PTA装置乙酸甲酯回用测试

乙酸甲酯是PTA生产过程中氧化反应的副产物。按照化学反应机理,将其回收后返回氧化反应器,通过提高生成物的浓度来抑制氧化副反应的进行,提高原料利用率,达到降低装置消耗的目的。同时通过测试暴露氧化系统投用乙酸甲酯技术存在的问题,为下一阶段氧化系统降低乙酸消耗提供依据。     

PTA装置氧化副产物回收利用技术

介绍了一种精对苯二甲酸装置对二甲苯氧化反应过程中副产物的回收与利用技术,通过回收不仅可以减少排放到大气和污水中的有机物,还可以得到苯二甲酸二甲酯、苯甲酸甲酯及醋酸等产品.     

乙酸甲酯胺化制N，N-二甲基乙酰胺的研究

介绍了应用不同催化剂就乙酸甲酯和二甲胺制N，N-二甲基乙酰胺的反应条件对乙酸甲酯转化率和N，N-二甲基乙酰胺选择性的影响。结果表明：催化剂的用量为原料乙酸甲酯的1％～3％(质量分数)，助剂的用量为原料乙酸甲酯的10％～30％(质量分数)，乙酸甲酯：二甲胺配比(摩尔比)为1．0：1．2，反应压力为2．0Mpa，反应温度为170℃，反应时间为4h，乙酸甲酯转化率高于99％，N，N-二甲基乙酰胺的选择性高于95％。     

乙酸液相催化氧化动力学的研究

以乙酸钴、乙酸锰为催化剂，四溴乙烷为促进剂，在半间歇搅拌釜式钛材反应器中对乙酸的液相催化氧化动力学进行了研究，弄清了乙酸氧化损失的规律，提出了降低乙酸氧化速率的可行措施，得到了二氧化碳及乙酸甲酯的生成速率方程。     

溶剂氯乙酸甲酯减压蒸馏规律

间歇釜式减压蒸发溶剂乙酸甲酯，蒸发强度有较明显的变化规律，最大蒸发强度约为平均蒸发强度的１．５倍；氯甲酯蒸汽的冷凝，宜采用双程或多程管式水冷却器回收，辅以盐水冷却器冷凝回收氯甲酯。既可保证氯甲酯回收效率，又可节约能源。     

生产醋酸的方法

正公开了一种生产乙酸的方法,在闪蒸容器中将将反应介质分离成液体再循环和包括乙酸、碘甲烷、乙酸甲酯和水的蒸气产品流。将蒸汽产品流被浓缩成在乙酸富集的液体流,并将该液体流进一步发送到蒸馏塔中以回收乙酸。该方法有利地改善了醋酸生产的能力,同时减少被回收的乙酸量。     

乐果中间体O，O—二甲基—二硫代（乙酸甲酯）磷酸酯提纯新工艺

利用减压蒸馏的方法，从O，O－二甲基－二硫代（乙酸 甲酯）磷酸酯 中回收氯乙酸甲酯和除去三甲酯（CH3O）2PSSCH3得到高含量的O，O－二甲基－二硫代（乙酸甲酯）磷酸酯，从而降低产品的消耗，提高产品的质量。     

聚乙烯醇醇解母液回收技术进展

对近几年醇解母液回收技术进展进行评述.将乙酸甲酯水解为乙酸和甲醇,告别回收的传统工艺,在乙酸甲酯浓缩、高效催化精馏水解、甲醇双效精馏精制及乙酸精制等方面均取得了明显进步,同时也出现了将乙酸甲酯精制为产品的醇解母液回收新思路.目前已实现工业化的有加盐萃取精馏和变压精馏两种技术方案.从工业运行结果来看,加压精馏工艺具有流程短、能耗低、产品纯度高的特点,更具大规模推广应用前景.     

对伞花烃裂解氧化产物苯甲酸的水相酯化方法研究

对伞花烃裂解氧化产物苯甲酸与硫酸二甲酯的反应可以采用水相酯化法。实验室小试结果显示，苯甲酸的转化率平均为89．97％，苯甲酸甲酯的得率平均为83．16％；车间放大试验结果显示，苯甲酸甲酯的得率为89．00％。水相酯化法与有机相酯化法相比，甲苯的单耗降低38．69％，硫酸二甲酯的单耗下降32．14％，废水量下降35．85％，耗时减少66．67％，设备利用率和生产能力显著提高，氧化催化剂也可以得到回收。     

