近日,可口可乐欧洲太平洋合作伙伴公司(CCEP)宣布与英国斯旺西大学合作,旨在开发能够利用从大气中捕集的CO2生产乙烯,从而替代化石燃料的技术.斯旺西大学研究团队负责CO2生产乙烯的新技术开发,CCEP负责可再生乙烯生产可再生聚乙烯.
吸附法是治理挥发性有机物(VOCs)的重要技术之一.近年来,多孔材料用于 VOCs 的吸附处理受到了研究者的广泛关注.本文总结了多种多孔材料,如活性炭、生物炭、活性碳纤维、石墨烯、沸石分子筛、金属有机骨架材料、多孔有机聚合物和复合材料等在VOCs吸附领域的应用和研究进展,阐述了各类材料在VOCs 吸附应用中存在的问题,探讨了其未来发展前景,总结了吸附剂失活的原因和再生的方法,为多孔材料在VOCs吸附领域的应用提供借鉴.
为实现甲醇制烯烃过程中产生的副产物丙酮能高选择性地转化为乙烯和丙烯,以SAPO-34分子筛为催化剂,在流化床反应器中考察了不同反应温度和丙酮浓度下连续运行时SAPO-34催化丙酮转化的结果,并与甲醇或丁酮转化的结果进行了比较.结合文献报道的丙酮转化路径,详细分析了实验现象.在反应温度为500 ℃、压力为0.28 MPa、原料空速为0.31h-1、原料浓度30％(质量分数)的条件下,丙酮转化率为94.37％,乙烯和丙烯的选择性达到53.32％.本研究对甲醇制烯烃过程副产丙酮的高效利用有一定的指导意义.
为了提高高溴指数原料工况下芳烃烷基转移装置的运行稳定性,在实验室模拟的高溴指数原料条件下,通过模型反应考察了原料中烯烃组分对芳烃烷基转移反应的影响,并通过调整反应温度、循环氢纯度等操作条件对芳烃烷基转移反应工艺进行了优化,为工业装置的运行优化提供了理论依据.基于实验室考察结果,通过对反应温度、循环氢纯度等工艺参数的优化,以及更换白土操作,提高了高溴指数原料工况下工业装置的运行稳定性和原料转化率,为高溴指数原料工况下芳烃烷基转移装置的运行优化提供了参考.
两步法合成了一种新型苯并羧酸类螺吡喃化合物分子3-[8'-甲氧基-1,1-二甲基-6'-硝基螺环(苯并[e]吲哚-2,2'-铬)-3(1H)-基]丙酸.利用紫外、荧光分光光度计、傅里叶红外光谱仪、高分辨质谱和核磁共振仪等表征手段分析螺吡喃类化合物的结构与性能.结果表明,该化合物对Fe3+和Pb2+具有裸眼识别、紫外与荧光识别能力,且兼具检测限低(Fe3+浓度为3.22×10-6 mol/L、Pb2+浓度为3.02×10-6 mol/L)和响应时间短等优点.
分别以MnO2和合成普鲁士蓝(PB/XC-72R)作为催化剂时,考察其对甲醇和双氧水的催化性能,发现两者均可以实现对双氧水的选择性催化.以开发的Z-NiPt为阳极催化剂,以MnO2与PB/XC-72R为阴极催化剂,组成甲醇双氧水单腔体电池,并测试电池的性能.结果表明:以PB/XC-72R为阴极的单腔体燃料电池的最大功率可达9.1 mW.该研究验证了甲醇单腔体新型燃料电池的可行性,为后续甲醇双氧水单腔体燃料电池开发奠定了基础.
以2-正丙硫基-4,6-二氯-5-氨基嘧啶为起始原料,经芳香亲核取代、重氮化、芳香亲核取代和脱亚异丙基保护四步反应制得抗凝血药替格瑞洛.结果表明:在第一步芳香亲核取代反应中,以三乙胺和N,N-二异丙基乙胺体系作为溶剂和缚酸剂,大幅缩短了反应时间,提高了转化率和收率;在第三步芳香亲核取代反应中,以碳酸钾为缚酸剂,简化了后处理过程,减少了对环境的污染.所用合成方法操作简单、易于纯化,为工业化放大生产提供了可能性.
