The Conversion of Syngas to Liquid Fuels in a Dual-Bed Single Reactor Process

The effects of HZSM-5 temperature and weight hourly space velocity (WHSV) on conversion of syngas to liquid fuels were investigated in a single reactor process. The temperature of FT catalyst was constant (463 K), whereas the temperature of HZSM-5 varied (523, 573, 623 K). The value of WHSV ranged between 16 and 24 h^?1. HZSM-5 addition suppressed the formation of CH₄ and remarkably enhanced the formation of iso-C₅-C₁₂ paraffins. An increase of HZSM-5 temperature resulted in an enhancement of gaseous hydrocarbons, C₁₈₊ paraffins, and olefins. The optimal HZSM-5 temperature and WHSV were identified as 523 K and 16 h^?1, respectively.     

MoO_3/HZSM-5催化剂上重芳烃加氢脱烷基反应

采用等体积浸渍法制备了不同负载量的MoO3/HZSM-5催化剂,考察了MoO3/HZSM-5催化剂上MoO3负载量和工艺条件对重芳烃(C9+)加氢脱烷基反应的影响;并用X射线衍射、吡啶吸附红外光谱、氨程序升温脱附等技术对催化剂进行了表征。实验结果表明,重芳烃在MoO3/HZSM-5催化剂上的反应性能与HZSM-5分子筛上MoO3的分散状态、催化剂的酸性和酸量及工艺条件有关;当MoO3/HZSM-5催化剂中MoO3的负载量(质量分数)接近15%时,MoO3在HZSM-5分子筛表面呈单层分散。采用15%MoO3/HZSM-5催化剂,在550℃、3.0MPa、重时空速3.62h-1及V(H2)∶V(C9+)=800的反应条件下,重芳烃转化率达55.94%,苯、甲苯、二甲苯(BTX)收率大于50%,BTX总选择性达90%以上。     

Cu-Ce/HZSM-5催化剂上的乙醇芳构化反应

以浸渍法制备了Ce/HZSM-5、Cu/HZSM-5、Cu-Ce/HZSM-5系列催化剂,采用XRD、氮气物理吸附和氨气程序升温脱附方法对其进行了表征,并考察了其催化乙醇芳构化性能。结果表明,Ce和Cu的负载降低了HZSM-5分子筛的比表面积,但分子筛保持原有的骨架结构,且强酸量减少、中强酸量和弱酸量增多;先浸渍Ce再浸渍Cu,Ce和Cu的负载量分别为1.2%和5%的HZSM-5催化剂具有最佳的乙醇芳构化催化性能,在反应温度350℃、质量空速1.0h-1条件下,芳烃收率可达67.6%。     

Aromatization of FCC Gasoline Over Modified HZSM-5 Catalyst

Zinc and phosphorus incorporated HZSM-5 catalyst was prepared by adopting incipient wet co-impregnation (Zn-P/HZSM-5). Zn-P/HZSM-5 catalyst exhibited the lowest acidity but the highest aromatization activity with stable performance in the studied period of 16 hr. The process conditions on aromatization reaction and the coke deactivation mechanism of Zn-P/HZSM-5 catalyst were studied on a small-scale, fixed bed reactor using FCC naphtha (75-120°C). The weight contents of ZnO and P₂O₅ were 2% and 4%, respectively. Results showed that Zn-P/HZSM-5 catalyst under a temperature of 450°C, liquid hourly space velocity of 1.0 h^-1, and pressure of 0.1 MPa, the conversions of olefins and alkanes are 96.77% and 88.94%, respectively, the contents of olefins, aromatics in liquid product are 6.79% and 74.57%, respectively. Carbon deposition was the major reason for catalyst deactivation due to the catalyst's good performance as a fresh catalyst after regeneration. All of the blending products fitted the standards of Chinese gasoline.     

