合成气制备增塑剂醇的初步研究

石油学报(石油加工)2012年6月ACTA PETROLEI SINICA (PE TROLEUM PROCESSING SECTION第28卷第3期文章编号:1001-8719(2012)03047006合成气制备增塑剂醇的初步研究熊莲2,罗彩容2,郭海军2,陈新德址2,陈勇3(1,中国科学院可再生能源与天然气水合物重点实验室,广东广州510640;中国科学院广州能源研究所,广东广州510640;3.中国科学院广州分院,广东广州,510640)摘要:采用热重差热分析( TG-DTG)、X射线衍射(XRD)、场发射扫描电镜( FE-SEM)手段对 Cu-Fe-Co/SO2催化剂进行表征,将 Cu-Fe-Co/SO2用于催化合成气制备增塑剂酶的反应,考察了不同工艺条件对总醇时空收率、增塑剂醇分布及CO转化率的影响。结果表明,Cu、Fe、Co3种活性组分在SO2载体上分散均匀,的孔隙丰富,孔道结构牢固,利于增塑剂醇合成反应的进行,随着反应温度的升高,增塑剂醇质量分数逐渐降低总醇时空收率呈现先上升后下降的趋势;反应压力增加,总醇时空收率增加,CO转化率缓慢上升,但幅度很小,增塑剂醇质量分数变化很小;当液时空速(GHSV)在3000~8000h-1范围内增加时,总醇时空收率增加,但CO转化率降低,增塑剂醇质量分数变化不明显。当T=623K、p=5,5MPa,GHSV=6000h-时,随着合成气中H2体积分数的增加,总醇时空收率先升高后降低,增塑剂醇质量分数降低;V(H2)/V(CO)=1时,总醇时空收率最高为260.79g/(kg·h),增塑剂醇质量分数为28.79%关键词:增塑剂醇;合成气;CO加氢; Cu-Fe-Co基催化剂中图分类号:O643文献标识码:Adoi:10.3969/isn.1001-8719.2012.03019Study on the Synthesis of Plasticizer Alcohols From SyngasXIONG Lian, LUO Cairong", GUO Haijun"2,CHEN Xinde., CHEN Yong(I. Key Laboratory of Renewable Energy and Natural Gas Hydrate, Chinese Academy of Sciences, Guangzhou 510640, China:uangzhou Institute of Energy Comversion, Chinese Academy of Sciences, Guangzhou 510640, china;3. Guang zhou Branch of Chinese Academy of Sciences, Guangzhou 510640, ChiAbstract: A prepared CurFe-Co/ SiO, catalyst was characterized by TG-DTG, XRD and FE-SEMand used to catalyze the synthesis of plasticizer alcohols. The effects of different process conditionson synthesis of plasticizer alcohols from syngas were investigated, which were judged by the timeand space yield of total alcohols, the distributions of plasticizer alcohols and CO conversion. Theresults indicated that the three active components Cu, Fe and Co in the catalyst were disperseduniformly on SiO2 carrier. The Cu-Fe-Co/SiO2 catalyst exhibited a wealthy and strong porestructure,which was conductive to synthesis of plasticizer alcohols. With the reaction temperatureincreasing,the mass fraction of plasticizer alcohols decreased gradually, and the time and spaceyield of total alcohols followed a trend of firstly increasing and then decreasing. The time and spaceyield of total alcohols and Co conversion increased slowly and slightly with the increase of reactionpressure. Little effect of reaction pressure appeared on distributions of plasticizer alcohols. WithGHSV increasing from 3000 h- to 8000 h", the time and space yield of total alcohols increased buthe CO conversion decreased, and the mass fraction of plasticizer alcohols收福日期:2011-05-17中国煤化工基金项目:中国科学院可再生能源与天然气水合物重点实验室基金项目(y107CNMHG)资助第一作者:熊莲,女,助理研究员,从事有机发弃物高效利用、石油化工相关工艺的研究通讯联系人:陈新德,男.