Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent f...Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent for fragrances,cosmetics,food additives,and detergents,and can also be served as a moisturizer in cosmetics,showing broad application prospects.The distribution of DPG isomers in the products synthesized from PO and PG has a significant impactΔrGΔrHΔfHθΔfGθPO+PG⇌DPG PO+DPG⇌TPG PG+PG⇌DPG+H_(2)O PG+DPG⇌TPG+H_(2)O on the quality of the products.Therefore,conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation.So,in this paper,the thermodynamic parameters of PO,1,2-PG,H_(2)O,tripropylene glycol(TPG)and three isomers of DPG under different reaction conditions is calculated.Additionally,the,and lnK for four potential reactions at various reaction temperatures and pressures are calculated.By designing isodesmic reactions and combining the results of thermodynamic calculations,the and for the isomers of DPG are obtained,and the relative error is less than 7%.The results show that in the process of preparing DPG by PO and PG,when PO∶PG=1,the reaction temperature ranges from 298.15 to 413.15 K,and the pressure ranges from 101.325 to 506.625 kPa,the reactions of and are thermodynamically spontaneous.While the reactions of and are thermodynamically unspontaneous.The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa.The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions.The accuracy of the computational results is verified through experimental design,and based on this,the factors affecting product distribution are analyzed.展开更多
We report a robust pillar-layered metal-organic framework,Zn‑tfbdc‑dabco(tfbdc:tetrafluoroterephthal-ate,dabco:1,4-diazabicyclo[2.2.2]octane),featuring the fluorinated pore environment,for the preferential binding of ...We report a robust pillar-layered metal-organic framework,Zn‑tfbdc‑dabco(tfbdc:tetrafluoroterephthal-ate,dabco:1,4-diazabicyclo[2.2.2]octane),featuring the fluorinated pore environment,for the preferential binding of propane over propylene and thus highly inverse selective separation of propane/propylene mixture.The inverse propane-selective performance of Zn‑tfbdc‑dabco for the propane/propylene separation was validated by single-component gas adsorption isotherms,isosteric enthalpy of adsorption calculations,ideal adsorbed solution theory calculations,along with the breakthrough experiment.The customized fluorinated networks served as a propane-trap to form more interactions with the exposed hydrogen atoms of propane,as unveiled by the simulation studies at the molecular level.With the advantage of inverse propane-selective adsorption behavior,high adsorption capacity,good cycling stability,and low isosteric enthalpy of adsorption,Zn‑tfbdc‑dabco can be a promising candidate adsorbent for the challenging propane/propylene separation to realize one-step purification of the target propylene substance.展开更多
Propylene oxide(PO),with its reactive three-membered epoxide functional group,exhibits remarkable functional versatility and serves as a crucial bridge connecting the gaps between fossil energy utilization and chemica...Propylene oxide(PO),with its reactive three-membered epoxide functional group,exhibits remarkable functional versatility and serves as a crucial bridge connecting the gaps between fossil energy utilization and chemical intermediate generation for new material innovation [1].For instance,PO's downstream derivatives,such as polyether polyols,carbonic esters,and polyurethanes,are widely utilized in wind power generation,battery electrolytes,solar cells,and CO_(2)-based degradable polymers,contributing to sustainable decarbonization in industry [2].展开更多