Aromatization of FCC Gasoline Over Modified HZSM-5 Catalyst

Abstract

Zinc and phosphorus incorporated HZSM-5 catalyst was prepared by adopting incipient wet co-impregnation (Zn-P/HZSM-5). Zn-P/HZSM-5 catalyst exhibited the lowest acidity but the highest aromatization activity with stable performance in the studied period of 16 hr. The process conditions on aromatization reaction and the coke deactivation mechanism of Zn-P/HZSM-5 catalyst were studied on a small-scale, fixed bed reactor using FCC naphtha (75–120°C). The weight contents of ZnO and P₂O₅ were 2% and 4%, respectively. Results showed that Zn-P/HZSM-5 catalyst under a temperature of 450°C, liquid hourly space velocity of 1.0 h^?1, and pressure of 0.1 MPa, the conversions of olefins and alkanes are 96.77% and 88.94%, respectively, the contents of olefins, aromatics in liquid product are 6.79% and 74.57%, respectively. Carbon deposition was the major reason for catalyst deactivation due to the catalyst's good performance as a fresh catalyst after regeneration. All of the blending products fitted the standards of Chinese gasoline.     

Zn/HZSM-5分子筛气固相循环法合成苯基二氯化膦

采用经HZSM-5分子筛改性的Zn/HZSM-5为催化剂,在固定床内由苯和三氯化磷为原料进行气固相催化反应制备苯基二氯化膦(DCPP)。考察了Zn负载量、原料配比、反应温度、反应时间等因素对反应的影响。采用X射线衍射、扫描电镜、傅里叶变换红外、低温氮吸附等手段对催化剂进行了表征。结果表明,Zn负载量为2.5%(质量分数)的Zn/HZSM-5分子筛25g,n(C6H6)∶n(PCl3)=3∶1,反应温度为320℃,反应5h时,苯基二氯化膦收率能达到17.6%。负载Zn后HZSM-5分子筛晶型并未被破坏,Zn组分的引入导致分子筛表面酸性有所变化,反应过程较HZSM-5分子筛易积炭。     

核壳型HZSM-5@SBA-15复合材料的合成及其甲醇芳构化催化性能的研究

采用酸性溶胶凝胶法,以P123为模板剂合成了核壳型HZSM-5@SBA-15复合分子筛。在结构性质以及甲醇转化制芳烃催化性能方面,将HZSM-5@SBA-15与HZSM-5@SiO2进行对比。这两种催化剂的SiO2壳层都可以减少HZSM-5的酸性位,进而减少了催化剂内积碳的形成。然而,在有序介孔SBA-15壳层中,芳烃和积碳前驱体相比于SiO2壳层中更容易扩散。因此,HZSM-5@SBA-15在催化甲醇芳构化反应中表现出更高的BTX选择性和更长的寿命。HZSM-5@SBA-15的寿命比HZSM-5@SiO2长50个小时,此条件下的BTX选择性为56%。     

浆态床反应器中熔铁催化剂的费托合成反应性能

研究了浆态床反应器中熔铁催化剂的费托合成反应性能,并与固定床反应器进行了比较。实验结果表明,熔铁催化剂在浆态床反应器中具有较好的费托合成反应活性和良好的稳定性;与固定床反应器相比,浆态床反应器中CH4和CO2的选择性明显降低。考察了反应温度、反应压力、合成气空速、合成气n(H2)∶n(CO)对浆态床反应器中熔铁催化剂费托合成反应性能的影响。实验结果表明,适当调变反应条件,可有效提高熔铁催化剂的费托合成反应活性,并使产物分布得到优化。在n(H2)∶n(CO)=1.6、2.0M Pa、250℃、GHSV=3 000h-1的条件下运行900h,浆态床反应器中CO的转化率达92%左右,CH4的选择性为5%左右,CO2的选择性为40%左右。     

Na离子修饰的Au/HZSM-5催化剂的制备、表征及催化合成气羰基化反应性能

采用负压沉积-沉淀法制备了负载型Au/HZSM-5催化剂,在此基础上负载了第二金属Na制得Na-Au/HZSM-5催化剂,采用XRD、ICP-AES、氮气吸附-脱附、NH3-TPD、OH-IR、Py-FT-IR等方法对Na/HZSM-5、Au/HZSM-5、Na-Au/HZSM-5物性进行分析,并考察酸中心对其催化合成...     

