Supplementary Information

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1 Supplementary Information When Magnetic Catalyst meets Magnetic Reactor: Etherification of FCC Light Gasoline as an Example Meng Cheng, 1 Wenhua Xie, 1 Baoning Zong, 1* Bo Sun 2 and Minghua Qiao 2* 1 State Key Laboratory of Catalytic Materials and Reaction Engineering, Research Institute of Petroleum Processing, Beijing , China. 2 Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai , China 1. Schematic Illustrations of the Commercial FCC Light Gasoline Etherification Process and the New Process Based on MSB Reactors The Photo of the Laboratory-Made MSB Reactor Preparation and Undecylenic Acid-Modification of Magnetite Nanoparticles Preparation of Poly(Styrene Divinylbenzene) Resin Embedded with Magnetite Nanoparticles Preparation of Sulphonated Poly(Styrene Divinylbenzene) Resin Embedded with Magnetite Nanoparticles Characterization Techniques and Results Analysis of FCC Light Gasoline and Etherified Products

2 1. Schematic Illustrations of the Commercial FCC Light Gasoline Etherification Process and the New Process Based on MSB Reactors Figure S1 a) A typical flow diagram of the commercial FCC light gasoline etherification process. (1) Distillation column; (2) Caustic washing tower (to remove thiols to avoid the deactivation of the noble metal catalyst for diolefin hydrogenation); (3) Water washing tower (to remove metal cations and basic compounds to avoid their adsorption on the acid resin catalyst); (4) Diolefin selective hydrogenation reactor (to avoid the formation of gums plugging the acid resin catalyst); (5) Pre-reactor; (6) Distillation column; (7) Side-stream reactor. b) An illustration of the flow diagram of the FCC light gasoline etherification process based on two MSB reactors. (1) Distillation column; (2) MSB reactor for FCC light gasoline etherification; (3) MSB reactor for catalyst recovery and supplement. 1

3 2. The Photo of the Laboratory-Made MSB Reactor Figure S2 A photograph of the laboratory-scale MSB reactor. 3. Preparation and Undecylenic Acid-Modification of Magnetite Nanoparticles The magnetite nanoparticles (MNPs) were prepared via coprecipitation of Fe(II) and Fe(III) ions in a basic solution derived from Massart s method. S1 In a mechanically stirred 2 L three-necked flask, the FeCl 2 solution was mixed with the FeCl 3 solution to achieve an Fe(II)/Fe(III) molar ratio of 0.75 and a total Fe concentration of 0.3 M. The ph of the mixed solution was then adjusted to by adding a 0.4 M NaOH solution. The resulting black precipitates were aged in the mother liquor at 323 K for 1.0 h. Then, undecylenic acid (UDA) was added to the flask and held at 323 K for 0.5 h, with the UDA/Fe(III) molar ratio of The ph of the mixture was decreased to 4 5 by adding a 0.4 M HCl solution, and the temperature was elevated to 353 K and held for 1 h. After being cooled down to room temperature, the UDA-modified MNPs (UDA-MNPs) were separated, washed with distilled water and absolute ethanol several times, and dried at 323 K for 12 h. 2

4 4. Preparation of Poly(Styrene Divinylbenzene) Resin Embedded with Magnetite Nanoparticles The magnetic resin was prepared by a two-step suspension polymerization approach. First, styrene, divinylbenzene, and heptane with the weight ratio of 3.0: 1.0: 3.6 were pre-polymerized on the UDA-MNPs in a 1 L three-necked flask at 353 K, using benzoyl peroxide as the initiator. Second, when the mixture became viscous, the dispersing agent, an aqueous solution containing 5 wt% of gelatine, 5 wt% of NaCl, and 0.1 wt% of polyacrylamide, was added to the flask. The volume of the dispersing agent was five times of the total volume of styrene and divinylbenzene. The mixture was held at 353 K for 2 h, raised to 358 K and held for 2 h, and finally aged at 363 K for 6 h. Vigorous mechanical stirring was executed during the whole preparation. After being cooled down to room temperature, the solids were separated, washed with distilled water and absolute ethanol several times, and dried at 353 K for 6 h. The as-synthesized magnetic resin, with the structure of poly(styrene divinylbenzene) resin embedded with MNPs, is termed as M-PSD. The nominal weight ratio of the MNPs was 20%. 5. Preparation of Sulphonated Poly(Styrene Divinylbenzene) Resin Embedded with Magnetite Nanoparticles Twenty grams of the M-PSD magnetic resin were loaded into a 250 ml three-necked flask equipped with a mechanical stirrer, a reflux condenser, and a thermometer. After the addition of 100 ml of sulfuric acid (98 wt%), the flask was heated to 393 K for 8 h. After cooling down to room temperature, the solids were separated from the sulfuric acid by applying an external magnetic field, and washed with 500 ml of 45 wt%, 30 wt%, and 10 wt% of sulfuric acid sequentially. Then, the solids were washed with a large amount of distilled water to ensure the thorough removal of sulfuric acid, and dried at 333 K overnight. The as-prepared magnetic acid resin, with the structure of sulphonated PSD embedded with MNPs, is termed as MS-PSD. 3

