Furfural Content Research Articles

입국과 제올라이트 사용이 고체 발효 증류주의 이취 성분 억제와 알코올 생산성에 미치는 효과

This study aimed to investigate the effect of using a combination of ipguk (koji) and zeolite, as an alternative to the traditional nuruk fermented agents and rice and rice husks combination, on off-flavor suppression in solid fermented spirits. In alcohol production from solid fermented mash, the traditional brewing combination (nuruk + rice husks) produced over 1.3 times more alcohol than that obtained using the alternative combination (ipguk + zeolite). The levels of acetic, butyric, isovaleric acids, and methyl mercaptan, the components causing the offensive odor of distilled liquor (25% alcohol), were significantly reduced upon using the alternative combination as compared to that by the traditional combination. The acetic acid level decreased from 99.38 mg/L to 19.34-24.12 mg/L when using the alternative combination. Butyric acid, isovaleric acid, and methyl mercaptan levels decreased from 95.90, 5.37, and 426.78 mg/L, respectively, to undetectable levels. The furfural content decreased up to 4.3 times. In contrast, acetaldehyde levels increased from 228.04 mg/L to 529.74-578.71 mg/L when using the alternative combination. As the moisture content of the solid-fermented mash prepared with the alternative combination increased (from 40 to 55%), the alcohol production also increased proportionally, and the alcohol content of the distillate was elevated (from 37.14 to 43.74%).

Removal of furfural in wastewater by Al-MIL-53 prepared in various solvents

Furfural is a typical biomass-derived chemical with great industrial applications. Its increasing production has put forward strong concern on its emission control, especially the removal of low concentration furfural in wastewater. Efficient and environment-friendly strategies for the adsorption/recovery of furfural in diluted aqueous solution are highly required. In this work, we have synthesized several Al-MIL-53 materials in different commonly used solvents, i.e. water (H2O), N,N’-dimethylformamide (DMF), ethanol (EtOH) and methanol (MeOH). The adsorption capacities of furfural on these materials have been investigated to illustrate the effect of solvents used in the synthesis on the furfural adsorption behavior of the obtained Al-MIL-53. We found that the solvents used in this work result in Al-MIL-53 with different morphology, porosity and performance of furfural adsorption. When water was used as a solvent, a framework with good crystallinity was obtained. The specific surface area and the pore volume were 1073 m2 g−1 and 0.58 cm3 g−1, respectively. The adsorption rate of furfural on Al-MIL-53 (H2O) was the fastest and the adsorption capacity could reach 774 mg g−1 at the furfural concentration of 14.34 g L−1, which is 11%, 16% and 25% higher than those on Al-MIL-53 (DMF), Al-MIL-53 (EtOH) and Al-MIL-53 (MeOH) under the identical condition, respectively. The high adsorption property of Al-MIL-53 (H2O) can be due to its better structural crystallinity and porosity. Al-MIL-53(MeOH) has the poorest structural crystallinity and porosity, however, showing the highest furfural adsorption capacity based on surface area (3.3 mg m−2). The characterization results suggest that Al-OH defect sites in crystallites with poor porosity may also favor the interaction between furfural and MOFs.

Extraction of furfural inhibitor from biomass hydrolysate of rice husk

The production of second generation ethanol (E2G) has proven to be an alternative to non-renewable fuels, through transforming lignocellulosic waste into renewable fuel. In turn, rice husk has great potential due to its availability and composition. The conversion of lignocellulosic biomass to biofuel comprises a fundamental pre-treatment step, however, at this stage, the formation of degradation products (inhibitory compounds) occurs, among them, furfural, which cause negative effects on the viability of fermentative cells, making the production of E2G unfeasible. Given the above, the objective of this work was to remove the furfural inhibitor present in the lignocellulosic broth after the pre-treatment process, using oleic acid, through liquid-liquid extraction. The quantification of total reducing sugars in the hydrolyzate did not show significant variation between the pre and post extraction stages. Regarding the furfural inhibitor, in tests performed with a solution made in the laboratory, removal of up to 62.30% was obtained when the initial concentration was 5.00 g.L-1. With respect to the tests with the hydrolyzate from the rice husk pre-treatment, the maximum removal observed was 10.40%, but the initial concentration of furfural was 1.64 g.L-1. The results obtained indicate the possibility of using oleic acid as an extracting agent of the furfural inhibitor from lignocellulosic hydrolysates.

