Linked strategy for the production of fuels via formose reaction
Jin Deng1, Tao Pan1, Qing Xu1, Meng-Yuan Chen1, Ying Zhang1, Qing-Xiang Guo1 & Yao Fu1*
1Anhui Province Key Laboratory of Biomass Clean Energy, Department of Chemistry, University
of Science and Technology of China, Hefei 230026, China.
Supplementary Information
Table of Contents
Part 1. Supplementary Methods………………….……………………………2
a. Integrated optimal conditions for the transformation of formaldehyde to fuels
b. Time on steam of continuous process
c. Preparation of C9-C15 branched-chain alkanes from 4-HMF
d. 13C-NMR experiments of the base-catalyzed condensation of dihydroxyacetone
Part 2. Supplementary Notes…………………………………………………12
Part 3. Supplementary Tables……………………………………………...... 13
Part 4. Supplementary Figures and Legends………………………………17
Part 5. Chromatograms for each analysis step and analytical conditions………………………………………………………………………….20
Part 6. NMR spectrograms…………………………………………………….31
Part 7. Supplemental References…………………………………………….41
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Part 1. Supplementary Methods
a. Integrated optimal conditions for the transformation of formaldehyde to fuels
Conversion of formaldehyde to dihydroxyacetone (DHA)
Batch process: Paraformaldehyde (10 wt% of the mixtures) and dioxane (450 ml) were heated to 373 K under nitrogen and then catalyst solution (1 mmol% of substrate, 50 ml) was added. The mixture was stirred at 373 K for 1 h. After reaction the reaction was quenched in ice water. The reaction mixture was analyzed by HPLC. Analysis of the reaction mixture showed that the yield of DHA is 85% and the conversion of formaldehyde is 99%. The reaction mixture was evaporated to remove the solvent. The residue was poured into water (100 ml) and extracted with dichloromethane (100 ml) three times to recycle the catalyst. The DHA aqueous solution was used directly in the following step.
Continuous process: details seeing Reference 20, 21 and fig. S10. The production of DHA from formaldehyde has a selectivity of 96% with a single-pass conversion of ca. 30%.
Isolation conditions: The DHA aqueous solution was evaporated to dryness and giving a syrupy product. The syrup was isolated to white powder of DHA dimer by recrystallization with ethanol and acetone.
Conversion of DHA to hexoses
Batch process: DHA aqueous solution and Amberlite® IRA-900 basic ion exchange resin (1 equiv of substrate) were stirred at 273K for 12h. After filtration to remove the resin, the filtrate was analyzed by HPLC. 100% conversion and 98.4% ketohexose selectivity (branched-chain ketohexose : straight-chain ketohexoses = 95.4 : 4.6) were achieved. The aqueous solution was used directly in the following step.
Continuous process: The Amberlite® IRA-900 basic ion exchange resin was packed in a fixed bed reactor and DHA aqueous solution was fed at LHSV =1 h-1 through the reactor at 273 K. The liquid effluent was collected for quantitative analysis by HPLC. 100% conversion and >99% ketohexose selectivity (branched-chain ketohexose : straight-chain ketohexoses = 94 : 6) were achieved. The aqueous solution was used directly in the following step.
Isolation conditions: The aqueous solution was isolated to white powder of dendroketose by recrystallization with ethanol and acetone.
Conversion of dendroketose to 4-HMF
Batch process 1: Amberlyst®-15 acidic ion exchange resin (50 wt% of substrate) was added in the dendroketose (20 wt%) DMSO solution. This mixture was stirred at 383 K for 5 hours and then cooled to room temperature and filtered. The product mixture was diluted analyzed with HPLC. 100% conversion and 93% 4-HMF selectivity was achieved.
Batch process 2: TA-p (10 wt% of substrate), dendroketose aqueous solution and MIBK (Vorg/Vaq= 1.5) were stirred at 453 K for 2 h. After filtration to remove the catalyst, the filtrate was analyzed by HPLC. 99% conversion and 80% 4-HMF selectivity was achieved.
Continuous process: Dendroketose aqueous solution and MIBK (feed ratio = 1:2) were fed to the fixed-bed reactor with LHSV= 2 h-1 at 453 K. The liquid effluent was collected and analyzed by HPLC. 71% conversion and 96% 4-HMF selectivity was achieved.