The Aromatization of Different FCC Naphtha Fractions over a P-Zn/HZSM-5 Catalyst

Abstract

The aromatization reaction performance of P-Zn/HZSM-5 catalyst was investigated on a fixed bed reactor using five fluid catalytic cracked (FCC) gasoline fractions (<100°C, 50°C–100°C, <120°C, 75°C–120°C, and full fraction) as feedstock, and the effect of feedstock on aromatization is discussed. The results showed that the activity and stability of P-Zn/HZSM-5 catalyst for the aromatization of the 50°C–100°C fraction were high in definite reaction conditions. After 16 hr, the content of olefin and aromatics in liquid product were 5.23 and 79.9%, respectively. The liquid product of low olefin and high aromatics was obtained. The distribution of benzene, toluene, and xylene in liquid product of 50°C–100°C fraction was investigated during aromatization, and the result showed that the toluene content was maximum among the three aromatics contents, the benzene content was minimum at the beginning of the reaction, xylene content became maximum, and benzene was still minimum after reacting for 20 hr. The content of C₉ ⁺ aromatics increased at the first stage of the reaction and then decreased with the increasing reaction time.     

The Reaction Kinetics of a Fischer-Tropsch Synthesis Over a Commercial Eggshell Co/SiO2 Catalyst

Abstract

The comprehensive kinetic model of Fischer-Tropsch synthesis over a commercial eggshell Co/SiO₂ catalyst in a fixed-bed reactor was investigated experimentally. This model was expressed in the combination of kinetic rate of CO consumption and the equation of the growth probability factor α was obtained. Through parameter evaluation and optimization, both the rate of CO consumption was given and the equation of a was obtained. It was also proved that the proposed model could predict the kinetic rate of CO consumption and the product distributions well. The appropriate operating conditions for this catalyst were concluded by the model and they were in good agreement with the results in the industrial pilot-scale research.     

Fe-Mn催化剂浆态床合成低碳烯烃的反应性能

在浆态床反应器中,对Fe-Mn催化剂上CO加氢合成低碳烯烃的反应性能进行了研究,考察了不同温度、空速和压力下Fe-Mn催化剂的催化性能,并借助XRD和N2物理吸附等手段对催化剂进行了表征。实验结果表明,Fe-Mn催化剂在运行300h后达到稳定运行状态。反应参数的适当调变,可有效提高Fe-Mn催化剂的活性和低碳烯烃收率,并使产物分布得到优化。在n(H2)∶n(CO)=2、320℃、2.0 MPa、合成气空速1 000 h-1的条件下,CO转化率83.10%,CH4选择性11.88%,C5+烃选择性39.06%,C2～4烃中烯烃与烷烃的质量比3.59,低碳烯烃收率38.50 g/m3(基于H2与CO的总体积)。     

HZSM-5分子筛的改性对合成气直接制二甲醚反应的影响

采用固态离子交换法改性合成气直接制二甲醚(DME)双功能催化剂中的甲醇脱水组分HZSM 5分子筛,制得一系列Mg ZSM 5催化剂,并用XRD和NH3 TPD表征其结构和表面酸性,发现改性后分子筛的晶型和结构未受到破坏,但分子筛表面弱酸中心增强,强酸中心减弱,酸中心分布较为集中。将由Mg ZSM 5分子筛与Cu基甲醇合成催化剂组成的双功能催化剂用于合成气直接制二甲醚反应,结果表明,目的产物DME选择性由改性前的53 62%提高到68 31%,而副产物CO2和烃类的选择性则分别由41 75%和0 23%下降至27 67%和0 02%。     

The Deactivation Factor of a ZnNi/HZSM-5 Catalyst During Aromatization

The effect of Si/Al ratio and aluminum content of the catalysts of ZnNi/HZSM-5 for aromatization is investigated in this paper. In the experiment, acid content, acidity, metal phase, and pore structure are measured using XRD, ASAP2400, and TG. From the relation of deposited carbon and acid content, we know that carbon deposition is an important reason for deactivation of catalyst, because the high-molecular-weight and high-boiling-point deposited carbon can clog the pores and cover the acid centers. The loss of zinc is another reason for deactivation. Ni was selected to be the second modifying metal to make up the loss of zinc and was confirmed to have a better result. Through this research, we find the reason for short life and bad stability for the catalyst so that we can produce high-quality catalyst.     