The production of high-purity propylene glycol monomethyl ether acetate(PMA)through the transesterification of propylene glycol monomethyl ether(PM)and methyl acetate(MeOAc)is traditionally catalyzed by sodium methoxi...The production of high-purity propylene glycol monomethyl ether acetate(PMA)through the transesterification of propylene glycol monomethyl ether(PM)and methyl acetate(MeOAc)is traditionally catalyzed by sodium methoxide.However,the practical application of this method is significantly hindered by the inherent limitations of sodium methoxide,such as its high sensitivity to moisture and propensity for solid precipitation,which impede its effective use in continuous processes.This work proposed a continuous catalytic distillation(CD)process utilizing Amberlyst 15 cation exchange resin as the catalyst.A comprehensive series of reaction kinetic and CD experiments were conducted to evaluate the performance of the proposed process.The results demonstrate that under the optimal operating conditions,namely an ester-to-ether molar ratio of 6:1,a refluxratio of 5:1,a total feed rate of 0.92 g‧min^(-1),and an evaporation rate of 266.47 m^(3)‧m^(-2)‧h^(-1),the conversion rate of PM achieves 99.95%,and the PMA yield is 97.31%.Based on these findings,a process flowsheet for a continuous CD process tailored for the production of electronic-grade PMA is presented.This design incorporates light and heavy removal steps to ensure the production of PMA with a purity of 99.99%.Additionally,the process utilizes pressure swing distillation to recover MeOAc,thereby enhancing the overall efficiencyand sustainability of the production process.The proposed continuous CD process offers a highly efficient,cost-effective,and environmentally sustainable solution for the production of electronic-grade PMA.展开更多
ITR zeolite could be potentially used as catalysts in methanol to propylene(MTP),where their performance is strongly related to its Al distribution.However,the control of Al distribution in ITR zeolite poses a signifi...ITR zeolite could be potentially used as catalysts in methanol to propylene(MTP),where their performance is strongly related to its Al distribution.However,the control of Al distribution in ITR zeolite poses a significant synthetic challenge.Herein,we demonstrate the possibility to control the Al distribution in ITR zeolites using zeolite A as an aluminum source(A-ITR).The A-ITR exhibited similar crystallinity,nanosheet morphology,textual parameters,and acidic concentration with those of conventional ITR made zeolites using aluminum isopropoxide as an aluminum source(C-ITR).Characterizations of the zeolite product with^(27)Al MQ.MAS NMR spectra,^(27)Al MAS NMR spectra,and 1-hexene cracking reveal that the A-ITR zeolites have more Al species distributed in T6 and T8 sites located in relatively smaller micropores of the framework than C-ITR.As a result,the A-ITR gave enhanced catalyst lifetime and propylene selectivity due to the suppression of the aromatic cycle in the MTP reaction,compared with the C-ITR.This work provides an alternative approach to prepare efficient ITR zeolites for MTP reaction.展开更多
A novel environmentally benign biphasic system composed of propylene carbonate(PC) and aqueous solution of p-toluenesulfonic acid(p-TsOH aq) was designed for the efficient valorization of lignocellulosic bamboo residu...A novel environmentally benign biphasic system composed of propylene carbonate(PC) and aqueous solution of p-toluenesulfonic acid(p-TsOH aq) was designed for the efficient valorization of lignocellulosic bamboo residues, resulting in more than 95.5% of hemicellulose and 97.2% of lignin digested under mild conditions of 130°C for 1 h. Meanwhile, 91.9% of cellulose was retained with loose structure, followed by 95.8% enzyme hydrolysis yield and 347.9 mg g-1of glucose yield. Notably, the synergistic effect between PC and p-TsOH on efficiency and selectivity was proposed by a control group experiment and subsequently verified, which is believed to be responsible for the simultaneous degradation and separation of lignin and hemicelluloses into oligomeric phenols and pentose, also facilitating subsequent valorization.Furthermore, the novel PC/p-TsOH aq biphasic system demonstrated excellent retrievability and adaptability to different feedstocks, offering a promising green strategy for the efficient valorization of lignocellulosic biomass in industrial biorefineries.展开更多
