Fuel 148 (2015) 226230

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Catalytic oxygen atom transfer from lignin to celluloseand hemicellulose and its importance in biorefining

http://dx.doi.org/10.1016/j.fuel.2015.01.1090016-2361/ 2015 Elsevier Ltd. All rights reserved.

Corresponding author at: Sun Pharmaceuticals, Inc., San Diego, CA 92128, USA.E-mail address: zuolinzhu@yahoo.com (Z. Zhu).URL: http://www.ussunpharm.com (Z. Zhu).

Zuolin Zhu a,b,, Jonathan Zhu aa Sun Pharmaceuticals, Inc., San Diego, CA 92128, USAb China Fuel (Huaibei) Bioenergy Technology Development Co., Ltd., Anhui 235000, China

h i g h l i g h t s

Oxygen atom transfer from lignin tocellulose is proposed and confirmed. All polymers of biomass are

hydrolyzed into small molecules inone-pot reaction. Lignin is converted quantitatively

into small molecular aromatics. Cellulose and hemicellulose are

transferred quantitatively into smallorganic acids. Small molecular aromatics can be

converted into diesel blends in one-step.

g r a p h i c a l a b s t r a c t

a r t i c l e i n f o

Article history:Received 2 December 2014Received in revised form 24 January 2015Accepted 29 January 2015Available online 11 February 2015

Keywords:Oxygen atom transferBiomassDieselSmall molecular aromaticsSmall organic acids

a b s t r a c t

A novel approach for biorefining is proposed and the proof of concept is accomplished. Catalytic oxygenatom transfer from non-oxidant lignin to cellulose or hemicellulose by organic chemicals is reported. Asexpected, the catalytic reaction is a novel method for the selective and quantitative hydrolytic depoly-merization of lignocelluloses into liquid products in a one-pot reaction. Lignin is converted quantitativelyinto small molecular aromatics, simultaneously, cellulose and hemicellulose are converted quantitativelyinto small organic acids with lactic acid up to 50%. Small molecular aromatics can be converted into dieselblend via one-step methylation. Neither black tar formation nor gasification is observed in the catalyticoxygen atom transfer reactions, conversion of biomass to products is quantitative.

2015 Elsevier Ltd. All rights reserved.

1. Introduction

Highly selective depolymerization of lignocellulose for decentyields of small molecular organics using the fewest number ofsteps is the key for economically producing fuels or chemicalsfrom biomass [1]. Small molecular organics function as excellent

intermediates for fuels or chemical products based on currenttechnologies [2,3]. Many well-known methods for the depolymer-ization of lignocelluloses, or its pure components, have beenproved to be commercially impractical due to a high operationcost. Thermal-chemical methods, such as liquefaction and pyroly-sis, show no product selectivity. These methods always result inthe formation of black tar and low yields of liquid products [4].Separation/isolation and purification of components first, fol-lowed by depolymerization, such as hydrolysis of cellulose into

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Fig. 1. Designed one-pot catalytic depolymerization of lignocelluloses. Through oxygen atom transfer, lignin will be converted into small molecular aromatics, and celluloseis transferred into small carboxylic acids.

Table 1The results of catalyst screening tests at 250 C. 1 l stainless steel, 750 ml of distilled water, 112 g of dried pinewood, 60 g of sodium, 2 g of catalyst.

Catalyst Gas (%) Tar (%) Residue (%) Catalyst Gas (%) Tar (%) Residue (%)

No 6.2 11 23 AQ 0 0 0.2PPh3 6.1 13 25 NaSO3AQ 0 0 0PMe2Ph 5.3 11 22.8 Pyridine 4.2 16 25PEtPh2 5.3 10.5 23.5 N-Me morpholine 3.8 16 24.6PEt3 5.1 11 24.2 Et3N 5.8 15 23.8RuO2 9.8 7.5 28.5 Me2S 5.4 12.6 24.1CeO2 11 6.8 30.2 H5PV2Mo10O40 8.6 9.2 15.3ZrO2 8.2 6.6 27.6 MeReO3 10.5 7.6 21.2OsO2 9.9 7.2 27.6 Ti(O-iPr)4 7.6 12 15.5Cr2O3 11 5.5 30 VO(acac)2 7.3 11 16.3MnO2 10.3 6.2 26.9 Cr(TPP)Cl 9.2 7.3 20.2Fe 10.2 7.8 25.5 Mn(TPP)Cl 8.9 7.2 20.7Zn 11 8.1 26.2 Fe(TPP)Cl 10 9.2 25.1

TPP: tetra phenyl porphyry.

