PIM-1/graphene pervaporation membranes for bioalcohol recovery

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1 Engineering Conferences International ECI Digital Archives Advanced Membrane Technology VII Proceedings /graphene pervaporation membranes for bioalcohol recovery Patricia Gorgojo University of Manchester, Monica Alberto University of Manchester Jose Miguel Luque-Alled University of Manchester Lei Gao University of Manchester Maria Illut University of Manchester See next page for additional authors Follow this and additional works at: Recommended Citation Patricia Gorgojo, Monica Alberto, Jose Miguel Luque-Alled, Lei Gao, Maria Illut, Aravind Vijayaraghavan, and Peter Budd, "/ graphene pervaporation membranes for bioalcohol recovery" in "Advanced Membrane Technology VII", Isabel C. Escobar, Professor, University of Kentucky, USA Jamie Hestekin, Associate Professor, University of Arkansas, USA Eds, ECI Symposium Series, (216). This Abstract and Presentation is brought to you for free and open access by the Proceedings at ECI Digital Archives. It has been accepted for inclusion in Advanced Membrane Technology VII by an authorized administrator of ECI Digital Archives. For more information, please contact

2 Authors Patricia Gorgojo, Monica Alberto, Jose Miguel Luque-Alled, Lei Gao, Maria Illut, Aravind Vijayaraghavan, and Peter Budd This abstract and presentation is available at ECI Digital Archives:

3 Advanced Membrane Technology VII September Cork, Ireland /graphene pervaporation membranes for bioalcohol recovery Monica Alberto, Jose Miguel Luque-Alled, Lei Gao, Maria Iliut, Aravind Vijayaraghavan, Peter M. Budd, Patricia Gorgojo School of Chemical Engineering and Analytical Science National Graphene Institute The University of Manchester

4 Energy consumption (Quadrillion Btu) Motivation: energy sector and transportation 3 25 History Projections Liquid fuels Coal Renewables Nuclear Natural gas Source: EIA, International Energy Outlook, May 216 Source: EIA, MER, March 216 The demand for energy requirement is increasingly growing. It is difficult to reach the world energy demand only by using fossil fuel Alternative: BIOFUELS 2

5 Biofuels: definition and facts A biofuel is any fuel source that is made from biological materials. The two most common kinds of biofuels are both gasoline alternatives: ethanol and biodiesel. A Volkswagen Golf model that uses E1 blended bioethanol The Ferrari F43 Spider Bio Fuel Concept car runs on E85 biofuel The Saab BioPower runs on E85 which has higher octane rating than petrol Reduces greenhouse gas emissions as the release of CO 2 from burning the biofuels is matched by the CO 2 absorbed by the plants growing the biomass used to produce it Using so-called second-generation technologies to convert material such as crop residues into bioenergy can avoid competition for land 3

6 Biofuels: how can membrane technology help? Bioethanol and biobutanol are produced via ferementation of biomass. Biomass (cellulose, hemicellulose, lignin) Pre-treatment/ Enzymatic hydrolysis Removal of Lignin Sugar monomers Fermentation Solvent recovery Bioalcohol <.5% water End-product inhibition is caused by the toxicity of the alcohol produced on the bacteria. A concentration of less than 2% of bioalcohol (ABE fermentation process for biobutanol production) is typically achieved. The bioalcohol needs to be purified from the fermentation broth (contains mainly water) by a series of distillation columns 6-8% of the total production costs. Step 1: Removal of alcohol form fermentation broth Organophilic membranes Step 2: Further purification of alcohol Hydrophilic membranes 4

7 Organophilic pervaporation membranes Vapour permeate Liquid feed Water Alcohol Inorganic membranes, zeolites: silicalite-1, ZSM-5 Polymeric membranes, polydimethylsiloxane (PDMS), poly[1-(trimethylsilyl)-1-propyne] (PTMSP), PEBA, PTFE Hybrid membranes, polymer matrices containing selective fillers e.g. silicalite-silicon rubber Polymers of intrinsic microporosity (PIMs) A continuous network of interconnected intermolecular voids, which forms as a direct consequence of the shape and rigidity of the component macromolecules. N.B. McKeown & P.M. Budd, Macromolecules, 21, 43, Swelling in the presence of organic solvents Reduction of the selectivity Ages over time Increase in selectivity and reduction of flux 5

