Furfural Residue Research Articles

Efficient preparation of P-doped carbon with ultra-high mesoporous ratio from furfural residue for dye removal

P-doped mesoporous carbon material is receiving increasing attention in various fields due to its special physicochemical properties, but the research in the field of pollutant removal is rarely reported. Herein, P-doped furfural residue-based carbon materials (PFRC) with ultra-high mesoporous ratio (93.9%), narrow pore size distribution and large surface area (1769.4 m2 g−1) was prepared by a simple method of fast pyrolysis of phosphoric acid treated furfural residue (FR). A series of characterizations were carried out to explore the physicochemical properties and P-doping mechanism of the materials systematically. With the increase of the activation temperature, the evolution of the P-doped structure is as follows: adsorbed phosphate → P-O-Caromatic → O3P-Caromatic → O2P-C2aromatic → OP-C3aromatic. The PFRC500 prepared at 500 °C has the most abundant P-O-Caromatic and P-Caromatic structures, which lead to a higher specific surface area, more developed pore structure and more graphite edge defects than other PFRCs. Methylene blue (MB) adsorption studies showed that PFRC500 had a good adsorption performance with 486 mg g−1 equilibrium adsorption capacity and 97.2% of removal rate (T = 298 K, C0 = 100 mg L−1). The adsorption kinetics and thermodynamics were studied. The role of P structure in MB adsorption was explored for the first time. the adsorption mechanism was explored. The P-O-Caromatic, O3P-Caromatic and O2P-C2aromatic structures are the main chemical adsorption sites, but C3aromatic-PO is not. This work can provide guidance for the design of P-doped mesoporous carbon materials with better adsorption performance in the future.

Development of a universal method for high yield of furfural and hydrogen from raw lignocellulosic biomass

In order to develop a universal method for the co-production of furfural and hydrogen from raw lignocellulosic biomass, three types of substrates (maple wood, wheat straw, and tall fescue) were investigated, integrating chemical and electrochemical technologies. The results show both furfural and pure hydrogen were produced from all the biomass substrates, and the substrate type, composition, concentration, and size all affected furfural and hydrogen production. The highest furfural production of 154 mg g−1 substrate was achieved from wheat straw. The highest conversion rate of 67% for the waste furfural residue was realized, and 335 ml pure hydrogen per gram of furfural residue with a Faradaic efficiency of 99.3% was obtained with a new electrolytic cell. A reaction mechanism for hydrogen evolution from furfural residue and a rule for co-production of furfural and hydrogen from raw biomass were proposed. The facts show that a promising universal method for the co-production of furfural and hydrogen from lignocellulosic biomass has been developed.

Formic acid–hydrogen peroxide treatment of furfural residue for production of nanocellulose, lignin, and nano-scale lignin

An environmentally friendly approach inspired by pulping was proposed to convert industrial furfural residue, which was difficult to further convert into nanocellulose, lignin, and nano-scale lignin.

Optimized preparation of activated carbon from furfural residue using response surface methodology and its application for bisphenol S adsorption.

Furfural residue (FR), a solid waste, was applied as the precursor to prepare activated carbon by steam activation. The Box-Behnken design (BBD) approach-based response surface methodology (RSM) was utilized to optimize the preparation conditions to evaluate their effects on the performance of activated carbon from furfural residue (FRAC). The optimum preparation conditions of FRAC were found as follows: activation temperature of 922 °C, activation time of 62 min, and the mass ratio of char to H2O of 1:4.5, resulting in 1,501.84 mg/g of iodine adsorption capacity and 1,662.41 m2/g of specific surface area. The FRAC was characterized and then the adsorption performance of bisphenol S (BPS) on FRAC was investigated. Langmuir and Koble-Corrigan isotherm models were well fitted to the experimental data, and the adsorption kinetics process was perfectly described by the pseudo-second-order model. Thermodynamic parameters showed that the adsorption of BPS was a spontaneous exothermic process. Besides, the regeneration efficiency of FRAC was over 97% after five consecutive cycles. The maximum monolayer adsorption capacity of FRAC for BPS was 3.2848 mmol/g at 298 K, indicating that the FRAC was an excellent adsorbent for the removal of BPS from aqueous solutions.

