化工生产中“绿色原料”——碳酸二甲酯的应用

碳酸二甲酯是一种环境友好的有机化学品。介绍了碳酸二甲酯替代光气、硫酸二甲酯、卤代甲烷等对环境危害大的原料,生产异氰酸酯、聚碳酸酯、苯甲醚等重要的化工产品,以及作为绿色溶剂在绿色化学中的应用。     

碳酸二甲酯的催化偶联合成及作汽油添加剂探索

碳酸二甲酯是一种具有芳香气味的无色液体,可混溶于碱类、酸类等有机溶液中,其化学合成物应用较为广泛,可用于羰基化剂和甲基化剂中,如植物保护剂、食品抗氧剂等。围绕碳酸二甲酯的催化和偶联反应,对其用作汽油添加剂方面的知识进行了深入探讨,旨在促使汽油抗爆性和燃烧性水平的提升。     

碳酸二甲酯的合成化学

碳酸二甲酯是重要的有机化工原料之一,有着有机合成的新基石和绿色化工产品之美称,是新的燃油添加剂,在21世纪将具有广阔的应用前景．论述了碳酸二甲酯的合成化学,特别是目前工业化非光气甲醇氧化羰基化制备碳酸二甲酯的化学过程,并给出了可能合成碳酸二甲酯的其他化学路线．     

二氧化碳合成碳酸二甲酯催化剂的研究进展

碳酸二甲酯是一种用途广泛的环境友好有机介成中间体,利用CO2合成碳酸二甲酯能有效利用C02资源,在环境保护和绿色合成化学方面具有重要的意义.综述了利用CO2合成碳酸二甲酯有机金属催化剂、氧化物催化剂、碱催化剂、负载型金属催化剂、醋酸盐催化剂及催化反应机理的研究进展,并展望了未来的发展方向.     

Novel eco-efficient reactive distillation process for dimethyl carbonate production by indirect alcoholysis of urea

Dimethyl carbonate is an eco-friendly essential chemical that can be sustainably produced from CO₂,which is available from carbon capture activities or can even be captured from the air.The rapid increase in dimethyl carbonate demand is driven by the fast growth of polycarbonates,solvent,pharmaceutical,and lithium-ion battery industries.Dimethyl carbonate can be produced from CO₂through various chemical pathways,but the most convenient route reported is the indirect alcoholysis of urea.Previous research used techniques such as heat integration and reactive distillation to reduce the energy use and costs,but the use of an excess of methanol in the trans-esterification step led to an energy intensive extractive distillation required to break the dimethyl carbonate-methanol azeotrope.This work shows that the production of dimethyl carbonate by indirect alcoholysis of urea can be improved by using an excess of propylene carbonate(instead of an excess of methanol),a neat feat that we showed it requires only 2.64 kW·h·kg^-1 dimethyl carbonate in a reaction-separation-recycle process,and a reactive distillation column that effectively replaces two conventional distillation columns and the reactor for dimethyl carbonate synthesis.Therefore,less equipment is required,the methanol-dimethyl carbonate azeotrope does not need to be recycled,and the overall savings are higher.Moreover,we propose the use of a reactive distillation column in a heat integrated process to obtain high purity dimethyl carbonate(>99.8 wt-%).The energy requirement is reduced by heat integration to just 1.25 kW·h·kg^-1 dimethyl carbonate,which is about 52%lower than the reaction-separation-recycle process.To benefit from the energy savings,the dynamics and control of the process are provided for
10%changes in the nominal rate of 32 ktpy dimethyl carbonate,and for uncertainties in reaction kinetics.     

绿色化工过程中的碳酸二甲酯

碳酸二甲酯是一种环境友好的有机化学品，可替代光气、硫酸二甲酯、卤代甲烷等对环境危害大的原料，用于羧基化、甲基化、甲氧基化等反应，实现对化工过程的绿色化效益。     

新型烷基酰胺丙基三甲基季铵盐表面活性剂的合成

以叔胺和碳酸二甲酯为原料,合成了新型季铵盐表面活性剂———C16/C18烷基酰胺丙基三甲基碳酸甲酯铵,通过质谱和红外光谱对其进行结构表征。利用得到的碳酸甲酯铵与有机酸反应,得到系列具有新型反离子X-〔X=HCOO,CH3COO,CH3CH(OH)COO〕的季铵盐。研究表明,该系列化合物随反离子亲水性的增强,最低表面张力变大,临界胶束浓度增大。     