Addressing the persistent challenge of shale hydration and swelling in water-based drilling fluids(WBDFs),this study developed a smart thermo-responsive shale inhibitor,Hyperbranched PolyethyleneiminePropylene Oxide-N...Addressing the persistent challenge of shale hydration and swelling in water-based drilling fluids(WBDFs),this study developed a smart thermo-responsive shale inhibitor,Hyperbranched PolyethyleneiminePropylene Oxide-N-isopropylacrylamide(HPN).It was synthesized by grafting hyperbranched polyethyleneimine(HPEI)with propylene oxide(PO)and N-isopropylacrylamide(NIPAM),creating a synergistic hydration barrier through hydrophobic association and temperature-triggered pore plugging.Structural characterization by Fourier-Transform Infrared(FTIR)spectroscopy and gel permeation chromatography(GPC)confirmed the successful formation of the HPN terpolymer,revealing a unique“cationic–nonionic”amphiphilic architecture with temperature-responsive properties.Performance evaluation demonstrated that HPN significantly outperforms conventional inhibitors,including potassium chloride(KCl),cationic polyacrylamide(C-PAM),polyethylene glycol(PEG),polyetheramine(PEA),and HPEI.It achieved a superior performance profile:a low yield point of 14.6 Pa,a maximum linear expansion of only 3.1 mm,and a high shale recovery rate of 62.8%at 20%bentonite content.The inhibition mechanism is attributed to a powerful synergy of electrostatic adsorption,hydrophobic association,and thermally induced aggregation,which provides robust performance under demanding conditions such as high salinity(200,000 mg/L NaCl)and high temperature(120℃ ).Thermogravimetric analysis confirmed excellent thermal stability,and the inhibitor exhibited low biological toxicity,complying with stringent environmental standards.These results establish HPN as an efficient,eco-friendly,and field-ready shale inhibitor well-suited for challenging drilling operations.展开更多
The increasing demand for efficient energy conversion and sustainable chemical production has driven research into advanced catalytic processes,with copper-based catalysts emerging as promising candidates due to their...The increasing demand for efficient energy conversion and sustainable chemical production has driven research into advanced catalytic processes,with copper-based catalysts emerging as promising candidates due to their cost-effectiveness and versatile redox properties.However,their practical application in electro-assisted organic reactions is often limited by challenges in achieving high selectivity and efficiency.This study introduces a novel approach that harnesses Cu^(+)-Cu^(0) defect-induced sites to enhance catalytic selectivity and efficiency in electro-assisted propylene oxidation.By inducing lattice distortions,a unique interplay between metallic and oxidized copper is achieved,improving O_(2) activation and stabilizing reactive intermediates.This dopant-controlled modification enriches the copper lattice with active sites,significantly boosting surface reactivity.Under ambient conditions,the Cu^(+)-Cu^(0) interface achieves high selectivity for propylene glycol through selective(*)^OOH formation.This work could lay the groundwork for new paradigms in catalytic design through engineered defects.展开更多
As an important chemical product,propylene(C_(3)H_(6))is widely used in production of many crucial chemical products such as polypropylene.Propane(C_(3)H_(8))is introduced as an inevitable gas impurity during the naph...As an important chemical product,propylene(C_(3)H_(6))is widely used in production of many crucial chemical products such as polypropylene.Propane(C_(3)H_(8))is introduced as an inevitable gas impurity during the naphtha cracking in propylene production.At present,thermal-driven energy-intensive cryogenic distillation is the most common purification method in industry.An energy-efficient,cost-effective and environmental-friendly separation technology is required to get polymer grade C_(3)H_(6)(higher than 99.5%).In face of the increasing demand of propylene,new separation technology based on porous adsorbents is expected to be a promising alternative.In recent years,metal-organic frameworks(MOFs)have obtained attention by their high porosity,regular adjustable pore shape and pore environment and keep making breakthroughs in separation and purification of many industrial gas mixtures,and are thus considered as one of the most potential types of adsorbents.The physical properties of C_(3)H_(6)and C_(3)H_(8),such as boiling point,size and kinetic diameter,are close to each other,making their separation a challenge.Most C_(3)H_(6)/C_(3)H_(8)sieving MOFs based on narrow sieving channels that restrict the access of molecules larger than their confined entrance purify mixtures at the cost of diffusion and capacity.To improve the adsorption of MOFs based on molecular sieving,a novel‘pearl-necklace’strategy was designed,which was named for its connected channel and molecular pocket vividly,but the diffusion limitation remains unsolved.展开更多
Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of pro...Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of products is profoundly influenced by the catalyst structure.In this study,Fe_(2)O_(3)-doped NiSO_(4)/Al_(2)O_(3) catalysts have been meticulously developed to facilitate the selective trimerization of propylene under mild conditions.Significantly,the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst demonstrates an enhanced reaction rate(48.5 mmol_(C3)/(g_(cat).·h)),alongside a high yield of C9(~32.2%),significantly surpassing the performance of the NiSO_(4)/Al_(2)O_(3) catalyst(C9:~24.1%).The incorporation of Fe_(2)O_(3) modifies the migration process of sulfate ions,altering the Lewis acidity of the electron-deficient Ni and Fe sites on the catalyst and resulting a shift in product distribution from a Schulz-Flory distribution to a Poisson distribution.This shift is primarily ascribed to the heightened energy barrier for theβ-H elimination reaction in the C6 alkyl intermediates on the doped catalyst,further promoting polymerization to yield a greater quantity of Type II C9.Furthermore,the validation of the Cossee-Arlman mechanism within the reaction pathway has been confirmed.It is noteworthy that the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst exhibits remarkable stability exceeding 80 h in the selective trimerization of propylene.These research findings significantly enhance our understanding of the mechanisms underlying olefin oligomerization reactions and provide invaluable insights for the development of more effective catalysts.展开更多
The elementary reactions of propylene polymerization catalyzed by conventional Ziegler-Natta catalysts was proposed according to the comprehensive view and without considering the effect of any impurity in the materia...The elementary reactions of propylene polymerization catalyzed by conventional Ziegler-Natta catalysts was proposed according to the comprehensive view and without considering the effect of any impurity in the material on propylene polymerization. The Monte Carlo simulation technique was employed to investigate the kinetics of propylene polymerization in order to determine the validity of the stationary state assumption and the effects of the polymerization temperature on the polymerization. The simulated total amount of active species, which only increases quickly at the beginning of the polymerization, indicates that the stationary state assumption in the studied system is valid. Moreover, significant effects of polymerization temperature on the polymerization conversion, and the molecular weight and its distribution were also analyzed. The simulated results show that the consumption rate of propylene increases with the increase of polymerization temperature; the maximum values of the number-average degree of polymerization are constant at different polymerization temperatures, however, the peak appears earlier with the higher temperature; as the polymerization temperature increases, the average molecular weight decreases and the molecular weight distribution changes greatly.展开更多
In order to further study the postpartum care technology of dairy cows,the effects of oral administration of propylene glycol or Ca-P-Mg mixture and compound oral rehydration salts on milk quality and SCC of dairy cow...In order to further study the postpartum care technology of dairy cows,the effects of oral administration of propylene glycol or Ca-P-Mg mixture and compound oral rehydration salts on milk quality and SCC of dairy cows after birth were investigated. The results showed that the milk fat and dry matter contents in the dairy cows administered with Ca-P-Mg mixture and compound oral rehydration salts were higher than those in the dairy cows administered with propylene glycol（P 〈0.05）. However, there were no significant differences in milk sugar and protein contents and SCC between the two administration groups.展开更多