正高级工程卿,博士,从事有机废弃物高效利用、石油化工相关工艺的研究;Emal:cxd.cxd@hotmail.com第3期合成气制备增塑剂醇的初步研究471significantly. It was proved that the time and space yield of total alcohols firstly increased thendecreased with the increase of hydrogen volume fraction, while reaction temperature, pressure andGHSV were 623 K, 5. 5 MPa and 6000 h respectively, under which and the value of V(H,)/v(Co)was 1, the time and space yield of total alcohols could reach to highest value of 260. 79 g/(kg.h)aswell as the mass fraction of plasticizer alcohols was 28. 79%Key words: plasticizer alcohols; syngas; CO hydrogenation: Cu-Fe-Co-based catalystC5~C醇是合成增塑剂及其它多种精细化工产的工艺条件。品的重要原料口,称为增塑剂醇,目前主要以内烯1实验部分或丁烯为原料经羰基合成反应制得。随着石油资源日益枯竭,研究和开发增塑剂醇制备的新原料和新1.1原料与试剂工艺迫在眉睫。载体SiO2(Scr为350~450m2/g,30~100目合成气主要成分为CO和H2,由合成气一步法颗粒),工业级,南京合一化工有限公司产品;催化合成混合醇是国内外能源化工领域的研究热点,Cu(NO)2·3HO、Fe(NO)3·9HO、Co(NO)2·6H2O已经开发出多种相关的催化剂体系(24。但目前的研KNO,分析纯,天津大茂试剂有限公司产品;去究主要集中在合成气制备低碳混合醇方面,制备增离子水,自制塑剂醇的报道很少见。国内仅有焦桂萍等采用活1.2催化剂的制备性炭为载体制备了15%C0/AC1、15C0%/AC2和称取19gCu(NO4)2·3H2O、21.6gFe(NO3)3Co2La2Zr/AC催化剂,并考察了CO加氢反应制备9H2O、4.9gCo(NO3)2·6H2O、1.6gKNO3高碳混合醇的催化性能,但还没有具有产业化可行15g去离子水置于200mL烧杯中,完全溶解后加性的研究成果人20gSO2,室温下浸渍3~10h,经393K烘干增塑剂醇的合成涉及C—_O键解离吸附、C—O得到催化剂前躯体,于空气气氛673K焙烧4h,粉键非解离吸附、C—C键形成、碳链增长、水煤气碎过筛,取60~80目颗粒,即得 Cu-Fe-Co/SiO2催变换反应以及加氢反应等复杂过程,相对合成低碳化剂。醇来说,必须考虑各组分间的相互作用和协同效应1.3催化剂活性测试才能解决催化反应机理中的碳链增长问题,也因此在内径为8mm的不锈钢固定床反应器上进行合成增塑剂醇的催化剂应由多组分构成,包括主活CO加氢反应,用以考察Cu-FeCo/SiO2催化剂活性组分、载体或助剂。催化剂的主活性组分以其性。催化剂装填量4mL。反应前,催化剂在T=特有的化学性质对催化反应过程的活性和选择性起673K、p=1.5MPa、GHSV=2000h-1、H2气氛决定性的作用0。如Cu是合成甲醇的活性成分,中活化8h。降温至100℃以下,调节不同的反应温有利于CO的非解离吸附;Co或Fe组分有利于CO度、压力、GHsv及V(H2)/v(CO),进行连续反的解离吸附,促使单碳中间体CH-*的形成,使应。产物经冷阱气液分离,尾气每2h通过采样阀高活性状态的单碳中间体相互结合,形成C—C键,导入日本岛津GC20B-1气相色谱测定其组成(载气实现碳链增长;Co具有较优的碳链增长和抗积碳性为Ar,填充柱,TCD检测器)。反应结束后收集液能,但价格高,可少量添加;Fe储量丰富,价格低体,采用日本岛津GC2010型气相色谱测定其组成廉,也具有较优的碳链增长性能,可作为低成本主(毛细管色谱柱,FID检测器)。要活性组分。催化剂中的助剂可使活性组分分散均1.4催化剂的表征匀,减少烃类生成,提高醇的选择性,例如碱金属采用德国耐池 OMNISTAR的STA409C/PCK可作为催化剂助剂。载体起到分散作用,进一步 PFEIFFER VACUUM分析仪进行 TG-DTG分析,提高催化剂的催化性能在空V凵中国煤化工升温至950K,进为开发一条新型的合成气一步法制备增塑剂醇检CNMHGpert Pro型X射线工艺,笔者研制了 Cu-Fe-Co基催化剂,表征了催衍射仪对催化剂样品进行XRD表征,CuKa(A=剂的结构性能,并考察了CO加氢合成增塑剂醇0.15418mm)辐射,石墨单色器,室温,20为20-80,472石油学报(石油加工)第28卷扫描步长0.02°。