Table 2The results of catalytic oxygen atom transfer with different temperatures. 1 l stainlesssteel, 750 ml of distilled water, 112 g of dried pinewood, 60 g of sodium, 2 g ofcatalyst.

Temperature (C) Gas (%) Tar (%) Residue (%)

200 0 1 11210 0 1 8220 0 0.5 5230 0 0.7 1.5240 0 0 0.3250 0 0 0260 0 0 0270 0 0 0280 0.2 0 0290 0.5 0 0300 1 0.5 0.5

Table 3The results of catalytic oxygen atom transfer with different catalyst loadings. 1 lstainless steel, 750 ml of distilled water, 112 g of dried pinewood, 60 g of sodium.

Catalyst loading (wt%) Gas (%) Tar (%) Residue (%)

10 0 0 05 0 0 02 0 0 01 0 0 00.5 0 0 00.2 0 0 00.1 0 0 0.50.05 Trace 0 0.50.02 Trace 0 0.60.01 0.2 0.7 1.30.005 0.3 0.7 1.5

Z. Zhu, J. Zhu / Fuel 148 (2015) 226230 227

glucose [5], or depolymerization of lignin into small moleculararomatics [6,7], show a huge loss of organic carbon in percentage.

One-pot co-depolymerization of cellulose, lignin, and hemicel-lulose with high product selectivity is possible. Lignin is a complexpolymer of aromatics with oxygen content up to 37% [8]. The idealproducts from lignin are small molecular aromatics with reduced

oxygen content. Meanwhile, cellulose and hemicellulose areoxygen acceptors and will be converted into small organic acids.Catalytic atom transfer reactions are preferred by industrial pro-cesses because these kinds of reactions have good to high productselectivity and atom economy [9].

228 Z. Zhu, J. Zhu / Fuel 148 (2015) 226230

Small molecular aromatics are important components in liquidtransportation fuels, and starting materials for high performancepolymers. With the increased yields of shale gas and methanehydrate that contain no aromatic components, the cost of produc-ing aromatics is expected to increase [10]. Organic acids are impor-tant commodity products with broad applications in many areas.For example, esters are better solvents for paints and ink thanalkane-based organic solvents, because esters are biodegradableand have excellent dissolving power [11]. Esters are also effectiveliquid fuels, possessing a higher or similar heat of combustion,and better anhydrous product yields, than that of ethanol. Addi-tionally, they are non-toxic and, unlike ethanol, non-corrosive.Organic acids can also be converted into many useful chemicals.For example, lactic acid can be converted into n-propanol, 1,2-pro-panediol, acrylic acid, propanoic acid, etc. Until now there is nocost effective method for making small organic acids from biomass.Alkaline hydrothermal methods produce a mixture of productscontaining more than a hundred different chemicals. Anotherproblem regarding the disproportionation reaction is that it hasno specificity in terms of products; the product mixture containsmore than 25 monocarboxylic acids, 22 dicarboxylic acids, and sev-eral cyclopentyl chemicals [12]. With oxidation methods [13]strong oxidants have to be used at elevated temperatures, suchas concentrated hydrogen peroxide [14,15] and nitric acid [16].There are safety issues using strong oxidants with these processes.Additionally, multi-hydroxyl organic acids, such as tartaric acid,glucaric acid, gluconic acid, and threonic acid, are formed. Multi-hydroxyl organic acids are difficult to isolate and purify, therefore,their use is limited.

Here we report a novel method for a catalytic one-pot hydro-lytic depolymerization of all natural organic polymers (CoDOPmethod), with good product selectivity, via catalytic oxygen atomtransfer from lignin to cellulose or hemicellulose mediated byorganic molecules. Catalytic oxygen atom transfer reaction fromnon-oxidant organic chemicals facilitated by organic moleculeshas not been reported before.