Isolation conditions: The liquid effluent containing the MIBK solution of 4-HMF, the aqueous solution of 4-HMF and unconverted dendroketose was introduced into the continuous countercurrent extractor and extracted by pure MIBK. 4-HMF in the aqueous solution was extracted into MIBK phase and organic phase was forwarded into distillator to give the product of 4-HMF.
Hydrogenolysis of 4-HMF to 2,4-DMF
4-HMF （4 wt%） dissolved 1-butanol and pre-reduced barium promoted CuCrO4 (20 wt% of substrate) were heated at 493K with 10 bar initial hydrogen pressure for 3 h. After 3h, 15%Cu-10%Ru/C (20 wt% of substrate) was added to the reactor. The reactor was pressurized with 7 bar initial hydrogen pressure and CO2 to achieve a total system pressure of 50 bar, and was heated to 493K for 0.5h. The product solution was analyzed by HPLC and GC-MS. 100% conversion and 72% 2,4-DMF selectivity was achieved.
Preparation of C9-C15 branched-chain alkanes from 4-HMF
The details were described below (Part 1-c).
In conclusion, under optimized conditions, the production of DHA from formaldehyde has a selectivity of 96% with a single-pass conversion of ca. 30%; the condensation of DHA into dendroketose achieved 100% conversion and >99% ketohexose selectivity (branched-chain ketohexose : straight-chain ketohexoses = 94:6); the dehydration of aqueous dendroketose into 4-HMF achieved a selectivity of 96% with a single-pass conversion of 71%; the hydrogenolysis of 4-HMF to 2,4-DMF achieved 100% conversion and 72% 2,4-DMF selectivity; the preparation of C9-C15 branched-chain alkanes from 4-HMF achieved 100% conversion and 68% selectivity.
b. Time on steam of continuous process
Conversion of DHA to hexoses
Continuous operation was operated for 36 h at 273 K. (Figure below)
Figure S1 Time on steam of conversion of DHA to hexoses
Conversion of dendroketose to 4-HMF
Continuous operation was proceeded for 120 h with LHSV= 2 h-1 at 453 K. (Figure below)
Figure S2 Time on steam of conversion of dendroketose to 4-HMF
c. Preparation of C9-C15 branched-chain alkanes from 4-HMF
Synthesis of 1,5-bis(4-(hydroxymethyl)-2-furanyl)-1,4-pentadien-3-one (F4-Ac-F4)
1,5-bis(4-(hydroxymethyl)-2-furanyl)-1,4-pentadien-3-one (F4-Ac-F4) was synthesized by aldol condensation of 4-hydroxymethylfurfural (4-HMF) and acetone. 4-HMF (4.75 g; 37.7 mmol) was dissolved in 0.5 equivalents (1.09g, 18.85mmol) of acetone and 50ml of 0.1 M KOH. The mixture was stirred at room temperature overnight. The solid precipitate was removed by filtration and washed to neutral with water. The wet solid product could be used directly in the following step or dried in a vacuum sulfuric acid desiccator under reduce pressure overnight to provide 3.68g (71%) of F4-Ac-F4 as a yellow powder.
1H-NMR: (400MHz, DMSO-d6, 293K, TMS): δ 4.38 (d, J=5.2, 4H), 5.12(t, J=5.2, 2H), 6.92-6.96 (d, J=15.6, 2H), 6.98 (s, 2H), 7.50-7.53 (d, J=15.6, 2H), 7.75(s, 2H).
13C-NMR: (100MHz, DMSO-d6, 293K, TMS): δ 54.49, 116.85, 122.54, 129.24, 129.63, 142.48, 151.12, 187.14.
Hydrogenation of F4-Ac-F4
The hydrogenation reaction was carried out in a stainless autoclave containing 1.2g F4-Ac-F4, 60ml water, and 0.24 g 5%Pd/C (Aldrich) at the reaction conditions of P(H2) = 5.3 MPa (ambient temperature) and T = 393 K under stirring (800 rpm). The reaction progress was measured by 13C-NMR spectroscopy and when no aromatic signals were detected anymore, the reaction was stopped. Then, the reactor was cooled down to room temperature, the catalyst was separated by filtration, and the filtrate was used directly in the following step.