Non-inhibitory effects of the potent antioxidant C-phycocyanin from Plectonema sp. on the in vitro glycation reaction

Abstract When glucose and Amadori products are auto-oxidized, glycation occurs, resulting in the formation of early (Amadori) and late advanced glycation end products (AGEs), as well as free radicals. Glycation and an increase in free radical activity induce diabetic complications. Antioxidant and antiglycation compounds may aid in the prevention of oxidation and glycation. The goal of this study was to assess the antiglycation and antioxidant capacity of C-phycocyanin (C-PC) derived from Plectonema sp. The DPPH (1, 1-diphenyl-2-picrylhydrazyl), nitric oxide, hydroxyl radical scavenging activities and ferric ions reducing antioxidant power (FRAP) assays were used to assess antioxidant activity, while an in vitro bovine serum albumin-methyl glyoxal glycation (BSA-MG) model was used to assess glycation inhibitory potential. Glycation inhibition was measured using a variety of spectroscopic and biochemical parameters, including UV-visible & fluorescence spectroscopy, ketoamine, carbonyl and hydroxymethyl furfural content, as well as free lysine & free arginine estimations. In vitro, C-PC exhibited dose-dependent potent antioxidant activity, but lacked significant antiglycation potential. As a result, it is recommended that further studies be conducted to evaluate the antiglycation potential of C-PC.

Fabrication of ceramic tube‐supported tetraethyl‐orthosilicate cross‐linked polydimethylsiloxane membranes for separation of furfural–water mixture by pervaporation technology

AbstractIn this study, polydimethylsiloxane/tetraethyl‐orthosilicate (PDMS/TEOS) hybrid materials with different TEOS ratios were synthesized by cross‐linking method. Ceramic tube‐supported PDMS/TEOS membranes were fabricated by dip‐coating method. Effect of TEOS content, feed concentration, and feed temperature through separation of a furfural–water mixture by pervaporation (PV) technology was investigated. The highest PV performance was obtained with the total flux of 1.19 kg/m2h with TEOS content of 1.8 g, furfural feed concentration of 30 wt.%, operating temperature, and vacuum pressure at 100 kPa and 50 °C, respectively. PDMS/TEOS was successfully synthesized and coated on ceramic tube‐supported with a thickness of 15 μm. The ceramic tube‐supported membrane demonstrated good hydrophobicity with a contact angle of 109.5° and excellent thermal stability at 450 °C. The obtained results demonstrated that the ceramic tube‐supported PDMS/TEOS membrane is potent to be utilized for the separation of the furfural‐water mixture by PV technology.

Study of furanic compound content in common Spanish culinary preparations. Influence of the food preparation setting

Common Spanish culinary preparations were analyzed for the content of two furanic compounds, 5-hydroxymethylfurfural (HMF) and furfural, chemicals used as thermal damage indicators in the industrial processing of foods. Eleven foods commonly consumed in the Spanish diet were selected, collected from different settings (household, industrial and collective catering services), and classified according to their food matrix into three groups (potato-based, cereal-based and cereal mixed with meat, fish or vegetables). The highest mean levels were found in torrijas (20.12 mg/kg) and sponge cake (12.11 mg/kg) for HMF content, and in sponge cake (0.56 mg/kg), patties (0.54 mg/kg) and puff pastry pies (0.42 mg/kg) for furfural content, with these foods also exhibiting the greatest exposure levels. Results corroborate that cereal-based foods are the main contributors to the furanic compounds in the diet. Most of the food groups analyzed showed the maximum levels in the collective catering services, compared with the industrial setting, which could suggest that the mitigation strategies applied for other contaminants (e.g. acrylamide) in the industrial sector are also controlling the formation of these compounds. The need for appropriate mitigation measures suitable in household and collective catering settings is proposed.

