Dehydration Of Xylose Research Articles

A comprehensive analysis of biphasic reaction system for economical biodiesel production process

Biofuels are promising sources of renewable energy, however the economically feasible biofuel process has not yet proposed because of the system complexity and a wide range of process variations. This study explores the practical potential of biodiesel production processes through sequential reactions. Proposed sequential reaction started with xylose dehydration reaction producing furfural followed by furfural hydrogenation, condensation, and hydrodeoxygenation for biodiesel production. Rigorous reaction and separation models were constructed by using reaction experiments and thermodynamic data. The optimal biofuel process has been also proposed through flowsheet optimization. Detail technoeconomic analysis and life cycle assessment are provided to assess the impacts of certain parameters on economics and greenhouse gas emission. The results of this study show that the levelized cost of biodiesel production is $3.66 gal−1, and the corresponding global warming potential (GWP) is 57.18 gCO2eq MJ−1 for the base case. The production cost and GWP can reach $3.26 gal−1 and 29.39 gCO2eq MJ−1 depending on the xylose concentration and the furfural yield. The feed costs of xylose and hydrogen account for more than 80% of the levelized cost of biodiesel production and the steam utility required for refining products takes the largest portion of GWP, ranging from 33% to 65% of the total. These results ascertain that the economic feasibility of biodiesel production can be achievable by using only the sugar components in biomass, and the economics and GWP depend on the feed condition and the use of efficient separation process.© 2022 Elsevier Science. All rights reserved.

Supramolecular preorganization synthesis of nitrogen-doped carbon nanotubes functionalized by Brønsted acidic ionic liquid for microwave-assisted production of promising furanic derivatives

Brønsted acidic ionic liquids functionalized nitrogen-doped carbon nanotubes catalysts, [C4SO3HN][OTf]-NCNTs (OTf = SO3CF3), are synthesized by an additive-free supramolecular preorganization-thermal condensation route followed by chemical modification. By controlling the molar composition of carbon–nitrogen based monomers, sequence of the monomers and thermal condensation temperature, the tubular morphology and porosity properties of the catalysts are well-adjusted. The [C4SO3HN][OTf]-NCNTs are successfully applied in the reactions of great relevance to the development of sustainable bio-economy, namely, microwave-assisted production of 5-hydromethylfurfural (HMF) and furfural (FFR) from the dehydration of fructose and xylose, and the important reaction parameters including microwave irradiation temperature and time as well as solvent are considered. Co-operation of strong Brønsted acidity, unique tubular nanostructures and microwave heating approach finally endows [C4SO3HN][OTf]-NCNTs the enhanced dehydration reactivity and selectivity, in which the [C4SO3HN][OTf]-NCNTs800-2 with perfect tubular nanostructures displays the highest HMF yield (82.6%, 15 min in THF media) and FFR yield (56.2%, 45 min in DMSO media). The [C4SO3HN][OTf]-NCNTs also exhibit good catalytic reusability, attributing to covalent bonding of the [C4SO3HN+][OTf−] units onto NCNTs frameworks; meanwhile, the formation of considerable amount of humins at the surface of the catalysts is effectively inhibited by using microwave heating mode.

Two carriages for efficient furfural production from biomass: Rational design of porous biochar catalyst and clever utilization of butyrolactone-water medium

In the conversion of lignocellulosic biomass to furfural, a low yield is often obtained due to the natural degradation-resistant structure of the biomass and the high reactivity of the furfural molecule. However, in this study, the efficient conversion of biomass to furfural (90.5 % furfural yield) was achieved by working in the coordination of both carbon-based solid acid catalyst and water-butyrolactone co-solvent system using bagasse pith biomass as feedstock. The solid acid catalyst prepared by loaded sulfonic acid groups and Fe3+ on biochar showed a high specific surface area and well-developed pore channels, which can facilitate the breakdown of the solid structure of bagasse pith and the adequate hydrolysis. Meanwhile, by adjusting the volume ratio of the co-solvent system, the water in the system can not only foster the hemicellulose hydrolysis in bagasse pith but also facilitate the dehydration of xylose to form furfural. Furthermore, it enables the butyrolactone in the system to form a protective layer around the furfural molecule in time to avoid the degradation condensation reaction of the furfural molecule in the acidic system. Eventually, the 90.5 % furfural yields were obtained at water-butyrolactone volume ratio, reaction temperature, and reaction time were 1:29, 190, and 3 h, respectively.

