固体碱催化剂K_2CO_3/Al_2O_3的制备及其催化餐饮废油制生物柴油的性能

采用浸渍法制备了K2CO3/Al2O3固体碱催化剂,考察了活性组分负载量、焙烧温度、焙烧时间等制备条件对催化剂在催化餐饮废油合成生物柴油的酯交换反应中催化活性的影响,并对其进行了FT-IR、XRD、TG-DTG、SEM和BET表征分析。实验结果表明,所制备的催化剂在催化餐饮废油合成生物柴油的酯交换反应中表现出良好的活性,在活性组分K2CO3负载量为50%、焙烧温度500℃、焙烧时间3 h的条件下制备的催化剂催化酯交换反应时,生物柴油产率可达86.70%。催化剂表征结果显示,K2CO3/Al2O3催化活性是因K2CO3与Al2O3经高温焙烧产生新的晶相有关。催化剂重复使用4次,生物柴油产率仍在75%以上。制得的生物柴油产品质量达到国家生物柴油B100标准。     

CaO-MgO@CoFe_2O_4磁性固体碱的制备及其大豆油酯交换反应催化性能

以草酸盐为前驱体采用两步法制备了一种以CaO-MgO作为活性组分,以CoFe_2O_4作为磁核的磁性固体碱催化剂,并用于大豆油与甲醇的酯交换反应合成生物柴油。对制备的磁性固体碱催化剂进行了磁滞回线、X-射线衍射(XRD)、CO_2-TPD及透射电镜(TEM)表征。考察了不同核壳物质的量比、焙烧温度、反应温度、反应时间、醇油物质的量比以及催化剂用量等因素对大豆油转化为生物柴油产率的影响。结果表明,采用核壳物质的量比为1∶6、焙烧温度为700℃所制备的CaO-MgO@CoFe_2O_4催化剂,当醇油物质的量比为12、催化剂用量为大豆油质量的1.0%时,在65℃下反应时间3 h,生物柴油收率高达97.1%。该催化剂具有较好的重复利用性能,重复利用四次后生物柴油的收率仍可达90%。     

CaO@SiO_2纳米固体碱的制备、表征及其大豆油酯交换反应催化性能

采用溶胶-凝胶法合成Ca O@Si O_2固体碱催化剂,以聚苯乙烯有机聚合物为硬模板剂和以P123为软模板剂对Ca O的微观形貌进行调控。并将其应用于大豆油与甲醇的酯交换制备生物柴油的反应体系中。通过对Ca O@Si O_2纳米固体碱催化剂进行X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电镜(TEM)、CO_2-TPD及N_2的吸附-脱附(BET)表征发现,不仅制备得到了形貌归整的纳米固体颗粒,而且得到了Ca O包裹在Si O_2表面的核壳结构。进一步考察了不同的硅钙质量比、反应温度、催化剂的用量以及油醇物质的量比对生物柴油收率的影响,生物柴油的收率最高可以达到95.6%。     

钙基负载型固体碱催化酯交换反应活性评价

动植物油脂与醇通过酯交换反应制备生物柴油,目前,工业上一般采用NaOH、KOH、NaOCH,等均相催化剂。均相催化剂的缺点是产品后处理复杂,产生大量含碱含油工业废水。而非均相固体碱催化酯交换反应,产品与催化剂分离容易,产品不需要水洗,避免了大量废液的排放。采用非均相固体碱制备生物柴油的文献报道较多,但固体碱的碱中心数、碱中心强度对酯交换反应影响的报道较少。本研究制备了钙基负载型固体碱催化剂,重点研究钙基负载型固体碱的制备工艺条件对碱强度、碱量分布的影响,考察碱强度、碱量分布对催化菜籽油与甲醇的酯交换反应制备生物柴油转化率的影响。     

固体碱KF/Sm2O3催化菜籽油制备生物柴油

以菜籽油为原料,研究了负载型固体碱催化剂KF/Sm2O3在酯交换制备生物柴油过程中的催化活性.用气相色谱法对酯交换产物进行分析,并用CO2-TPD,XRD,Ramaa等技术对催化剂进行了表征.当催化剂焙烧温度为873 K,KF负载量为15%,甲醇跟菜籽油的计量比为12:1,催化剂用量为菜籽油质量的3%,反应温度为338 K,反应时间为1 h时,生物柴油产率达到95.1%.     