采用日本 Hitachi公司S4800型场可能是由于催化剂中组分间较强的协同作用所致,发射扫描电镜对催化剂样品进行 FE-SEM扫描,工正是催化剂中的Cu、Fe、Co这3种金属物种的相作电压2.5kV,工作电流94A。互作用,促进了合成气向增塑剂醇的转化。2结果与讨论CuO·Fe2O3*Co2O42.1 Cu-Fe-Co/SiO2催化剂的表征结果2.1.1 TG-DTG分析图1为 Cu-Fe-Co/SiO2催化剂前躯体的DTG曲线。由图1可知,对应DTG曲线4个较为明显的峰形,TG曲线出现4个失重峰,依次对应于催化剂前躯体中Fe(NO3)3分解、Cu(NO3)2分解、Co(NO3)2分解和KNO3分解。由于KNO3无结20304050607080晶水且含量较低,因而780K的峰形较小,这与徐慧远等2的研究结果一致。由于KNO3主要起分散作图2加氢反应前后 Cu-Fe-Co/SO2催化剂的XRD谱用,分解后反而不利于其发挥作用,因此焙烧温度要Fig 2 XRD patterns of Cu-Fe-Co/ SiO catalysts before and低于780K并高于660K(Co(NO3)2完全分解的温after hydrogenation reaction(1)Before hydrogenation reaction; (2) After hydrogenation reaction度)。 Cu-Fe-Co/SiO2催化剂前躯体采用673K焙烧。2.1.3 FE-SEM分析图3为加氢反应前后 Cu-Fe-Co/SiO2催化剂不同放大倍数的 FE-SEM照片。由图3可见,加氢反应前后,Cu-FeCo/SiO2催化剂孔隙结构均比较明引|占显;加氢反应后催化剂表面分布一些白色点状物,400K可能是金属组分活化后产生的微晶,结合XRD表征结果可知,加氢反应前后催化剂发生了晶相变化。519K由图3还可见,加氢反应前 Cu-Fe-Co/SiO2催化剂的活性组分均匀分布在催化剂表面,内部有大量孔300400500600700800900TIK状结构,在加氢反应后仍然得到了较好的保持,未图1 CurFe-Co/SiO2催化剂前躯体的 TG-DTG曲线形成堵塞,说明催化剂的孔道结构比较牢固。Fg1 TG-DTG patterns of CurFe-Co/SiO2 catalyst precursor2.2 CuFe-Co/SiO2催化剂催化合成气制备增塑剂醇的工艺条件2.12XRD分析图2为加氢反应前后 Cu-Fe-Co/SiO2催化剂的2.2.1反应温度的影响表1为反应温度对 Cu-Fe-Co/SiO2催化合成气XRD谱。与标准图谱库比较可知,加氢反应前的Cu-Fe-Co/SO2催化剂XRD谱中,归属于aFe2O制备增塑剂醇反应的影响。由表1可见,随着反应的特征衍射峰峰形较为弥散,CuO特征衍射峰较温度升高,CO的转化率增加,总醇时空收率呈先强,CoO特征衍射峰较弱,表明 Cu-Fe-Co/SiO2升商后降低的趋势,在623K时达到最高;在53催化剂主要物相为aFe2O2和CuO,也存在少量623K范围内,吸附在催化剂表面的分子未达到足CoO;与cuO的标准衍射峰相比,衍射角位置向以完全进行反应的活化能,成磨反应受动力学控制,高角度方向发生了不同程度的偏移,这可能是由于升高反应温度利于反应正向进行;当反应温度高于几种金属组分间的相互作用引起的,这种相互作用623K时,由于CO加氢反应是放热反应,主要受也使Co、Fe组分更易均匀分布于载体表面,与徐热力学限制,反应平衡不利于正向进行,总醇时空杰等的结果类似。加氢反应后 Cu-Fe-Co/SO2催收率中国煤化工降趋势;可能是反化剂XRD谱中,显示出归属于Cu、Fe和CoO物应温CNMHG物种作用强度比Cu种的特征衍射峰,表明加氢反应过程中aFe2O3和物种低,成醇反应快而C—C/C=C键形成慢,导CuO被还原,而Co3O4的还原停留在CoO中间态,致碳链增长能力变差。第3期合成气制备增塑剂醇的初步研究473图3加反应前后 CuFeCo/SMO2催化剂不同放大倍的FSEM照片Fig 3 FE-SEM photos under different magnifications of CuFe-Co/SiO catalyst before and after hydrogenation reaction(a)Before hydrogenation reaction, 1000 times: (b) After hydrogenation reaction, 1000 times;(c)Before hydrogenation reaction, 5X10 times:(d) After hydrogenation reaction, 5X10 times褒1反应温度(T对 ClEcO/SMO2催化合成气制备增塑剂醇反应的影响Table 1 Effect of reaction temperature(T) on synthesis of plasticizer alcohols from syngas over CurFe-Co/SiO,Alcohol distribution, w/%T/Kx(CO)/%Y/(g·(kg·h)-1)C1-C421.3532.2963.1317.0510.699.010.060.0636.8771.9210.535.494.553.3432.8374.1310.395.153.902.732.041.6625.8780.42153.972.96152.0182.787.791.511.1587.435.791.851.0412.57653447.072.161.150.620.47Reaction conditions: GHSV=4000 h- P-5 5MPa: V(H2)/V(CO)=2.02.2.2反应压力的影响考虑总醇时空收率及增塑剂醇质量分数,反应压力表2为反应压力对 Cu-Fe-co/SO2催化合成气为5.5MPa时较利于增塑剂醇制备。