2. Experimental

The organic acids are analyzed using HPLC method. All volatileproducts such as phenols are analyzed using GCMS. LCMS methodis used for the analysis of molecular mass of small molecular

Lignin

OH R OO

O

O

O

R O

RO

O

OR H

H OHOH

Fig. 2. Possible catalytic oxygen transfer pathways for the catalytic one-pothydrolytic depolymerization of lignocellulose.

aromatics. Gasification of the reaction is measured via gas productanalysis (see Supplementary data for details).

Screening tests are carried out using a 1 l stainless steel auto-clave equipped with mechanical stirrer. 750 ml of distilled wateris used as solvent, 112 g of dried pine wood particles (2 mm size,contains cellulose: 40%, lignin: 30%, hemicellulose: 28%, ash: 1%,the carbon content is 51%), 60 g of sodium hydroxide is used toneutralize small organic acids, and 2 g of catalyst is used (the back-ground is the reaction without using any proposed catalyst). Thetemperature screened is 150, 170, 190, 210, 230, 250, 270, 290,and 310 C. The screening procedure is: the autoclave is sealedafter all materials are loaded, purged with nitrogen three times,then filled with a positive nitrogen pressure P0, heated to designedreaction temperature at a rate of 5 C/min and maintain at thistemperature for 60 min. After cooling to room temperature, thefinal pressure Pf is recorded and compared with P0. Gas productis collected and sampled for gas analysis. The liquid mixtureobtained is worked out for non-reacted biomass, black tar, andhydrolysis yield (see Supplementary data for details).

3. Results and discussion

3.1. Screening tests

For catalytic oxygen-atom transfer from lignin to cellulose andhemicellulose, there will only be two kinds of products of smallorganic chemicals from biomass depolymerization: organic acidsand small molecular aromatics, shown by Fig. 1. Lignin is not con-sidered as an oxidant in current chemistry. In order to show theproof of concept, many chemicals that have the ability to acceptoxygen atoms were selected for the screening tests. These chem-icals include pure metal powder such as Fe and Zn; metal oxidessuch as BaO, RuO2, CeO2, ZrO2, RuO2, OsO2, MnO2, and Cr2O3;metal complexes such as Ti(O-iPr)4, VO(acac)2, Cr(TPP)Cl,Mn(TPP)Cl, Fe(TPP)Cl, and MeReO3; phosphines such as PPh3,PEt2Ph, PEtPh2, and PMe2Ph; polyoxometalates such asH5PV2Mo10O40; organics such as pyridine, N-methylmorpholine,triethylamine, dimethyl sulfide, anthraquinone, and sodiumanthraquinone-2-sulfate. The results of screening tests show thatgasification (10%) and large quantities of solid residue (2030%)are observed for all the reactions when transition metals are pres-ent in catalysts. Phosphines, amines, and sulfide have no effect onthe designed reaction (compared with background reaction thatdid not use any catalyst). Anthraquinone and sodium anthraqui-none-2-sulfate give expected results, there is almost no solid res-idue after reaction, and no gasification detected. Because thedesigned oxygen-atom transfer reaction will produce only smallmolecular aromatics and small organic acids, these two kinds ofproducts are soluble in solution in reaction media. There shouldbe neither gaseous molecules that contain carbon nor solid resi-due after reaction. Table 1 contains the results of a screening testthat was carried out at 250 C. This data is the average of threeexperiments. Gas is the carbon molar percentage of the startingmaterial, calculated by measuring the total carbon in gaseousproduct (CO, CO2, and CH4), then dividing by the total molar car-bon in starting materials. Residue is the solid left after reaction.Tar is the methanol soluble part of the residue. Both of themare reported as weight percentage to starting material.

3.2. The results of catalytic oxygen atom transfer

Two parameters are chosen for the optimization of catalyticoxygen atom transfer, they are temperature and loading of catalyst(weight percentage to biomass). The results of these experimentsare tabulated in Tables 2 and 3.

Lignocelluloses

Catalytic One-pot Quantitative Hydrolysis

Small Molecular Aromatics

Small Organic Acids

Small Organic Molecules100%

Extraction

~100%Aqueous Layers

1. Removal of water at pH=102. Extraction with ether/HCl gas>99%

Fig. 3. Biorefining scheme for the catalytic one-pot hydrolytic depolymerization of lignocellulose via oxygen atom transfer. (The yield of small molecular aromatics iscalculated based on the percentage content of lignin in biomass used. The yield of small organic acids is calculated based on the percentage content of cellulose andhemicellulose in biomass used.)