Ni/Al2O3催化甲烷裂解

分别通过浸渍法和共沉淀法制备了不同Ni负载量的Ni/Al2O3催化剂。考察了Ni负载量、制备方法以及反应温度对Ni/Al2O3催化甲烷裂解性能的影响。结果表明,在550℃,浸渍法制备的Ni/Al2O3催化剂,当Ni负载量为20%(质量分数)、Ni金属平均粒径为11.25 nm时,具有最佳的甲烷催化裂解效果,其每摩尔Ni的氢气产量和每克Ni碳产量分别为164 mol和15.30 g。催化剂制备方法对Ni/Al2O3甲烷催化裂解反应有显著影响,相同Ni负载量共沉淀法制备的Ni/Al2O3甲烷催化裂解总体效果要好于浸渍法制备的Ni/Al2O3,而且反应过程中生成的碳纤维较长,管径也较均一。550℃时,共沉淀法制备的Ni负载量为41.2%(质量分数)的Ni/Al2O3催化剂在反应至350 min时,仍保持着30%以上的转化率。     

负载型CuO/TiO2催化剂催化CO2加氢制甲醇

采用浸渍法制备了CuO/TiO_2负载型催化剂,并将其用于CO2加氢制甲醇反应。重点考察了铜的负载量对催化剂性能的影响,并对其物化性能和催化性能之间的关系进行了讨论。结果发现,随着铜负载量的增加,催化剂中金属铜的比表面先增加后减小,当铜的负载量为10%(质量百分数)时达到最大值。催化剂的表面碱性位数量随铜含量的增加持续减小,中等碱位和强碱位的强度下降。当铜的负载量不高于10%时,CO2的转化率与铜的比表面积呈线性关系。甲醇选择性与催化剂的表面碱位性质有关,过强的碱性位会降低甲醇选择性。     

双核碱性离子液体催化棉籽油酯交换制备生物柴油

采用两步法制备了五种新型咪唑类碱性双核功能化离子液体化合物,并考察了对棉籽油酯交换制备生物柴油的催化性能。结果表明,咪唑类碱性双核功能化离子液体具有很好的催化活性,其催化活性与阳离子中碳链长度有关。其中,双-(3-甲基-1-咪唑)亚乙基双氢氧化物离子液体的催化活性最好。催化剂量、反应时间、反应温度及醇油比对生物柴油中脂肪酸甲酯含量及选择性影响的研究发现,在催化剂用量为0.4%(质量分数),醇油摩尔比为12,反应温度为55℃,反应时间为4 h时,脂肪酸甲酯的含量和选择性分别达98.5%和99.9%。催化剂7次循环后,产物中脂肪酸甲酯含量仍达到96.2%,单甘酯和双甘酯的含量很少,表明该催化剂重复使用良好。     

WO_3-TiO_2/SBA-15的制备及其光催化氧化脱硫性能

采用孔道内水解法制备了WO_3-TiO_2/SBA-15催化剂用于光催化氧化柴油脱硫,利用XRD、SEM、EDS、N2吸附-脱附、FT-IR、TG-DTA和UV-vis等技术对该催化剂进行了表征,考察了WO_3和TiO_2负载量、焙烧温度和焙烧时间对其光催化氧化脱硫性能的影响。结果表明,WO3和Ti O2负载量分别为1.6%和15%,焙烧温度500℃,焙烧时间为3 h条件所制备的催化剂性能最佳;在该条件下制备的WO_3-TiO_2/SBA-15催化剂仍保持SBA-15的六方介孔结构,模拟柴油的脱硫率高达87.9%,且具有良好的回收再生性能。     

