The traditional ammonia synthesis via the Haber–Bosch process requires large consumption of highpurity H_(2) and causes significant carbon emissions owing to the energy-intensive and complex hydrogen production steps...The traditional ammonia synthesis via the Haber–Bosch process requires large consumption of highpurity H_(2) and causes significant carbon emissions owing to the energy-intensive and complex hydrogen production steps conducted under harsh reaction conditions.Herein,we report a cyclic catalytic process for the production of NH_(3) by directly utilizing earth-abundant CH_(4) as a hydrogen source for N_(2) hydrogenation while simultaneously co-producing H_(2) over an alumina-supported iron catalyst(Fe/Al_(2)O_(3)).It achieves exceptional productivities of 2300μmol g^(-1)h^(-1)for NH_(3) and 400 mmol g^(-1)h^(-1)for H_(2) at700℃.By eliminating the coke that results from CH_(4) pyrolysis through a reaction with the greenhouse gas CO_(2) to produce valuable CO,we establish an atom-economic cyclic catalytic process while producing a CO stream intrinsically separated in the regeneration step.Mechanistic investigations indicate that the iron species in Fe/Al_(2) O_(3) serve as tri-functional active sites for CH_(4) pyrolysis,N_(2) hydrogenation,and coke elimination to produce CO,thus enabling an efficient and environmentally friendly cyclic catalytic process.展开更多
Terpenoids have drawn much attention to scientists in synthesizing high-performance bio-jet fuels due to their ring structures,which feature potential high densities.Here,a facile biphasic catalytic process has been d...Terpenoids have drawn much attention to scientists in synthesizing high-performance bio-jet fuels due to their ring structures,which feature potential high densities.Here,a facile biphasic catalytic process has been developed for the production of high-density tricyclic hydrocarbon biofuels from a monoterpenoid,1,8-cineole,using sulfuric acid(H2SO4)as the homogeneous catalyst.A^100%conversion of 1,8-cineole and a>40%carbon yield of cyclic dimers were achieved at 100℃within two hours.The mechanism for the acid-catalyzed conversion of 1,8-cineole to cyclic hydrocarbon dimers were explored.In particular,the formation of the diene intermediates and the following dimerization of dienes was essential to synthesize tricyclic terpene dimers.The biphasic catalytic process accelerated the deoxygenation rate and enabled the dimerization with the aid of organic solvent while controlling the reaction rates to avoid the formation of solid residues.Moreover,this process also facilitated the product separation by organic solvent extraction while enabling easy recycle of the homogenous catalysts.展开更多
This minireview's primary focus is to review recent studies from my research program on the development of one-pot,two-step processes for the synthesis of di-and tri-block polymers.In all of these prepared polymer...This minireview's primary focus is to review recent studies from my research program on the development of one-pot,two-step processes for the synthesis of di-and tri-block polymers.In all of these prepared polymeric materials at least one component is a polycarbonate derived from the copolymerization of CO_(2)and epoxides.Synthetic methodology for the preparation of polycarbonate diols of well-defined molecular weights with narrow polydispersities are presented using(salen)CoX/onium salt catalyst systems.These polyols were subsequently utilized in the synthesis of di-and tri-block polylactide/polycarbonate or polyphosphoester/polycarbonate polymers employing organocatalysts.In addition,the introduction of these polyols to a second epoxide/CO_(2)copolymerization process provided block polycarbonate materials.Of particular interest,the first or second epoxide monomer incorporated into the copolymer can possess vinyl groups for postpolymerization modification by thiol-ene chemistry.These degradable polymeric materials have significant potential for use in biomedical applications.展开更多
In this work,a new process for achieving the recovery of elemental sulfur by utilizing a fluidized catalytic cracking(FCC) riser reactor for SOxtreatment(FCC-DeSOx) is proposed.The process leverages the high temperatu...In this work,a new process for achieving the recovery of elemental sulfur by utilizing a fluidized catalytic cracking(FCC) riser reactor for SOxtreatment(FCC-DeSOx) is proposed.The process leverages the high temperatures and hydrocarbon concentrations in the FCC riser reactor to convert SOxinto H_(2)S.Subsequently,H_(2)S,along with the cracked gas,is processed downstream to produce sulfur.Thermodynamic analysis of the key reduction reactions in the FCC-DeSOxprocess revealed that complete conversion of SOxto H_(2)S is feasible in the dry gas(hydrogen-rich) prelift zone,as well as the upper and lower zones of the riser,upon achieving thermodynamic equilibrium.Experimental studies were conducted to replicate the conditions of these reaction zones using a low concentration of hydrogen gas as the reducing agent.Through process optimization,investigation of the minimum reaction time,and kinetic studies,the potential of this method for the complete reduction of SOxwas further confirmed.展开更多