Z. Zhu, J. Zhu / Fuel 148 (2015) 226230 229

The results show that a suitable reaction temperature is in therange of 230270 C in a one hour reaction time. Below 230 C,unreacted starting material is obvious. Gasification is observedfor the reaction with temperature above 280 C. Considering theloading of catalyst (sodium anthraquinone-2-sulfate), 0.1 wt% ofcatalyst to biomass is enough as it still gives completed hydrolysisof biomass. Unreacted starting material biomass is isolated andgasification is observed for the reaction with catalyst loadingbelow 0.05 wt%.

3.3. Scale up, product separation and identification: catalytic one-pot,selective, hydrolytic depolymerization of lignocelluloses

Scale up is carried out in a 10 l stainless steel autoclaveequipped with mechanical stirrer using modified screening proce-dure. 1120 g of pinewood is used, and the ratio of solid biomass tosolvent is 1:7. The catalyst (sodium anthraquinone-2-sulfate) load-ing is 1.12 g (0.1 wt%). The autoclave is sealed, purged with nitro-gen three times, then filled with nitrogen at a positive pressure,heated to 250 C, and stirred at this temperature for 60 min. Aftercooling to a temperature below 50 C, a brown colored solution isobtained. This color is similar to the color of the biomass (pine-wood) used, which suggests that there is no black tar formation.The color darkens after the mixture is exposed to air, which sug-gests that some phenols are formed and oxidized to quinones oncecontact with air. Filtration shows no signs of solid residue in theproduct solution, concluding that the percentage of hydrolyticdepolymerization is about 100%. The reaction mixture is collectedand the autoclave is washed with a small amount of 1% NaOHaqueous solution, 910 ml liquid is obtained.

HPLC analysis of the solution shows that only several smallorganic acids are formed, such as formic acid, glycolic acid, aceticacid, lactic acid and succinic acid. It contains 399 g of lactic acid(>50% of cellulose plus hemicellulose), 138.5 g of glycolic acid,151 g of formic acid, 19.8 g of acetic acid, 38 g of succinic acid,and the rest are 2-hydroxyl isobutyric acid, fumaric acid, etc.Fig. S1 illustrates the product distribution of small organic acidsfor this scale up of catalytic one-pot hydrolytic depolymerizationof lignocellulose.

The reaction solution is mixed with equal volumes of benzylalcohol and acidified with hydrochloric acid to pH = 4.2. Theorganic phase is separated and washed once with a half volumeof water. HPLC analysis shows there is no organic acid in organicsolution. The benzyl alcohol is carefully removed under reducedpressure to obtain 293 g of sticky products. GC analysis shows it

contains 4.9% benzyl alcohol. The weight of the small aromaticsobtained is 278.6 g-its yield is 100% based on lignin weight. Molec-ular mass analysis shows they are mixtures (Fig. S2), most with amolecular weight between 162 and 340. Elemental analysis showsthat the oxygen content of this product is 18%, far below the oxy-gen content of lignin (36%). This result suggests that more than50% of oxygen atoms are transferred from lignin to cellulose orhemicellulose, because this 18% of oxygen in small molecular aro-matics includes some oxygen incorporated from water via ligninhydrolysis reaction.

Methylated small molecular aromatics are obtained asdescribed in experimental section. 1H NMR of this aromaticproduct shows that the ratio of aliphatic hydrogen to aromatichydrogen is 4.8:1 (Fig. S3), a ratio of the current diesels.

3.4. Possible catalytic pathways

Based on the results of our experiments, dioxirane intermediateis proposed as a potential key catalytic substance, as shown inFig. 2.

First, the ether linkage of lignin is broken by a hydroxide anionto form a alkoxide anion; then the alkoxide (or phenoxide) anionattacks the carbonyl group of anthraquinone, the formed anthra-quinone anion intermediate rearrange to kick off alkyl (or phenyl)group and produce dioxirane intermediate, meanwhile, alkyl (orphenyl) group abstract hydrogen from water to yield smallermolecular aromatic with reduced oxygen content. The ether link-age of smaller molecular aromatics can be used for further reac-tions until there is no ether linkage inside the molecules. Thesekinds of molecules are the expected products of small moleculararomatics. Dioxirane is known to be good oxidant for oxidizing pri-mary alcohols to carboxylic acids [17] and secondary alcohols toalpha-hydroxy ketones [18]. Monosaccharide units of celluloseand hemicellulose contain many secondary alcohols, and are oxi-dized by dioxirane to ketone intermediates. Then these ketoneintermediates go on rearrangement [19] to form carboxylic acidsuch as formic acid, lactic acid and acetic acids. These small organicacids are the another kind of expected products.