Organic-inorganic bi-functionalized hybrid KIT-5: A toolbox for catalytic dehydration of xylose to n-hexyl levulinate

Levulinate esters are bio-based molecules with wide industrial applications as solvents, flavorings, fragrances, diesel blend components, and plasticizers. The current study deals with the synthesis and characterization of a series of acidic mesoporous alumino-silicates (KIT-5, Al-KIT-5x (X = 20,10,5), and a hybrid organic-inorganic Al-KIT-5(20)-Pr-SO3H) and their application in the preparation of n-hexyl levulinate from xylose. The prepared catalysts were thoroughly characterized using various techniques, including FT-IR, XRD, N2 adsorption-desorption, ICP, and SEM. The best catalytic performance was achieved in the presence of Al-KIT-5(20)-Pr-SO3H, which is found to be a bi-functionalized Lewis/Bronsted acid catalyst. The yield of n-hexyl levulinate reached a maximum of 52% at 170 °C in only 7 h. Al-KIT-5(20)-Pr-SO3H represents not only excellent reusability over four successive runs but also shows simple separation from the reaction mixture.

Natural lignocellulose welded Zr–Al bimetallic hybrids for the sustainable conversion of xylose to alkyl levulinate

The processing of C6 sugars to alkyl levulinate (AL), a versatile biomass-derived building block, can be readily implemented via the straightforward acid-catalyzed reaction in alcohol medium while it remains a challenge to produce AL from C5 sugars in the one-pot procedure over a monolithic catalyst. In this contribution, a budget and multifunctional natural lignocellulose welded Zr–Al bimetallic hybrid (ZrAl@CS-MSA) has been successfully constructed with crude corn stalk as a sustainable support. The becoming Lewis and Brønsted acid sites of ZrAl@CS-MSA catalyst guarantee a high AL yield of 54.3% from xylose via a one-pot process in a renewable n-butanol medium. Experimental findings revealed that the sulfonic group of ZrAl@CS-MSA plays a significant role in the xylose dehydration, furfuryl alcohol etherification and alcoholysis reactions while Zr species is in charge of the transfer hydrogenation of furfural. The Al species enclosed in ZrAl@CS-MSA can regulate its Brønsted and Lewis acidity, accelerating the etherification and alcoholysis reactions as well as alleviating the over hydrogenation of AL. This work opens a green, sustainable and reliable avenue for producing C5 sugar-based AL using natural lignocellulose-related multifunctional catalysts.

Efficient Synthesis of Biobased Furoic Acid from Corncob via Chemoenzymatic Approach

Valorization of lignocellulosic materials into value-added biobased chemicals is attracting increasing attention in the sustainable chemical industry. As an important building block, furoic acid has been commonly utilized to manufacture polymers, flavors, perfumes, bactericides, fungicides, etc. It is generally produced through the selective oxidation of furfural. In this study, we provide the results of the conversion of biomass-based xylose to furoic acid in a chemoenzymatic cascade reaction with the use of a heterogeneous chemocatalyst and a dehydrogenase biocatalyst. For this purpose, NaOH-treated waste shrimp shell was used as a biobased carrier to prepare high activity and thermostability of biobased solid acid catalysts (Sn-DAT-SS) for the dehydration of corncob-valorized xylose into furfural at 170 °C in 30 min. Subsequently, xylose-derived furfural and its derivative furfuryl alcohol were wholly oxidized into furoic acid with whole cells of E. coli HMFOMUT at 30 °C and pH 7.0. The productivity of furoic acid was 0.35 g furoic acid/(g xylan in corncob). This established chemoenzymatic process could be utilized to efficiently valorize biomass into value-added furoic acid.

Highly efficient conversion of sunflower stalk-hydrolysate to furfural by sunflower stalk residue-derived carbonaceous solid acid in deep eutectic solvent/organic solvent system

Sunflower stalk was utilized as a source of raw material and catalyst for furfural production, and efficient conversion of xylose-rich hydrolysate into furfural was developed in an aqueous deep eutectic solvent/organic solvent medium by carbonaceous solid acid catalyst SO42−/SnO2-SSXR. The structural characteristics of SO42−/SnO2-SSXR was characterized by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Fourier-transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Pyridine Adsorption Fourier-transform Infrared (Py-IR) and Raman. Under the optimum catalytic conditions, furfural (110.1 mM) yield reached 82.6% in a ChCl-MAA/toluene medium at 180 °C in 15 min by 3.6 wt% SO42−/SnO2-SSXR. Additionally, quite importantly, SO42−/SnO2-SSXR, ChCl-MAA and toluene had good recyclability for furfural production. The potential catalytic path of xylose dehydration into furfural was proposed by co-catalysis with SO42−/SnO2-SSXR and ChCl-MAA. This study revealed high potential sustainable application of furfural production.

