = 5·71 × 10^?6 s^?1, respectively. The diphenylzinc-butanone system was not an effective catalyst for styrene oxide polymerization.     

Surface and aqueous properties of anionic gemini surfactants having dialkyl amide,carboxyl, and carboxylate groups

A systematic study of the equilibrium surface properties (in water and in the presence of 10⁻² M NaCl) of a novel series of anionic gemini surfactants, (CH₂)₂[N(COC_nH_2n+1)CH(COOH)CH₂COOH]·2NaOH (GA), where (n+1)=8, 10, 12, 14, and 16, was investigated. The responses of humans to closed patch tests with (CH₂)₂[N(COC₁₁H₂₃)CH(COOH)−CH₂COOH]₂·2NaOH (GA-12) were also investigated. Premicellar self-aggregation (both in water and 10⁻² M NaCl) occurred when the N-acyl group contained more than 14 carbon atoms, since the critical micelle concentration (CMC) values decreased and the pC₂₀ values increased as (n+1) increased for (n+1) ≤14; the CMC values increased and the pC ₂₀ values decreased as (n+1) increased for (n+1)>14, both in water and in 10⁻² M NaCl. The absence of a break in the specific conductance-surfactant molar concentration plots for the GA homologs indicates protonation of the carboxylate group and strong Na⁺ release during micellization. This is a structural characteristic of the anionic geminis having N-dialkylamide and carboxylate groups in a molecule. The skin irritation potential of GA-12 is lower than that of the corresponding “monomer”, C₁₁H₂₃CON(CH₃)CH(COOH)CH₂(COOH)·NaOH, and the analog, C₁₁H₂₃CON(CH₃)CH₂COONa·H₂O.     

低碳烯烃叠合法柴油合成催化剂的研究与探讨

探讨了Fe2/3xNi1-xSO4-助剂/g-Al2O3催化剂对丙烯叠合柴油反应的催化性能.考察了Fe/(Fe Ni) 原子分率和SO2-4/(Fe Ni)摩尔比的影响及加入助剂的效果,发现Fe/(Fe Ni) 原子分率0.72和SO2-4/(Fe Ni)摩尔比在1.2～2.2,催化剂活性和选择性最高.加入助剂P2O5效果较好.通过NaOH对催化剂的中毒及其对催化活性的关联,证明该催化剂上的丙烯叠合反应是以酸催化反应机理进行.     

疏水缔合水溶性聚合物P(AM/NaAA/DiAC14)水溶液的黏度行为

采取前加碱二元胶束共聚-共水解法合成了三元疏水缔合水溶性聚合物聚(丙烯酰胺/丙烯酸钠/N,N-双烯丙基十四胺)〔P(AM/NaAA/D iAC14)〕,研究了其水溶液的黏度行为。当x(D iAC14)=0.10%~0.40%时,在30℃、c(NaC l)=1 mo.lL-1水溶液中,P(AM/NaAA/D iAC14)的特性黏数[η]、黏均相对分子质量Mη、Huggins常数KH、平均线团密度ρequ分别为18.88~22.22 dL.g-1、9.98×106~12.24×106g.mol-1、0.117~0.299和0.112~0.132 g.dL-1;KH小于0.8,表明其分子内缔合作用较弱。P(AM/NaAA/D iAC14)在矿化度为19 334μg.g-1盐水溶液中的表观黏度随疏水单体摩尔分数的增加而增加,随温度、剪切速率的增加而降低。在NaC、lCaC l2的离子强度分别为1.26×10-3~4.88×10-3mol.kg-1、1.073×10-4~5.28×10-4mol.kg-1的水溶液中,P(AM/NaAA/D iAC14)出现盐增黏现象,疏水单体摩尔分数越大,盐增黏效应越显著。随疏水单体摩尔分数的增加,临界缔合质量浓度(CAC)降低;与后加的十二烷基硫酸钠(SDS)〔ρ(SDS)=0~0.07 g.dL-1〕的疏水缔合作用增强,黏度增加的幅度增大。     

Electrochemical degradation of aqueous phenols using graphite electrode in a divided electrolytic cell

Untreated industrial effluents invariably contain large amounts of heavy metals and organics. This paper reports the electrochemical oxidation of synthetic water containing 200 ppm of phenol. Studies have been carried out in a compartmentalized cell using platinum (cathode) and graphite (anode). Electrolysis has been done for 40 h at constant applied potential of 5 V in different electrolytes, such as, NaCl (aq), NaOH (aq) and a mixture containing both NaCl (aq) and NaOH (aq) as the anolyte and acid as the catholyte. Phenol concentration decreased from the initial value of 200 to about 10 ppm.; the corresponding COD values, respectively, are ∼400 to ∼100 ppm. The reaction goes through chloro-compounds as intermediates before being mineralized. The carbon anode seems to be passivated with a thin layer of poly-phenol. A concomitant amount of hydrogen is generated during the electrolytic degradation of phenol.     