4. Conclusions

Catalytic oxygen atom transfer from lignin to cellulose andhemicellulose is proved to be possible. Quantitative conversion oflignocellulose into small organic molecules is achieved. This novel

230 Z. Zhu, J. Zhu / Fuel 148 (2015) 226230

approach has very high product selectivity as there are only twokinds of products formed (Fig. 3). Lignin is converted into smallmolecular aromatics with reduced oxygen content. Meanwhile,cellulose and hemicellulose are oxidized into small organic acidswith lactic acid up to 50%. Small molecular aromatics can be con-verted into diesel blend via one-step methylation. This novelmethod for biorefining has the huge potential to make liquid fuelsand chemicals with a lower cost than that of the products frompetro-chemical process. Our current study is focused on a novelmethod for stabilizing small organic acids other than neutraliza-tion with base, in the hope to further lower process cost.

Acknowledgments

This research was supported by grants from the Key Project ofthe National 863 Program of China (2010AA10Z404). We acknowl-edge the financial support from Huaibei Mining Group.

Appendix A. Supplementary material

Supplementary data associated with this article can be found, inthe online version, at http://dx.doi.org/10.1016/j.fuel.2015.01.109.

References

[1] Zhu ZL, Sun M, Su C, Zhao H, Ma X, Zhu ZD, Shi X, Gu K. One-pot quantitativehydrolysis of lignocelluloses mediated by black liquor. Bioresour Technol2013;128:22934.

[2] Werpy T, Petersen G. Top value added chemicals from biomass, vol. I. USDOEreport; August 2004.

[3] Holladay JE, Bozell JJ, White JF, Johnson D. Top value added chemicals frombiomass, vol. II. USDOE report PNNL-16983; October 2007.

[4] Toor SS, Rosendahl L, Rudolf A. Hydrothermal liquefaction of biomass: a reviewof subcritical water technologies. Energy 2011;36:232842.

[5] Kazi FK, Fortman J, Anex R, Kothandaraman G, Hsu D, Aden A, Dutta. Techno-economic analysis of biochemical scenarios for production of cellulosicethanol. Technical report, NREL/TP-6A2-46588; June 2010.

[6] Sturgeon MR, OBrien MH, Ciesielski PN, Katahira R, Kruger JS, Chmely SC,Hamlin J, Lawrence K, Hunsinger GB, Foust TD, Baldwin RM, Biddy MJ,Beckham GT. Lignin depolymerisation by nickel supported layered-doublehydroxide catalyst. Green Chem 2014;16:82435.

[7] Zakzeski J, Bruijnincx PCA, Jongerius AL, Weckhuysen BM. The catalyticvalorization of lignin for the production of renewable chemicals. Chem Rev2010;110:355299.

[8] Guerra A, Filpponen I, Lucia LA, Argyropoulos DS. Comparative evaluation ofthree lignin isolation protocols for various wood species. J Agric Food Chem2006;54:9696705.

[9] Trost BM. On inventing reactions for economy. Acc Chem Res2002;35:695705.

[10] Allen K. The shale revolution and its impacts on aromatics supply, pricing andtrade flows. Special reports: aromatics; November 2013.

[11] Bene P, Baro J, Schulte H-G. Complex esters as solvent for printing inks. Patentpublication number: US 20100184896 A1.

[12] Niemela K. The formation of hydroxy monocarboxylic acids and dicarboxylicacids by alkaline thermochemical degradation of cellulose. J Chem TechnolBiotechnol 1990;48:1728.

[13] Jin FM, Enomoto H. Hydrothermal conversion of biomass into value-addedproducts: technology that mimics nature. Bioresources 2009;4:70413.

[14] Zhou Z, Jin F, Enomoto H. A continuous flow reaction system for producingacetic acid by wet oxidation of biomass. J Mater Sci 2006;41:15017.