Hβ沸石催化甲醛和甲酸甲酯的偶联反应

在釜式反应器中研完了Hβ沸石催化甲醛和甲酸甲酯的偶联反应。系统考察了原料配比、反应温度、反应时间、Hβ沸石的用量及催化剂重复使用等因素对乙醇酸甲酯和甲氧基乙酸甲酯生成量的影响,得到最佳反应条件为：反应物料配比n（甲醛）：n（甲酸甲酯）=1：1．5,反应温度150℃,反应时间3h,Hβ沸石的用量为甲醛质量的15％。在此条件下,乙醇酸甲酯和甲氧基乙酸甲酯的生成量最大,总生成量达到56．84％。该催化剂具有较高的催化活性,易于回收,可重复使用五次以上。     

甲烷部分氧化过程的热力学

对杂多酸与醋酸混合溶剂体系,碘为催化剂的甲烷液相部分酯化过程进行了热力学计算。在298.15—1 000 K温度下,分别计算了甲烷部分氧化反应可能存在的4条反应途径的反应焓变,吉布斯自由能变及平衡常数。结果表明,甲烷液相部分氧化反应中,经由甲烷与碘生成中间物碘甲烷,碘甲烷再与醋酸酯化合成醋酸甲酯的过程是可以实现的,为提高甲烷转化率需改进控制步骤甲烷与碘生成碘甲烷的反应速率。     

A new process for catalyst-free production of biodiesel using supercritical methyl acetate

Production of glycerol is unavoidable in the conventional processes for biodiesel fuel (BDF) production. In this research, therefore, we investigated conversion of rapeseed oil to fatty acid methyl esters (FAME) and triacetin (TA) by processing of supercritical methyl acetate. As a result, it was discovered that the trans-esterification reaction of triglycerides with methyl acetate can proceed without catalyst under supercritical conditions, generating FAME and triacetin. In order to study the effect of the triacetin addition to FAME, its effect was investigated on various fuel characteristics. It was, consequently, discovered that there were no adverse effects on the main fuel characteristics when the molar ratio of methyl oleate to triacetin was 3:1, corresponding to the theoretically derived mole ratio from the trans-esterification reaction of rapeseed oil with methyl acetate. Moreover, the addition of triacetin to methyl oleate improved the pour point and triacetin has high oxidation stability. Therefore, by defining BDF as a mixture of methyl oleate with triacetin, we can obtain an improved yield of 105% of BDF by the supercritical methyl acetate, in excess of the yield of the conventional process.     

Oxidation of methyl formylstearate with molecular oxygen

Methyl formylstearate, containing soluble rhodium complex from rhodium-catalyzed hydroformylation of methyl oleate, is oxidized in an emulsion to methyl carboxystearate. The reaction is carried out in a closed system at 20–25 C in the presence of either air or oxygen (1–3 atm). Conversion to methyl carboxystearate is 87–89% in 2–3 hr; when catalytic amounts of calcium acetate are present, 93–95% is converted. The principal byproduct of oxidation is methyl formyloxystearate, formation of which is suppressed by calcium acetate. Distillation of crude methyl carboxystearate yields a residue containing soluble rhodium (and calcium acetate if used), which after calcining in the presence of a refractory support produces an effective hydroformylation catalyst. Recovery and regeneration of this catalyst provide an economically feasible batch process for methyl carboxystearate. Presented at AOCS spring meeting, Dallas, April, 1975.     

一种4-氮甾体激素化合物的合成

以孕甾双烯醇酮醋酸酯为起始原料,经次溴酸钠氧化、甲醇甲酯化得到3-羰基-4-雄甾烯-17-羧酸甲酯,再经Oppenauer氧化、双键的氧化切断、氨解环合、Δ~5双键加氢、酯氨解反应得酰胺类中间产物,然后碘化和脱碘反应进行1,2位脱氢合成非那甾胺.     

Determination of Oxidation of Methyl Ricinoleates

Ricinoleate esters have desirable properties as biolubricants, but their oxidative stability has been questioned. To systematically study the stability of ricinoleate ester and its derivative, methyl esters of castor oil were prepared and methyl ricinoleate was isolated by solvent partitioning. Methyl 12‐acetyl ricinoleate was synthesized from the methyl ricinoleate by interesterification with excess methyl acetate and was then purified by solvent partitioning. The rates of oxidation of methyl linoleate, methyl oleate and the two ricinoleate esters were measured by oxidation of lipid dispersed on glass beads under three temperatures (40–80 °C). The relative amounts of the unoxidized methyl esters were determined periodically by gas chromatography, and the peroxide value of the oils was also determined. The oxidation rates were determined as the peroxide value increase rate, as well as the ester disappearance rate, and the stability of the various esters was compared. Overall, methyl ricinoleate was much more oxidatively stable than methyl oleate at mildly elevated temperatures, and the acetylation of the hydroxyl group on the 12th carbon decreased the stability.     