5 6. Characterization Techniques and Results The Brunauer Emmett Teller (BET) surface area (S BET ) and porosity were acquired by N 2 physisorption at 77 K on a Micromeritics 2010 apparatus. Prior to the measurements, the acid resin catalyst was outgassed at 343 K for 8 h. The acid capacity was determined by the method described as follows. First, 50 ml of the MS-PSD acid resin catalyst was placed in the ion-exchange column and washed successively with 50 ml of 1.0 M NaOH solution, distilled water, 1.25 L of 1.0 M HCl solution, and distilled water. Each water washing was ended at ph = 7. The flow rates of NaOH, HCl, and water were about , 6, and 10 ml min 1, respectively. Then, 1.5 g of the acid resin catalyst dried at 323 K was immersed in 100 ml of 0.1 M NaOH solution for 4 h. Twenty five ml of the resulting NaOH solution was pipetted and titrated by 0.1 M HCl solution. The methyl red-methylene blue solution was used as the indicator. Table S1 A comparison of the physicochemical properties between the as-synthesized MS-PSD acid resin and typical commercial acid resin. Acid resin S BET (m 2 g 1 ) V pore (ml g 1 ) Acidity (mmol g 1 ) MS-PSD S-PSD a Amberlyst 15 b a This acid resin is synthesized in the same way as that of MS-PSD but in the absence of the MNPs. b Cited from Ref. S2. Powder X-ray diffraction (XRD) patterns were recorded on a Philips X Pert Pro powder X-ray diffractometer using Cu Kα radiation (λ = nm). The tube voltage was 40 kv, the current was 30 ma, and the scan speed was 4 min 1. 4

6 (311) Intensity UDA-MNPs (220) (400) (422) (511) (440) M-PSD MS-PSD θ / degree Figure S3 XRD patterns of UDA-MNPs, M-PSD, and the MS-PSD acid resin catalyst. The reflections labeled on the figure correspond to magnetite (JCPDS ). Thermogravimetric analysis (TGA) was performed on a TA Modulated DSC2910 instrument under an ultrahigh purity N 2 atmosphere with a heating rate of 10 K min Weight Percentage / % M-PSD MS-PSD Temperature / K Figure S4 TGA curves of M-PSD and the MS-PSD acid resin catalyst. 5

7 7. Analysis of FCC Light Gasoline and Etherified Products The compositions of FCC light gasoline and the etherified products were analyzed on an Agilent 7890 gas chromatograph equipped with a flame ionization detector (FID) and a PONA capillary column and an SE-54 capillary column (50 m 0.2 mm 0.5 μm for both columns). During analysis, the temperature of the columns were kept at 308 K for 15 min, and then raised to 453 K at a ramping rate of 2 K min 1. The temperatures of the FID and the sample injector were kept at 553 and 523 K, respectively. The flow rate of the He carrier gas was 0.4 ml min 1. The sample was analyzed on these two columns individually, and the compositions obtained from both columns were integrated to derive the final composition of the sample. This method is specific for the analysis of gasoline with oxygen-containing compounds. In the present FCC light gasoline sample, it is identified that there are two C 5 tertiary olefins (2-methyl-1-butene and 2-methyl-2-butene) and five C 6 tertiary olefins (2,3-dimethyl-1-butene, 2-methyl-1-pentene, 2-methyl-2-pentene, trans-3-methyl-2-pentene, and 1-methyl cyclopentene) that are reactive for etherification. Etherification of 2-methyl-1-butene and 2-methyl-2-butene with methanol only leads to one product, 2-methylbutyl methyl ether (2-methoxy-2-methylbutane, TAME). The etherification product of 2,3-dimethyl-1-butene is 2,3-dimethylbutyl methyl ether (2,3-dimethyl-2-methoxybutane). Etherification of 2-methyl-1-pentene and 2-methyl-2-pentene also only leads to one product, 2-methylamyl methyl ether (2-methoxy-2-methylpentane). The etherification product of trans-3-methyl-2-pentene is 3-methylamyl methyl ether (3-methoxy-3-methylpentane). Etherification of 1-methyl cyclopentene results in 1-methylcyclopentyl methyl ether (1-methoxy-1-methylcyclopentane). 2,3-Dimethylbutyl methyl ether, 2-methylamyl methyl ether, 3-methylamyl methyl ether, and 1-methylcyclopentyl methyl ether from C 6 tertiary olefins are known as THxMEs. Table S2 Composition of FCC light gasoline. Hydrocarbon Comp. (wt%) Hydrocarbon Comp. (wt%) Iso-butene trans-3-methyl-2-pentene butene methylcyclopentane