超声作用下KF/CaO催化酯交换反应制备生物柴油

等体积浸渍法制备了KF/CaO固体碱催化剂,用于催化大豆油与甲醇酯交换反应制备生物柴油,在反应体系中引入超声作为辅助条件。研究表明,KF/CaO催化活性高。在超声的辅助作用下,酯交换反应速率加快,生物柴油的收率提高。实验考察了反应条件对产品中脂肪酸甲酯含量的影响。醇油摩尔比为12∶1,反应温度65℃,催化剂与大豆油的质量比为3%,反应1 h,超声频率20 kHz,超声声强1.01 W/cm2,在此反应条件下,产品中脂肪酸甲酯的质量分数达到99.6%。     

Synthesis of biodiesel over ZnO/Ca(OH)2/KF catalyst prepared by the grinding method

A novel ZnO/Ca(OH)₂/KF solid base catalyst was prepared by the grinding method and applied to biodiesel synthesis by the transesterification of soybean oil. The effect of various parameters such as KF molar amount, calcination temperature, the amount of catalyst, molar ratio of methanol to oil, reaction temperature, and time on the activity of the catalyst were investigated. The catalysts were characterized by several techniques of thermogravimetry/derivative thermogravimetry, X–ray diffraction, Hammett indicator method, and scanning electron microscopy. The analysis results indicated that the KF interacted with Ca(OH)₂ and formed KCaF₃ phase before calcination of the catalyst. The formed KCaF₃ crystal phase was the main catalytic active component for the catalyst activity. In addition, the basicity of ZnO/Ca(OH)₂/KF was greatly influenced by the different calcination temperates, and the catalyst activity was correlated closely with the basicity. A desired biodiesel yield of 97.6 % was obtained at catalyst amount of 3 %, methanol/oil of 12:1, and reaction time of 1.5 h at 65 °C.     

Montmorillonite-supported KF/CaO: a new solid base catalyst for biodiesel production

Biodiesel is an alternative to petroleum-derived diesel fuel; development of a high-efficiency base catalyst to be used in heterogeneous biodiesel production is still a challenge. In this paper, a novel solid base catalyst, KF- and CaO-supported montmorillonite (KCa/MMT) was successfully synthesized by a facile impregnation method, and used for producing biodiesel in transesterification of commercial soybean oil with methanol. The catalysts were characterized by X-ray diffraction, carbon dioxide temperature-programmed desorption and scanning electron microscopy. Effects of the parameters, such as the loading amount of KF, the amount of KCa/MMT, and the methanol to oil molar ratios, on the yield of biodiesel were investigated. A maximum biodiesel yield of 98 % was obtained under the optimal reaction conditions. The separated catalyst can be directly used in the next round of reactions and gave a satisfactory yield. Furthermore, analysis of the catalyst's tolerance to oil-containing water or free fatty acids, and a kinetic study were also carried out. Koros–Nowak tests were designed and conducted, and it was proven that the heat and mass transfer were not limited by the reaction rate.     

硅胶固定功能化离子液体的制备及其在5-羟甲基糠醛合成中的应用

通过γ-氯丙基三甲氧基硅烷将磺基功能化离子液体-N-磺丙基咪唑盐化学键合到微球硅胶上,制得微球硅胶固定化离子液体(IL3). 用FTIR、TG、~(13)C NMR、SEM、BET及酸度测定等测试技术对IL3进行了表征,并考察其在果糖脱水合成5-羟甲基糠醛(HMF)过程中的催化性能. 研究结果表明,氯丙基三甲氧基硅烷可以将磺基功能化咪唑型离子液体化学键合到微球硅胶上. 微球硅胶固定化磺基咪唑离子液体能有效催化果糖脱水生成HMF. 果糖在固载率45.4%的IL3催化下、乙二醇甲醚(EGME)溶剂中、115 ℃反应5 h,HMF收率可达82.1%. 催化剂循环使用4次后,HMF的收率下降为53.0%.     