Catalytic chemical processes such as hydrocracking,gasification and pyrolysis play a vital role in the renewable energy and net zero transition.Due to the complex and non-linear behaviours during operation,catalytic c...Catalytic chemical processes such as hydrocracking,gasification and pyrolysis play a vital role in the renewable energy and net zero transition.Due to the complex and non-linear behaviours during operation,catalytic chemical processes require a powerful modelling tool for prediction and optimisation for smart operation,speedy green process routes discovery and rapid process design.However,challenges remain due to the lack of an effective modelling and optimisation toolbox,which requires not only a precise analysis but also a fast optimisation.Here,we propose a hybrid machine learning strategy by embedding the physics-based continuum lumping kinetic model into the data-driven artificial neural network framework.This hybrid model is adopted as the surrogate model in the multi-objective optimisation and demonstrated in the benchmarking of a hydrocracking process.The results show that the novel hybrid surrogate model exhibits the mean square error less than 0.01 by comparing with the physics-based simulation results.This well-trained hybrid model was then integrated with non-dominated-sort genetic algorithm(NSGA-II)as the surrogate model to evaluate and optimise the yield and selectivity of the hydrocracking process.The Pareto front from the multi-objective optimisation was able to identify the trade-off curve between the objective functions which is essential for the decision-making during process design.Our work indicates that adopting the hybrid machine learning strategy as the surrogate model in the multi-objective optimisation is a promising approach in various complex catalytic chemical processes to enable an accurate computation as well as a rapid optimisation.展开更多
Ammonia(NH3)is mainly produced via the Haber-Bosch process.It was discovered that the performance of a wide variety of catalysts in NH3 synthesis could be considerably enhanced by the addition of rare earth elements(R...Ammonia(NH3)is mainly produced via the Haber-Bosch process.It was discovered that the performance of a wide variety of catalysts in NH3 synthesis could be considerably enhanced by the addition of rare earth elements(REEs).As a result,catalysts promoted by REEs,especially the Ru-based ones have been extensively investigated.In this review,we summarize the progress of utilizing REEs for ammonia synthesis and outline the prospects of using them in the design and development of highly efficient and stable catalysts for ammonia synthesis.展开更多
An electric discharge plasma reactor combined with a catalytic reactor wasstudied for removing nitrogen oxides. To understand the combined process thoroughly, dischargeplasma and catalytic process were separately stud...An electric discharge plasma reactor combined with a catalytic reactor wasstudied for removing nitrogen oxides. To understand the combined process thoroughly, dischargeplasma and catalytic process were separately studied first, and then the two processes were combinedfor the study. The plasma reactor was able to oxidize NO to NO_2 well although the oxidation ratedecreased with temperature. The plasma reactor alone did not reduce the NO_x (NO+NO_2) leveleffectively, but the increase in the ratio of NO_2 to NO as a result of plasma discharge led to theenhancement of NO_x removal efficiency even at lower temperatures over the catalyst surface(V_2O_5-WO_3/TiO_2). At a gas temperature of 100℃, the NO_x removal efficiency obtained using thecombined plasma catalytic process was 88% for an energy input of 36 eV/molecule or 30 J/l.展开更多
MgH_(2),albeit with slow desorption kinetics,has been extensively studied as one of the most ideal solid hydrogen storage materials.Adding such catalyst as Ni can improve the desorption kinetics of MgH_(2),whereas the...MgH_(2),albeit with slow desorption kinetics,has been extensively studied as one of the most ideal solid hydrogen storage materials.Adding such catalyst as Ni can improve the desorption kinetics of MgH_(2),whereas the catalytic role has been attributed to different substances such as Ni,Mg_(2)Ni,Mg_(2)NiH0.3,and Mg_(2)NiH4.In the present study,Ni nanoparticles(Ni-NPs)supported on mesoporous carbon(Ni@C)have been synthesized to improve the hydrogen desorption kinetics of MgH_(2).The utilization of Ni@C largely decreases the dehydrogenation activation energy from 176.9 to 79.3 kJ mol^(−1) and the peak temperature of dehydrogenation from 375.5 to 235℃.The mechanism of Ni catalyst is well examined by advanced aberration-corrected environmental transmission electron microscopy and/or x-ray diffraction.During the first dehydrogenation,detailed microstructural studies reveal that the decomposition of MgH_(2)is initially triggered by the Ni-NPs,which is the rate-limiting step.Subsequently,the generated Mg reacts rapidly with Ni-NPs to form Mg_(2)Ni,which further promotes the dehydrogenation of residual MgH_(2).In the following dehydrogenation cycle,Mg_(2)NiH4 can rapidly decompose into Mg_(2)Ni,which continuously promotes the decomposition of MgH_(2).Our study not only elucidates the mechanism of Ni catalyst but also helps design and assemble catalysts with improved dehydriding kinetics of MgH_(2).展开更多
Light olefins,particularly ethylene and propylene,are the most important building blocks for the petrochemical industry,and demand for their production has been increasing.The catalytic pyrolysis process(CPP)and the c...Light olefins,particularly ethylene and propylene,are the most important building blocks for the petrochemical industry,and demand for their production has been increasing.The catalytic pyrolysis process(CPP)and the corresponding catalyst,developed by SINOPEC Research Institute of Petroleum Processing Co.,Ltd.,are designed to maximize the light olefin yield from catalytic cracking of heavy feedstocks.However,owing to the continuing degradation of feedstocks,the original catalyst can no longer maintain its activity.Herein,we describe the rational design of the new catalyst,Epylene,from a new metal-modified hierarchical ZSM-5 zeolite and matrix.Epylene was tested in the CPP unit of Shaanxi Yanchang Coal Yulin Energy and Chemical Company.A test run and base run were conducted to demonstrate the better performance of Epylene compared with the original catalyst.The properties of the feedstocks and the operating conditions in both runs were similar.The light olefin yield was increased from 33.95%to 36.50%and the coke yield was only 9.58%in the test run,which was lower than that in the base run.展开更多
