Commercial Test of Flexible Dual-Riser Catalytic Cracking Process

Advances in Refining TechnologyCommercial Test of Flexible Dual-RiserCatalytic Cracking ProcessTang Haitao'; Wang Longyan'; Wang Guoliang'; Zhang Lixin'Wei Jialu2; Chen Zhenghong; Teng Tiancan'; Sun Zhonghang'(I.Luoyang Petrochemical Enginnering Company of SINOPEC,Luoyang,4710032.Qingjiang Petrochemical Company' of SINOPEC)Abstract:The technical features and commercial test results of flexible dual-riser f1uidived catalytic cracking(FDFCC) process are presented for refiners to choose an efficient process to upgrade FCC naphtha and boostpropylene production in a RFCC unit. The commercial Lest resuls indicatce that the olefin content of catalyi-cally cracked gasoline can be sigmificanly reduced to lcss than 20 vV%, while sulfur content reduced by 15%6625% and RON incrcased by 0.5- 2 units in a RFCC unit. In addition. propylene yield and the production ratioof dicscl to gasoline can also be remarkably enhanced in the RFCC unit,key words: RFCC; dual-riser: commercial test下年2 A1 Introductionupgrade naphtha in scparatc riscr reactors under differentopcration conditions. I nol only eficintly upgrades naphtha.Flexible dual-riser catalytic cracking (FDFCC) process devel- but also makes operation in residue riser reactor more efctive.oped by Luoyang Petrochemical Engineering Companyadopts dual-riser technology to process low grade residueThere are two options for upgrading naphtha in FDFCC. Inand upgrade naphtha in separate riser reactors and under Option A, a second fractionator is sct up at the outlet ofdifferent operation conditions. Commercial test of this pro-naphtha upgrading rcactor and upgraded naphtha directlycess in Qingjiang Petrochemical Company passed technical cntcrs the absorption/stabilization system, eliminating mix-appraisal organized by R&D department of SINOPEC. It ising and recycling of upgraded naphtha with to-be -upgradedconcluded by thc appraisal that as compared with conven-naphtha and greatly enhancing the efficiency of naphthational FCC process FDFCC can reduce olefin content of gaso-upgrading. The operation of the main fractionator of RFCC isline by more than 20 v%. sulfur content by 15%- 25% andnot affected. In Option B, naphtha upgrading reactor andincrease RON and MON by 0.5- 2 units each in a RFCC unit.residue riser reactor share the same fractionator. UpgradedThe production ratio of diesel to gasoline can be remarkablynaphtha is scent back to the main fractionator to be mixed withenbanced and propylene yield can be increased by 3%- 6 %.to-be-upgraded naphtha. One part of the mixed naphtha en-Commercial application of FDFCC is strongly recommended.ters the adsorption/stabilization system and the other partenters naphtha upgrading reactor for recyeled upgrading. TheCommercial test of FDFCC process was conducted byflow diagrams of these two options arc shown below.Luoyang Petrochemical Engineering Company and QingjiangPetrochemical Company in a 120 kta dual-riser RFCC unit toThe 120 kt/a dual-riser FCC unit in Qingjiang Petrochemicalverify pilot test results and accumulate commercial operationc ompany is designed by Luoyang Petrochemical Engineer-experience.ing Company. Residue riser reactor and naphtha upgradingriser reactor have separate disengagers, but share common2 Technical Features and Commercialstripper, regenerator and fractionator.Test Plan中国煤化工DuringYHC N M H Gochemical CompanyFDFCC adopts dual-riser to process low. grade residue andOption A was simulated with two risers and two firactionators.29China Petroleum Processing and Petrochemical TechnologyNo. l, March 20033 FDFCC Feed and CatalystThe 120 kta dual-riser FCC unit used 75%i atmospheric resi-言due of Subei Oil Field and 25%、acuum residue of Subei Oil当Field as feed for residue riser reactor. Ihe 500 kta RFCC unitused 60% Subei almospheric residue and 40%。