以Mg,K和Cs改性的VOx/SiO2为催化剂,氧气为氧化剂,在固定床反应器中以邻二甲苯为原料氧化合成2-甲基苯甲醛,系统地考察了改性催化剂种类、反应温度、氧气与原料物质的量之比以及液时空速对氧化反应的影响.结果表明:催化剂表面碱性的增加有利于提高2-甲基苯甲醛的选择性.较优的反应条件为:以K-VOx/SiO2为催化剂,反应温度为400℃,氧气与邻二甲苯物质的量之比为4.5,邻二甲苯液时空速为0.36 h-1.优化条件下,邻二甲苯氧化合成2-甲基苯甲醛具有较高的催化反应性能,邻二甲苯的转化率为10.5％,2-甲基苯甲醛的选择性达到98％以上.K-VOx/SiO2催化剂的稳定性较好,具有良好的工业应用前景.
以对氟苯甲醛和4-甲基-3-氧-N-苯-2-(苯亚甲基)戊酰胺为起始原料,噻唑溴化物和三乙胺作为催化剂,通过Stetter反应合成阿托伐他汀关键中间体2-[2-(4-氟苯基)-2-氧代-1-苯基乙基]-4-甲基-3-氧代-N-苯基戊酰胺.根据可能的反应机理,从质子、非质子溶剂和不同极性大小的溶剂中寻找合适的溶剂提高Stetter反应收率和产品质量.研究了溶剂类型、反应温度、溶剂用量、催化剂种类和反应时间等因素对反应的影响,得到的优化工艺条件为:以四氢呋喃作为反应溶剂,用量为原料质量的2.7倍,以溴化3-乙基-5-(2-羟基乙基)-4-甲基噻唑和三乙胺作为催化剂,在65℃下反应16 h.在上述条件下,阿托伐他汀关键中间体2-[2-(4-氟苯基)-2-氧代-1-苯基乙基]-4-甲基-3-氧代-N-苯基戊酰胺的纯度大于99.5％,收率高于88％,产品质量和收率大幅提高,明显减少了脱氟杂质(Des-fluoro)及其他副反应,有利于提高产品的竞争力.
采用氨水、碳酸铵碱性溶液作为浸出剂,在水热条件下浸出处理废弃钴钼加氢催化剂,探究了影响金属元素Mo和Co浸出的主要因素.结果表明:在水热条件下,以氨水和碳酸铵作为复合浸出剂能有效抑制Al的浸出,同时对金属元素Mo和Co的浸出率较高.在氨水浓度为10 mol/L,碳酸铵浓度为2 mol/L,固液比为1:18 g/mL和反应温度为90℃的条件下,Mo和Co的单级浸出率分别达到81.7％和52.6％.进一步采用沉淀法分离回收浸出液中的Mo,制备了花瓣状形貌的(NH4)3PO4(MoO3)12·4H2O产品;利用焙烧后的浸余残渣作为载体负载Cu和Ni制备萘选择加氢催化剂,其催化效果与商品氧化铝载体制备的催化剂相当.
连续流微反应技术的迅速发展为化学合成技术提供了一条可精准控制的路径.其微反应器中尺度效应和构型对参反流体的流场结构、混合传质以及化学反应影响极大.本工作组建有效的串行竞争反应格子Boltzmann模型,通过该模型对Y型和倒Y型微反应器的流场结构、混合传质和化学反应进行数值模拟研究.结果表明:微反应器中的流动以层流为主,其混合器中的对流传质强度很小,微反应器中化学反应以扩散传质为基础进行反应.数值模拟所得结论可为连续流微反应器设计以及微反应精准控制提供有意义的参考.
