At present, furan resin is the largest selling no-bake system of moulding sands. The most commonly used furan no-bake binders(FNB) are condensation products of furfuryl alcohol(FA) urea, formaldehyde and phenol. They ...At present, furan resin is the largest selling no-bake system of moulding sands. The most commonly used furan no-bake binders(FNB) are condensation products of furfuryl alcohol(FA) urea, formaldehyde and phenol. They are generally cured by exposure to organic sulfonic acids. FNB provide excellent mold and core strength, cure rapidly and allow the sand to be reclaimed at fairly high yields, generally 75%-80%, especially in applications where due allowance is made for the need to keep total sulfur content below 0.1%. However, due to probable carcinogenic properties of furfuryl alcohol, the EU Directive limits the content of this substance(in a monomer form in resin) to 25%. The classification of furfuryl alcohol and the resulting furan resin products has changed from "harmful" to "toxic by inhalation". The aim of this study was to determine the effect of free furfuryl alcohol content in the resin on the emission of harmful substances from the BTEX(Benzene Toluene Ethylbenzene & Xylene) and PAHs(polycyclic aromatic hydrocarbon) group exposed to high temperature and how it affects the emissions allowance of reclaimed sand in the matrix. Three resins from a leading manufacturer were examined, which contain a free furfuryl alcohol content of 71%-72%, about 50% and < 25%, respectively. The hardener for each resin was 65% aqueous solution of paratoluenesulfonic acid. Tests were carried out in semi-industrial conditions where liquid cast-iron was poured into sample sand mold at 1,350 °C. The matrix of the studied sands was reclaimed in the amount of 0, 50%, 100%, respectively.With the increase of free furfuryl alcohol content, the volume of evolved gases decreased. For all resins the main component from the BTEX group dominating in the emitted gases was benzene; however toluene also appeared in the amount of a few percentages. In contrast, ethylbenzene and xylenes occurred only in the gases emitted from resin-bonded sands with the largest furfuryl alcohol content. The increase in the share of reclaimed sands resulted in very significant increase in the volume of gas generated and participation of benzene in these gases. In terms of emission of compounds from the PAHs group virtually for all resins, the total content of these substances was comparable(within the limits of error). The main components were: fluoranthene, pyrene and benzo(a) anthracene.展开更多
Based on a special synthesis process of furan resin,the furfuryl alcohol(FA),the main component of typical no-bake furan resins is substituted by ethanol and xylitol mother liquor which is relatively low price and che...Based on a special synthesis process of furan resin,the furfuryl alcohol(FA),the main component of typical no-bake furan resins is substituted by ethanol and xylitol mother liquor which is relatively low price and chemically active.Through orthogonal test,the optimal amount of xylitol liquor,ethanol and modifier has been determined.Finally,the test results on technical properties show that the performance can meet the production requirement well,which indicate a success in this substituting attempt.展开更多
Simple bio-based abrasive grinding wheel based on thermosetting resin matrix was developed starting with condensed tannin and furfuryl alcohol,which are mainly derived from forest and agricultural products like tree b...Simple bio-based abrasive grinding wheel based on thermosetting resin matrix was developed starting with condensed tannin and furfuryl alcohol,which are mainly derived from forest and agricultural products like tree barks,wheat and crops.Fourier transform infrared spectra(FTIR)signified the acidic conditions are quiet efficient for the reaction of furfuryl alcohol,urea and glyoxal all together and the-CH_(2)-NH-and-CH_(2)-O-CH(OH)-groups are predominating in cross-linking of the tannin-furfuryl alcohol-urea-glyoxal(TFUG)resin.The strengthening contribution of the tannin was also confirmed by the preservation of its distinct crystallinity using X-ray diffraction(XRD).Differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA)ensured that TFUG resin can be cured at low temperature and offer higher heat resistance compared with phenol-formaldehyde(PF)resin.The high hardness and excellent compressive strength revealed by the corresponding investigations such as Brinell hardness,compression resistance,and grinding tests suggested a strong abrasive ability using the new grinding wheel compared with lab-made grinding wheel based on PF resin.This could be ascribed to the absence of cracks and low content of formed holes as confirmed using scanning electron microscopy(SEM)and balanced reaction conditions that leads to network structure with regular local reinforcements and homogeneous crosslink density.展开更多