8 Biofuels: how can membrane technology help? Bioethanol and biobutanol are produced via ferementation of biomass. Biomass (cellulose, hemicellulose, lignin) Pre-treatment/ Enzymatic hydrolysis Removal of Lignin Sugar monomers Fermentation Solvent recovery Bioalcohol <.5% water End-product inhibition is caused by the toxicity of the alcohol produced on the bacteria. A concentration of less than 2% of bioalcohol (ABE fermentation process for biobutanol production) is typically achieved. The bioalcohol needs to be purified from the fermentation broth (contains mainly water) by a series of distillation columns 6-8% of the total production costs. Step 1: Removal of alcohol form fermentation broth Organophilic membranes Step 2: Further purification of alcohol Hydrophilic membranes 6

9 Hydrophilic graphene oxide (GO) membranes R. R. Nair et al. Science, 212, 335, 442 R.K. Joshi et al. Science, 214, 343, 752 7

10 membranes with graphene Simulations Experimental work? A. Gonciaruk et al., Micropor. Mesopor. Mater., 29 (215) is soluble just in few organic solvents, (CHCl 3, THF, DMAc) Direct mechanical exfoliation of graphite in these solvents is not good GO and rgo flakes prepared via oxidation of graphite cannot be dispersed Functionalization of GO with alkylamines can lead to monolayer and few-layered graphene flakes that are easily dispersed in CHCl 3 8

11 Preparation of graphene-like flakes Oxidation GO Graphite Hummers modified method Graphene Oxide (GO) Octylamine (OA) Functionalization Octadecylamine (ODA) GO-ODA GO-OA Chemical reduction (hydrazine) GO-ODA rgo-oa rgo-oa D. Li, et al., Nature Nanotechnology, 28, 3(2), GO-ODA rgo-oda 9

12 Transmitance (a.u.) Characterization of graphene-like flakes: FTIR N-H C-NH-C -CH 2 rgo-oa Peaks at 285/292 cm -1 -CH 2 of alkylamines GO-OA rgo-oda Decrese in intensity for reduced samples loss of some alkylamine upon treatment with hydrazine C-O (epoxy) GO-ODA GO Peaks at 147 cm -1 and 158 cm -1 covalent bonds (C-N-C) between alkylamines and GO C=C C-O (alkoxy) C=O (carboxylic) OH stretching Wavenumber (cm -1 ) 1

13 Intensity (a.u.) Intensity (a.u.) Intensity (a.u.) Intensity (a.u.) Intensity (a.u.) Characterization of graphene-like flakes: XPS Raw Fitted C=C sp2 C-C sp3 C-OH C-O-C C=O O=C-OH C-Si GO Long chain alkylamine functionalization GO-ODA Binding energy (ev) rgo-oda Raw Fitted C=C sp2 C-C sp3 C-N C-O-C C=O O=C-OH C-Si Binding energy (ev) Chemical reduction Raw Fitted C=C sp2 C-C sp3 C-N C-O-C C=O O=C-OH C-Si GO-OA Binding energy (ev) rgo-oa Short chain alkylamine functionalization Raw Fitted C=C sp2 C-C sp3 C-N C-O-C C=O O=C-OH C-Si Chemical reduction Raw Fitted C=C sp2 C-C sp3 C-N C-O-C C=O O=C-OH C-Si The higher C:O ratio corresponds to the sample functionalised with the alkylamine that has the longer chain C:O ratio decreases upon chemical reduction as a result of a small portion of the grafted alkyl chains being removed Binding energy (ev) Binding energy (ev) 11

14 Weight loss (%) Weight loss (%) Characterization of graphene-like flakes: TGA -2-4 GO rgo-oda GO-ODA rgo-oa Temperature ( C) Temperature ( C) Enhancement in the hydrophobicity degree of starting material GO in this order: rgo-oda > GO-ODA > rgo-oa Presence of both physically adsorbed and chemically bonded ODA to the GO flakes Weight loss for rgo-oda > rgo-oa as ODA chains having larger mass 12