Positive Influences of Ohmicsonication on Phytochemical Profile and Storage Stability of Not-from-Concentrate Mango Juice.

Processing technique and storage conditions are the main factors that affect the phytochemical profile of Not-from-Concentrate (NFC) juice, which could decrease the nutritional and bioactive properties of the corresponding juice. The aim of this study was to evaluate the quality changes that occurred in NFC mango juice after Ohmicsonication (OS) and during storage in comparison to other processing methods such as sonication (S), thermosonication (TS), ohmic heating (OH), and conventional heating (CH). Quality attributes such as polyphenoloxidase (PPO) and pectinmethylesterase (PME) activities, ascorbic acid and hydroxymethyl furfural (HMF) contents, total phenolics, total flavonoids, total carotenoids, electric conductivity, color values and microbial load (total plate count, mold, yeast, and psychrophilic bacteria) were examined. OS and OH treatments demonstrated the highest inactivation of PPO (100%), while CH and TS displaying inhibitions 89% and 90%, respectively and only S treatment exhibited insufficient inactivation of both PPO and microbial load. However, the inhibition of PME followed the order OS (96.5%) > OH (94.9%) > TS (92.5%) > CH (88.5%). The best treatment, with the highest retention of phytochemical contents (ascorbic acid, total carotenoids, antioxidant activity, total flavonoids, and total phenolic content) for NFC mango juice and during storage was obtained with OS treated samples compared to other treatments (in the order from the lowest to highest percentage, OS < OH < TS < CH). Consequently, the results indicated that OS could be applied as a new mild thermal treatment in the production of mango juice with improved quality properties of stored NFC mango juice.

Highly sensitive and reproducible CNTs@Ag modified Flower-Like silver nanoparticles for SERS situ detection of transformer Oil-dissolved furfural

Accurately evaluating the aging state of oil paper insulation in electrical equipment is a key to ensure the safe operation of the power transformer. For achieving highly sensitive in-situ detection of dissolved furfural in transformer oil with good reproducibility, flower-like silver nanoparticles modified with carbon nanotubes (CNTs@Ag-F-AgNPs) was synthesized by a combination of electroless silver plating and redox method. The large specific surface area and strong adsorption capacity of CNTs@Ag promoted the formation of more “hot spots”. CNTs@Ag-F-AgNPs were adsorbed on Si-Au substrate via mercapto groups on the coupling agent 1′4 phenyldimercaptan molecule (BDT). Using rhodamine 6G (R6G) as probe molecule, the enhanced factor reached 6.96 × 109. Then, the substrate was used for in-situ SERS detection of transformer oil-dissolved furfural at different concentrations and the detection limit was 2.25 mg/L at 1703 cm−1 (Stretching vibration of C = O in furfural molecule), fulfilling requirements of furfural content detection after severe aging of transformer (4 mg/L). Besides, the relative standard deviation (RSD) of characteristic peak intensity at ten different positions was only 1.74%. These results exhibite that three-dimensional nanostructure with high sensitivity and good reproducibility exhibited a wide application range for in situ detection of dissolved trace furfural in transformer oil.

Novel Method for Estimating Furfural Content in Transformer Insulating Oil Using Spectroscopic Analysis and Pattern Recognition

The transformer is the most essential component in electrical power transmission. Once a transformer is installed, it is generally used for decades. When failure occurs in a transformer, serious problems can arise, and numerous electrical components that depend on the transformer may be affected. Thus, deterioration diagnosis of transformers is important. The furfural content in the insulating oil of a transformer is widely used as an indicator of transformer deterioration, as furfural is generated by decomposition of the insulating paper. Although the degree of transformer deterioration can be estimated by measuring the furfural content, this measurement is time‐consuming. This paper proposes a novel method for estimating the amount of furfural contained in insulating oil within a short time. The method is realized by combining spectroscopic analysis in the visible region with a pattern recognition technique. The effectiveness of the proposed method is verified through a series of experiments. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Physico-chemical monitoring of biodegradation of furfural from oil industry effluents from the Arzew refinery (Oran) Algeria