Hydrodeoxygenation
The hydrogenation reaction was carried out in a stainless autoclave containing 9 ml hydrogenation crude reaction mixture, 90 mg 5%Pt/C(Aldrich) or 90 mg 5%Pd/C (Aldrich), and 30 mg Zeolite HZSM-5 (supplied by the Catalytic Factory of Nankai University, Si/Al=50). After flushing the reactor with H2 for three times, reactions were conducted at 523-553 K in presence of 5.5 MPa H2 (ambient temperature) for 4 h with a stirring speed of 800 rpm. After cooled to ambient temperature, the organic products were extracted by hexane. The organic phase was analyzed by GC-MS and GC. Internal standard (hexadecane, TCI, purity≥99.5%) was used to determine the amount of alkanes.
d. 13C-NMR experiments of the base-catalyzed condensation of dihydroxyacetone (DHA)
Due to a variety of configurations of carbohydrate compounds, we first dissolved the purified DL-dendroketose and the standard D-fructose and L-Sorbose in heavy water respectively (containing sodium formate as a carbon chemical shift internal standard) to confirm their respective carbon chemical shifts (Figure S3, S4 and S5).
Then, 10.5 mg of DL-dendroketose, 11.1 mg of D-fructose and 10.0 mg of L-Sorbose were mixed and dissolved in heavy water (containing sodium formate as a carbon chemical shift internal standard) (Figure S6).
Selecting hemiacetal carbon (less interference) as calculation object and L-Sorbose as basis (the least configurations of the isomers) (Figure S7).
Calculation of calibration factors:
DL-Dendroketose: 10.5mg; δ: 103.197; Integral area: 0.900; Correction factor: 0.857
D-Fructose: 11.1mg; δ: 98.086; Integral area: 0.929; Correction factor: 0.837
L-Sorbose: 10.0mg; δ: 97.749; Integral area: 1.000; Correction factor: 1.000
Then, 10wt% of DHA aqueous solution was catalyzed by IRA-900 (OH-) resin at 273K for 12h. After filtering to remove the resin and concentrating under vacuum, the mixture was dissolved in heavy water (containing sodium formate as a carbon chemical shift internal standard) for 13C-NMR (Figure S8).
Calculation of the ratio of DL-dendroketose to D-fructose & L-Sorbose：
DL-Dendroketose: Integral area: 1.000; Correction factor: 0.857; Correction integral area: 1.167;
Fructose: Integral area: 0.038; Correction factor: 0.837; Correction integral area: 0.045;
Sorbose: Integral area: 0.020; Correction factor: 1.000; Correction integral area: 0.020;
Dendroketose : (Fructose + Sorbose) = 1.167 : (0.045 + 0.020) = 94.7 : 5.3.
Figure S3 13C-NMR of DL-Dendroketose
Figure S4 13C-NMR of D-Fructose
Figure S5 13C-NMR of L-Sorbose
Figure S6 13C-NMR of DL-dendroketose, D-fructose and L-Sorbose
Figure S7 13C-NMR of DL-dendroketose, D-fructose and L-Sorbose (L-Sorbose as basis)
Figure S8 13C-NMR of the base-catalyzed condensation of dihydroxyacetone
Figure S9 13C-NMR of the base-catalyzed condensation of dihydroxyacetone for different time
Part 2 Supplementary Notes
Sample PTE and liquid fuel yield calculations for comparing linked strategy and gasfication-FT route
Lower heating values (LHV) of compounds are:
Methanol (32.04g/mol): 19.93MJ/kg
Formaldehyde (30.03g/mol): 15.98MJ/kg
Dihydroxyacetone (90.08g/mol): 14.48MJ/kg
Dendroketose (180.16g/mol): 14.13MJ/kg
4-HMF (126.11g/mol): 20.93MJ/kg
2,4-DMF (96.13g/mol): 32.17MJ/kg
Formaldehyde production:
3CH4O → 3CH2O + 3H2 (1)
3CH4O + 1.5O2 → 3CH2O + 3H2O (2)
Formose reaction:
6 CH2O → 2 C3H6O3 (3)
Aldol condensation:
2 C3H6O3 → C6H12O6 (4)
Acid dehydration:
C6H12O6 → C6H6O3 + 3H2O (5)
Hydrogenolysis:
C6H6O3 +3H2 → C6H8O + 2H2O (6)
Combined Eq.1 to Eq.6, the net reaction is:
6CH4O + 1.5O2 → C6H8O + 8H2O (7)
The theoretically PTE of methanol to 2,4-DMF is 0.81 and yield of 2,4-DMF is 0.5kg(2,4-DMF)/kg(methanol) according to Eq.7. The maximum PTE of biomass to methanol is 0.65 and maximum yield of methanol is 554kg(MeOH)/Mg(dry biomass) according to Spath, P.L. and Dayton, D.C.10. So, we can estimate that the PTE of biomass to 2,4-DMF is 0.53 and yield of 2,4-DMF is 277kg(2,4-DMF)/Mg(dry biomass). Whereas, the maximum PTE of biomass to FT is 0.43 and maximum yield of FT fuel is 159kg(FT fuel)/Mg(dry biomass) according to Spath, P.L. and Dayton, D.C.10. So, we can conclude that linked strategy has ca. 1.2 times energy recovery and ca. twice liquid fuels yield compared with gasification-FTS route.