An effect of phase compositions(rutile,Rut and anatase,Ant)of TiO_(2)supports on the selective hydrogenation of furfural to furfuryl alcohol was investigated.The 15%wt Ni/TiO_(2)catalysts were prepared by incipient im...An effect of phase compositions(rutile,Rut and anatase,Ant)of TiO_(2)supports on the selective hydrogenation of furfural to furfuryl alcohol was investigated.The 15%wt Ni/TiO_(2)catalysts were prepared by incipient impregnation method.The result showed that Ni supported on anatase-rutile mixed phase TiO_(2)(91%Rut and 9%Ant,A2)provided the highest furfuryl alcohol yield at 43.8%due to the relatively strong Ni-TiO_(2)interaction,its appropriate crystallite sizes,and high average pore sizes.Furthermore,the effect of cobalt as a promoter on Ni/TiO_(2)-A2 catalysts was studied.The result showed that the Ni-Co/TiO_(2)-A2 catalysts exhibited poorer catalyst performances compared to the monometallic Ni/TiO_(2),probably because addition of cobalt can lower the reduction temperatures of Ni/TiO_(2)and weaken the metal-support interaction.展开更多
Selective activation of C-O bond is of fundamental importance in the precise conversion of oxygenates into value-added compounds in an atom-economic and sustainable manner, and meanwhile, the structurally well-defined...Selective activation of C-O bond is of fundamental importance in the precise conversion of oxygenates into value-added compounds in an atom-economic and sustainable manner, and meanwhile, the structurally well-defined dual-atoms catalysts (DACs) have been scarcely investigated in this field. In this study, a series of transition metal DACs anchored on nitrogen-doped graphene (TM2/NC, TM=Pt, Ir, Rh, Pd, Ru, Co, Ni and Cu) was constructed to make a comprehensive investigation of their selectivity in the hydrogenative transformation of furfuryl alcohol (FAL), an important biomass platform molecule, to 1,2-pentanediol (1,2-PeD) via selective cleavage of furanic C5-O bond, by density functional theory (DFT) calculations and microkinetic modeling. We found that Ir2/NC demonstrated a high selectivity for the cleavage of furanic C5-O bond to produce 1,2-PeD, while the production of THFAL or 1,5-pentanediol (1,5-PeD) on other TM2/NC catalysts are more favorable. Furthermore, we found that the selective C-O bond cleavage of FAL furan ring is affected by the orbital overlap between the d-orbitals of the anchored metal atoms and the p-orbitals of the adsorbed C atom in FAL, suggesting that the selectivity of the C-O bond cleavage is inextricably related with the electronic property of the anchored metals.展开更多
Catalytic transfer hydroge nation(CTH)of furfural(FF)to furfu ryl alcohol(FFA)has received great intere st in recent years.He rein,Cu-Cs bimetallic supported catalyst,CuCs(2)-MCM,was developed for the CTH of FF to FFA...Catalytic transfer hydroge nation(CTH)of furfural(FF)to furfu ryl alcohol(FFA)has received great intere st in recent years.He rein,Cu-Cs bimetallic supported catalyst,CuCs(2)-MCM,was developed for the CTH of FF to FFA using formic as hydrogen donor.CuCs(2)-MCM achieved a 99.6%FFA yield at an optimized reaction conditions of 170℃,1 h.Cu species in CuCs(2)-MCM had dual functions in catalytically decomposing formic acid to generate hydrogen and hydrogenating FF to FFA.The doping of Cs made the size of Cu particles smaller and improved the dispersion of the Cu active sites.Impo rtantly,the Cs species played a favorable role in enhancing the hydrogenation activity as a promoter by adjusting the surface acidity of Cu species to an appropriate level.Correlation analysis showed that surface acidity is the primary factor to affect the catalytic activity of CuCs(2)-MCM.展开更多
The synthesis of a low cost no-bake furan resin with a high strength was researched in this paper. Through the analysis of main factors influencing the strength of furan resin, an orthogonal experiment was conducted t...The synthesis of a low cost no-bake furan resin with a high strength was researched in this paper. Through the analysis of main factors influencing the strength of furan resin, an orthogonal experiment was conducted to optimize synthesis of urea-formaldehyde furan resin with 3% nitrogen. The critical factors and their optimal levels were confirmed, and high strength property was obtained. Subsequently, some active substitute materials, including polyols A agent, methyl alcohol, mother liquid of xylitol, polyols B agent and ethanol, were used for partly substitution of furfural alcohol, the main material component of furan resin. A good combination of the substitute materials was determined to achieve a high strength, and the overall proportion of substitute materials to the resin is 20%. In this study, the substitution mechanism on furan resin was also characterized and analyzed by IR.展开更多