在气升式反应器冷模实验装置中,研究了气体分布器类型及结构参数对流场和传质的影响规律.结果表明:与环形分布器和四喷嘴分布器相比,采用半球形分布器时平均气含率更高、气含率径向分布更均匀、气泡直径更小、比表面积更大、下降段液速更大、液相体积传质系数更高.气升式废水处理反应器中选用半球形气体分布器可获得更好的混合和传质效果.进一步考察了半球形分布器开孔率和开孔角度对气含率、下降段液速和体积传质系数的影响,确定了最优开孔率为0.457％、最优开孔角度为45o.研究结果可为气升式反应器的工业设计和操作优化提供依据.
静态混合器广泛应用于溶剂萃取,改造静态混合器的入口结构可以提升混合效果.为探究不同入口结构对液液分散的影响,以传统SK型静态混合器、非对流入口静态混合器、Roughton静态混合器、Y-静态混合器4种不同入口结构的静态混合器为研究对象,通过计算流体力学-种群平衡模型(CFD-PBM)数值模拟方法,考察了不同入口结构对静态混合器中液体流速、混合效果和Sauter平均直径(d32)的影响.模拟结果表明:不同入口结构的静态混合器具有显著差异的流体流动状态、混合效果和液液分散效果.混合效果和液液分散效果从好到差依次为Y-静态混合器、Roughton静态混合器、非对流入口静态混合器和传统SK型静态混合器.在混合元件区,4种入口类型的静态混合器的流速相同,但是混合元件发挥混合和分散的作用不同.Y-静态混合器和Roughton静态混合器作为液液分散设备,可以以较少的混合元件数实现高分散效果.
Cu（OH） 2 /Al 2 O 3 precursors were synthesized by equal volume impregnation,and Cu-based catalysts supported with Al 2 O 3 were prepared by acetylene treatment and hydrogen reduction.X-ray diffraction （XRD）,transmission electron microscopy （TEM）,N 2 -physical adsorption were used to characterize the catalyst precursor and the catalyst,and the effect of copper hydroxide loading,acetylene treatment temperature,acetylene treatment time and hydrogen reduction temperature on the selective hydrogenation performance of the prepared catalyst were systematically investigated in a fixed-bed reactor.The results showed that the catalyst with high activity for the selective hydrogenation of acetylene was obtained when the Cu（OH） 2 loading was 30%（mass fraction）,the acetylene treatment temperature was140℃,the acetylene treatment time was 2 h and the hydrogen reduction temperature was 150℃.When the reaction temperature was 115℃,the conversion of acetylene was 98.50%,the selectivity of ethylene was66.15%,the selectivity of ethane was 15.75%and the selectivity of C 4 was 18.10%.
In order to solve the problems of heavy oil with water and light oil-gas with heavy oil in the circulating heat transfer separation system of slurry-bed Fischer-Tropsch synthesis plant, the circulating heat transfer system and the related upstream and downstream processes were analyzed and simulated. The influence tendency of different process conditions on the separation system of the circulating heat transfer separator were studied. The results showed that under different process conditions, the operating conditions of the outlet of the circulating heat exchanger separator should be controlled above the dew point temperature of water, so that the water content in the heavy oil can be significantly reduced. When the temperature of the circulating heat exchanger separator decreased, the steam production of the reactor increased and the load of the air cooler decreased. When the pressure of high temperature oil-gas increased,the dew point temperature of water increased, but there was only a little effect on the by-product steam quantity of the temperature-controlled deaerating water in the reactor and the load of air cooler. With the increase of heavy oil content in high-temperature oil, the dew point temperature of water also increased.