制备增塑剂醇反应的影响。可以看出,增加反应压2.2.3液时空速的影响力,可以明显地提高总醇时空收率,而C5+醇质量表3为液时空速(GHSv)对 Cu-Fe-Co/SiO2催分数降低,CO转化率则总体呈现微弱升高趋势。合化合成气制备增塑剂醇反应的影响。由表3可见,成气制备合成增塑剂醇反应是体积减小的过程,随着GHsV增加,使反应平衡正向移动,促进产物增加反应压力增加,吉布斯自由能减小,反应平衡正向移并抑制副反应的发生,总醇时空收率增大;但GHSv动,且反应压力增加有利于 CurFe-Co/SO催化剂表增加缩短了催化剂与合成气的接触时间,使得CO转面吸附H2和CO,但CO吸附增长幅度比H2的小,化率降低;在两种因素相互作用下,GHsV变化对合因此总醇时空收率升高但C+醇质量分数减少。综合成气制备增塑剂醇质量分数影响较小。表2反应压力(p)对 CtFe-Co/SMO2催化合成气制备增塑剂醇反应的影响Table 2 Effect of reaction pressure( p) on synthesis of plasticizer alcohols from syngas over Cur-FeCo/SiOAlcohol distribution, w/%P/MPa r(CO)/% Y/(g(kg. h)-1)52.723.152.1621.12中国煤化工1.3620.1679152.017.793.34CNMHG1.081.226.553.96163.752.70YHS3.68Reaction conditions: GHSV=4000 h-I, T=623 K, V(H:)/V(CO)=2.0474石油学报(石油加工)第28卷表3液时空速(GHSⅤ)对cu-FeCo/SlO2催化合成气制备增塑剂醇反应的影响Table 3 Effect of GHSV on synthesis of plasticizer alcohols from syngas over CurFe-Co/Sio,GHSV/x(CO)/%Y/(g,(kg,h)-1)69.5278,1310.265.190.382.6121.873.341.1553.36159.6579.914,152.911.421.101.5780047.21216,1420.55Reaction conditions: T= Ki P=5. 5 MPa; V(H; )/V(CO)=2. 02.2.4V(H2)/V(CO)的影响v(H2)/V(CO)偏小时,CO占据大部分活性位点由表3可知,GHSV=6000h-时总醇的时空C—O/C—C键容易形成,CO转化率高且碳链增长收率以及C5+醇质量分数较高,后续实验以GHsV快;H2含量少则较难吸附到活性表面,易使解离6000h作为反应条件之一。表4为V(H2)/(CO)C-OCC中的碳覆盖在催化剂孔道结构上而导致对 Cu-Fe-Co/SiO2催化合成气制备增塑剂醇反应的积碳,降低催化剂活性;当合成气中V(H2)影响。由表4可见,随着V(H2)/v(CO从0.5增V(CO偏大时,H2占据较多活性位,加氢成醇较至2,总醇时空收率呈现先增长后降低的趋势,C3+容易,碳链增长困难,但催化剂不易积碳、活性稳醇质量分数及CO转化率呈递减趋势;当V(H2)/定。考虑到总醇时空收率以及C+醇质量分数,v(CO)=1时,总醇时空收率最高。当合成气中V(H2)/V(CO)=1为制备增塑剂醇较优的条件。表4v(H)/v(CO)对 Ce-Fe-Co/SiO催化合成气制备增塑剂醇反应的影响Table 4 Effect of V(H, )/v(CO)on synthesis of plasticizer alcohols from syngas over Cu-Fe-Co/SiO,V(H,)/Alcohol distribution, w/%x(CO)/%Y/(g.(kg.h)-1)Cr-Ce63.8115.836.643.402.439536.1912.125.81235.9675.0310.745.033.542.048.5172.7278.954.361.32Reaction conditions: GHSV-6000 h-Ii A=5. 5 MPa; T=623 K260.79g/(kg.h),C+醇质量分数达28.79%。3结论笔者认为,可以对本催化剂进行改进,以提高(1) Cu-Fe-Co/SiO2催化剂的活性中心分布时空收率和C3+醇选择性,如调整Cu、Fe、Co3种匀,孔道结构牢固,利于催化合成气制备增塑剂醇组分间的比例使组分分布合理,各级反应速率相匹的反应。配;调整催化剂制备方法使其具有更好的物性和结(2) Cu-Fe-Co/sO2催化剂用于增塑剂醇合成,构等。在T=623K、p=5.5MPa时,反应效果较好;随考文献GHsⅴ在3000~8000hˉ增加,总薛时空收率增大,CO转化率降低,增塑剂醇质量分数变化较小中国煤化立化江科技市场(3)T=623 K, p=5.5 MPa, GHSV=CN G Chem Tech market6000 h-, V(H,)V(CO)=1 af, Cu-Fe-Co/SiO催化合成气制备增塑剂醇反应的总醇时空收率达到[2]李德宝,马玉刚,齐会杰,等,CO加氢合成低碳混合第3期合成气制备增塑剂醇的初步研究醇催化体系研究新进展[J.