丙烯氯醇化反应器操作优化

以１０,０００吨／年环氧丙烷装置氯醇化反应工段为对象,采用简化的机理模型,通过两相法实施过程的操作优化,考察了操作变量对反应过程的影响,并比较了不同优化目标对优化效果的影响,通过优化显著地提高过程的运行效益,并提出了进一步提高生产能力和优化效果的途径。     

Uncalcined TS-2 immobilized Au nanoparticles as a bifunctional catalyst to boost direct propylene epoxidation with H2 and O2

Developing stable yet efficient Au–Ti bifunctional catalysts is important but challenging for direct propylene epoxidation with H₂ and O₂. This work describes a novel strategy of employing uncalcined titanium silicalite-2 (TS-2-B) to immobilize Au nanoparticles as a bifunctional catalyst for the reaction. Under no promoter effects, the Au/TS-2-B catalyst compared to the referenced Au/TS-1-B catalyst delivers outstanding catalytic performance, that is, exceptionally high stability over 100 hr, propylene oxide (PO) formation rate of 118 g_PO·hr⁻¹·kg_cat⁻¹, PO selectivity of 90% and hydrogen efficiency of 35%. The plausible relationship of catalyst structure and performance is established by using multiple techniques, such as UV–vis, high-angle annular dark-field scanning transmission electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy. A unique synergy of Au–Ti⁴⁺–Ti³⁺ triple sites is proposed for our developed Au/TS-2-B catalyst with the higher stable PO formation rate and hydrogen efficiency. The insights reported here could shed new light on the rational design of highly stable and efficient Au–Ti bifunctional catalysts for the reaction.     

丙烯-H2O2氧化制环氧丙烷绿色合成技术进展

环氧丙烷传统的工业生产方法如氯醇法路线或共氧化技术由于环境污染或成本较高等原因阻碍了其进一步发展,开发既清洁又经济的绿色合成技术是环氧丙烷工业今后的发展方向。综述了近几年来在以过氧化氢为氧化剂的丙烯环氧化制环氧丙烷绿色合成方面的技术进展情况,包括丙烯环氧化催化剂及丙烯环氧化与过氧化氢生产的集成工艺开发情况,并对其前景进行了评述和展望。     

Tensile elongation of high‐fluid polypropylene/ethylene–propylene rubber blends: Dependence on molecular weight of the components and propylene content of the rubber

We studied tensile behavior of low‐molecular‐weight (MW) polypropylene (PP)/ethylene–propylene rubber (EPR; 70/30) blends from the viewpoint of the MWs of PP and EPR and the compatibility between PP and EPR. The value of the melt flow rate of PP varied from 30 to 700 g/10 min at 230°C. We studied the compatibility between PP and EPR by varying the propylene content in EPR (27 and 68 wt %). At the initial elongation stage, crazes were observed in all blends. When blends included EPR with 27 wt % propylene, the elongation at break of the low‐MW PP improved little. The blends with EPR and 68 wt % propylene content were elongated further beyond their yielding points. The elongation to rupture was increased with increasing MW of EPR. Molecular orientation of the low‐MW PP was manifested by IR dichroism measurements and X‐ray diffraction patterns. The blends of low‐MW PP and EPR could be elongated by the partial dissolution of EPR of high‐MW in the PP amorphous phase. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 46–56, 2002     

丙烯氯醇化反应过程的模型化

将单塔自然液相循环的丙烯氯醇化反应器视为两个串联的鼓泡塔 ,在两塔分别进行溶氯和氯醇化反应 .在对反应机理和宏观动力学进行探讨的基础上 ,建立了反应器的一维定态模型 .通过流程模拟 ,研究了操作参数对反应结果的影响 .结果表明 ,所建立的一维定态模型能正确描述重要操作参数的影响规律     

氯醇法环氧丙烷产品除醛方法的研究探讨

工业用环氧丙烷GB/T 14491-2015颁布实施后,下游聚醚客户对环氧丙烷质量要求更高。通过优化氯醇法环氧丙烷工艺降低环氧丙烷产品总醛质量分数,满足客户需求。     

Synthesis,characterization, and properties of two‐component amphiphilic polyoxyethylene–containing multiblock copolymers

Amphiphilic (oxyethylene–oxypropylene) and (oxyethylene–styrene) multiblock copolymers, both with high molecular weights, were synthesized by coupling poly(ethylene glycol) (PEG) with poly(propylene glycol) (PPG) or with telechelic dihydroxy polystyrene using 2,4‐toluene diisocyanate as a coupling agent, respectively. The polymerization conditions were investigated. The products were purified and characterized by IR, ¹H‐NMR spectroscopy, and membrane osmometry and identified as multiblock copolymers. Crystallinity of the two kinds of multiblock copolymers was determined by DSC. They showed good emulsifying properties. Their complexes with LiClO₄ showed high room‐temperature conductivities from 3 × 10⁻⁵ to 4 × 10⁻⁴ S/cm at 30°C. High molecular weight (oxyethylene–oxypropylene) multiblock copolymers, at a weight ratio of PEG/PPG = 6/4, behave like thermoplastic elastomers. The (oxyethylene–styrene) copolymer functions as a good compatibilizer for the blend of chlorohydrin rubber and polystyrene. An amount of only 3 wt %, based on the blend, is needed to increase the tensile strength of the blend almost sixfold. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1295–1301, 2005     