Pyrolysis of pellets prepared from pure and blended biomass feedstocks: Characterization and analysis of pellets quality

Recently, pyrolysis integrated with pelletization has received great attention. In the current study, various physical, mechanical, chemical and thermal characteristics of furfural residue pellets (FRPs), sewage sludge pellets (SSPs), furfural residue-sewage sludge pellets (FRSSPs) were studied at different pyrolysis temperature (200–850 °C) and residence time (15–45 min). The mass and energy yields of pellets dropped drastically with increasing pyrolysis temperature. Higher heating values (HHV) of pyrolysed furfural residue pellets (PYFRPs) and furfural residue-sewage sludge pellets (PYFRSSPs) increased from 22.22 to 26.76 MJ/kg, and 20.59–23.72 MJ/kg, respectively with increasing temperature from 200 to 850 °C. However, the HHV of pyrolysed sewage sludge pellets (PYSSPs) decreased with increasing temperature. The lowest pellet density and strength were found at 850 °C and residence time of 45 min. The pellets remained dimensionally stable during the water immersion test and after a storage time of 2 weeks, the relaxed densities and strength remained unchanged. The volumetric energy density of PYFRPs (30.35 kJ/m3) was found to be higher than PYSSPs (8.92 kJ/m3) and PYFRSSPs (23.85 kJ/m3) at the same process conditions. Thermal treatment enhanced the hydrophobicity of pellets. The lowest moisture uptake of 1.14 wt%, 1.8 wt%, and 1.58 wt% for the corresponding PYFRPs, PYSSPs and PYFRSSPs were observed at pyrolysis temperature of 300 °C. The maximum methylene blue and iodine adsorption values (i.e. 96 and 244.8 mg/g), (191 and 314.7 mg/g) and (121.6 and 263 mg/g) for PYFRPs, PYSSPs and PYFRSSPs were found, respectively, at temperature of ≥ 450 °C. Pyrolysis at higher temperature significantly reduced the heavy metals in PYFRSSPs and PYSSPs.

Reactivity and kinetics of furfural residue air gasification based on-line gas releasing behaviors in a bubbling fluidized bed

Furfural residue (FR), as an industrial by-product, has a huge annual output. The air gasification of FR in fluidized beds is a promising technology to produce high-quality syngas. Understanding the reactivity and kinetics of FR gasification can guide and achieve the directional regulation of target products. The use of a fluidized bed to study air gasification kinetics of FR was proposed to avoid the technical difficulties in thermogravimetric analysis and fixed beds. A bubbling fluidized bed with an on-line analysis system was developed to systematically investigate the synergistic effects of the equivalence ratio (ER) and the temperature on real-time gas releasing behaviors of FR. The shrinking core model (SCM), homogenous model (HM) and modified volume reaction model (MVRM) were used to describe the kinetics characteristics of volatile and char gasification, respectively. The gasification mechanisms were revealed by the reaction model functions. The results showed that the rapid devolatilization of FR led to the maximum rate of volatile gasification at about 1–1.5 min, then the char gasification reaction occurred at about 2 min. In addition, the char gasification time was about 4 times longer than that of the volatile, dominating the whole gasification process. The optimal ER value was 0.3 when the temperature was 800 °C, while it was 0.25 at temperatures above 850 °C, and the volume fraction of CO increased from 47% to 57% with the temperature increase. The SCM performed the best for describing the air gasification kinetics of FR. The activation energies of volatile and char gasification were the largest at the ER of 0.25, being 54 kJ/mol and 112 kJ/mol, respectively. In the fluidized bed gasification, the nucleation and growth mechanism was the most accurate for describing the volatile gasification process, while for the char gasification, the shrinkage geometrical mechanism worked the best.