[15] Jin FM, Kishita A, Moriya T, Enomoto H. Kinetics of oxidation of food wasteswith H2O2 in supercritical water. J Supercrit Fluids 2001;19:25162.

[16] Fisher K, Bipp HP. Generation of organic acids and monosaccharides byhydrolytic and oxidative transformation of food processing residues. BioresourTechnol 2005;96:83142.

[17] Mello R, Cassidei L, Fiorentino M, Fusco C, Huemmer W, Jaeger V, Curci R.Oxidation by methyl (trifluoromethyl) dioxirane. J Am Chem Soc1991;113:22058.

[18] Bovicelli P, Lupattelli P, Sanetti A, Mincione E. Selective oxidation of diols byhydrogen peroxide/TS-1 system and by DMDO. Tetrahedron Lett1994;35:847780.

[19] Novotny O, Cejpek K, Velisek J. Formation of carboxylic acids duringdegradation of monosaccharides. Czech J Food Sci 2007;26:11731.

http://dx.doi.org/10.1016/j.fuel.2015.01.109http://refhub.elsevier.com/S0016-2361(15)00139-8/h0005http://refhub.elsevier.com/S0016-2361(15)00139-8/h0005http://refhub.elsevier.com/S0016-2361(15)00139-8/h0005http://refhub.elsevier.com/S0016-2361(15)00139-8/h0020http://refhub.elsevier.com/S0016-2361(15)00139-8/h0020http://refhub.elsevier.com/S0016-2361(15)00139-8/h0030http://refhub.elsevier.com/S0016-2361(15)00139-8/h0030http://refhub.elsevier.com/S0016-2361(15)00139-8/h0030http://refhub.elsevier.com/S0016-2361(15)00139-8/h0030http://refhub.elsevier.com/S0016-2361(15)00139-8/h0035http://refhub.elsevier.com/S0016-2361(15)00139-8/h0035http://refhub.elsevier.com/S0016-2361(15)00139-8/h0035http://refhub.elsevier.com/S0016-2361(15)00139-8/h0040http://refhub.elsevier.com/S0016-2361(15)00139-8/h0040http://refhub.elsevier.com/S0016-2361(15)00139-8/h0040http://refhub.elsevier.com/S0016-2361(15)00139-8/h0045http://refhub.elsevier.com/S0016-2361(15)00139-8/h0045http://refhub.elsevier.com/S0016-2361(15)00139-8/h0060http://refhub.elsevier.com/S0016-2361(15)00139-8/h0060http://refhub.elsevier.com/S0016-2361(15)00139-8/h0060http://refhub.elsevier.com/S0016-2361(15)00139-8/h0065http://refhub.elsevier.com/S0016-2361(15)00139-8/h0065http://refhub.elsevier.com/S0016-2361(15)00139-8/h0070http://refhub.elsevier.com/S0016-2361(15)00139-8/h0070http://refhub.elsevier.com/S0016-2361(15)00139-8/h0075http://refhub.elsevier.com/S0016-2361(15)00139-8/h0075http://refhub.elsevier.com/S0016-2361(15)00139-8/h0080http://refhub.elsevier.com/S0016-2361(15)00139-8/h0080http://refhub.elsevier.com/S0016-2361(15)00139-8/h0080http://refhub.elsevier.com/S0016-2361(15)00139-8/h0085http://refhub.elsevier.com/S0016-2361(15)00139-8/h0085http://refhub.elsevier.com/S0016-2361(15)00139-8/h0085http://refhub.elsevier.com/S0016-2361(15)00139-8/h0090http://refhub.elsevier.com/S0016-2361(15)00139-8/h0090http://refhub.elsevier.com/S0016-2361(15)00139-8/h0090http://refhub.elsevier.com/S0016-2361(15)00139-8/h0095http://refhub.elsevier.com/S0016-2361(15)00139-8/h0095Catalytic oxygen atom transfer from lignin to cellulose and hemicellulose and its importance in biorefining1 Introduction2 Experimental3 Results and discussion3.1 Screening tests3.2 The results of catalytic oxygen atom transfer3.3 Scale up, product separation and identification: catalytic one-pot, selective, hydrolytic depolymerization of lignocelluloses3.4 Possible catalytic pathways4 ConclusionsAcknowledgmentsAppendix A Supplementary materialReferences