In this article VLE data for a ternary system (propylene-methanol-water) under 30～60 C,0. 3～0. 9 MPa with a mass ratio of methanol to water of 9:1, 8: 2, 7: 3 were determined with a static equilibrium still, and wer...In this article VLE data for a ternary system (propylene-methanol-water) under 30～60 C,0. 3～0. 9 MPa with a mass ratio of methanol to water of 9:1, 8: 2, 7: 3 were determined with a static equilibrium still, and were correlated by using Peng-Robinson model. The average relative error ofpropylene concentration in liquid phase is 1. 46 %. The results indicate that the models are very suitablefor the ternary system and the data are reliable.展开更多
基金Supported by the Natural Science Foundation of Shanxi Province(202203021221303)the Science and Technology Major Project of Shanxi Province(202005D121002)the Science and Technology Cooperation and Communication Project of Shanxi Province(202304041101016)。
文摘Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent for fragrances,cosmetics,food additives,and detergents,and can also be served as a moisturizer in cosmetics,showing broad application prospects.The distribution of DPG isomers in the products synthesized from PO and PG has a significant impactΔrGΔrHΔfHθΔfGθPO+PG⇌DPG PO+DPG⇌TPG PG+PG⇌DPG+H_(2)O PG+DPG⇌TPG+H_(2)O on the quality of the products.Therefore,conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation.So,in this paper,the thermodynamic parameters of PO,1,2-PG,H_(2)O,tripropylene glycol(TPG)and three isomers of DPG under different reaction conditions is calculated.Additionally,the,and lnK for four potential reactions at various reaction temperatures and pressures are calculated.By designing isodesmic reactions and combining the results of thermodynamic calculations,the and for the isomers of DPG are obtained,and the relative error is less than 7%.The results show that in the process of preparing DPG by PO and PG,when PO∶PG=1,the reaction temperature ranges from 298.15 to 413.15 K,and the pressure ranges from 101.325 to 506.625 kPa,the reactions of and are thermodynamically spontaneous.While the reactions of and are thermodynamically unspontaneous.The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa.The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions.The accuracy of the computational results is verified through experimental design,and based on this,the factors affecting product distribution are analyzed.
文摘We report a robust pillar-layered metal-organic framework,Zn‑tfbdc‑dabco(tfbdc:tetrafluoroterephthal-ate,dabco:1,4-diazabicyclo[2.2.2]octane),featuring the fluorinated pore environment,for the preferential binding of propane over propylene and thus highly inverse selective separation of propane/propylene mixture.The inverse propane-selective performance of Zn‑tfbdc‑dabco for the propane/propylene separation was validated by single-component gas adsorption isotherms,isosteric enthalpy of adsorption calculations,ideal adsorbed solution theory calculations,along with the breakthrough experiment.The customized fluorinated networks served as a propane-trap to form more interactions with the exposed hydrogen atoms of propane,as unveiled by the simulation studies at the molecular level.With the advantage of inverse propane-selective adsorption behavior,high adsorption capacity,good cycling stability,and low isosteric enthalpy of adsorption,Zn‑tfbdc‑dabco can be a promising candidate adsorbent for the challenging propane/propylene separation to realize one-step purification of the target propylene substance.
基金supported by the National Natural Science Foundation of China (29792072, 22278441, 22478452)National Key Research and Development Program of China (937) (2006CB202508)the SINOPEC Project (419019-2, 413108)。
文摘Propylene oxide(PO),with its reactive three-membered epoxide functional group,exhibits remarkable functional versatility and serves as a crucial bridge connecting the gaps between fossil energy utilization and chemical intermediate generation for new material innovation [1].For instance,PO's downstream derivatives,such as polyether polyols,carbonic esters,and polyurethanes,are widely utilized in wind power generation,battery electrolytes,solar cells,and CO_(2)-based degradable polymers,contributing to sustainable decarbonization in industry [2].
基金supported by the National Natural Science Foundation of China(22378065,22278077 and 22278076)the Key Program of Natural Science Foundation of Fujian Province of China(2022J02019).