乙二醇生产新技术研究进展

对乙二醇生产新技术进行了介绍，并对各公司新技术的工艺条件，反应转化率，选择性进行了对比，重点对乙二醇和碳酸二甲酯联产技术的优势进行了分析。充分利用环氧乙烷装置排放的二氧化碳来合成碳酸乙烯酯，然后进一步与甲醇反应乙二醇和碳酸二甲酯，该工艺路线不仅大大降低了生产成本，而且获得了高附加值环保型产品碳酸二甲酯，因而具有很好的发展前景。     

甲基碳酸酯季铵盐及其衍生物的研究进展

以碳酸二甲酯作为季铵化试剂替代传统的卤甲烷、硫酸二甲酯等有毒物质进行季铵化反应。主要介绍了各类叔胺与碳酸二甲酯进行季铵化反应的研究进展,同时对所制备的新型季铵盐类阳离子表面活性剂在制备不同阴离子季铵盐和高纯度季铵碱方面的应用进行了介绍,最后对过量的碳酸二甲酯和甲醇的回收与循环利用情况进行了说明,提出了今后研究工作的发展方向。     

Simultaneous Synthesis of Dimethyl Carbonate and Poly（ethylene terephthalate） Using Alkali Metals as Catalysts

Dimethyl carbonate （DMC） and poly（ethylene terephthalate） was simultaneously synthesized by the transesterification of ethylene carbonate （EC） with dimethyl terephthalate （DMT） in this paper. This reaction is an excellent green chemical process without poisonous substance. Various alkali metals were used as the catalysts. The results showed alkali metals had catalytic activity in a certain extent. The effect of reaction condition was also studied. When the reaction was carded out under the following conditions： the reaction temperature 250℃, molar ratio of EC to DMT 3 ： 1, reaction time 3h, and catalyst amount 0.004 （molar ratio to DMT）, the yield of DMC was 68.9%.     

The chemistry of dimethyl carbonate

Dimethyl carbonate (DMC) is a versatile compound that represents an attractive eco-friendly alternative to both methyl halides (or dimethyl sulfate) and phosgene for methylation and carbonylation processes, respectively. In fact, the reactivity of DMC is tunable: at T = 90 degrees C, methoxycarbonylations take place, whereas at higher reaction temperatures, methylation reactions are observed with a variety of nucleophiles. In the particular case of substrates susceptible to multiple alkylations (e.g., CH(2)-active compounds and primary amines), DMC allows unprecedented selectivity toward mono-C- and mono-N-methylation reactions. Nowadays produced by a clean process, DMC possesses properties of nontoxicity and biodegradability which makes it a true green reagent to use in syntheses that prevent pollution at the source. Moreover, DMC-mediated methylations are catalytic reactions that use safe solids (alkaline carbonates or zeolites), thereby avoiding the formation of undesirable inorganic salts as byproducts. The reactivity of other carbonates is reported as well: higher homologues of DMC (i.e., diethyl and dibenzyl carbonate), are excellent mono-C- and mono-N-alkylating agents, whereas asymmetrical methyl alkyl carbonates (ROCO(2)Me with R > or = C(3)) undergo methylation processes with a chemoselectivity up to 99%.     

CO2和CH3OH直接合成碳酸二甲酯催化剂研究进展

碳酸二甲酯是一种绿色的有机合成中间体,由CO2直接合成碳酸二甲酯备受关注。本文介绍了CO2和CH3OH直接合成碳酸二甲酯的各种催化剂,分析了催化剂的优缺点,探讨了催化反应的机理。同时介绍了合成碳酸二甲酯的新技术和新方法。最后指出了由CO2直接合成碳酸二甲酯的研究趋势。     

合成碳酸二甲酯的催化剂研究进展

碳酸二甲酯以其优良的性质在化学反应和石油产品中得到了广泛应用.作者介绍了合成碳酸二甲酯的4种方法,包括甲醇氧化羰基化法、酯交换法、尿素醇解法和二氧化碳-甲醇合成方法.重点介绍了每种方法使用的催化剂对碳酸二甲酯的选择性及对副产品的影响.综述了负载型分子筛催化剂在催化合成碳酸二甲酯研究进展.研究负载型分子筛催化剂催化合成碳...     