Furfural is one of the petroleum products posing a potential danger to the environment and human health. However, the decontamination of these pollutants released into the environment is primarily governed by biodegra-dation processes. This study is based on biodegradation kinetics at increasing concentrations of furfural by natural mixed culture in order to assess the potential of this process in the elimination of furfural from petrochemical effluents from the ARZEW refinery. This biodegradation was measured through physicochemical parameters such as pH, electrical conductivity, con-centration of hydrocarbons, the chemical oxygen demand (COD), biochemi-cal oxygen demand (BOD5) and the concentration of furfural. The results obtained show at a concentration of 250ppm of injected furfural: a decrease in pH 4.9 and an increase in other parameters (conductivity 3450 μS.cm-1, HC 102 mg / l; furfural 210 ppm, COD 327mg / l, BOD5 98mgO2 / l. The study findings indicated that the injection of these effluents with concentrations greater than 180 ppm leads to values of pH, EC, HC, Furfural, COD, BOD5 which do not comply with direct discharge standards and disrupt biological treatment. The high levels of furfural not only cause a pollution problem but can also disrupt the functioning of bacteria at the biological treatment level. Therefore, dilution with the filtration wash water before switching to biologi-cal treatment is recommended in order to reduce the concentrations below 180 ppm.

A Rapid HPLC Method for the Simultaneous Determination of Organic Acids and Furans: Food Applications

Concerns over the potential adulteration of commercially produced foods give rise to a requirement for a simple and fast analytical method capable of quantifying potential adulterants. This work demonstrates a simple HPLC method tailored to detect major organic acids and furans within ingredients in commercial food products, for example, pomegranate molasses, balsamic vinegar, and apple cider vinegar. The relative importance of this method is in its simplicity and its use of an environmentally friendly aqueous mobile phase under isocratic conditions, providing results in a less than 20 min runtime. The chromatographic separation was achieved using an Acclaim® OA, 5 µm, 120 Å (4.0 × 250 mm) column; a UV-DAD detector set at 210 nm; and a 200 mM Na2SO4 mobile phase with 0.55 mL/L methanosulfonic acid as a pH modifier. The method was then validated by quantifying the concentration of acetic acid, formic acid, citric acid, and hydroxymethyl furfural (HMF) in pomegranate molasses, balsamic vinegar, and apple cider vinegar commercial products. The concentration of acetic acid and HMF in balsamic vinegar was 80.380 mg/mL (±1.272 mg/mL) and 2.153 mg/mL (±0.021 mg/mL), respectively. The apple cider vinegar was composed only of acetic acid with a concentration of 44.139 mg/mL (±0.053 mg/mL). The concentrations of citric acid and HMF were 123.425 mg/mL (±2.502 mg/mL) and 11.382 mg/mL (±0.582 mg/mL), respectively, in pomegranate molasses. Furthermore, this method is also capable of determining various organic acids and furans in biomass: levulinic acid, formic acid, furfurals, diformylfuran, and gamma-valerolactone.

Utilization of mensiang (Actinoscorpus grosus L.) as a cellulose-rich material for furfural synthesis

The cellulose content of mensiang varies from 22% in the flower to 33% in the root. This could be used as a starting point for furfural synthesis. To separate furfural, several conditions are set for the distillation and evaporation processes. The conditions were rootstock part (A), upper stem part (B), whole stem part (C), whole stem with flowers part (D), and whole stem, flowers, and root part (E). Furfural content in the mensiang plant was conducted using Gas Chromatography-Mass Spectroscopy (GCMS) for the highest yield 11.78%, D treatment. Furfural synthesized from the mensiang plant has a furfural content of 96%. Furfural's density was 1.160 g/ml, boiling point was 161 o C, refractive index was 1.5120 o brix, and its viscosity was 1.46 cp.