In order to realize the high value-added utilization of coal-bed methane, a coal/bio-based hierarchical porous carbon material can be prepared by adding biomass and KOH to coal, and it is applied to the direct cracking of coal-bed methane to produce hydrogen. Which can not only produce high-purity hydrogen, but also obtain a certain amount of carbon materials. In view of the problems of many influencing factors in the preparation process of coal/bio-based hierarchical porous carbon, the Design-Expert software was used to build an experimental scheme for preparing coal/bio based graded porous carbon materials.Combined with the experimental data for the catalytic cracking reaction of coalbed methane to produce hydrogen over the synthesized porous carbon materials. The influencing factors were analyzed and the fitting equation between the influencing factors and the reaction conversion was established,furthermore, the experimental scheme was optimized. The results showed that temperature and alkali-carbon ratio were the main influential factors in the preparation process of coal/bio-based hierarchical porous carbon. The maximum error between the theoretical optimal solution and the experimental value for preparing coal/bio based graded porous carbon materials was 3.3%, indicating that the optimization of the preparation process by the Design-Expert software was accurate and reliable. The catalytic activity of the coal/bio-based hierarchical porous carbons for the cracking reaction of coal-bed methane was higher than that of raw coal materials. The former produced a large number of carbon spheres while the latter produced a large number of carbon spheres and carbon fibers, on the surface of materials after the reaction.
The multi-mode/multi-wavelength photoluminescence from a single chromophore can avoid the error of emission properties, which is easily generated from different batches of samples upon mixing of multiple chromophores. Thus, this photoluminescent behavior has better prospects and a wider range of applications. To achieve the multi-mode photoluminescence in a single chromophore, structural modifications from the classic molecules with anti-Kasha rule luminescence properties can be carried out.On the other hand, molecular design with the construction of hydrogen bonding, supramolecular force, and other non-covalent bonds to regulate the singlet-triplet energy level of the chromophores can also be valid.This paper reviewed some representative development and achievements reported in recent years, providing multi-mode luminescence properties by controlling high-low excitation states and singlet-triplet states.Meanwhile, it showed achievements about controlling intensity and ratio of luminescence by using different stimuli. It also made an outlook on applications in function materials about adjustment of multi-mode emissions of single chromophores.
The spectral properties of molecular probes are closely related to their chemical structures.Therefore,the study of the relationship between molecule structure and its spectral properties cannot be ignore for rationally designing molecular probes with excellent performance.In this paper,the asymmetric chlorofluoroboron dipyrrole dye was used as the matrix,and the electron-absorbing group with quinoline salt as the matrix structure was introduced through the Knoevenagel reaction.Only different substituents at the same position were changed.Four hydrogen sulfide molecular probes （BOD-NO 2 ,BOD-H,BOD-BOC and BOD-NH 2 ） were designed and synthesized to investigate systematically the performance differences caused by the change of substituents.The results proved that the accompanying change of the different quinoline salt was the different electron withdrawing ability of probe,which leaded to the change of the reaction performance of the probe with H 2 S.These four probes showed specifical responsiveness to H 2 S.With the enhancement of the electron absorption ability of the substituents,the rate and extent of nucleophilic substitution reaction between the probes and H 2 S increased,meanwhile the absorption spectrum red-shifted and the photoacoustic imaging effect was better.Finally,the probe BOD-NO 2 with excellent photoacoustic performance was successfully screened out through the investigation of the probe structure-activity relationship,which responded specifically to H 2 S with fast response and high selectivity.This study provides a novel idea for the design of photoacoustic probes targeting H 2 S.
The technology of olefin oligomerization to synthesize liquid fuel has broad application prospects in military and civil fields. Based on the theory of finite-time thermodynamics, the chemical process model including a mixer, a compressor, a heat exchanger and an ethylene oligomerization reactor was established and optimized. The compressor outlet pressure, the heat exchanger outlet temperature and the optimal temperature configurations of the heat reservoirs outside the heat exchanger and the reactor for the minimum entropy generation rate of the chemical process were derived under the condition of a given yield of C10H20.The optimization results were also compared with those for the reference chemical process and the process with the minimum entropy generation rate of the reactor. The results showed that the entropy generation rate for the optimal process was reduced by 3.21% compared to that for the reference chemical process and by 1.30% compared to that for the process with the minimum entropy generation of the reactor when the heat exchanger outlet temperature was 608.18 K and compressor outlet pressure was 2.68 MPa. The obtained results in this paper could be a certain theoretical guidance for the optimal design of olefin oligomerization reaction process.