负载型钾盐催化剂用于合成苯甲醚的研究

采用固定床连续进料的反应器代替传统间歇反应釜作为评价反应器,以环境友好的碳酸二甲酯为甲基化试剂,由苯酚合成苯甲醚的反应新工艺。采用SiO2负载的钾盐类催化剂,考察了反应温度、进料空速、原料配比、活性组分负载量以及催化剂用量等对反应性能的影响。研究表明,在该负载型钾盐催化剂上苯酚的转化率均较高,且生成苯甲醚的选择性较好。尤其是在KF/SiO2催化剂上,在DMC/苯酚摩尔比为2∶1,进料空速为2 h-1,反应温度为250℃时,苯甲醚收率和选择性分别高达93.93%和98.19%。而且该负载型催化剂活性比较稳定,未发现活性组分流失,反应运行16 h催化剂未见失活。     

Statistical optimization of biodiesel production from para rubber seed oil by SO3H-MCM-41 catalyst

The experimental parameters for biodiesel production from para rubber seed oil and methanol using a SO₃H-MCM-41 catalyst were optimized statistically. The SO₃H-MCM-41 catalyst was synthesized by co-condensation in the presence of tetraethyl orthosilicate, 3-mercaptopropyl (methyl) dimethoxysilane (MPMDS) and cetyl-trimethylammonium bromide. In the last step, the solid catalyst (SH-MCM41) was oxidized by H₂O₂ to SO₃H-MCM-41. The acid capacity of the obtained SO₃H-MCM-41 catalyst was quantified by back titration with 0.1 M sodium hydroxide. The physical and chemical properties of the SO₃H-MCM-41 were characterized by nitrogen adsorption/desorption, X-ray diffractometry, Fourier transform infrared spectroscopy and thermogravimetric analysis. The effect of varying the catalyst loading (wt.%), reaction time (h) and temperature (°C) and molar composition of MPMDS on the biodiesel yield were investigated using a 2^k factorial design. The optimal conditions to maximize the biodiesel yield, obtained from the response surface analysis using a Box–Behnken design, was a 14.5 wt.% catalyst loading, and a reaction time and temperature of 48 h and 129.6 °C. Under these conditions a fatty acid methyl ester (biodiesel) yield of 84% was predicted, and an 83.10 ± 0.39% yield experimentally obtained.     

KF/Al2O3催化合成2-甲基-3-(3,4-亚甲二氧基苯基)丙烯醛

缩合;催化剂;洋茉莉醛;KF/Al2O3催化合成2-甲基-3-(3;4-亚甲二氧基苯基)丙烯醛     

超声波辅助固体酸催化塔尔油脂肪酸制备生物柴油

将强酸性阳离子交换树脂加入塔尔油脂肪酸和甲醇混合液中,并在超声波辐射辅助下得到生物柴油,对生物柴油的制备工艺和性能进行研究,同时建立动力学模型。结果表明,超声波辐射的辅助强化,能有效提高生物柴油的得率;在反应温度65℃、反应时间1h、甲醇与TOFA摩尔比为10∶1、脱水剂用量为TOFA6%、树脂NKC-9用量为TOFA40%的最佳工艺条件下,反应平衡常数可达11.18,生物柴油得率为90.0%。建立的动力学模型补充了超声波辐射辅助酯化反应动力学参数,并用此模型解释了各工艺参数呈现的规律。以廉价的制浆黑液回收物塔尔油脂肪酸为原料制备生物柴油,能有效地降低生物柴油价格,提高其市场竞争力,实现塔尔油高附加值利用,具有良好的发展前景。