This article describes the application of technology for quenching catalytic pyrolysis gas at the Daqing commercial CPP test unit and the Shenyang commercial CPP production unit.On the basis of results for application...This article describes the application of technology for quenching catalytic pyrolysis gas at the Daqing commercial CPP test unit and the Shenyang commercial CPP production unit.On the basis of results for application of the Shenyang CPP unit this paper puts forward an improved process flow scheme for quenching the pyrolysis gas and made calculations using the process flowsheet software.Case Ⅰ of the process flow scheme,which is designed for full circulation of slurry,intends to use the pyrolysis light oil and fresh feed oil as the quenching media with the product slurry oil and fresh feedstock being discharged from the quench cooler bottom and routed directly to the reactor so that the fresh feed oil can be preheated prior to pyrolysis.Case Ⅱ of the process flow scheme intends to adopt recycle oil as the quenching medium with the product slurry and recycle oil being discharged from the quench cooler bottom to the fractionator,which then delivers the slurry from the bottom.These two cases for improving the process flow diagram can all effectively control the density and viscosity of the quenching medium to secure the smooth operation of quench cooler.展开更多
A novel nonlinear combination process monitoring method was proposed based on techniques with memo- ry effect （multivariate exponentially weighted moving average （MEWMA）） and kernel independent component analysis ...A novel nonlinear combination process monitoring method was proposed based on techniques with memo- ry effect （multivariate exponentially weighted moving average （MEWMA）） and kernel independent component analysis （KICA）. The method was developed for dealing with nonlinear issues and detecting small or moderate drifts in one or more process variables with autocorrelation. MEWMA charts use additional information from the past history of the process for keeping the memory effect of the process behavior trend. KICA is a recently devel- oped statistical technique for revealing hidden, nonlinear statistically independent factors that underlie sets of mea- surements and it is a two-phase algorithm., whitened kernel principal component analysis （KPCA） plus indepen- dent component analysis （ICA）. The application to the fluid catalytic cracking unit （FCCU） simulated process in- dicates that the proposed combined method based on MEWMA and KICA can effectively capture the nonlinear rela- tionship and detect small drifts in process variables. Its performance significantly outperforms monitoring method based on ICA, MEWMA-ICA and KICA, especially for lonu-term performance deterioration.展开更多
Due to the rapid development of China's economy and the rapid progress of science and technology in recent years, especially in China's industrial field, the level of environmental protection production techno...Due to the rapid development of China's economy and the rapid progress of science and technology in recent years, especially in China's industrial field, the level of environmental protection production technology and operation process determines and affects the quality of China's future production and living environment. In actual production and operation, due to the strict requirements of various production processes and technologies, a large amount of polluted industrial wastewater may be formed, which is difficult to be completely oxidized and degraded. In addition, there are also some persistent organic heavy metal pollutants with high industrial concentration, which makes our environmental protection work more difficult and has also attracted great attention from the leaders of relevant technicians. As the long-term chemical and biological treatment of organic wastewater in the past inevitably brings many environmental restrictions, how to effectively, properly, timely and efficiently treat these industrial wastewater to meet the objective needs of environmental discharge and water quality management has become the most important technical work in our country. Therefore, there is an urgent need for an environment-friendly sewage treatment method with good pollutant treatment effect and relatively large pollution cost saving and investment. Studies by relevant departments abroad have found that the catalytic biological oxidation degradation method can indeed achieve environmental protection, which is a key work objective. The mechanism mainly lies in improving the biocatalytic decomposition effect of the catalyst itself and enhancing the reduction rate of the bio-oxidation degradation reaction products. In order to effectively treat various volatile organic polymer pollutants with high concentration and difficult natural degradation and utilization, it can be combined with various wastewater and sludge treatment processes used in the past in China, such as biocatalytic treatment, chemical sludge flocculation precipitation, and then directly applied to the resource treatment project of organic wastewater pollutants, enabling China to better treat various industrial wastewater.展开更多
Processive catalysis represents a transformative approach to molecular transformations,wherein a catalyst remains bound to its substrate and undergoes multiple reaction cycles before dissociating.