Efficient synthesis of furfural from xylose over HCl catalyst in slug flow microreactors promoted by NaCl addition

AbstractEfficient synthesis of furfural from xylose over the HCl catalyst in a water‐methyl isobutyl ketone biphasic system was achieved in slug flow microreactors, using NaCl as a promotor which facilitates xylose dehydration and suppresses xylose condensation. An optimized furfural yield of 93% was obtained from 1 M xylose over 0.2 M HCl with 10 wt% NaCl at 180°C within 4 min. A comprehensive kinetic model was developed from monophasic experiments in water in microreactors, by incorporating the acidity in water and kinetic constants as a function of the chloride ion concentration. The coupling of kinetic model with furfural extraction, with consideration of phase volume change as a function of temperature and partial phase miscibility, enables to predict the results of biphasic experiments in microreactors where mass‐transfer limitation was eliminated. The aqueous phase containing HCl and NaCl could be readily recycled and reused multiple times without noticeable performance loss.

Kinetic model for the dehydration of xylose to furfural from a boronate diester precursor.

A comprehensive kinetic model describes the dehydration of xylose starting from the boronate diester-protected xylose (PBA2X). The model incorporates (de)esterification of PBA2X, partitioning, and xylose dehydration, and aims to evaluate the effects of the solvent system on these steps. The model explores the effect of the water contents in monophasic solvent systems, and that of ionic strength and mixing in biphasic aqueous-organic systems. At low water content, hydrolysis of PBA2X is the rate-limiting step, while xylose dehydration is fast. Conversely, in a monophasic three-solvent system, where the water content is higher, complete hydrolysis of the diester is achieved quickly. Under biphasic conditions, xylose dehydration is fast at high ionic strengths, but the slower partitioning/hydrolysis of PBA2X results in an overall slower furfural production. Furthermore, the observed different but high, constant xylose-to-furfural selectivities observed experimentally are tentatively ascribed to a higher order of parallel side-product formation.

Dehydration of Xylose to Furfural over Imidazolium-Based Ionic Liquid with Phase Separation

An environmentally friendly catalyst and task-specific ionic liquid (IL), 1-(4-sulfonic acid) butyl-3-cetyl-2-methyl imidazolium hydrogen sulfate, was applied to the dehydration of xylose to furfural. Its structure was determined by FT-IR, 1H NMR technologies. The solubility of IL in water changed with the temperature, and had the advantages of homogeneous and heterogeneous catalysts. At the given conditions, xylose conversion of 95.3% and furfural yield of 67.5% were achieved over IL.

Enhanced Furfural Production in Deep Eutectic Solvents Comprising Alkali Metal Halides as Additives.

The addition of alkali metal halide salts to acidic deep eutectic solvents is here reported as an effective way of boosting xylan conversion into furfural. These salts promote an increase in xylose dehydration due to the cation and anion interactions with the solvent being a promising alternative to the use of harsh operational conditions. Several alkali metal halides were used as additives in the DES composed of cholinium chloride and malic acid ([Ch]Cl:Mal) in a molar ratio of 1:3, with 5 wt.% of water. These mixtures were then used as both solvent and catalyst to produce furfural directly from xylan through microwave-assisted reactions. Preliminary assays were carried out at 150 and 130 °C to gauge the effect of the different salts in furfural yields. A Response Surface Methodology was then applied to optimize the operational conditions. After an optimization of the different operating conditions, a maximum furfural yield of 89.46 ± 0.33% was achieved using 8.19% of lithium bromide in [Ch]Cl:Mal, 1:3; 5 wt.% water, at 157.3 °C and 1.74 min of reaction time. The used deep eutectic solvent and salt were recovered and reused three times, with 79.7% yield in the third cycle, and the furfural and solvent integrity confirmed.

Sustainable production and purification of furfural from waste agricultural residue: An insight into integrated biorefinery

Furanic chemicals are the most significant renewable bio-chemicals with furfural being the basic platform chemical that can serve as a viable alternative to replace several petroproducts. Industrial furfural production poses several drawbacks such as poor yields, highly toxic effluents, energy intensive operations and accumulation of low value solid residue that restricts its tremendous potential. In this purview, the present research maneuvered a two-step translation strategy of corncobs, an abundant agricultural residue to furfural in a cost effective as well as environmental benign manner. Initially, the corncob is hydrolyzed using an aqueous low transition temperature mixture (LTTM) that selectively converts xylan in the lignocellulose matrix to xylose without disrupting the remaining biopolymers. The obtained xylose solution is enriched through strategic recycle of the hydrolysate with a cumulative yield of 76% after four cycles which is a potential substrate for subsequent xylose dehydration without any additional catalyst. Interestingly, autocatalysis in the LTTM media could yield 70% of theoretical furfural using nitrogen as a stripping media with 44% lower dilution of the furfural condensate. Furfural is further purified through an ecofriendly extraction technique utilizing hydrophobic deep eutectic solvents (HDES) as an effective extractant with the highest distribution coefficient being 66.2 for 1-tetradecanol and thymol based HDES portraying 98.6% recovery. The proposed furfural production process exhibits 13.8% overall yield with respect to corncob and 30% higher recovery of cellulose in the pretreated residue compared to conventional route which presents a high value integrated biorefinery with environmental compatibility.