8 butane ,4-dimethylpentane trans-2-butene methyl-1,3-pentadiene cis-2-butene ,3,3-trimethyl-1-butene methyl-1-butene methyl-1,3-cyclopentadiene Iso-pentane ,3-cyclohexadiene pentene ,4-dimethyl-1-pentene methyl-1-butene ,3-dimethyl-1,4-pentadiene pentane ,4-dimethyl-1-pentene trans-2-pentene methyl cyclopentene cis-2-pentene benzene methyl-2-butene ,3-dimethylpentane ,3-pentadiene methyl-1-hexene ,3-cyclopentadiene cyclohexane cyclopentene trans-2-methyl-3-hexene methyl-1-pentene ,3-dimethyl-1,4-pentadiene methyl-1-pentene methyl-1-hexene ,3-dimethyl butane methylhexane + trans-5-methyl-2-hexene ,3-dimethyl-1-butene ,3-dimethylpentane methylpentane methylhexane trans-4-methyl-2-pentene cis-1,3-dimethylcyclopentane methylpentane methyl-4-pentene trans-1,3-dimethylcyclopentane trans-1,2-dimethylcyclopentane hexane heptane trans-3-hexene cis-3-heptene cis-3-hexene trans-3-methyl-3-hexene

9 trans-2-hexene ,4,4-trimethyl-1-pentene methyl-2-pentene cis-1,2-dimethylcyclopentane methyl cyclopentene methylcyclohexane ,4-dimethyl-4-pentene cis-2-hexene methylbenzene + 2,3,3-trimethylpentane Table S3 Composition of the etherified FCC light gasoline on the MSB reactor and on the fixed-bed reactor. a Comp. (wt%) MSB reactor Fixed-bed reactor 2-methyl-1-butene methyl-2-butene ,3-Dimethyl-1-butene methyl-1-pentene methyl-2-pentene trans-3-methyl-2-pentene methylcyclopentene TAME ,3-dimethylbutyl methyl ether methylamyl methyl ether methylamyl methyl ether methylcyclopentyl methyl ether other hydrocarbons a Reaction conditions: temperature of 353 K, pressure of 0.7 MPa, LHSV of 0.5 h 1 on the fixed-bed reactor, and 1.0 h 1 on the MSB reactor. The magnetic field strength of the MSB reactor is 30.0 ka m 1. 8

10 THxMEs Yield (wt %) THxMEs Yield (wt %) Fixed Bed MSB MeOH/Tertiary Olefin (mol/mol) Pressure (MPa) Fixed Bed MSB THxMEs Yield (wt %) THxMEs Yield (wt %) Fixed Bed MSB Temperature (K) LHSV (h -1 ) Fixed Bed MSB Figure S5 Comparison between the catalytic performances of the MS-PSD acid resin catalyst on the fixed-bed reactor and on the MSB reactor in the etherification of C 6 tertiary olefins in FCC light gasoline. (Top left) Effect of the feed ratio on the yield of THxMEs. Other reaction conditions: temperature of 353 K, pressure of 0.7 MPa, and LHSV of 1.0 h 1. (Top right) Effect of the reaction temperature on the yield of THxMEs. Other reaction conditions: pressure of 0.7 MPa, MeOH/tertiary olefin ratio of 1.4, and LHSV of 1.0 h 1. (Bottom left) Effect of the system pressure on the yield of THxMEs. Other reaction conditions: temperature of 353 K, MeOH/tertiary olefin ratio of 1.4, and LHSV of 1.0 h 1. (Bottom right) Effect of the LHSV on the yield of THxMEs. Other reaction conditions: temperature of 353 K, pressure of 0.7 MPa, MeOH/tertiary olefin ratio of 1.4, and LHSV of 1.0 h 1. The magnetic field strength is 30 ka m 1 for the MSB reactor. References S1 Massart, R. Preparation of aqueous magnetic liquids in alkaline and acidic media. IEEE Trans. Magn. 17, (1981). S2 Girolamo, M. D. et al. Liquid-phase etherification/dimerization of isobutene over sulfonic acid resins. Ind. Eng. Chem. Res. 36, (1997). 9