Subei gasoilas feed. The catalyst for commercial test was comnmercial mixedcquilibrium catalyst of maximum diesel yicld type LRC-99 andResidue .MLC-500.The properties of feed oil and calalyst are listed inTable 1 and Table 2.Option 4: FDFCC process with dual riser,4 Commercial Test Resultsdual fractionuator4.1 Option A (dual riser, dual fractionator)Product distribution of naphtha upgrading and properties凰before and after upgrading for simulated Option A commer-cial test are listed in Tablc 3 and fable 4 respectively.百RFCC producl distribution and its performance for Option Aarc listed in Table 5. Upgrading percentagc refers to the ratioTable I Properties of feed oil for commercial testRcsuduc[temOption A .Option BOption B: FDFCC process with dual riser,| Residue feedsingle fractionatorDensity( 20cC).kg/m?90029193Figure I The f!owv diagrams of theseViscosiy(100ocC),mm'/s10.7424.571v0 optionsSulfur,ug/g32063128Carbon residue, %3.527.05Outsourced naphtha frum 500 kt/a RFCC unit was Laken asSaturated hydrocarbon. %60.750.2the fccl for naphtha upgrading riser reactor. Then 0)ption BAromatic hydrocarbon, %22.428.2was lested by using naphtha from the 120 kU/a dual-riser FCCResin & asphaltene, %16.921.6unit itself as the feed for naphtha upgrading riser reactor. Theperformance of naphtha upgrading riser reactor was exam-Table 2 Properties of equilibrium catalyst forined and its impact on FCC product ditribution and qualitycommercial testwas studicd .Option A.Option BSpecific surface area, m/g107.7116.6In the process of comnercial test and calibration. in additionPore volume, mUg0.1310.152to metering and sampling analysis of conventional FCCprocess. a special ditillatle sanpling device was installed atApparent density, g/ml0.83the outlet of naphtha upgrading riser reactor for periodic sam-Ni, mg/g87659347pling and analysis. The composition and properties of gasV.mg中国煤化工0.10600and liquid products of naphtha upgrading can be directlyCarbonMicrorYHCNMHG63.0monitored.30Advances in Refining TechnologyTable 3 Product distribution of naphtha upgrad- percentage. the cracking severity of naphtha and gas yielding for Option A%increase quickly and naphtha upgrading becomes moreeffective.Reaction temperature, °C 450500 550600Catalyst oil ratio729.4 13.517.6Therefore, in order to reduce olefin content to produce clean|Dry gas3.253.90 5.426.78gasoline a milder operation at reaction temperature 450 °C-| LPG11.89 .13.96 L 19.73 28.57500 °C is recommended. In order to significantly increaseGasoline78.89 74.95 66.85 53.10diesel-to-gasoline ratio and propylene yield at the same timeDiesel fuel。3.584.65 I 5.168.48Coke2.172272.642.86of producing clean gasoline, a severe operation at reactiontempcralure 550 °C to 600 °C is recommended.Loss.220.27 0.20021Total100.00 100.00 100.00 100.004.2 Option B (dual riser, single fractionator)in which Propylene6.107.16 10.1214.65In Option B comercial test. naphtha from residue riser reac-Table 4 Properties of naphtha before and aftertor of 120 ku/a RFCC unit iself was used as feed forupgrading for Option Anaphtha upgrading riser reactor and the impact ofnaphtha upgrading under various operation condi-temRFCC naphthaUpgraded gasolinetions on RFCC product distribution and propertiesReaction temperature,°C500550was studied. RFCC product distribution and perfor-9.13.5mance are listed in Tablc 6. The properties ofRFCCDensity( 20oC). kg/m’708.47193| 728.9 737.2naphtha and mixcd naphtha afier upgrading are listedSulfur, ug/g .380311300286in Table 