Catalytic Conversion of Xylose to Furfural by p-Toluenesulfonic Acid (pTSA) and Chlorides: Process Optimization and Kinetic Modeling.

Furfural is one of the most promising precursor chemicals with an extended range of downstream derivatives. In this work, conversion of xylose to produce furfural was performed by employing p-toluenesulfonic acid (pTSA) as a catalyst in DMSO medium at moderate temperature and atmospheric pressure. The production process was optimized based on kinetic modeling of xylose conversion to furfural alongwith simultaneous formation of humin from xylose and furfural. The synergetic effects of organic acids and Lewis acids were investigated. Results showed that the catalyst pTSA-CrCl3·6H2O was a promising combined catalyst due to the high furfural yield (53.10%) at a moderate temperature of 120 °C. Observed kinetic modeling illustrated that the condensation of furfural in the DMSO solvent medium actually could be neglected. The established model was found to be satisfactory and could be well applied for process simulation and optimization with adequate accuracy. The estimated values of activation energies for xylose dehydration, condensation of xylose, and furfural to humin were 81.80, 66.50, and 93.02 kJ/mol, respectively.

Use of amorphous Nb2O5 and Nb2O5/Al2O3 as acid catalysts for the dehydration of xylose to furfural

Use of amorphous Nb2O5 and Nb2O5/Al2O3 as acid catalysts for the dehydration of xylose to furfural

Acid-catalyzed fractionation of almond shells in γ-valerolactone/water

The fractionation of almond shells, an agro-industry residue available in some Mediterranean climate regions, was investigated using acid-catalyzed hydrolysis in γ-valerolactone (GVL)/water. A set of non-isothermal experiments at nominal temperatures of 120, 140, and 160 °C and sulfuric acid concentrations from 25 to 75 mM were developed using a constant 80% w/w GVL in water concentration and a reaction time of up to 120 min. GVL was an efficient medium and promoted solubilization of both lignin and hemicellulose, even at low temperature during the initial period of reactor heating, while cellulose conversion was limited. A temperature of 160 °C gave the highest extraction of lignin and hemicellulose, but recovery of hemicellulose carbohydrates was better below 140 °C. Sulfuric acid concentrations above 45 mM promoted excessive dehydration of xylose and glucose to furans and humins, which were recovered with lignin. A model was developed to describe the kinetics of lignin and hemicellulose solubilization. It distinguished three fractions of different reactivity in each polymer (lignin or hemicellulose): fast-reacting, slow-reacting, and unreactive. The amount of each fraction was correlated with acid concentration and reaction temperature. Activation energies and the other parameters in the model were obtained numerically by least-squares optimization using the data from the non-isothermal experiments. Activation energies for the fast-reacting and slow-reacting fractions of hemicellulose were 142 and 39.7 kJ mol−1, and for those of lignin 134 and 71.7 kJ mol−1, respectively. Acid concentration had a larger influence than temperature on establishing the amounts of slow-reacting hemicellulose and lignin, whereas temperature was the dominant variable concerning the fractions of non-reacting polymers.

Synthesis of lignin-carbohydrate complex-based catalyst from Eragrostis tef straw and its catalytic performance in xylose dehydration to furfural

A new catalyst was successfully prepared by functionalization of the lignin-carbohydrate complex structure in the Eragrostis tef straw via simultaneous carbonization and sulfonation. The physical and chemical properties of the surface of the synthesized catalyst were checked by FTIR and XRD. The FTIR results indicate the prepared catalyst exhibited functional groups such as –SO3H, -COOH, and –OH. The synthesis conditions like the temperature and time of carbonization and sulfonation showed significant effect the amount of the strong acid doped into the carbonized lignin-carbohydrate matrix. The newly prepared catalyst was checked for dehydration of xylose to furfural and revealed of course that it has the potential. The maximum yield of furfural 62.4% was achieved and the catalyst showed excellent reusability for 5 runs without significant loss of catalystic activity. The use of catalysts prepared from Eragrostis tef straw is a green strategy for converting xylose to furfural, as these catalysts are solving the problems associated with the use of mineral acid catalysts.