文摘The production of high-purity propylene glycol monomethyl ether acetate(PMA)through the transesterification of propylene glycol monomethyl ether(PM)and methyl acetate(MeOAc)is traditionally catalyzed by sodium methoxide.However,the practical application of this method is significantly hindered by the inherent limitations of sodium methoxide,such as its high sensitivity to moisture and propensity for solid precipitation,which impede its effective use in continuous processes.This work proposed a continuous catalytic distillation(CD)process utilizing Amberlyst 15 cation exchange resin as the catalyst.A comprehensive series of reaction kinetic and CD experiments were conducted to evaluate the performance of the proposed process.The results demonstrate that under the optimal operating conditions,namely an ester-to-ether molar ratio of 6:1,a refluxratio of 5:1,a total feed rate of 0.92 g‧min^(-1),and an evaporation rate of 266.47 m^(3)‧m^(-2)‧h^(-1),the conversion rate of PM achieves 99.95%,and the PMA yield is 97.31%.Based on these findings,a process flowsheet for a continuous CD process tailored for the production of electronic-grade PMA is presented.This design incorporates light and heavy removal steps to ensure the production of PMA with a purity of 99.99%.Additionally,the process utilizes pressure swing distillation to recover MeOAc,thereby enhancing the overall efficiencyand sustainability of the production process.The proposed continuous CD process offers a highly efficient,cost-effective,and environmentally sustainable solution for the production of electronic-grade PMA.
基金supported by the National Key Research and Development Program of China(2022YFA1503602)the National Natural Science Foundation of China(22288101,U21B20101 and 22172141)+1 种基金the BASF International Network of Centers of Excellence projectthe Zhejiang Provincial Natural Science Foundation of China(LR24B030001)。
文摘ITR zeolite could be potentially used as catalysts in methanol to propylene(MTP),where their performance is strongly related to its Al distribution.However,the control of Al distribution in ITR zeolite poses a significant synthetic challenge.Herein,we demonstrate the possibility to control the Al distribution in ITR zeolites using zeolite A as an aluminum source(A-ITR).The A-ITR exhibited similar crystallinity,nanosheet morphology,textual parameters,and acidic concentration with those of conventional ITR made zeolites using aluminum isopropoxide as an aluminum source(C-ITR).Characterizations of the zeolite product with^(27)Al MQ.MAS NMR spectra,^(27)Al MAS NMR spectra,and 1-hexene cracking reveal that the A-ITR zeolites have more Al species distributed in T6 and T8 sites located in relatively smaller micropores of the framework than C-ITR.As a result,the A-ITR gave enhanced catalyst lifetime and propylene selectivity due to the suppression of the aromatic cycle in the MTP reaction,compared with the C-ITR.This work provides an alternative approach to prepare efficient ITR zeolites for MTP reaction.
基金the Fundamental Research Foundation of CAF(CAFYBB2022QB001)National Nature Science Foundation of China(32222058)for financial support.
文摘A novel environmentally benign biphasic system composed of propylene carbonate(PC) and aqueous solution of p-toluenesulfonic acid(p-TsOH aq) was designed for the efficient valorization of lignocellulosic bamboo residues, resulting in more than 95.5% of hemicellulose and 97.2% of lignin digested under mild conditions of 130°C for 1 h. Meanwhile, 91.9% of cellulose was retained with loose structure, followed by 95.8% enzyme hydrolysis yield and 347.9 mg g-1of glucose yield. Notably, the synergistic effect between PC and p-TsOH on efficiency and selectivity was proposed by a control group experiment and subsequently verified, which is believed to be responsible for the simultaneous degradation and separation of lignin and hemicelluloses into oligomeric phenols and pentose, also facilitating subsequent valorization.Furthermore, the novel PC/p-TsOH aq biphasic system demonstrated excellent retrievability and adaptability to different feedstocks, offering a promising green strategy for the efficient valorization of lignocellulosic biomass in industrial biorefineries.
基金supported by the Major Scientific and Technological Project of China National Offshore Oil Corporation(CNOOC-KJ135ZDXM38ZJ05ZJ).