Water oxidation to molecular dioxygen driven by visible light is essential but difficult in solar fuel production due to its sluggish reaction kinetics.Although the catalytic process is highly dependent on the coordin...Water oxidation to molecular dioxygen driven by visible light is essential but difficult in solar fuel production due to its sluggish reaction kinetics.Although the catalytic process is highly dependent on the coordination-unsaturated metal sites in coordination catalysts,the controllable design of catalysts with such catalytic sites remains challenging.Herein,we report two new Co-MOFs(CoBIM-1 and CoBIM-2)for photocatalytic water oxidation under visible light.The coordination environment of Co in Co-MOFs can be easily manipulated by changing the atmosphere and concentration of deprotonated solvent during synthesis.CoBIM-1 with coordinatively unsaturated Co sites showed good performance with an O_(2)production of 2.0 mmol g^(−1)h^(−1),in sharp contrast to its counterpart CoBIM-2.Furthermore,through isotope tracing experiments,we confirmed that the dioxygen was produced from water oxidation.This work highlights that the atmosphere during synthesis and solvent selection greatly regulate the crystal structures of MOFs and further manipulate their photocatalytic performance.展开更多
Carbon nanotube （CNT） arrays were fabricated on Ct-Me-N-（O） alloys with content of Ct in the range of 6-40 at.% by chemical vapour deposition. The Ct was a catalytic metal from the group of the following elements...Carbon nanotube （CNT） arrays were fabricated on Ct-Me-N-（O） alloys with content of Ct in the range of 6-40 at.% by chemical vapour deposition. The Ct was a catalytic metal from the group of the following elements： Ni, Co, Fe, Pd, while Me was a transition metal from the group of IV-VII of the periodic table （where Me=Ti, V, Cr, Zr, Nb, Mo, Ta, W, Re）. Carbon nanotubes were found to grow efficiently on the alloy surface with its composition containing Ti, V, Cr, Zr, Hf, Nb or Ta. The growth of CNTs was not observed when the alloy contained W or Re. Additions of oxygen and nitrogen in the alloy facilitated the formation of oxynitrides and catalyst extrusion on the alloy surface. Replacement of the metals in alloy composition affected the diameter of the resulting CNTs. The obtained results showed that the alloy films of varying thickness （10-500 nm） may be used for the CNTs growth. The resulting CNT material was highly homogenous and its synthesis reproducible.展开更多
A stable organometallic Pd (Ⅱ) compound Pd(ptac-C,N)(acac-O,O) (Hacac = acetyl acetone, Hptac = 3-(2-pyridinethioxy)-acac, formula: C15H17NO4SPd, Mr = 413.76) 1 has been synthesized and its crystal structure was dete...A stable organometallic Pd (Ⅱ) compound Pd(ptac-C,N)(acac-O,O) (Hacac = acetyl acetone, Hptac = 3-(2-pyridinethioxy)-acac, formula: C15H17NO4SPd, Mr = 413.76) 1 has been synthesized and its crystal structure was determined by X-ray crystallography. The crystal is of monoclinic with space group C2/c, a = 17.9342(3), b = 17.7791(4), c = 13.1800(1) ? b = 128.400(1), V = 3293.5(1) 3, Z = 8, Dc = 1.669 g/cm3, F(000) = 1664, m = 1.269 mm-1, R = 0.0261 and wR = 0.0710 for 2653 observed reflections (I > 2s(I)). There exist two Pd rings in the title compound, C(14)O(4)PdO(3)C(12)C(13) and C(1)NPdC(8)S, with the palladium atom taking a square-planar coordination. Two oxygen atoms from the acetyl acetone ligand (PdO, 1.991(2) and 2.036(2) ), one N atom (PdN 2.019 ? and the g-carbon atom (PdC 2.067(3) ? from the ptac ligand are coordinated to Pd.展开更多
We offered the new theory of neutron （magnetic isotope） catalysis. For the first time it was shown that the number of neutrons in the atom, which have anomalous magnetic effect, have a great influence on the chemica...We offered the new theory of neutron （magnetic isotope） catalysis. For the first time it was shown that the number of neutrons in the atom, which have anomalous magnetic effect, have a great influence on the chemical properties. Our proposed theory of neutron （magnetic isotope） catalysis takes into account the influence of the magnetic field on the catalytic processes.展开更多
A new process named CPP (Catalytic Pyrolysis Process) for producing ethylene andpropylene from heavy oil feedstock has been developed. The catalyst CEP was specially designedfor this process, which has bi-functional c...A new process named CPP (Catalytic Pyrolysis Process) for producing ethylene andpropylene from heavy oil feedstock has been developed. The catalyst CEP was specially designedfor this process, which has bi-functional catalytic activities for both carbonium ion reaction andfree radical reaction, so as to maximize the yields of ethylene and propylene. The commercial trialshowed that the yield of ethylene and propylene was 20.37% and 18.23% respectively inmaximum ethylene operation with Daqing AR as feedstock, and the yield of ethylene and propylenewas 9.77% and 24.60% respectively in maximum propylene operation by using the same feedstock.Compared with steam cracker, the feed cost of CPP is much lower for producing ethylene andpropylene.展开更多
Based on the analysis of recent projections by the International Energy Agency(IEA),to meet the growing and subsequently declining demands of oil from now to 2040,we need up to around 770 billion barrels of oil.Since ...Based on the analysis of recent projections by the International Energy Agency(IEA),to meet the growing and subsequently declining demands of oil from now to 2040,we need up to around 770 billion barrels of oil.Since the worldwide total proved reserves of easy-and-cheaper-to-produce conventional oils is roughly only 520.2 billion barrels,the remaining 249.8 billion barrels must be obtained from unconventional petroleum resources(i.e.heavy oils and bitumen).These resources are however very difficult and costly to upgrade and produce due to their inherently high asphaltene contents which are reflected in their very high viscosities and large densities.However,still they should prove attractive development prospects if,as much as practicably possible,their upgrading can be performed in conjunction with in situ or downhole catalytic upgrading processes.Such projects will contribute significantly towards smoother and greener transition to full decarbonisation.Advanced technologies,such as the toe-to-heel air injection coupled to its add-on in situ catalytic process(i.e.THAI-CAPRI processes),have the potential to develop these reserves,but require further developmental understanding to realise their full capability.In this work,a new detailed procedure for numerically simulating the THAI-CAPRI processes is presented.The numerical model is made-up of