Production of Pellets from Furfural Residue and Sawdust Biomass: Effect of Moisture Content, Particle Size and a Binder on Pellet Quality and Energy Consumption

Production of Pellets from Furfural Residue and Sawdust Biomass: Effect of Moisture Content, Particle Size and a Binder on Pellet Quality and Energy Consumption

Pyrolysis of furfural residue pellets: Physicochemical characteristics of pyrolytic pellets and pyrolysis kinetics

Biomass pelletization technology has recently gained significant interest, where pyrolyzed pellets have a very wide range of applications (e.g., as pellet fuels and adsorbents). In this study, furfural residue pellets (FRPs) were pyrolyzed at temperatures of 200–850 °C in a tube furnace. The physical and chemical properties of the pyrolyzed FRPs (PFRPs) obtained at various temperatures were compared, and the kinetic parameters of the pyrolysis process were calculated using the distributed activation energy model (DAEM). The PFRPs prepared at 450, 650, and 850 °C had higher volumetric energy densities than coal, whereas other properties (e.g., H/C and O/C ratios) were found to be similar to those of coal. The maximum iodine adsorption value (i.e. 317.8 mg/g) and methylene blue adsorption value (i.e. 96.4 mg/g) were achieved by pyrolysis at 650 °C and 450 °C, respectively, indicating that pyrolysis promoted the formation of micropore structures at 650 °C. Two-dimensional correlation spectroscopy (2D-COS) was employed to explore the temperature-sensitivity of the surface functional groups of the PFRPs. Based on comparison of the volumetric energy density, hydrophobicity, particle density, and strength, the PFRPs prepared at 250–300 °C afforded the best overall performance, where the sample prepared at 300 °C exhibited the maximum hydrophobicity.

Effects of additives on physical, chemical, and microbiological properties during green waste composting

Composting is an environmentally friendly and sustainable way to transform Green waste (GW) into a useful product. GW, however, contains substantial quantities of lignocelluloses that extend the composting period unless substances that accelerate composting are added. The objective of this research was to assess the influence of the following additives on GW composting (w/w dry matter contents of the additives were indicated): sugarcane bagasse at 15%; bean dregs at 35%; silage at 45%; flue gas desulfurization gypsum at 5%; maifanite at 4%; and furfural residue at 20%. Based on the composting temperature, compost density, porosity, particle-size distribution, water retention, pH, cation exchange capacity, available nutrient contents, humification coefficient, organic matter loss, microbial populations, and phytotoxicity, the best additives were 45% silage and 5% flue gas desulfurization gypsum. The latter two additives produced a high-quality product in only 35 and 37 days, respectively.

Furfural and hydrogen production from corncob via tandem chemical and electrochemical approach

Furfural and hydrogen co-production from raw corncob was demonstrated via the tandem chemical/electrochemical route. The operating conditions for furfural production were optimized with AlCl3 catalyst in a water/CPME biphasic system. A high furfural yield (85%) was obtained via chemical conversion by implementing an AlCl3 catalyst in a biphasic solvent system. The furfural waste from the chemical conversion was electrochemically upgraded into hydrogen with a 0.48% weight yield implementing a FeCl3 electrochemical mediator. The energy consumption for hydrogen evolution from waste furfural residue is 50% lower than water electrolysis. The facts indicate that a novel and promising method for the co-production of furfural and hydrogen from renewable biomass is developed.

Experimental Study on Mechanical Properties and Micro-Mechanism of All-Solid-Waste Alkali Activated Binders Solidified Marine Soft Soil

Utilizing granulated blast furnace slag (GBFS), coal fly ash (FA), and furfural residue incineration ash (FRIA) as pozzolanic materials, then activated with calcium carbide residue (CCR) respectively to prepare all-solid-waste alkali activated binders (ASW binders). The laboratory tests were performed to research the effects of pozzolanic materials with different reactivity on the macro- and micro- characteristics of solidified marine soft soil. Results show that the mechanical properties and alkali-activation process of ASW binders solidified soil was determined mainly by the reactivity of pozzolanic materials, the higher reactivity of the pozzolanic materials in ASW binders couldn’t change the main hydration products, however, it would accelerate the hydrate reaction. The degree of hydrate reaction increased, the microstructure became denser with the increase of the reactivity of the pozzolanic materials in ASW binders solidified soil, on the macro- side, the strength and deformation modulus of the solidified soil increased, meanwhile, the brittleness of the solidified soil will be more obvious during the deformation resistance process. ASW binders (CCR:GBFS=1:1) solidified soil could reach the strength of cemented soil under the same conditions.