Sulfonated foam catalysts for the continuous dehydration of xylose to furfural in biphasic media

This paper demonstrates the use of sulfonated foam structures, acting both as catalyst and liquid-liquid contactor, during the continuous dehydration of xylose to furfural in biphasic media. First, we develop and optimize a coating procedure comprising a two-step polymerization technique (polypropylene and polystyrene-divinylbenzene), followed by swelling and sulfonation. The method was highly reproducible and led to a stable, well-adhered, 12–50 μm layer of sulfonic resin with an ion exchange capacity of 0.1 meq/cmfoam3. The catalytic foams showed the same activity than H2SO4 in terms of conversion and selectivity versus residence time and temperature. The enhanced mass transfer properties of the foam-based reactor facilitated rapid furfural extraction, thus allowing for higher temperature operations (ca. 20–50 °C higher) and shorter residence times (ca. 10 min vs. 4–5 h) than conventionally reported in the literature, while preserving high furfural selectivity (ca. 70–80%). Finally, the stability of the sulfonated foam catalyst during operation was demonstrated up to 170 °C, although higher temperatures led to a visible decay in activity. We conclude that the sulfonated foams show great potential for this application.

New Approach to Dehydration of Xylose to 2-Furfuraldehyde Using a Mesoporous Niobium-Based Catalyst.

Furfural chemistry is one of the most promising platforms directly derived from lignocellulose biomass. In this study, a niobium-based catalyst (mNb-bc) was synthesized by a new fast and simple method. This new method uses microemulsion to obtain a catalyst with a high specific surface area (340 m2 g–1), defined mesoporosity, and high acidity (65 μmol g–1). Scanning electron microscopy revealed that mNb-bc has a rough surface. The mNb-bc was used to catalyze the conversion reaction of xylose into 2-furfuraldehyde in a monophasic system using water as a green solvent. This reaction was investigated using a 23 experimental design by varying the temperature, time, and catalyst-to-xylose ratio (CXR). The responses evaluated were xylose conversion (Xc), reaction yield (Y), and selectivity to 2-furfuraldehyde (S). The optimized reaction conditions were used to evaluate the reaction kinetics. At milder reaction conditions of 140 °C, 2 h, and a CXR of 10%, mNb-bc led to an Xc value of 41.2%, an S value of 77.1%, and a Y value of 31.8%.

Synthesis of furfural from Acacia mangium wood sawdust‐derived xylose by continuous distillation method using sulfonated carbonaceous catalyst from the same source

AbstractIn this study, the hydrolysate containing ~15 g/L of xylose, which was obtained from Acacia mangium wood sawdust was used for the synthesis of xylose by a continuous distillation method. The synthesis was conducted at 150 °C for 7 h using a carbon‐based sulfonated catalyst (CBSC) from the same biomass source with an acid density of about 4.0 mmol/g. The CBSC showed its efficient catalytic activity in the dehydration of xylose to furfural. Under the optimal catalyst dosage of 20 wt% over xylose, the yield of furfural was 20.4 mol% and 34 wt% of xylose was transformed to furfural. The results presented a successful utilization of a wood‐derived solid acid catalyst for production of furfural from the same biomass source as a sustainable production of furans for biofuel additives.

Maximization of furanic compounds formation by dehydration and hydrogenation of xylose in one step over SO3–H functionalized H-β catalyst in alcohol media

Furanic compounds such as furfural (FUR); furfuryl alcohol (F. Alc) are important renewable platform chemicals can be used as such or further convert for preparation of other value added products such as Levulinic acid (LA), Alkyl Levulinates, 2-Methyltetrahydrofuran (MTHF), and Tetrahydrofuran (THF) etc. Sulfonated H-β zeolite was successfully prepared and used for the synthesis of furanic compounds especially FUR and F. Alc from d-xylose in one step using isopropanol as alcohol media. Prepared catalyst was well characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), BET, NH3-Temperature programmed desorption (TPD) and carbon-hydrogen-nitrogen-sulfur analysis (CHNS). It was found the total acid amount was increased with increase in sulfur loading which confirmed the sulfonic acid group (SO3–H) was successfully grafted onto zeolite structure. 3 wt% H-β–SO3–H catalyst with optimized reaction parameters of 150 °C, 7 h, 25 wt% catalyst loading was tuned to get the highest furanic compound yield of 88.5% (FUR 76.8% + F.Alc 11.7%).The reusability study confirmed that there was a marginal drop of ~25% after 3 recycle runs.