분유 첨가 고체발효 술덧의 증류 방법에 따른 증류 분획물의 특성

To enhance the flavor of solid-state fermented spirits, the effects of powdered milk on the composition of the distillation fractions obtained by two different distillation methods were evaluated. In the solid-state fermented product, the addition of whole milk powder did not affect alcohol production. However, the addition of milk increased the amino acid content and reducing sugar content, and decreased the formic, acetic, and succinic acid contents. Distillation using a microwave was four times faster than distillation using steam; however, the resulting number of fractions was high, with a wide range of alcohol flow rates. After the addition of whole milk powder, the contents of ethyl acetate and ethyl caproate were 2 times and 16-27 times higher, respectively, in the fraction, and the contents of butyric, valeric, and hexanoic acids among the volatile organic acids increased. In addition, the content of furfural, an odor component, increased 3.45 times from 1,393.73 mg/L to 4,801.93 mg/L. The microwave distillation method resulted in a 1.46-fold higher ethyl caproate content in the distillate compared with that obtained by steam distillation. However, as the temperature of the solid-state fermented mash was raised to over 300°C, the content of furfural increased by 3.29 times. These results support the use of milk powder in distilled spirits and may guide the development of optimized methods.

Valorization of olive endocarp from olive oil and table olive processing as a low-cost bioadsorbent for the removal of furfural from aqueous solutions

Furfural presence in fermentation culture media provokes an inhibition effect in yeast growth. In fact, is a key toxin in lignocellulosic hydrolyzates. This research work attempts to analyze the use of olive endocarp (OE) as adsorbent to remove furfural from aqueous solutions. The adsorption experimental sets studied the effect of particle size, agitation speed, adsorbent load, temperature, and initial furfural concentration. As results, higher adsorption percentages were observed when fragmented OE was smaller than 1.2 mm, agitation speed in the range 80–250 rpm, and the adsorbent load was 90 g OE/300 cm3 of furfural solution (1 g dm−3). The equilibrium adsorption capacities, qe, values were varied from 0.270 to 4.750 mg g−1 for initial furfural concentrations of 0.78 g dm−3 to 5.89 g dm−3. The adsorption data fit to pseudo-second order kinetic model showed good fit values (R2 ≥ 0.997, SE ≤ 5%). Dubinin-Radushkevich (DR) model was considered as the best fit (R2 = 0.999, SE = 2.95%) for the different studied isotherms. An adsorption free energy value of 896 J mol−1 indicated a physical adsorption mechanism. Remarkable increases in furfural adsorption percentages have been achieved submitting natural olive endocarps to acid treatments.

Method Development for Leachable Furfural Determination in Wood-Based Panels by HPLC-Uv System

Analytical method has been developed and validated to determine free or leachable furfural concentration in wood-based panels. Particleboards obtained from birch wood and suberinic acids binder were chosen as a reference material. Two methods and two solvents were tested. Acetone extracts of the samples were analyzed with gas chromatography (GC) flame ionization detector system. Water extracts were analyzed with high-performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV) system. After the GC data in acetone extracts furfural concentration was below method limit of detection. HPLC-UV data showed that in water extracts furfural concentration was possible to determine. It was concluded that HPLC-UV is suitable and fast method for furfural determination in wood-based panels water extracts.

Investigation of Furfural Formation and Mechanical Properties of Suberinic Acids-Bonded Particleboards Depending on their Preparation Parameters

Silver birch (Betula pendula) outer bark suberin can be used as a raw material to make an adhesive for particleboards (PBs). It is a promising formaldehyde-free alternative to traditional synthetic resins. However, the adhesive is acidic, which can catalyse furfural (FUR) formation from xylans in wood particles that are used for the preparation of PBs. FUR being a volatile organic compound can be emitted from the PBs and exposure to it can have harmful effects on humans. In the scope of this study, the effects on technological parameters (wet adhesive pH: 3, 6 and 9), glycerol as an additive to adhesive and hot-pressing temperature (180...230 °C) were investigated on the FUR formation in PBs. The FUR content was determined with high-performance liquid chromatography-ultraviolet spectroscopy system from the extracts of milled PBs. Mechanical properties (modulus of elasticity, bending strength, and thickness swelling) of the PBs were also studied. When using an adhesive with a pH 6 at hot-pressing temperature 230 °C with no glycerol added, it was possible to obtain PBs that satisfied the requirements of EN 312 P2 (boards for interior fitments). The FUR yield of these boards were more than 6 times lower than for the PBs pressed at 230 °C with a wet adhesive pH value 3.