Chemical constitution of polyfurfuryl alcohol investigated by FTIR and Resonant Raman spectroscopy

The actual chemical structure of polyfurfuryl alcohol (PFA) is still uncertain in spite of several studies on the topic, variations during the polymerization processes being one reason that must be addressed. The use of a limited set of analytical techniques is often insufficient to provide an exhaustive chemical characterization. Moreover, it is still not possible to exactly determine presence and amount of each specific functional group in the polymeric structure. We employed both Fourier Transform Infrared Spectroscopy (FTIR) and Resonant Raman spectroscopy (RR), corroborated by quantum mechanically aided analysis of the experimental spectra, to infer about the chemical structure of two samples of PFAs, synthetized in different ways and appearing macroscopically different, the first one being a liquid and viscous commercial sample, the second one being a self-prepared solid and rigid sample produced following a thermosetting procedure. The vibrational spectroscopic analysis confirms the presence of differences in their chemical structures. The viscous form of PFA is mainly composed by short polymeric chains, and is characterized by the presence of isolated furfuryl alcohol and furfural residues similar to 5-hydroxymethylfurfural; the thermosetted PFA is formed by more cross-linked structures, characterized by several ketones and alkene double bonds, as well as a significant presence of Diels-Alder structures. In summary, the present study evidences how the use of both FTIR and RR spectroscopy, the latter carried out at several laser excitation wavelengths, indicates an accurate way to spectroscopically investigate complex polymers enabling to satisfactorily infer about their peculiar chemical structure.

Co-pelletization of sewage sludge, furfural residue and corn stalk: Characteristics and quality analysis of pellets

In this study, pelletization of sewage sludge (SS), furfural residue (FR) and corn stalk (CS) and mixture of SS with FR and CS was performed, and various quality parameters and their dependency on process variables were investigated. Addition of SS in ratios of 20–40% to FR had not enhanced the pellet densities (e.g. particle and relaxed) of furfural residue sludge mixed pellets (FRSPs). However, mixing SS with CS in ratio of 20–80% had resulted in higher density, strength and hardness of corn stalk sludge mixed pellets (CSSPs). Addition of sludge to 20% with FR had resulted in higher strength and hardness (i.e. 7 ± 0.22 MPa and 508 ± 28.1 N/mm2) of pellets. While the highest strength and hardness i.e. 13.4 ± 0.12 MPa and 392 ± 5.96 N/mm2 were found for CSSPs-40 and CSSPs-80. Pelletization at 200 °C was found to be beneficial as it improved the mechanical characteristics of FRSPs and CSSPs and reduced the energy consumption. Energy consumption of pellets was decreased markedly with increasing sludge ratio and the lowest was found at SS proportion of 80%. Heating values of sludge mixed pellets were found higher than sewage sludge pellets. Compression models had well evaluated the compaction behavior of FR, SS, CS and their corresponding mixture with R2 ≥ 0.9. Using SS in lower proportion (e.g. 20%) could reduce the odor during pelletization or even in the pellets. The results showed that co-pelletization of SS with FR and CS could be feasible approach to enhance the characteristics of pellets and reduced the energy consumption.

Pellet production from furfural residue and sawdust: Evaluating the characteristics and quality of pellets and their dependency on process parameters

A single pellet press was employed for production of furfural residue pellets (FRPs) and wood pellets (WPs). The effects of temperature (70–200 °C), pressure (70–160 MPa), moisture content (MC) (5.5–28%), particle size (0.25–0.5 and 0.5–1.41 mm) and a binder on the physical and mechanical characteristics and energy consumption of FRPs and WPs were investigated. Temperature and pressure were found to be the most dominant factors followed by MC and particle size. For FRPs, pellet density, strength and hardness increased with increasing temperature from 70 to 130 °C and increasing pressure from 70 to 160 MPa and then decreased at >130 °C and a MC of 5.5%. The highest particle density of ~1.43 g cm−3, strength >8 and 5.56 MPa, hardness 438.5 and 350.2 N mm−2 for particles 0.25–0.5 and 0.5–1.41 mm, respectively, was found at 130 °C, 160 MPa and 5.5% MC. For WPs, the highest pellet density, strength and hardness were achieved at 200 °C, ≥100 MPa. FRPs and WPs remained dimensionally stable particularly at temperature ≥130 °C, pressure 160 MPa and 5.5% MC. For a MC of 5.5%, pellets made at 200 °C were found to be water resistive. Increasing temperature, MC and use of a binder reduced the energy consumption of FRPs and WPs. Use of a binder was more beneficial for WPs compared to FRPs. FRPs had better quality and lower energy consumption than WPs. Temperatures of 130 °C and 200 °C, particle size of 0.25–0.5 mm and MC of 5.5% and 18% were found to be optimal for FRPs and WPs quality.