炼厂碳四资源的利用途径

对国内炼厂碳四的利用状况进行了分析,对混合碳四与甲醇合成甲基叔丁基醚,正丁烯经水合、脱氢反应制备甲乙酮和正丁烯与乙酸反应制备乙酸仲丁酯的生产情况进行了介绍;对醚后混合碳四制丙烯和乙烯、异构化制异丁烯、芳构化、与乙酸反应制备乙酸仲丁酯的应用和研究状况进行了分析,认为利用醚后混合碳四制备丙烯和制备乙酸仲丁酯是未来的发展方向;对异丁烷脱氢、异丁烷选择氧化、正丁烷制顺酐等技术研究进展和使用现状进行简述,认为异丁烷的利用是未来的研究重点。     

Conversion of methyl 9(10)-formylstearate to carboxymethylstearate

Methyl 9(10)-formylstearate was converted to methyl 9(10)-carboxymethylstearate. The reactions to prepare the intermediates methyl 9(10)-hydroxymethyl-, 9(10)-ace toxymethyl-, 9(10)-methylene-, and 9(10)-formylmethylstearate are described. Methyl 9(10)-hydroxy methylstearate readily loses methanol and forms a trimeric polymer. The acetate of the primary alcohol when pyrolyzed gives 59% yield of methyl 9(10)-methylenestearate. Hydroformylation of the methylene compound followed by permanganate oxidation gave methyl carboxymethylstearate. Evidence is presented to show that pyrolysis of the acetate ester and hydroformylation of the pyrolysis product produce, respectively, only the methylene and formylmethylstearates. Rates of esterification-transes terification of methyl 9(10)-carboxymethyl sterate show that the carboxymethyl group is 2–3 times as active as the carboxyl group in methyl 9(10)-carboxystearate and that the terminal carboxyl group is about 10 times more active towards esterification than the branched carboxymethyl group.     

Radikalische Additionen an ungesättigte Fettstoffe

Free Radical Additions to Unsaturated Fatty Acids Unsaturated fatty acids e.g. oleic acid are 1,2-dialkyl substituted alkenes with an electron-rich C,C-double bond. Elektrophilic free radicals can be added to the double bond to give functionalized and branched fatty acids. The electrophilic free radicals have been generated a) by oxidation of enolizable compounds by manganese (III) acetate prepared in situ by addition of potassium permanganate to catalytic amounts of manganese (II) acetate; b) with di-tert.-butylperoxide as initiator. Free radical addition of the radical to methyl oleate occurs to give an adduct radical which can be stabilized by hydrogen transfer or by oxidative elimination with copper (II) acetate. We have been able to add also alkanes e.g. cyclohexane to methyl oleate. A review of free radical additions to oleic acid is given.     

Liquid phase oxidation of substituted toluenes by air for the production of pharmaceutical intermediates

Liquid phase oxidation of several substituted methyl aromatic compounds by air in an acetic acid medium, using cobalt acetate as a catalyst and sodium bromide or paraldehyde as a promoter, has been investigated with a view to developing manufacturing processes for the production of various pharmaceutical intermediates. In most cases carboxylic acids and aldehydes were the major products of oxidation. The process parameters such as temperature, period of reaction, and concentrations of the substrate, catalyst and promoter were chosen to obtain a high proportion of the desired oxidation product.     

A study of the structures and reactions of some methyl substituted unsaturated C18 ester intermediates in the synthesis of a racemic mixture of 10-methyloctadecanoic acid

Methyl 10-undecenoate was hydrated to methyl 10-hydroxyundecanoate using mercury (II) acetate in aqueous tetrahydrofuran (THF). Chromic acid oxidation of methyl 10-hydroxyundecanoate gave methyl 10-oxoundecanoate, which was hydrolyzed to 10-oxoundecanoic acid. Reaction of n-octyl magnesium bromide complex in THF with 10-oxoundecanoic acid furnished 10-hydroxy-10-methyloctadecanoic acid after hydrolysis. The latter compound was esterified, and dehydration of methyl 10-hydroxy-10-methyloctadecanoate withp-toluenesulfonic acid in benzene gave a mixture of unsaturated branched fatty ester intermediates:viz. methyl 10-methyl-9-octadecenoate, 10-methyl-10-octadecenoate and 10-octyl-10-undecenoate. Treatment of the mixture of unsaturated branched fatty ester intermediates with mercury (II) acetate in methanol gave exclusively methyl 10-methoxy-10-methyloctadecanoate. Epoxidation of the same mixture of unsaturated fatty esters withm-chloroperbenzoic acid provided a mixture of epoxy derivatives: methyl 9,10-epoxy-10-methyloctadecanoate, 10,11-epoxy-10-methyloctadecanoate and 2-octyl-oxirane-nonanoate. Catalytic hydrogenation of the mixture of unsaturated fatty esters gave a racemic mixture of methyl 10-methyloctadecanoate, which was hydrolyzed to 10-methyloctadecanoic acid. The structures of the mixture of unsaturated branched fatty ester intermediates and their derivatives were characterized by chemical and spectroscopic analyses.