Evaluation of Analysis Methods for Formaldehyde, Acetaldehyde, and Furfural from Fast Pyrolysis Bio-oil.

Fast pyrolysis bio-oil (FPBO), a second-generation liquid bioenergy carrier, is currently entering the market. FPBO is produced from biomass through the fast pyrolysis process and contains a large number of constituents, of which a significant part is still unknown. Various analytical methods have been systematically developed and validated for FPBO in the past; however, reliable methods for characterization of acetaldehyde, formaldehyde, and furfural are still lacking. In this work, different analysis methods with (HS-GC/ECD, HPLC, UV/Vis) and without derivatization (GC/MSD, HPLC) for the characterization of these components were evaluated. Five FPBO samples were used, covering a range of biomass materials (pine wood, miscanthus, and bark), storage conditions (freezer and room temperature), and after treatments (none, filtration, and vacuum evaporation). There was no difference among the methods for the acetaldehyde analysis. A significant difference among the methods for the determination of formaldehyde and furfural was observed. Thus, more data on the accuracy of the methods are required. The precision of all methods was below 10% with the exception of the HPLC analysis of acetaldehyde with an RSD of 14%. The concentration of acetaldehyde in the FPBO produced from the three different biomasses and stored in a freezer after production ranged from 0.24 to 0.60 wt %. Storage at room temperature and vacuum evaporation both decreased significantly the acetaldehyde concentration. Furfural concentrations ranged from 0.11 to 0.36 wt % for the five samples. Storage and after treatment affected the furfural concentration but to a lesser extent than for acetaldehyde. Storage at room temperature decreased formaldehyde similarly to acetaldehyde; however, after vacuum-evaporation the concentration of formaldehyde did not change. Thus, the analysis results indicated that in FPBO the equilibrium of formaldehyde and methylene glycol is almost completely on the methylene glycol side, as in aqueous solutions. All three methods employed here actually measure the sum of free formaldehyde and methylene glycol (FAMG).

Carbon based conductive materials mediated recalcitrant toxicity mitigation during anaerobic digestion of thermo-chemically pre-treated organic fraction of municipal solid waste

High-temperature thermal pretreatment alone or in conjugation with chemical pretreatment (highly acidic or alkaline) produced recalcitrant compounds, which inhibits the anaerobic digestion (AD) process performance. This study aims to develop a strategy to use carbon-based conductive materials to mitigate the recalcitrant toxicity and enhance the methane generation in the downstream AD. The formation of recalcitrant compounds, mainly the furan derivatives, i.e., furfural and 5-HydroxyMethyl furfurals (5-HMF) during thermo-chemical pretreatment of OFMSW at 150 °C, 175 °C, 200 °C with 3 g/L-NaOH dose, and the alleviation of their inhibitory effects by adding 25 g/L of each of granular activated carbon (GAC) and granular biochar (GBC) during mesophilic AD were studied. The addition of conductive materials resulted in the highest biogas yield of 462 mL/gVSadded (GAC) and 449 mL/gVSadded (GBC) for 175°C-3g/L-NaOH pretreatment, which was >45% higher over control. The highest improvement of >65% in biogas yield was observed for 200°C-3g/L-NaOH pretreatment despite the lower biogas yield. The conductive materials amended digester shows a significant decrease in the 5-HMF and furfurals concertation. The highest reduction in 5-HMF (44%) and furfural (51%) concentrations were observed for 200°C-3g/L-NaOH pretreatment, and 25 g/L GBC amended tests. The score plots from the principal component analysis (PCA) of the characterization of the digestate showed that the data were significant, whereas the loading plots depicted the correlation of different experimental parameters studied (like fate of recalcitrant, biogas yield and other parameters post AD of OFMSW when aided with conductive materials). Application of regression models in all the batch assays depicted that a lag phase of 2–4 days was observed in Modified Gompertz Model (MGM), 4–5 days in Logistic Model (LM) and a rapid hydrolysis was proven with the value of hydrolysis coefficient being between 0.003 and 0.029 from the first-order (FO) model.