Athabasca-type bitumen and it has a horizontal producer(HP)well that is surrounded by an annular layer of alumina-supported cobalt-oxide-molybdenum-oxide(CoMo/γ-Al2O3)catalyst.The simulation is performed using the computer modelling group(CMG)reservoir simulator,STARS.This new work has shown that the choice of the frequency factor of the catalytic reactions allowed model validation based on the degree of catalytic upgrading in form of API gravity.Overall,the work herein identifies the important parameters,such as API gravity,peak temperature,oil production rate,cumulative oil production,produced oxygen concentration,temperature distribution profile,extent of coke deposition on the catalyst surface,etc.,governing the successful operation of the THAI-CAPRI processes.In particular,this study has shown that even in the vicinities of the mobile oil zone(MOZ)where the catalytic upgrading is expected to be taking place,the catalyst surfaces are covered with high concentration of coke.This finding is in parallel to the observations reported from experiment of CAPRI process alone.Therefore,it is concluded that when experimental studies of the THAI-CAPRI processes are to be conducted,a catalyst regeneration mechanism must be put in place in order to prolong the effectiveness and thus the life of the catalyst so that proper field operation design can be made.Additionally,the study has also shown that the temperature of the MOZ is less than 306°C and that implies that an external source of heating the annular catalyst layer must be provided in order to effect the catalytic upgrading in the THAI-CAPRI processes.Thus,a new study should look at the feasibility of targeted heating(in the case of microwave)or conductive or resistive heating(in the case of electrical heating)to raise the temperature of the annular catalyst layer to that required to achieve the catalytic upgrading.展开更多
基金financial support from the National Key R&D Program of China(2022YFA1504500 and 2023YFA1506300)the National Natural Science Foundation of China(22588201,22225204,and 22472169)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0600100)Liaoning Binhai Laboratory(LBLG-2024-03)。
文摘The traditional ammonia synthesis via the Haber–Bosch process requires large consumption of highpurity H_(2) and causes significant carbon emissions owing to the energy-intensive and complex hydrogen production steps conducted under harsh reaction conditions.Herein,we report a cyclic catalytic process for the production of NH_(3) by directly utilizing earth-abundant CH_(4) as a hydrogen source for N_(2) hydrogenation while simultaneously co-producing H_(2) over an alumina-supported iron catalyst(Fe/Al_(2)O_(3)).It achieves exceptional productivities of 2300μmol g^(-1)h^(-1)for NH_(3) and 400 mmol g^(-1)h^(-1)for H_(2) at700℃.By eliminating the coke that results from CH_(4) pyrolysis through a reaction with the greenhouse gas CO_(2) to produce valuable CO,we establish an atom-economic cyclic catalytic process while producing a CO stream intrinsically separated in the regeneration step.Mechanistic investigations indicate that the iron species in Fe/Al_(2) O_(3) serve as tri-functional active sites for CH_(4) pyrolysis,N_(2) hydrogenation,and coke elimination to produce CO,thus enabling an efficient and environmentally friendly cyclic catalytic process.
文摘Terpenoids have drawn much attention to scientists in synthesizing high-performance bio-jet fuels due to their ring structures,which feature potential high densities.Here,a facile biphasic catalytic process has been developed for the production of high-density tricyclic hydrocarbon biofuels from a monoterpenoid,1,8-cineole,using sulfuric acid(H2SO4)as the homogeneous catalyst.A^100%conversion of 1,8-cineole and a>40%carbon yield of cyclic dimers were achieved at 100℃within two hours.The mechanism for the acid-catalyzed conversion of 1,8-cineole to cyclic hydrocarbon dimers were explored.In particular,the formation of the diene intermediates and the following dimerization of dienes was essential to synthesize tricyclic terpene dimers.The biphasic catalytic process accelerated the deoxygenation rate and enabled the dimerization with the aid of organic solvent while controlling the reaction rates to avoid the formation of solid residues.Moreover,this process also facilitated the product separation by organic solvent extraction while enabling easy recycle of the homogenous catalysts.
基金National Science Foundation of USA(CHE 1057743)Robert A.Welch Foundation of Texas(A-0923)。
文摘This minireview's primary focus is to review recent studies from my research program on the development of one-pot,two-step processes for the synthesis of di-and tri-block polymers.In all of these prepared polymeric materials at least one component is a polycarbonate derived from the copolymerization of CO_(2)and epoxides.Synthetic methodology for the preparation of polycarbonate diols of well-defined molecular weights with narrow polydispersities are presented using(salen)CoX/onium salt catalyst systems.These polyols were subsequently utilized in the synthesis of di-and tri-block polylactide/polycarbonate or polyphosphoester/polycarbonate polymers employing organocatalysts.In addition,the introduction of these polyols to a second epoxide/CO_(2)copolymerization process provided block polycarbonate materials.Of particular interest,the first or second epoxide monomer incorporated into the copolymer can possess vinyl groups for postpolymerization modification by thiol-ene chemistry.These degradable polymeric materials have significant potential for use in biomedical applications.
基金supported by General Program of National Natural Science Foundation of China (22178385)。
文摘In this work,a new process for achieving the recovery of elemental sulfur by utilizing a fluidized catalytic cracking(FCC) riser reactor for SOxtreatment(FCC-DeSOx) is proposed.The process leverages the high temperatures and hydrocarbon concentrations in the FCC riser reactor to convert SOxinto H_(2)S.Subsequently,H_(2)S,along with the cracked gas,is processed downstream to produce sulfur.Thermodynamic analysis of the key reduction reactions in the FCC-DeSOxprocess revealed that complete conversion of SOxto H_(2)S is feasible in the dry gas(hydrogen-rich) prelift zone,as well as the upper and lower zones of the riser,upon achieving thermodynamic equilibrium.Experimental studies were conducted to replicate the conditions of these reaction zones using a low concentration of hydrogen gas as the reducing agent.Through process optimization,investigation of the minimum reaction time,and kinetic studies,the potential of this method for the complete reduction of SOxwas further confirmed.