The insights into the catalytic performance of rare earth metal ions on lactic acid formation from biomass via microwave heating

• Ln 3+ showed special activity for lactic acid formation from biomass. • The activity increased monotonically with the atomic number of Ln 3+ . • Smaller ionic radius of Ln 3+ led to stronger interaction with glucose. • Ln 3+ with smaller ionic radius exhibited higher electron-withdrawing ability. • The orbital-stabilization ability of transition state increased with atomic number. The unique properties of rare earth metal offer attractive potentials for the application as catalyst in biomass valorization. In present work, we found that rare earth metal ions exhibited specific catalytic activity for lactic acid production from biomass, giving 75.9% and 71.0% carbon molar yield of lactic acid from glucose and furfural residue, respectively. The activity of lanthanide(III) ions increased monotonically with the atomic number, as well as the decreasing ionic radius, from La 3+ to Lu 3+ . The increasing oxidation potential with atomic number might facilitate the disproportionation reaction in glucose conversion via an intramolecular H-shift. DFT calculation further revealed that smaller ionic radius of lanthanide(III) ions led to stronger interaction between lanthanide(III) ions and glucose/fructose, as well as the less composition of 4 f in LUMO that enabled more activation of glucose. More importantly, lanthanide(III) with smaller ionic radius exhibited higher electron-withdrawing ability from the oxygen atom in -C = O. This enhanced the electrophilicity of C2, C3, and C4 atoms, and led to the more exposure especially for C4 atom, thereby significantly weakening C3-C4 bond. In addition to the increasing orbital-stabilization ability at the bond-breaking site in the corresponding transition state with atomic number, the energy barrier for C3-C4 cleavage in fructose was greatly reduced by heavy lanthanide(III) ions. These factors contributed to the special activity for lactic acid formation from biomass. The insights in this work might give some useful clues for the widespread application of rare earth metal in biomass valorization.

Comparison and analysis of one- and two-step activation for preparation of activated carbon from furfural residues

Activated carbon (AC) was prepared from furfural residue (FR) in a horizontal tube reactor under a carbon dioxide atmosphere comparing one- and two-step activation methods. Considerable differences were observed between ACs produced from these two methods in microscopic morphology, structural properties, organic structure, and crystallinity. It showed that the AC obtained by one-step activation (800 oC, 20 min, K2CO3: FR = 0.5:1) exhibited microporous and alkaline surface characteristics, and achieved the highest iodine value of 1305.7 mg/g and BET surface area 2083.6 m2/g. While, for the two-step method, the iodine value was 1004.9 mg/g and the BET surface area was only 726.3 m2/g. Furthermore, one-step activation obtained a higher yield of high-quality AC in a shorter activation time than the two-step method. The adsorption data fitted well with the Redlich-Peterson isotherm model and reached the highest value of 1761.1 mg/g, while the adsorption kinetics agreed well with the pseudo-second-order model.

Characterization and analysis of condensates and non-condensable gases from furfural residue via fast pyrolysis in a bubbling fluidized bed reactor

Pyrolysis of furfural residue (FR) was performed at 450–850 °C by employing a fluidized bed pyrolyzer (FBP). Addition of Kaolin and Ca-bentonite to FR considerably increased the condensate yields. The highest condensate yield (24.96 wt%) was obtained at 650 °C when Ca-bentonite was added. Fourier transform infra-red (FTIR) spectrum of pyrolysis oil (PO) indicated that catalysts promoted generation of alkene, amine, sulfate, sulfonyl chloride and oxime during pyrolysis. Gas chromatography mass spectrometry (GC–MS) demonstrated that catalysts significantly increased the content of furfural and phenol in PO and the maximum phenol content (15.36%) was achieved in PO650-3 for CaO. The quite low relative proportion (RP) of ammonia nitrogen in liquid indicated that the dominant form of nitrogen in liquid was not ammonia nitrogen. CaO had the ability to reduce H2S release, indicating significant sulfur retention capacity. The maximum RP (99.29%) of chlorine in bio-char (BC) was observed with the addition of CaO, showing its strong chlorine retention capacity.

