摘要
浆态床铁基中温费托(MTFT:260~290℃)合成技术首次在国内大规模工业应用,建成400万t/a煤炭间接液化装置,其核心单元费托(F-T)合成装置具有浆态床反应器系列多、规模大、配置复杂的特点,导致装置操作难度大,反应器之间、反应器和下游装置间相互影响、相互干扰较大,降低了系统运行稳定性。工业运行结果表明:MTFT合成中间产品结构发生显著变化。与设计值相比较,蜡减少105.88万t/a,而重油和轻油分别增加了53.16万t/a和27.82万t/a。与低温费托(LTFT)产物相比,MTFT合成中间产物具有α-烯烃质量分数高和C^+5收率高的优点,C^+5收率达到92.82%,且主要由α-烯烃和正构烷烃组成。轻油中α-烯烃质量分数达到66.34%,其中1-己烯占C6组分总量的62.47%,1-辛烯占C8组分总量70.43%;重油中α-烯烃和正构烷烃组成合计约89.63%,且随着碳数增加,α-烯烃质量分数降低。合成的蜡蒸馏出90%,达到720℃。MTFT合成(C^+22)的选择性较高,选择性达到59.79%,与LTFT合成蜡选择性相当,但烯烃质量分数高。经过加氢精制和加氢裂化处理,生产的MTFT合成柴油主要由链烷烃组成,具有较高的十六烷值(不小于60),是高品质的洁净燃料,但密度偏低,最高仅为780 kg/m^3,达不到车用柴油(GB 19147—2013)规定标准。MTFT石脑油不含环烷烃和芳烃,因此其辛烷值很低(小于50),不能作为汽油调和组分,但可以作为蒸汽裂解生产乙烯和丙烯的优质原料,乙烯的收率可到37.56%,丙烯收率20.16%,三烯总收率>61.82%。针对项目产品结构单一的局限,提出以生产柴油组分为主,联产α-烯烃、液体石蜡、F-T蜡、润滑油基础油等高附加值化工品的技术路线,并逐步实施,取得显著的经济效益。
The medium temperature Fischer-Tropsch(MTFT:260-275℃)synthesis process was first in a large-scale industrial application in China,and an industrial demonstration plant with a capacity of 4 million tons per year has been built.The core unit of the industrial demonstration plant is characterized by many series of synthesis reactors,a large scale and complex configuration,which causes many problems,such as the difficulty in the operation of the unit,the interaction between the reactors,and the interference between the reactors and downstream units,reducing the operation stability of the system.The industrial operation results show that the composition of the MTFT intermediates appears a significant change.Compared with the design value,the wax decreased by 1058800 t/a,while heavy oil and light oil increased by 531600 t/a and 278200 t/a,respectively.The MTFT products have the advantages of a higherα-olefin content and a higher C^+5 yield in comparison with the products from the low temperature Fischer-Tropsch(LTFT)synthesis.The yield of C^+5 with the main components ofα-olefin and n-alkane is 92.82%.The content ofα-olefin in the light oil is 66.34%.The 1-hexene account is 62.47%in the total content of C6,and the 1-octene account is 70.43%in the total content of C8.The composition ofα-olefin and n-alkane is about 89.63%in the MTFT heavy oil,in which the content ofα-olefin decreases with the increase of carbon number.The temperature at which 90%of the material is distilled from the synthesized wax is 700℃.The selectivity of C^+22 synthesized from the MTFT process is 59.79%,which is equivalent to that of the LTFT wax,but the olefin content is higher.After a hydrotreating and hydrocracking process for the MTFT intermediates,the MTFT diesel oil is mainly composed of alkanes,with high cetane number(≥60).It is a high-quality clean fuel,but its density is low with the highest value of 780 kg/m^3,which does not meet the standard of vehicle diesel oil(GB 19147—2013).The octane number of the MTFT naphtha without cycloalkanes and aromatics is very low(less than 50).It cannot be used as a blending component to producing gasoline,but it is a high-quality raw material for the production of ethylene and propylene by a steam cracking process.The yield of ethylene can reach 37.56%,the yield of propylene is 20.16%,and the total yield of ethylene,propylene and 1,3-butadiene is more than 61.82%.In terms of the limitation of the single product structure of the project,a technical route of CO-production of the diesel oil as a main product and high value-added chemicals such asα-olefin,liquid paraffin,F-T wax,lubricating oil base oil and so on is proposed and gradually implemented in practice.The significant economic benefits have been achieved.
作者
王峰
郭中山
王铁峰
WANG Feng;GUO Zhongshan;WANG Tiefeng(Ningxia Coal Industry Co.Ltd.,China Energy Group,Yinchuan 750411,China;Department of Chemical Engineering,Tsinghua University,Beijing 100084,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2020年第4期1267-1274,共8页
Journal of China Coal Society
基金
国家重点研发计划资助项目(2017YFB0602500)
宁夏回族自治区重点研发计划资助项目(2019BFH02016)。
关键词
中温费托合成
Α-烯烃
费托柴油
浆态床反应器
medium temperature Fischer-Tropsch
α-olefin
Fischer-Tropsch diesel
slurry bed reactor