The Deactivation Factor of a ZnNi/HZSM-5 Catalyst During Aromatization

Abstract

The effect of Si/Al ratio and aluminum content of the catalysts of ZnNi/HZSM-5 for aromatization is investigated in this paper. In the experiment, acid content, acidity, metal phase, and pore structure are measured using XRD, ASAP2400, and TG. From the relation of deposited carbon and acid content, we know that carbon deposition is an important reason for deactivation of catalyst, because the high-molecular-weight and high-boiling-point deposited carbon can clog the pores and cover the acid centers. The loss of zinc is another reason for deactivation. Ni was selected to be the second modifying metal to make up the loss of zinc and was confirmed to have a better result. Through this research, we find the reason for short life and bad stability for the catalyst so that we can produce high-quality catalyst.     

Influence of Aromatization Reaction Conditions in the Presence of HZSM-5 Catalyst

The reaction conditions include temperature, weight hourly space velocity (WHSV), catalyst loading amount Ga and Si/Al, vapor, calcination temperature, soaking order, pretreatment, oxygen, and microwave heating method. The study introduces the influence of aromatization reaction conditions over HZSM-5 catalyst in detail. The proper temperature, low weight hourly space velocity (WHSV), modified HZSM-5, non-oxygen and microwave heating method are beneficial to the aromatization reaction.     

钾助剂对Co/SiO2费-托合成催化剂性质及反应性能的影响

 考察了钾（K）助剂 (质量分数0.17%～4.98%) 对Co/SiO₂ 催化剂结构及其费-托合成（F-T）反应性能的影响。结果表明, K助剂趋向于存在催化剂的外表面,K助剂的添加显著降低了催化剂的比表面积。 在H₂气氛下对催化剂还原处理,添加K助剂不会降低催化剂的还原能力,反而会促进Co₃O₄的还原。在CO+H₂气氛中,K助剂会促进金属Co的氧化,使催化剂活性降低。少量的K助剂使催化剂的催化活性有所下降,但使产物中的C₁~C₄含量降低,烯/烷比增加。     

Fe-Co-K/SiO_2催化剂对Fischer-Tropsch合成反应的催化性能

采用浸渍法制备了Fe-Co-K/SiO2催化剂,在连续流动固定床反应器上考察了反应温度、反应压力、重时空速和n(H2)∶n(CO)对该催化剂催化Fischer-Tropsch合成反应性能的影响。实验结果表明,随反应温度的升高,催化剂的活性提高,CO转化率和CH4选择性增大,重质烃(C 5+)选择性减小;升高反应压力有利于提高CO转化率和重质烃选择性;增大重时空速不利于重质烃的生成,同时CO转化率减小,CH4选择性增大;随n(H2)∶n(CO)的增大,CO转化率和CH4选择性增大,重质烃选择性减小。Fe-Co-K/SiO2催化剂用于Fischer-Tropsch合成反应较适宜的工艺条件为:反应温度503～513 K、反应压力1.5 MPa、重时空速600～800 h-1、n(H2)∶n(CO)=2.00。     

Influence of Aromatization Reaction Conditions in the Presence of HZSM-5 Catalyst

Abstract

The reaction conditions include temperature, weight hourly space velocity (WHSV), catalyst loading amount Ga and Si/Al, vapor, calcination temperature, soaking order, pretreatment, oxygen, and microwave heating method. The study introduces the influence of aromatization reaction conditions over HZSM-5 catalyst in detail. The proper temperature, low weight hourly space velocity (WHSV), modified HZSM-5, non-oxygen and microwave heating method are beneficial to the aromatization reaction.     

Conversion of syngas to liquid hydrocarbons via a sorption-enhanced dual bed reactor

Fischer–Tropsch synthesis (FTS) plays an important role in the production of clean liquid transportation fuels, chemicals, and other hydrocarbon products. This study proposes a novel dual bed configuration of FTS reactor in which Zeolite 4A, with the composition of Na₁₂ (Si₁₂Al₁₂O₄₈)?27H₂O, is considered as water adsorbent inside the first reactor. In the second converter, the heat of reaction is used to pre-heat the synthesis gas to the first bed. The simulation results show an enhancement in the gasoline production, a main decrease in undesirable product formation (CO₂ and CH₄), and a favorable temperature profile along the proposed concept rather than the conventional reactor. This paper shows how the concept of in-situ water adsorption is feasible and beneficial for dual bed FTS.