基金supported by the National Centre for Research and Development(PolandNo PBS2/A5/30/2013)
文摘At present, furan resin is the largest selling no-bake system of moulding sands. The most commonly used furan no-bake binders(FNB) are condensation products of furfuryl alcohol(FA) urea, formaldehyde and phenol. They are generally cured by exposure to organic sulfonic acids. FNB provide excellent mold and core strength, cure rapidly and allow the sand to be reclaimed at fairly high yields, generally 75%-80%, especially in applications where due allowance is made for the need to keep total sulfur content below 0.1%. However, due to probable carcinogenic properties of furfuryl alcohol, the EU Directive limits the content of this substance(in a monomer form in resin) to 25%. The classification of furfuryl alcohol and the resulting furan resin products has changed from "harmful" to "toxic by inhalation". The aim of this study was to determine the effect of free furfuryl alcohol content in the resin on the emission of harmful substances from the BTEX(Benzene Toluene Ethylbenzene & Xylene) and PAHs(polycyclic aromatic hydrocarbon) group exposed to high temperature and how it affects the emissions allowance of reclaimed sand in the matrix. Three resins from a leading manufacturer were examined, which contain a free furfuryl alcohol content of 71%-72%, about 50% and < 25%, respectively. The hardener for each resin was 65% aqueous solution of paratoluenesulfonic acid. Tests were carried out in semi-industrial conditions where liquid cast-iron was poured into sample sand mold at 1,350 °C. The matrix of the studied sands was reclaimed in the amount of 0, 50%, 100%, respectively.With the increase of free furfuryl alcohol content, the volume of evolved gases decreased. For all resins the main component from the BTEX group dominating in the emitted gases was benzene; however toluene also appeared in the amount of a few percentages. In contrast, ethylbenzene and xylenes occurred only in the gases emitted from resin-bonded sands with the largest furfuryl alcohol content. The increase in the share of reclaimed sands resulted in very significant increase in the volume of gas generated and participation of benzene in these gases. In terms of emission of compounds from the PAHs group virtually for all resins, the total content of these substances was comparable(within the limits of error). The main components were: fluoranthene, pyrene and benzo(a) anthracene.
文摘Based on a special synthesis process of furan resin,the furfuryl alcohol(FA),the main component of typical no-bake furan resins is substituted by ethanol and xylitol mother liquor which is relatively low price and chemically active.Through orthogonal test,the optimal amount of xylitol liquor,ethanol and modifier has been determined.Finally,the test results on technical properties show that the performance can meet the production requirement well,which indicate a success in this substituting attempt.
基金supported by the Youth Fund of the Natural Science Foundation of China(Grant No.31800482)Yunnan Provincial Natural Science Foundation(Grant No.2018FG001-095)+1 种基金Yunnan Provincial Reserve Talents for Middle&Young Academic and Technical Leaders(2019HB026)the Yunnan Provincial Youth Talent Support Project.
文摘Simple bio-based abrasive grinding wheel based on thermosetting resin matrix was developed starting with condensed tannin and furfuryl alcohol,which are mainly derived from forest and agricultural products like tree barks,wheat and crops.Fourier transform infrared spectra(FTIR)signified the acidic conditions are quiet efficient for the reaction of furfuryl alcohol,urea and glyoxal all together and the-CH_(2)-NH-and-CH_(2)-O-CH(OH)-groups are predominating in cross-linking of the tannin-furfuryl alcohol-urea-glyoxal(TFUG)resin.The strengthening contribution of the tannin was also confirmed by the preservation of its distinct crystallinity using X-ray diffraction(XRD).Differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA)ensured that TFUG resin can be cured at low temperature and offer higher heat resistance compared with phenol-formaldehyde(PF)resin.The high hardness and excellent compressive strength revealed by the corresponding investigations such as Brinell hardness,compression resistance,and grinding tests suggested a strong abrasive ability using the new grinding wheel compared with lab-made grinding wheel based on PF resin.This could be ascribed to the absence of cracks and low content of formed holes as confirmed using scanning electron microscopy(SEM)and balanced reaction conditions that leads to network structure with regular local reinforcements and homogeneous crosslink density.