丙烯氢氧环氧化动力学与反应器概念设计研究进展

环氧丙烷（PO）在全球产能最高的35种化学品中,是仅次于聚丙烯的第二大丙烯衍生物,主要用于生产聚醚多元醇、聚氨酯等。相比传统的氯醇法、共氧化法和双氧水直接氧化法（HPPO）等PO生产工艺,丙烯在氢氧混合气中一步环氧化制PO（HOPO）具有工艺简单、选择性高、产物易分离、能耗低等突出优势,是生产PO的理想工艺。重点介绍了丙烯氢氧环氧化反应动力学研究进展,包括主、副反应动力学模型以及催化剂失活模型。总结了基于该过程安全操作的反应器概念设计进展。分析了丙烯氢氧环氧化反应存在的挑战,从副产物生成途径、失活动力学及颗粒催化剂上的动力学等方面展望了可能的研究方向。     

环氧丙烷生产技术分析与比较

介绍了环氧丙烷的传统生产路线——氯醇法、联产法、过氧化氢氧化法以及氧气直接环氧化法,分析对比了联产法和过氧化氢氧化法的工艺优缺点,并对环氧丙烷市场发展进行了预测。最后指出：新建环氧丙烷装置要实现经济规模,要选用清洁节能的新技术,要与下游装置实现一体化合作。     

KOH沉淀剂对Ag/TS-1催化剂用于丙烯气相环氧化的影响

采用沉积-沉淀法制备Ag/TS-1催化剂,在423 K、常压条件下用于丙烯气相环氧化反应,研究了碱金属沉淀剂KOH的影响。结果表明,以KOH为沉淀剂、TS-1为载体制备的Ag/TS-1催化剂反应性能最佳,丙烯转化率为1.8%,环氧丙烷选择性为91.7%;K+的存在对反应有促进作用。     

INFLUENCE OF K+ AND NA+ IONS ON DIRECT ELECTROSYNTHESIS OF SOLID K2FEO4 AND COMPARISON OF THE PHYSICOCHEMICAL PROPERTIES OF K2FEO4 SAMPLES

The influence of K⁺ and Na⁺ ions on the direct electrosynthesis of solid K₂FeO₄ was investigated in 14 M OH^? solutions. At 50 or 60°C, the maximum current efficiency of electrosynthesis is obtained in 9 M KOH +5 M NaOH solution. The maximum current efficiency of 64.9% is obtained at 60°C in 9 M KOH +5 M NaOH solution, similar to the maximum value of 63.9% at 70°C in 14 M KOH solution in the temperature ranges studied. The result shows that the temperature at which the maximum current efficiency is obtained in 9 M KOH +5 M NaOH is much lower than that in 14 M KOH. Solid K₂FeO₄ powders directly electrosynthesized in 9 M KOH +5 M NaOH and 14 M KOH solutions were characterized by Fourier transform-infrared spectrometry (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD), and their electrochemical performance was investigated by means of galvanostatic discharge. The result shows that the two samples have similar physical properties and discharge performance.     

Dissociation et hydratation de nitrates alcalins dans le carbonate de propylene aqueux

Dissociation of lithium, sodium, potassium and tetraethylammonium nitrates and perchlorates in propylene carbonate has been studied by conductometry. Dissociation constants of alkali nitrates are 3·14 × 10^?3 (LiNO₃), 8·35 × 10^?3 (NaNO₃ and 1·92 × 10^?2 (KNO₃) at 25°C. The perchlorates and tetraethylammonium nitrate are strong electrolytes. The solubility products are 4·1 × 10^?4 (LiNO₃), 1·2 × 10^?5 (NaNO₃ and 2·5 × 10^?5 (KNO₃). The conductivity of saturated solutions of nitrates in the aqueous solvent has been determined up to 0·6 M water. Results are used to calculate the equilibrium constants for the reaction I^± + H₂O = I^± H₂O; Li⁺ 6·5, Na⁺ 2·5, K⁺ 0·5 and NO^?₃ 2·4. Dissociation constants, solubility products and hydration constants are compared with values reported for other solvents.     

多金属氰化络合物催化环氧丙烷的聚合

用多金属氰化络合物(MMC)催化环氧丙烷开环均聚,考察了酸及起始剂对聚合诱导期的影响,以及转化单体/起始剂摩尔比、酸用量、加料方式及催化剂等对聚合物相对分子质量及其分布的影响。并用FTIR、1HNMR、SEC-MALLS对聚合产物结构进行了表征。结果表明,以MMC为催化剂,在w(H2SO4)<5×10-5、温度130℃、连续加料、w(MMC)>1×10-4时,所合成聚醚相对分子质量分布较窄(Mw/Mn=1.1~1.2),且相对分子质量可控;FTIR、1HNMR及SEC-MALLS分析结果表明,所合成聚醚具有预期结构。实验发现,聚合反应体系只存在一种活性中心,其机理可能为配位阳离子聚合。