15 Thickness (nm) Thickness (nm) Thickness (nm) Thickness (nm) Characterization of graphene-like flakes: AFM a) GO x ( m) b) x ( m) GO-ODA lateral dimensions of GO sheets are in the expected range with flakes of sizes ranging from few tens of nanometers to few micrometers c) rgo-oda d) rgo-oa x ( m) monolayer and few-layered structures are observed x ( m) 13

16 Membrane fabrication 1. Preparation of casting solutions wt.% Filler rgo-oda GO-ODA rgo-oa Filler in CHCl 3 5 wt.% in CHCl 3 Casting solution 2. Casting-evaporation on flat petri dishes + rgo-oda Dope solution Drying ~3days 14

17 Membrane fabrication Membrane code Filler wt% of filler Values from the preparation of casting solutions wt% of filler Values from UV of re-dissolved membranes * Membrane Thickness (µm)* ± 9.1.1GO-ODA.1.4 ±.8 54 ± 6.5.1GO-ODA ± ± 4.2 GO-ODA.5GO-ODA.5.61 ± ± 2.2 1GO-ODA ± ± 8.8.1rGO-ODA.1.18 ±.3 59 ± rgo-oda.1.65 ± ± 2.4 rgo-oda.5rgo-oda ± ± 7.6 1rGO-ODA 1.74 ± ± 6.9.1rGO-OA.1.31 ±.6 48 ± 3.9.1rGO-OA ± ± 2.1 rgo-oa.5rgo-oa ± ± 6.3 1rGO-OA ± ± 6.1 (*) Average of 1 measurements with a screw gauge in different areas of the membrane. 15

18 Membrane characterization: SEM a) b).1 rgo-oda c).1 rgo-oda 2 µm 2 µm 2 µm d) 1 rgo-oda e) 1 GO-ODA f) 1 rgo-oa 2 µm 2 µm 2 µm 16

19 Membrane characterization: STEM GO-ODA Presence of single-layer flakes of GO-ODA and rgo-oa in the polymeric matrices 2 nm 2 nm rgo-oa O:C ratio mapping features correspond to alkylamine - functionalized GO flakes 2 nm 2 nm 17

20 Solvent uptake, SU (%) Membrane characterization Contact angle ( o ) Contact angle GO-ODA rgo-oda rgo-oa 1GO-ODA 1rGO-ODA 1rGO-ODA Water Ethanol Butanol Solvent uptake.1go-oda.1go-oda.5go-oda 1GO-ODA.1 rgo-oda.1 rgo-oda.5rgo-oda 1rGO-ODA.1rGO-OA.1rGO-OA.5rGO-OA 1rGO-OA All values for water ranged from 8 to 9 addition of graphene-like fillers do not change significantly the surface properties ethanol contact angles (13 for ) butanol contact angles (9 for ).1GO-ODA.1rGO-ODA.1rGO-OA SU = m f m i m i 1% 3 days All the membranes show preferential sorption butanol > ethanol > water, Graphene-based fillers improve in all cases the sorption towards alcohols Chemically reduced samples hinder the sorption of water 18

21 Pervaporation set-up Recirculating water bath Feed sampling point Membrane cell Membrane Feed Cold trap (Liquid nitrogen) Permeate Vacuum pump Liquid samples are analysed with a GC equipped with FID 19

22 Normalized flux (µm kg m -2 h -1 ) Separation factor, β PV performance of MMMs Experiment conditions Feed composition: ~5wt% EtOH/BtOH in H 2 O Feed temperature: 65 o C Downstream pressure: 1 mbar Effective membrane area: 2.5 x 1-4 m 2 Flux, J J = m A t m: weight of the permeate (kg) A: effective area of the membrane (m 2 ) t: permeate collection time (h) Separation factor, β β = Y/(1 Y) X/(1 X) Y: mole fraction of the alcohol in the permeate X: mole fraction of the alcohol in the feed side GO-ODA rgo-oda rgo-oa 4 3 β EtOH/H 2 O β BtOH/H 2 O Total flux EtOH/H2O Total flux BtOH/H2O.1rGO-ODA.1rGO-ODA.5rGO-ODA 1rGO-ODA.1rGO-OA.1rGO-OA.5rGO-OA 1rGO-OA 2