Converting furfural residue wastes to carbon materials for high performance supercapacitor

Sustainable development based on the value-added utilization of furfural residues (FRs) is an effective way to achieve a profitable circular economy. This comprehensive work highlights the potential of FRs as precursor to prepare porous carbons for high performance supercapacitors (SCs). To improve the electrochemical performance of FR-based carbon materials, a facile route based on methanol pretreatment coupled with pre-carbonization and followed KOH activation is proposed. More defects could be obtained after methanol treatment, which is incline to optimize textural structure. The activated methanol treated FR-based carbon materials (AFRMs) possess high specific surface area (1753.5 m2 g−1), large pore volume (0.85 cm3 g−1), interconnected micro/mesoporous structure, which endow the AFRMs with good electrochemical performance in half-cell (326.1 F g−1 at 0.1 A g−1, 189.4 F g−1 at 50 A g−1 in 6 mol L−1 KOH). The constructed symmetric SCs based on KOH, KOH–K3Fe(CN)6 and KOH-KI electrolyte deliver energy density up to 8.9, 9.9 and 10.6 Wh kg−1 with a capacitance retention of over 86% after 10,000 cycles. Furthermore, the self-discharge can be restrained by the addition of K3Fe(CN)6 and KI in KOH electrolyte. This study provides an effective approach for high-valued utilization of FR waste.

Furfural production from sugarcane bagasse along with co-production of ethanol from furfural residues

Cellulosic ethanol production from non-detoxified furfural residues produced at different operating conditions from sugarcane bagasse was investigated. Simultaneous saccharification and fermentation (SSF) technique and preconditioned industrial strains of Saccharomyces cerevisiae, i.e., EthanolRed® and CelluX™4, were used for fermentation. The highest furfural yield of 69% (11.44 g/100 g of dry bagasse) was achieved at 170 °C and 0.5 wt.% H2SO4 (170–200 °C and 0–1 wt.% H2SO4), with corresponding ethanol yields of 77–95% (9.57–11.58 g/100 g of dry bagasse). The mass of ethanol produced reflected conversion of about 50% of cellulose in raw biomass due to cellulose degradation during furfural production. No production conditions could be found where both furfural and ethanol yields were maximized, indicating an unavoidable compromise between the two co-products. Furfural production conditions that provided an acceptable compromise between furfural and ethanol during co-production from sugarcane bagasse were 170 °C and 0.25 wt.% H2SO4, resulting in furfural mass of 7.64 g/100 g of dry bagasse and ethanol mass of 9.86 and 10.91 g/100 g of dry bagasse when using EthanolRed® and CelluX™4, respectively.

Enhanced production of levulinic acid/ester from furfural residue via pretreatment and two-stage alcoholysis

A two-stage alcoholysis was developed for improved conversion of furfural residue (FR) into levulinic acid (LA) and methyl levulinate (ML). Mixed acids including 0.01 M of H2SO4 and Al2(SO4)3 and methanol/water (50/50 v/v%) were identified as the suitable catalyst and reaction medium. The optimum alcoholysis conditions were 198 °C and 1.5 h for the 1st stage and then 163 °C and 1.3 h for the 2nd stage, and the maximum total yield of LA and ML can reach 25.64%. The reaction kinetics and possible conversion pathways for ML and LA production were proposed. On the basis, HCOOH/H2O2 pretreatment was screened for the pretreatment of FR, which increased the cellulose content of FR from 40.01 to 71.91%. The maximum total yield of LA and ML from pretreated FR was 44.96% under the optimum conditions of 195 °C and 1.9 h for the 1st stage and then 166 °C and 1.1 h for the 2nd stage, which was 16.09% higher than that of isothermal alcoholysis. The reusability tests showed that the Al2(SO4)3 was stable and can be reused at least 5 times. This study developed a new method for high-value utilization of FR and cleaner production of LA and ML.