7.Olefin, v%44.517313.7Aromatics, v%13.827930.0Option B commercial test results listed in Tablc 6 andSaturates, v%41.754.8“56.356.0Table 7 indicate that with a higher upgrading percenl-RON90.691.892.792.9age the cracking severity of naphtha becomes higherMON80.981.6| 82.082.3and diesel-lo _gasolinec ratio and propylene yield in-Table 5 RFCC product distribution for OptionA %crease significantly. Al an upgrading percent-age of 50%, clean gasoline with olefin con-Residue riser temperature, °C505tent lower than 35 v% can be directly pro-Naphtha riser temperature,°Cduced with the dual-riser, singlc fractionatorUpgrading percentage, %50100FDFCC process.Dry gas3.754.595.435.216.67LPG17.72 20.73 23.73 23.8730.015 Commercial Application of43.0237.64 32.24 32.9222.84 |FDFCC ProcessDiesel fuel24.4825.48 26.49「 26.318.13Oil slurry1.31131Commercial test in Qingjiang Petrochemical9.22 .9.7010.19 9.8310.45 |Company provides useful infornation to0.500.550.610.59reach the goal of producing clean gasoline100.00 100.00 100.00 | 100.00 100.00with olefin content lower than 35 v%. At out-in which propylene6.818.359.899.96tha upgrading riser re-中国煤化工ouprded naphaof upgradcd naphtha flowrale lo naphtha stream flowrate en- is 75TYH.CNMHGeratioofcapacityoftering the main fractionator. With a higher upgrading naphtha upgrading riser reactor to the capacity of residue31China Petroleum Procssing and Petrochemical TechnologyNo.l, March 2003Table 6 RFCC product distribution for Option Briser reactor Y(%) is| Residue riser temperature,。C5001. Option ANaphtha riser temperature,。C450600Y(%)= Y X(X-35)/(X-20)Upgrading percentage, %50Dry gas3.234.604.805.585.992. Option B| LPG14.5619.50| 20.25| 22.65 26.17Y(%) - Y,X(X-35)15Gasoline37.4928.7027.10 23.38 18.28in which: Yq gasoline yield of residue riser| Diesel oil34.8836.4036.917.31 38.38reactor. %Coke9.4210.3010.41 10.54 10.61X olefin content of gasolinc frum| Loss0.420.500.53 0.54 0.57residue riser reactor. v%Total100.00| 100.00| 100.00 100.00 | 100.00| Prolylene6.128.809.2010.50 12.12| Diesel-to gasoline ratio0.931271.36| 1.602.10Design capacity of naphtha upgrading riserreactor for typical RFCC unit producingclcan gasoline with olefin content lower than 35 v% withTable 7 Properties of RFCC naphtha andOption A and Option B FDFCC process is shown inmixed naphtha after upgrading for Option BTable 8.ltemRFCC naphtha_ Mixed naphthaReaction temperature. °C450 I 500] 550As shown in Table 8. with increasing nuphtha yield andCatalyst-oil-ratio7.0 9.213.1olefin content from residue riser reactor the capacity of5(nuphtha upgrading riser reactor should be greatcr. InDensity( 20ocC),kgm'715.4718.6 721.4 726.1Option B with dual riser and single fractionator, someSulfur, v%542504| 485 487upgraded naphtha is mixed with to-be-upgraded naph-Olefin, v%50.332.8 31.7。33.4 tha and reyeled for upgrading. a greater capacity ofAromatics, v%23.228.0 28.6| 28.8naphtha upgrading riser reactor is required.Saturated HC, v%392| 39.7| 37.8RON90.891.091.2 913 ] 6 ConclusionsTable 8 Design capacity of naphtha riser reactor inAccording to the commercial test results inFDFCC processQingjjang Petrochemical Company. the fllowingItemResidue reactor naphthaNaphtha reactor capacity to conclusions are reached.residue reactor capacityYield,Y.I Olefin, x. v%Y,%(1) Dual-riser technology in FDFCC process fllyProcess flowOption AOption Butilizes the combustion heat of coke generatcd in40103RFCC unit and the naphtha thus produccd canl527be upgraded with a high selectivity in a different20reaction zone. FDFCC is featured by reasonable2353process flow design. smooth and flexible2557opcration.151145l830(2) In FDFCC process upgrading of naphtha canX0中国煤化工aphtha