23 Normalized flux (µm kg m -2 h -1 ) Separation factor, β Water flux ( m kg m -2 h -1 ) PV performance of MMMs Experiment conditions Feed composition: ~5wt% EtOH/BtOH in H 2 O Feed temperature: 65 o C Downstream pressure: 1 mbar Effective membrane area: 2.5 x 1-4 m 2 Flux, J J = m A t m: weight of the permeate (kg) A: effective area of the membrane (m 2 ) t: permeate collection time (h) Separation factor, β β = Y/(1 Y) X/(1 X) Y: mole fraction of the alcohol in the permeate X: mole fraction of the alcohol in the feed side β EtOH/H 2 O 1 β BtOH/H 2 O GO-ODA 1/ BtOH/H2O Water flux rgo-oda rgo-oa Total 4 flux EtOH/H2O Total flux BtOH/H2O / BtOH/H2O rGO-OA.1rGO-OA.5rGO-OA 1rGO-OA.1rGO-ODA.1rGO-ODA.5rGO-ODA 1rGO-ODA.1rGO-OA.1rGO-OA.5rGO-OA 1rGO-OA 21

24 Normalized flux Normalized flux Normalized flux Separation factor, Separation factor, Comparison with reported values GO-ODA GO-ODArGO-ODA GO-ODA rgo-oda rgo-oa Separation factor, BtOH/H2O Normalized flux, ( m Kg m -2 h -1 ) Separation factor, Separation factor, β Flux 2 Total flux EtOH/H2O Total flux BtOH/H2O 16 ( m Kg m -2 h -1 ) PDMS/CNT (1wt%) [5] PDMS [8] PDMS/6 wt% silicalite-1 [8] PDMS/PE [43] PEBA/25 wt% ZIF-71 [13] PEBA 2533 [1] PEBA/1 wt% CNT [44] PTFE [11] this work.1rgo-oa this work.1rgo-oda this work EtOH/H 2 O BtOH/H 2 O Total flux (g m -2 h -1 ).1GO-ODA.1GO-ODA.5GO-ODA EtOH/H 2 O BtOH/H 2 O Total flux EtOH/H2O Total flux BtOH/H2O 1GO-ODA.1GO-ODA.1GO-ODA ( m Kg m -2 h -1 ).5GO-ODA.1rGO-ODA GO-ODA.1rGO-ODA ( m µm ( m kg Kg Kg m -2 h -1-1 ).5rGO-ODA EtOH/H O EtOH/H β 2 O BtOH/H 2 O BtOH/H β 2 O Total 2 flux EtOH/H2O Total flux flux EtOH/H2O 16 Total flux BtOH/H2O Total 16 flux flux BtOH/H2O rGO-ODA.1GO-ODA.1GO-ODA.1GO-ODA.1rGO-ODA.5GO-ODA.1rGO-OA.1rGO-ODA.1GO-ODA.1GO-ODA.1GO-ODA.1GO-ODA.1GO-ODA 1GO-ODA.1rGO-OA.5GO-ODA.5GO-ODA.5rGO-ODA 22 1G 1G.5GO-ODA 1GO 1rGO.5rGO

25 Conclusions i. Alkylamine-functionalized GO and rgo (GO-ODA, rgo-oda, rgo-oa that could be dispersed in chloroform was prepared. ii. Free-standing MMMs were prepared with and these graphenelike materials. iii. The MMMs were tested for ethanol and butanol recovery from water via pervaporation iv..1 wt% of filler showed the highest improvement in selectivity towards butanol 23

26 Acknowledgments Molecular separations (School of Chem. Eng.) & Nano-fuctional materials (School of Materials) Dr Haigh and Dr Prestat TEM experts Prof Budd s group School of Chemistry 24