基金The work is supported by the PhD studentship provided by the Department of Chemical Engineering,Loughborough University.Jin Xuan would like to acknowledge the support from EPSRC under the grant numbers EP/V042432/1 and EP/V011863/1.
文摘Catalytic chemical processes such as hydrocracking,gasification and pyrolysis play a vital role in the renewable energy and net zero transition.Due to the complex and non-linear behaviours during operation,catalytic chemical processes require a powerful modelling tool for prediction and optimisation for smart operation,speedy green process routes discovery and rapid process design.However,challenges remain due to the lack of an effective modelling and optimisation toolbox,which requires not only a precise analysis but also a fast optimisation.Here,we propose a hybrid machine learning strategy by embedding the physics-based continuum lumping kinetic model into the data-driven artificial neural network framework.This hybrid model is adopted as the surrogate model in the multi-objective optimisation and demonstrated in the benchmarking of a hydrocracking process.The results show that the novel hybrid surrogate model exhibits the mean square error less than 0.01 by comparing with the physics-based simulation results.This well-trained hybrid model was then integrated with non-dominated-sort genetic algorithm(NSGA-II)as the surrogate model to evaluate and optimise the yield and selectivity of the hydrocracking process.The Pareto front from the multi-objective optimisation was able to identify the trade-off curve between the objective functions which is essential for the decision-making during process design.Our work indicates that adopting the hybrid machine learning strategy as the surrogate model in the multi-objective optimisation is a promising approach in various complex catalytic chemical processes to enable an accurate computation as well as a rapid optimisation.
基金Project supported by the National Natural Science Foundation of China(22038002,21972019)。
文摘Ammonia(NH3)is mainly produced via the Haber-Bosch process.It was discovered that the performance of a wide variety of catalysts in NH3 synthesis could be considerably enhanced by the addition of rare earth elements(REEs).As a result,catalysts promoted by REEs,especially the Ru-based ones have been extensively investigated.In this review,we summarize the progress of utilizing REEs for ammonia synthesis and outline the prospects of using them in the design and development of highly efficient and stable catalysts for ammonia synthesis.
文摘An electric discharge plasma reactor combined with a catalytic reactor wasstudied for removing nitrogen oxides. To understand the combined process thoroughly, dischargeplasma and catalytic process were separately studied first, and then the two processes were combinedfor the study. The plasma reactor was able to oxidize NO to NO_2 well although the oxidation ratedecreased with temperature. The plasma reactor alone did not reduce the NO_x (NO+NO_2) leveleffectively, but the increase in the ratio of NO_2 to NO as a result of plasma discharge led to theenhancement of NO_x removal efficiency even at lower temperatures over the catalyst surface(V_2O_5-WO_3/TiO_2). At a gas temperature of 100℃, the NO_x removal efficiency obtained using thecombined plasma catalytic process was 88% for an energy input of 36 eV/molecule or 30 J/l.
基金supported by the National Natural Science Foundation of China(Nos.22279111,51971195,and 11935004)the Natural Science Foundation of Hebei Province(No.B2020203037)Subsidy for Hebei Key Laboratory of Applied Chemistry after Operation Performance(No.22567616H).
文摘MgH_(2),albeit with slow desorption kinetics,has been extensively studied as one of the most ideal solid hydrogen storage materials.Adding such catalyst as Ni can improve the desorption kinetics of MgH_(2),whereas the catalytic role has been attributed to different substances such as Ni,Mg_(2)Ni,Mg_(2)NiH0.3,and Mg_(2)NiH4.In the present study,Ni nanoparticles(Ni-NPs)supported on mesoporous carbon(Ni@C)have been synthesized to improve the hydrogen desorption kinetics of MgH_(2).The utilization of Ni@C largely decreases the dehydrogenation activation energy from 176.9 to 79.3 kJ mol^(−1) and the peak temperature of dehydrogenation from 375.5 to 235℃.The mechanism of Ni catalyst is well examined by advanced aberration-corrected environmental transmission electron microscopy and/or x-ray diffraction.During the first dehydrogenation,detailed microstructural studies reveal that the decomposition of MgH_(2)is initially triggered by the Ni-NPs,which is the rate-limiting step.Subsequently,the generated Mg reacts rapidly with Ni-NPs to form Mg_(2)Ni,which further promotes the dehydrogenation of residual MgH_(2).In the following dehydrogenation cycle,Mg_(2)NiH4 can rapidly decompose into Mg_(2)Ni,which continuously promotes the decomposition of MgH_(2).Our study not only elucidates the mechanism of Ni catalyst but also helps design and assemble catalysts with improved dehydriding kinetics of MgH_(2).
基金This research was financially supported by the National Key R&D Program of China(grant number 2022YFB3504000)the Contract Projects of China Petroleum&Chemical Corporation(SINOPEC Corp.)(grant number ST22005).