Combined Eq.2 to Eq.5, the net reaction of formaldehyde to 4-HMF is:
6CH2O → C6H6O3 + 3H2O (8)
The theoretically PTE of formaldehyde to 4-HMF is 0.92 and yield of 2,4-DMF is 0.7kg(4-HMF)/kg(formaldehyde) according to Eq.8.
Part 3 Supplementary Tables
Tables S1. Batch process for conversion of DHA to hexoses at different temperature. DHA (0.5g), IRA-900 basic ion exchange resin (0.5g), and water (5ml). And continuous process at different LHSV. DHA aqueous solution concentration (10 wt.%) and IRA-900 basic ion exchange resin as catalyst. Conversion is calculated based on the amount of unconverted DHA. Ketohexoses selectivity is defined as [Yieldbranched-chain ketohexoses × ( 1+Straight-chain ketohexoses/Branched-chain ketohexoses)]/ConversionDHA × 100. The ratio of Branched-chain ketohexoses/ Straight-chain ketohexoses (abbreviated as B/S in this table) is calculated based on the ratio of Yield4-HMF to Yield5-HMF after acid catalyst dehydration of ketohexoses.
Entry / Temp. (K) / Time (h) / LHSV (h-1) / DHA Conversion (%) / Ketohexoses Selectivity (%) / B/S1 / 273 / 12 / - / 100 / 98.4 / 95.4:4.6
2 / 278 / 12 / - / 100 / 97.8 / 94.6:5.4
3 / 283 / 12 / - / 100 / 97.1 / 93.8:6.2
4 / 293 / 12 / - / 100 / 95.6 / 91.5:8.5
5 / 303 / 12 / - / 100 / 91.1 / 88.3:11.7
6 / 273 / - / 0.5 / 100 / >99 / 93.3:6.7
7 / 273 / - / 1.0 / 100 / >99 / 94.1:5.9
8 / 273 / - / 2.0 / 90.9 / >99 / 94.8:5.2
9 / 273 / - / 3.0 / 66.0 / >99 / 95.8:4.2
10 / 273 / - / 5.0 / 41.6 / >99 / 96.1:3.9
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Tables S2. Continuous process for conversion of dendroketose to 4-HMF at different LHSV. Dendroketose aqueous solution concentration (10 wt.%), MIBK as organic phase and tantalum phosphate as catalyst. Conversion is calculated based on the amount of unconverted dendroketose. Selectivity is defined as Yield4-HMF/Conversiondendroketose × 100.
Entry / LHSV(/h-1) / Feed ratio
(org : aq) / Conversion
(%) / Selectivity
(%)
1 / 1.0 / 1.5 : 1.0 / 92 / 75
2 / 1.0 / 2.0 : 1.0 / 91 / 81
3 / 1.0 / 2.5 : 1.0 / 92 / 81
4 / 0.5 / 2.0 : 1.0 / 96 / 46
5 / 1.5 / 2.0 : 1.0 / 86 / 85
6 / 2.0 / 2.0 : 1.0 / 71 / 96
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Tables S3. Properties of DMFs
DMFs / CAS Number / B.p(°C) / Density
(g/ml) / Water Solubility
(g/L) / Caloric Value
(kJ/g) / RON
/ 625-86-5 / 93.5 / 0.8995 / 2.3 / 33.7 / 119
/ 3710-43-8 / 94.0 / 0.8996 / 3.2 / 34.0 / 120
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Tables S4. Toxicities of DMFs33
DMFs / Carcinogenicity Probability / Mutagenicity Probability / Rat Oral LD50 (mg/kg) / Chronic LOAEL (mg/kg) / Skin Sensitization Probability/ n/a / Negative / 653.4 / 46.9 / Negative
/ n/a / Negative / 625 / 23.3 / Negative
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