文摘An effect of phase compositions(rutile,Rut and anatase,Ant)of TiO_(2)supports on the selective hydrogenation of furfural to furfuryl alcohol was investigated.The 15%wt Ni/TiO_(2)catalysts were prepared by incipient impregnation method.The result showed that Ni supported on anatase-rutile mixed phase TiO_(2)(91%Rut and 9%Ant,A2)provided the highest furfuryl alcohol yield at 43.8%due to the relatively strong Ni-TiO_(2)interaction,its appropriate crystallite sizes,and high average pore sizes.Furthermore,the effect of cobalt as a promoter on Ni/TiO_(2)-A2 catalysts was studied.The result showed that the Ni-Co/TiO_(2)-A2 catalysts exhibited poorer catalyst performances compared to the monometallic Ni/TiO_(2),probably because addition of cobalt can lower the reduction temperatures of Ni/TiO_(2)and weaken the metal-support interaction.
基金the National Key R&D Program of China(No.2022YFA1504601)Startup Program of the State Key Laboratory for Oxo Synthesis and Selective Oxidation of LICP,China(No.E0SX0184)+1 种基金the National Natural Science Foundation of China(Nos.22102193,21972151)the Key Research Program of Frontier Science of CAS(No.QYZDJSSW-SLH051).
文摘Selective activation of C-O bond is of fundamental importance in the precise conversion of oxygenates into value-added compounds in an atom-economic and sustainable manner, and meanwhile, the structurally well-defined dual-atoms catalysts (DACs) have been scarcely investigated in this field. In this study, a series of transition metal DACs anchored on nitrogen-doped graphene (TM2/NC, TM=Pt, Ir, Rh, Pd, Ru, Co, Ni and Cu) was constructed to make a comprehensive investigation of their selectivity in the hydrogenative transformation of furfuryl alcohol (FAL), an important biomass platform molecule, to 1,2-pentanediol (1,2-PeD) via selective cleavage of furanic C5-O bond, by density functional theory (DFT) calculations and microkinetic modeling. We found that Ir2/NC demonstrated a high selectivity for the cleavage of furanic C5-O bond to produce 1,2-PeD, while the production of THFAL or 1,5-pentanediol (1,5-PeD) on other TM2/NC catalysts are more favorable. Furthermore, we found that the selective C-O bond cleavage of FAL furan ring is affected by the orbital overlap between the d-orbitals of the anchored metal atoms and the p-orbitals of the adsorbed C atom in FAL, suggesting that the selectivity of the C-O bond cleavage is inextricably related with the electronic property of the anchored metals.
基金supported by the National Natural Science Fund of China(Nos.21776234,21978246)。
文摘Catalytic transfer hydroge nation(CTH)of furfural(FF)to furfu ryl alcohol(FFA)has received great intere st in recent years.He rein,Cu-Cs bimetallic supported catalyst,CuCs(2)-MCM,was developed for the CTH of FF to FFA using formic as hydrogen donor.CuCs(2)-MCM achieved a 99.6%FFA yield at an optimized reaction conditions of 170℃,1 h.Cu species in CuCs(2)-MCM had dual functions in catalytically decomposing formic acid to generate hydrogen and hydrogenating FF to FFA.The doping of Cs made the size of Cu particles smaller and improved the dispersion of the Cu active sites.Impo rtantly,the Cs species played a favorable role in enhancing the hydrogenation activity as a promoter by adjusting the surface acidity of Cu species to an appropriate level.Correlation analysis showed that surface acidity is the primary factor to affect the catalytic activity of CuCs(2)-MCM.
文摘The synthesis of a low cost no-bake furan resin with a high strength was researched in this paper. Through the analysis of main factors influencing the strength of furan resin, an orthogonal experiment was conducted to optimize synthesis of urea-formaldehyde furan resin with 3% nitrogen. The critical factors and their optimal levels were confirmed, and high strength property was obtained. Subsequently, some active substitute materials, including polyols A agent, methyl alcohol, mother liquid of xylitol, polyols B agent and ethanol, were used for partly substitution of furfural alcohol, the main material component of furan resin. A good combination of the substitute materials was determined to achieve a high strength, and the overall proportion of substitute materials to the resin is 20%. In this study, the substitution mechanism on furan resin was also characterized and analyzed by IR.
基金Shanxi Province Science Foundation for Youths(20210302124057)Doctoral Scientific Research Foundation of Taiyuan University of Science and Technology(2019060)+2 种基金Scientific and Technological Innovation Project of Colleges and Universities in Shanxi Province(2020L0353)Outstanding Doctoral Award Fund in Shanxi Province(20202017)National Natural Science fund of China(51871158).
基金supported by the National Natural Science Foundation of China(2113301121203221+1 种基金21473224)the Natural Science Foundation of Gansu Province(1308RJZA281)~~