文摘Addressing the persistent challenge of shale hydration and swelling in water-based drilling fluids(WBDFs),this study developed a smart thermo-responsive shale inhibitor,Hyperbranched PolyethyleneiminePropylene Oxide-N-isopropylacrylamide(HPN).It was synthesized by grafting hyperbranched polyethyleneimine(HPEI)with propylene oxide(PO)and N-isopropylacrylamide(NIPAM),creating a synergistic hydration barrier through hydrophobic association and temperature-triggered pore plugging.Structural characterization by Fourier-Transform Infrared(FTIR)spectroscopy and gel permeation chromatography(GPC)confirmed the successful formation of the HPN terpolymer,revealing a unique“cationic–nonionic”amphiphilic architecture with temperature-responsive properties.Performance evaluation demonstrated that HPN significantly outperforms conventional inhibitors,including potassium chloride(KCl),cationic polyacrylamide(C-PAM),polyethylene glycol(PEG),polyetheramine(PEA),and HPEI.It achieved a superior performance profile:a low yield point of 14.6 Pa,a maximum linear expansion of only 3.1 mm,and a high shale recovery rate of 62.8%at 20%bentonite content.The inhibition mechanism is attributed to a powerful synergy of electrostatic adsorption,hydrophobic association,and thermally induced aggregation,which provides robust performance under demanding conditions such as high salinity(200,000 mg/L NaCl)and high temperature(120℃ ).Thermogravimetric analysis confirmed excellent thermal stability,and the inhibitor exhibited low biological toxicity,complying with stringent environmental standards.These results establish HPN as an efficient,eco-friendly,and field-ready shale inhibitor well-suited for challenging drilling operations.
基金supported by financial aid from the National Key Research and Development Project of China(2022YFC2905201)the National Natural Science Foundation of China(92262301)+2 种基金financial aid from the Science and Technology Agency of Henan Province(222102240120)the Key Research and Development Project of Jiangxi Province(20243BBG71021)the Pioneer Talent Recruitment Program(Category B),Chinese Academy of Sciences(E425C002)。
文摘The increasing demand for efficient energy conversion and sustainable chemical production has driven research into advanced catalytic processes,with copper-based catalysts emerging as promising candidates due to their cost-effectiveness and versatile redox properties.However,their practical application in electro-assisted organic reactions is often limited by challenges in achieving high selectivity and efficiency.This study introduces a novel approach that harnesses Cu^(+)-Cu^(0) defect-induced sites to enhance catalytic selectivity and efficiency in electro-assisted propylene oxidation.By inducing lattice distortions,a unique interplay between metallic and oxidized copper is achieved,improving O_(2) activation and stabilizing reactive intermediates.This dopant-controlled modification enriches the copper lattice with active sites,significantly boosting surface reactivity.Under ambient conditions,the Cu^(+)-Cu^(0) interface achieves high selectivity for propylene glycol through selective(*)^OOH formation.This work could lay the groundwork for new paradigms in catalytic design through engineered defects.
基金support of the National Natural Science Foundation of China(Nos.22378369 and 22205207)Major Project of Natural Science Foundation of Zhejiang Province(LD24B060001).
文摘As an important chemical product,propylene(C_(3)H_(6))is widely used in production of many crucial chemical products such as polypropylene.Propane(C_(3)H_(8))is introduced as an inevitable gas impurity during the naphtha cracking in propylene production.At present,thermal-driven energy-intensive cryogenic distillation is the most common purification method in industry.An energy-efficient,cost-effective and environmental-friendly separation technology is required to get polymer grade C_(3)H_(6)(higher than 99.5%).In face of the increasing demand of propylene,new separation technology based on porous adsorbents is expected to be a promising alternative.In recent years,metal-organic frameworks(MOFs)have obtained attention by their high porosity,regular adjustable pore shape and pore environment and keep making breakthroughs in separation and purification of many industrial gas mixtures,and are thus considered as one of the most potential types of adsorbents.The physical properties of C_(3)H_(6)and C_(3)H_(8),such as boiling point,size and kinetic diameter,are close to each other,making their separation a challenge.Most C_(3)H_(6)/C_(3)H_(8)sieving MOFs based on narrow sieving channels that restrict the access of molecules larger than their confined entrance purify mixtures at the cost of diffusion and capacity.To improve the adsorption of MOFs based on molecular sieving,a novel‘pearl-necklace’strategy was designed,which was named for its connected channel and molecular pocket vividly,but the diffusion limitation remains unsolved.