苯基亚膦酸二甲酯的合成

以苯、三氯化磷、甲醇为主要原料,经两步反应合成了苯基亚膦酸二甲酯,并通过正交实验优化了合成条件。第一步反应：苯和三氯化磷在三氯化铝催化剂作用下生成苯基二氯化膦,n（苯）：n（三氯化铝）：n（三氯化磷）=1：3：1．3,回流时间9h,三氯氧磷为处理剂,收率为95．5％。在第二步反应中苯基二氯化膦在三乙胺存在下与甲醇作用生成目的物,反应温度20～30％,优化的物料配比为n（苯基二氯化膦）：n（甲醇）：n（三乙胺）=1：2．2：2．7,在此条件下反应收率为88．4％。     

4,4′-二苯甲烷二胺与碳酸二甲酯合成4,4′-二苯甲烷二氨基甲酸甲酯

研究了无水乙酸锌〔Zn(CH3COO)2〕催化下4,4′-二苯甲烷二胺(MDA)与碳酸二甲酯(DMC)合成4,4′-二苯甲烷二氨基甲酸甲酯(MDC)的反应。用高效液相色谱/质谱/质谱联用仪对反应体系副产物进行了检测分析。结果表明,MDC生成的适宜工艺条件为:催化剂用量n〔Zn(CH3COO)2〕∶n(MDA)=5∶1,反应物配比n(DMC)∶n(MDA)=20∶1,反应温度180℃,反应时间2 h。在该条件下MDC收率为98%,MDA转化率100%。分析结果表明,主要副产物为单氨基甲酸酯和3种N-甲基化物。在上述基础上,讨论了N-甲基化物可能的生成机制和副产物的形成对MDC生成的影响。     

煤制乙二醇装置联产碳酸二甲酯精馏工艺优化

在煤制乙二醇的生产过程中,会副产碳酸二甲酯（DMC）、甲酸甲酯、甲缩醛等,目前煤制乙二醇联产残液大都未进行有效分离和纯化,只能作为低纯度碳酸二甲酯或廉价杂醇处理,这样不仅造成甲醇损耗,而且降低了装置应有的经济性,因此经济合理地回收碳酸二甲酯具有重要的意义。由于甲醇与DMC形成二元共沸物,常规精馏方法无法将二者彻底分离。本文总结了各种DMC-甲醇分离方法,并优选采用变压精馏技术进行甲醇与DMC分离。利用煤制乙二醇中富含碳酸二甲酯以及甲醇、甲酸甲酯等杂质的副产残液为原料,提出3种改进工艺,获得99.9%以上高纯度DMC产品。计算结果表明,3种工艺方法分别适用于含量低于高压共沸组成、高于常压共沸组成、90%以上浓度DMC物料的分离,实现以更低能耗、更优化流程获得高纯度DMC产品。     

基于UNIFAC模型的基团-OCOO-与-CH3,ACH,CH3OH和CH3COO-的交互作用参数估算与验证

Isobaric vapor-liquid equilibria (VLE) are experimentally measured for the binary systems of dimethyl carbonate (DMC) ethylene carbonate and methanol ethylene carbonate at 101.325kPa. The thermodynamic consistency of these experimental data is tested with an available statistic method. Interaction parameters of the carbonate group —OCOO— with the group —CH3, ACH, CH3OH and CHACO0— in UNIFAC model are determined using the experimental and literature VLE data. The results show that the calculated VLE data using the new UNIFAG parameters agree excellently with the experimental data in this work and in literature. These results are useful in the research on DMG and diphenyl carbonate synthesis by transesterification in design of reactor and distillation tower.     

Ionic conductivity of lithium conducting SiO2 gels at room temperature

Fresh silica gels have been used as hosts for liquid organic lithium electrolytes. The residual liquid inside the fresh gels was exchanged by the solutions of selected lithium salts (lithium hexafluorophosphate, lithium tetrafluoroborate) in organic solvents: propylene carbonate (PC), dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), 1,2-diethoxyethane (DEE) and dimethyl carbonate (DMC). The immersion of the gels in solutions based on DEE, DMF and DMC leads to the fast deterioration of the gels. The gels immersed in the solutions based on PC and DMSO exhibit stable conductivities in the range of 10–3Scm–1 at room temperature. That conductivity is close to the conductivity of the corresponding lithium salt solutions.     

甲醇和二氧化碳合成碳酸二甲酯催化剂的研究进展

碳酸二甲酯是一种重要的绿色化工产品,甲醇和二氧化碳直接合成碳酸二甲酯是符合"绿色化学"的合成路线。综述了近年来该路线合成碳酸二甲酯催化剂的研究进展,简述了各类催化剂的催化机理、催化效能及发展趋势。     

新型烷基酰胺丙基三甲基季铵盐表面活性剂的绿色合成

在高压条件下,以叔胺和碳酸二甲酯为原料,合成了新型季铵盐表面活性剂-C16/C18烷基酰胺丙基三甲基碳酸甲酯铵,通过质谱和红外光谱对其进行表征。利用得到的碳酸甲酯铵分别与相应的酸进行反离子转化反应,得到系列具有新型反离子X- (X=HCOO, CH3COO, CH3CH(OH)COO)的季铵盐。初步研究了此系列化合物的表面张力,结果表明反离子对季铵盐的表面性能有影响。