riser reactor.552660|YHC N M H Gditios, olefin con-2875tent can be reduced by more than 30 v%. sulfur32Advanccs in Refining Technologycontent reduced by 15%025%, and RON increased by 1-2 (4) Option A (dual riser, dual fractionator) of FDFCC pro-unit.cess avoids recycled upgrading of upgraded naphtha, therebymaking upgrading more efficient and decreasing the size of(3) With a higher reaction intensity and upgrading percent- naphtha riser reactor. At a capacity of naphtha riser reactorage in FDFCC process, diesel-lo-gasoline ratio and propy- that meets the requirement of producing clean gasoline withlene yield in RFCC can be signifcantly increased. Dicsel-to- olefin content lower than 35 v%, either Option A (dual riser,gasoline ratio is generally increased by 0.2 -0.7, and propy- dual fractionator) or Option B (dual riser. single fractionator)lene yield increased by 3%- 6%.can directly produce clean gasoline at RFCC unit.PTA Plant to Be Built in ShaoxingA 500kia purificd PTA plant will be built by Sanxin ('hemical be 4207million RMB.Company recently in Shaoxing. Zhejiang. The project is 10- PTA is the main raw material for polyester production, andcated in the coastal industrial park of Shaoxing wih total Shaoxing is one of the largest polyester consumers in China.investment of2.46 billion RMB. The technology package and A large scale PTA plant in Shaoxing will reduce the cost ofbasic design are imported and project design is made by the local polyester and its downstream products. adjust industryChina Textile Industry Design Institute and others. The plant chain structure and lay the foundation of speedy growth ofis expected to be built and put into production in 2004. Al textile industry in Shaoxing by integrating the whole busi-that time sales revenue will be 2.24 bllion RMB and profit will ncss chain.Expansion of Ethyl Acetate Plant inShandongExpansion of ethyl acetatc plant ofGold Yimeng GroupLtd, in tion capacity of ethyl acetate developed by the group in 1995Shandong has been started. which is the largest ethyl acctate was only 5000tia. Afterwards new technology was devel-production base in Asia 10 be built in Shandong.oped in cooperation with Tsinghua University and produc-tion capacity was increased 1<0 80kt/a. Its quality product has(iold Yimeng Group is a large-scale private cnterprise group been sold on the world market. The expansion project will bemainly engaged in fine chemicals production, and pharma- completed and put into production in June 2003 with capac-ceutical chemicals, electronic materials as well. The produc- ity increascd to 200kt/a.Cyclopentane Project Passed AppraisalThe cyclopentane prajcct undertaken by the Research Insti-using rectification tcchnology. Foamed polyurethane withtute of Chemical Industry. SINOPEC has passed thc tcchni- cyclopentane has cxcellent free density, thermal conductiv-cal appraisal organized by the R&D Division of SINOPEC. ity and compressive strength. A unique foaming formulationCyclopcntane is one of the components of C; fraction after and technology have been developed. The separation pro-hydrogenation. Separation and utilization of cyclopentane cess developed by the research institule is simple and rea-has important significance. Cyclopentane is the second-gen- sonable and the sinulation caleulation can be used for scalc-eration foaming agent t replace chlorofluorocarbons. which up. Its application will creale the condition for implementinghas the advantage of zcro ozone consumption.the Md中国煤化工consuming materialsin Chirch achievements areThe cyclopentane project is to oblain high purity (>98%) said twYHCNMH Gina.cyclopentane from hydrognenated cracking C。fraction by3.