文摘Light olefins,particularly ethylene and propylene,are the most important building blocks for the petrochemical industry,and demand for their production has been increasing.The catalytic pyrolysis process(CPP)and the corresponding catalyst,developed by SINOPEC Research Institute of Petroleum Processing Co.,Ltd.,are designed to maximize the light olefin yield from catalytic cracking of heavy feedstocks.However,owing to the continuing degradation of feedstocks,the original catalyst can no longer maintain its activity.Herein,we describe the rational design of the new catalyst,Epylene,from a new metal-modified hierarchical ZSM-5 zeolite and matrix.Epylene was tested in the CPP unit of Shaanxi Yanchang Coal Yulin Energy and Chemical Company.A test run and base run were conducted to demonstrate the better performance of Epylene compared with the original catalyst.The properties of the feedstocks and the operating conditions in both runs were similar.The light olefin yield was increased from 33.95%to 36.50%and the coke yield was only 9.58%in the test run,which was lower than that in the base run.
文摘This article describes the application of technology for quenching catalytic pyrolysis gas at the Daqing commercial CPP test unit and the Shenyang commercial CPP production unit.On the basis of results for application of the Shenyang CPP unit this paper puts forward an improved process flow scheme for quenching the pyrolysis gas and made calculations using the process flowsheet software.Case Ⅰ of the process flow scheme,which is designed for full circulation of slurry,intends to use the pyrolysis light oil and fresh feed oil as the quenching media with the product slurry oil and fresh feedstock being discharged from the quench cooler bottom and routed directly to the reactor so that the fresh feed oil can be preheated prior to pyrolysis.Case Ⅱ of the process flow scheme intends to adopt recycle oil as the quenching medium with the product slurry and recycle oil being discharged from the quench cooler bottom to the fractionator,which then delivers the slurry from the bottom.These two cases for improving the process flow diagram can all effectively control the density and viscosity of the quenching medium to secure the smooth operation of quench cooler.
基金The National Natural Science Foundation ofChina(No60504033)
文摘A novel nonlinear combination process monitoring method was proposed based on techniques with memo- ry effect （multivariate exponentially weighted moving average （MEWMA）） and kernel independent component analysis （KICA）. The method was developed for dealing with nonlinear issues and detecting small or moderate drifts in one or more process variables with autocorrelation. MEWMA charts use additional information from the past history of the process for keeping the memory effect of the process behavior trend. KICA is a recently devel- oped statistical technique for revealing hidden, nonlinear statistically independent factors that underlie sets of mea- surements and it is a two-phase algorithm., whitened kernel principal component analysis （KPCA） plus indepen- dent component analysis （ICA）. The application to the fluid catalytic cracking unit （FCCU） simulated process in- dicates that the proposed combined method based on MEWMA and KICA can effectively capture the nonlinear rela- tionship and detect small drifts in process variables. Its performance significantly outperforms monitoring method based on ICA, MEWMA-ICA and KICA, especially for lonu-term performance deterioration.
文摘Due to the rapid development of China's economy and the rapid progress of science and technology in recent years, especially in China's industrial field, the level of environmental protection production technology and operation process determines and affects the quality of China's future production and living environment. In actual production and operation, due to the strict requirements of various production processes and technologies, a large amount of polluted industrial wastewater may be formed, which is difficult to be completely oxidized and degraded. In addition, there are also some persistent organic heavy metal pollutants with high industrial concentration, which makes our environmental protection work more difficult and has also attracted great attention from the leaders of relevant technicians. As the long-term chemical and biological treatment of organic wastewater in the past inevitably brings many environmental restrictions, how to effectively, properly, timely and efficiently treat these industrial wastewater to meet the objective needs of environmental discharge and water quality management has become the most important technical work in our country. Therefore, there is an urgent need for an environment-friendly sewage treatment method with good pollutant treatment effect and relatively large pollution cost saving and investment. Studies by relevant departments abroad have found that the catalytic biological oxidation degradation method can indeed achieve environmental protection, which is a key work objective. The mechanism mainly lies in improving the biocatalytic decomposition effect of the catalyst itself and enhancing the reduction rate of the bio-oxidation degradation reaction products. In order to effectively treat various volatile organic polymer pollutants with high concentration and difficult natural degradation and utilization, it can be combined with various wastewater and sludge treatment processes used in the past in China, such as biocatalytic treatment, chemical sludge flocculation precipitation, and then directly applied to the resource treatment project of organic wastewater pollutants, enabling China to better treat various industrial wastewater.
基金supported by National Natural Science Foundation of China(No.23CAA01015)China Petroleum&Chemical Corporation Seed Plan(No.2550042076).
文摘Processive catalysis represents a transformative approach to molecular transformations,wherein a catalyst remains bound to its substrate and undergoes multiple reaction cycles before dissociating.
基金supported by the National Natural Science Foundation of China(No.22171106,21871172,22201101,and 22001094)the Guangdong Major Project of Basic and Applied Research(No.2019B030302009)+4 种基金Guangdong Natural Science Foundation(No.2022A1515011937)the Fundamental Research Funds for the Central Universities(No.21622103)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110523)open fund of Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications(No.2022A06)Jinan University.