文摘Propylene,a readily accessible and economically viable light olefin,has garnered substantial interest for its potential conversion into valuable higher olefins through oligomerization processes.The distribution of products is profoundly influenced by the catalyst structure.In this study,Fe_(2)O_(3)-doped NiSO_(4)/Al_(2)O_(3) catalysts have been meticulously developed to facilitate the selective trimerization of propylene under mild conditions.Significantly,the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst demonstrates an enhanced reaction rate(48.5 mmol_(C3)/(g_(cat).·h)),alongside a high yield of C9(~32.2%),significantly surpassing the performance of the NiSO_(4)/Al_(2)O_(3) catalyst(C9:~24.1%).The incorporation of Fe_(2)O_(3) modifies the migration process of sulfate ions,altering the Lewis acidity of the electron-deficient Ni and Fe sites on the catalyst and resulting a shift in product distribution from a Schulz-Flory distribution to a Poisson distribution.This shift is primarily ascribed to the heightened energy barrier for theβ-H elimination reaction in the C6 alkyl intermediates on the doped catalyst,further promoting polymerization to yield a greater quantity of Type II C9.Furthermore,the validation of the Cossee-Arlman mechanism within the reaction pathway has been confirmed.It is noteworthy that the 0.25Fe_(2)O_(3)-NiSO_(4)/Al_(2)O_(3) catalyst exhibits remarkable stability exceeding 80 h in the selective trimerization of propylene.These research findings significantly enhance our understanding of the mechanisms underlying olefin oligomerization reactions and provide invaluable insights for the development of more effective catalysts.
基金The National Natural Science Foundation of China(No.20406016)the Project of Fujian Petrochemical Company of SIN-OPEC (No.MS/FJ-08-JS-15-2005-01).
文摘The elementary reactions of propylene polymerization catalyzed by conventional Ziegler-Natta catalysts was proposed according to the comprehensive view and without considering the effect of any impurity in the material on propylene polymerization. The Monte Carlo simulation technique was employed to investigate the kinetics of propylene polymerization in order to determine the validity of the stationary state assumption and the effects of the polymerization temperature on the polymerization. The simulated total amount of active species, which only increases quickly at the beginning of the polymerization, indicates that the stationary state assumption in the studied system is valid. Moreover, significant effects of polymerization temperature on the polymerization conversion, and the molecular weight and its distribution were also analyzed. The simulated results show that the consumption rate of propylene increases with the increase of polymerization temperature; the maximum values of the number-average degree of polymerization are constant at different polymerization temperatures, however, the peak appears earlier with the higher temperature; as the polymerization temperature increases, the average molecular weight decreases and the molecular weight distribution changes greatly.
基金Supported by Technology Research,Demonstration and Promotion Project of Beijing Vocational College of Agriculture(XY-YF-14-17,XY-YF-14-11)~~
文摘In order to further study the postpartum care technology of dairy cows,the effects of oral administration of propylene glycol or Ca-P-Mg mixture and compound oral rehydration salts on milk quality and SCC of dairy cows after birth were investigated. The results showed that the milk fat and dry matter contents in the dairy cows administered with Ca-P-Mg mixture and compound oral rehydration salts were higher than those in the dairy cows administered with propylene glycol（P 〈0.05）. However, there were no significant differences in milk sugar and protein contents and SCC between the two administration groups.
文摘In this article VLE data for a ternary system (propylene-methanol-water) under 30～60 C,0. 3～0. 9 MPa with a mass ratio of methanol to water of 9:1, 8: 2, 7: 3 were determined with a static equilibrium still, and were correlated by using Peng-Robinson model. The average relative error ofpropylene concentration in liquid phase is 1. 46 %. The results indicate that the models are very suitablefor the ternary system and the data are reliable.