Bioethanol production from grass pea and wild oat hydrolysates using S.cerevisiae ETP53, K. marxianus ETP87, and P. fermentans ETP22

Conversion of lignocellulosic biomass into bioethanol is essential to reduce dependency on fossil fuels. After the grass pea and wild oat straws were characterized, they were hydrolyzed by live fungi (in situ), crude fungal enzymes, and chemical methods (sodium hydroxide and sulphuric acids at 0.5, 1, 2, and 3%). The fungi used for in situ degradation and crude lignocellulosic enzymes were Aspergillus niger JMC22344, Trichoderma reesei JMC22, Pleurotus ostreatus M2191, and Pleurotus sajor-caju M2145. Furfural content of hydrolysates was analyzed by GC–MS. The potential of activated charcoal, overliming, and sequential activated charcoal-overliming potential to reduce furfural in the acid hydrolysates were evaluated. The hydrolysates were fermented by S. cerevisiae ETP53, K. marxianus ETP87, and P. fermentans ETP22. Sulphuric acid hydrolyzed common wild oat (8.91 g/L) yielded higher sugars than NaOH (3.88 g/L) and NaOH treated wild oat (8.14 g/L) was superior in terms of sugars released than grass pea (4.21 g/L). P. ostreatus M2191 liberated the highest sugar (18.63 g/L) extracts than T. reesei JMC22676, A. niger ETP22344 and P. sajor-caju M2145. The 23–77% of the furfural in acid hydrolysates was reduced by overliming, activated charcoal, and the sequential activated charcoal-overliming. Yeasts produced optimal ethanol from straws hydrolyzed by crude enzymes from A. niger JMC22344. Generally, the ethanol titer was directly proportional to the amount of sugars released.

Uncovering Insights to the Reaction Mechanism of the Electrochemical Hydrogenation and Hydrogenolysis of Furanic Species

Biomass derived compounds may be used as platform molecules for valorization to value-added products and biofuels. Two such molecules are furfural (FF) and 5-(hydroxymethyl)furfural (HMF). Using electricity as the energy source, FF and HMF can be upgraded by electrochemical hydrogenation and hydrogenolysis (ECH) reactions. The products of interest when FF is used as the starting molecule are the hydrogenation product, furfuryl alcohol (FA), a chemical intermediate, and the hydrogenolysis product, 2-methylfuran (MF), a biofuel. Similarly, HMF undergoes ECH to form 2,5-dihydroxymethylfuran (DHMF), a chemical intermediate, and 2,5-dimethylfuran (DMF), a biofuel. Existing studies probe the effect of electrode, electrolyte, applied potential, and temperature on reaction efficiency and selectivity, however fundamental questions remain about the reaction pathway and kinetics. This study elucidates the reaction pathway of FF and HMF to products through bulk electrolysis ECH.The ECH reactions were carried out via potentiostatic bulk electrolysis in an H-type cell with Cu flag working electrode in acidic electrolyte (0.5M H2SO4). By sampling the electrolyte at various times throughout the reaction, the product distribution with time for the ECH reactions was developed. The concentration of HMF and its products was determined by HPLC and the concentration of FF and its products was determined by GCMS. For 90 minutes of FF ECH, the concentration of both FA and MF increased steadily with reaction time; neither showed signs of further consumption. This observation indicates that FF ECH occurs over two separate, parallel paths to FA and MF. This is further evidenced by the lack of reaction to MF when FA is used as the starting molecule for ECH.