化学进展,2004,16(4)alcohol synthesis[J]. Catal Rev, 1991, 33(1):109-168584-592.(LI Debao, MA Yugang, QI Huijie, et al. [8] MAHDAVI V, PEYROVI M H, ISLAMI M, et alProgress in synthesis of mixed alcohols from COSynthesis of higher alcohols from syngas overhydrogenation[J]. Prog Chem, 2004, 16(4): 584-592.)Cu-Co2O,/ZnO, Al2 O, catalyst [JJ. Appl Catal A:3]士丽敏,储伟,刘增超.合成气制低碳醇用催化剂的研General,2005,281:259265究进展[冂].化工进展,2011,30(1):162-165.(SH1[9] NGUYENT T, HOU A, SERGE K, CharacterizationLimin. CHU Wei. LIU Zengchao, Research progress ofand reactivity of nanoscale La(Co, Cu)O, perovskiteynthesis fromanalyst precursors for CO hydrogenation[J].J SolidChem Ind Eng Prog. 2011, 30(1): 162-165.)State Chem,2008,181:2006-2019[4]定明月,李凯,李宇萍,等,费托组元改性的低碳混合[10] ANIL K G, EDWIN L K, JEAN B C,eal. A kinetic醇催化剂研究进展[].化工进展,2010,29:142-147model for the synthesis of high-molecular-weight(DING Mingyue, LI Kai, LI Yuping, et al. Advance inalcohols over a sulfided Co-K-Mo/C catalyst [J]. Indmodified F-T synthesis catalyst for higher alcoholsEng Chem Res,1998,37(6):2107-2115synthesisLJJ. Chem Ind Eng Prog, 2010, 29, 142-147.) [11] KOUACHI K, LAFAYE G, ESPECEL C. et al. Effects「5]焦桂萍,丁云杰,朱何俊,等,活性炭负载钴基催化剂of support and metal loading on the characteristics of (上合成气制混合醇[J].催化学报,2009,30(8):825based catalysts for selective hydrogenation of citral[j]. J829.(JIAO Guiping, DING Yunjie, ZHU Hejun, et aLMol Catal A-Chem, 2008, 280. 52-60.Synthesis of linear mixed high alcohols from syngas over[12]徐黧远,储伟,周俊,CO加氢合成低碱醇用CuCo/ctivated carbon-supported Co-Based catalystsLJ]. Chin JSiO催化剂的反应性能研究[J].工业催化,2008,16Cata,2009,30(8):825-829.)(10): 105-109. (XU Huiyuan, CHU Wei, ZHOU Jun.[6]焦桂萍,丁云杰,朱何俊,等,还原温度对Co/1a/Zr/Catalytic behaviors of CuCo/SiO catalyst for hydrogenationAC催化剂合成气制高碳混合醇性能的影响[冂.催化学of Co to lower alcohols[J]. Ind Catal, 2008, 16(10):dR, 2009, 30(2):92-94. ( JIAO Guiping, DING105-109.)Yunjie, ZHU Hejun,et,al. Effect of the reduction[13]徐杰,杨贯羽,辛勤,等,合成醇用负载型铜基催化剂temperature of CorLa-Zr/AC on the synthesis of higher的表征[J].催化学报19(3):206-209.(XUalcohols from syngas[J]. Chin J Catal, 2009, 30(2).Jie, YANG Guanyu, XIN Qin, et al. Characterization of92-94.)supported copper based catalyst for synthesis of alcohols[7] FORZATTI P, TRONCONI E, PASQUON L. Higher[J]. Chin J Catal,1998,19(3);206209.)中国煤化工CNMHG