文摘Water oxidation to molecular dioxygen driven by visible light is essential but difficult in solar fuel production due to its sluggish reaction kinetics.Although the catalytic process is highly dependent on the coordination-unsaturated metal sites in coordination catalysts,the controllable design of catalysts with such catalytic sites remains challenging.Herein,we report two new Co-MOFs(CoBIM-1 and CoBIM-2)for photocatalytic water oxidation under visible light.The coordination environment of Co in Co-MOFs can be easily manipulated by changing the atmosphere and concentration of deprotonated solvent during synthesis.CoBIM-1 with coordinatively unsaturated Co sites showed good performance with an O_(2)production of 2.0 mmol g^(−1)h^(−1),in sharp contrast to its counterpart CoBIM-2.Furthermore,through isotope tracing experiments,we confirmed that the dioxygen was produced from water oxidation.This work highlights that the atmosphere during synthesis and solvent selection greatly regulate the crystal structures of MOFs and further manipulate their photocatalytic performance.
基金financially supported by the Russian Science Foundation(No.16-19-10625)
文摘Carbon nanotube （CNT） arrays were fabricated on Ct-Me-N-（O） alloys with content of Ct in the range of 6-40 at.% by chemical vapour deposition. The Ct was a catalytic metal from the group of the following elements： Ni, Co, Fe, Pd, while Me was a transition metal from the group of IV-VII of the periodic table （where Me=Ti, V, Cr, Zr, Nb, Mo, Ta, W, Re）. Carbon nanotubes were found to grow efficiently on the alloy surface with its composition containing Ti, V, Cr, Zr, Hf, Nb or Ta. The growth of CNTs was not observed when the alloy contained W or Re. Additions of oxygen and nitrogen in the alloy facilitated the formation of oxynitrides and catalyst extrusion on the alloy surface. Replacement of the metals in alloy composition affected the diameter of the resulting CNTs. The obtained results showed that the alloy films of varying thickness （10-500 nm） may be used for the CNTs growth. The resulting CNT material was highly homogenous and its synthesis reproducible.
基金the State Key Basic Research and Development Plan of China (001CB108906), the NNSF of China (No. 29733090 and No. 20173063), Key Project in KIP of CAS (KJCX2-H3) and the NSF of Fujian province (E0020001)
文摘A stable organometallic Pd (Ⅱ) compound Pd(ptac-C,N)(acac-O,O) (Hacac = acetyl acetone, Hptac = 3-(2-pyridinethioxy)-acac, formula: C15H17NO4SPd, Mr = 413.76) 1 has been synthesized and its crystal structure was determined by X-ray crystallography. The crystal is of monoclinic with space group C2/c, a = 17.9342(3), b = 17.7791(4), c = 13.1800(1) ? b = 128.400(1), V = 3293.5(1) 3, Z = 8, Dc = 1.669 g/cm3, F(000) = 1664, m = 1.269 mm-1, R = 0.0261 and wR = 0.0710 for 2653 observed reflections (I > 2s(I)). There exist two Pd rings in the title compound, C(14)O(4)PdO(3)C(12)C(13) and C(1)NPdC(8)S, with the palladium atom taking a square-planar coordination. Two oxygen atoms from the acetyl acetone ligand (PdO, 1.991(2) and 2.036(2) ), one N atom (PdN 2.019 ? and the g-carbon atom (PdC 2.067(3) ? from the ptac ligand are coordinated to Pd.
文摘We offered the new theory of neutron （magnetic isotope） catalysis. For the first time it was shown that the number of neutrons in the atom, which have anomalous magnetic effect, have a great influence on the chemical properties. Our proposed theory of neutron （magnetic isotope） catalysis takes into account the influence of the magnetic field on the catalytic processes.
文摘A new process named CPP (Catalytic Pyrolysis Process) for producing ethylene andpropylene from heavy oil feedstock has been developed. The catalyst CEP was specially designedfor this process, which has bi-functional catalytic activities for both carbonium ion reaction andfree radical reaction, so as to maximize the yields of ethylene and propylene. The commercial trialshowed that the yield of ethylene and propylene was 20.37% and 18.23% respectively inmaximum ethylene operation with Daqing AR as feedstock, and the yield of ethylene and propylenewas 9.77% and 24.60% respectively in maximum propylene operation by using the same feedstock.Compared with steam cracker, the feed cost of CPP is much lower for producing ethylene andpropylene.
文摘Based on the analysis of recent projections by the International Energy Agency(IEA),to meet the growing and subsequently declining demands of oil from now to 2040,we need up to around 770 billion barrels of oil.Since the worldwide total proved reserves of easy-and-cheaper-to-produce conventional oils is roughly only 520.2 billion barrels,the remaining 249.8 billion barrels must be obtained from unconventional petroleum resources(i.e.heavy oils and bitumen).These resources are however very difficult and costly to upgrade and produce due to their inherently high asphaltene contents which are reflected in their very high viscosities and large densities.However,still they should prove attractive development prospects if,as much as practicably possible,their upgrading can be performed in conjunction with in situ or downhole catalytic upgrading processes.Such projects will contribute significantly towards smoother and greener transition to full decarbonisation.Advanced technologies,such as the toe-to-heel air injection coupled to its add-on in situ catalytic process(i.e.THAI-CAPRI processes),have the potential to develop these reserves,but require further developmental understanding to realise their full capability.In this work,a new detailed procedure for numerically simulating the THAI-CAPRI processes is presented.The numerical model is made-up of Athabasca-type bitumen and it has a horizontal producer(HP)well that is surrounded by an annular layer of alumina-supported cobalt-oxide-molybdenum-oxide(CoMo/γ-Al2O3)catalyst.The simulation is performed using the computer modelling group(CMG)reservoir simulator,STARS.This new work has shown that the choice of the frequency factor of the catalytic reactions allowed model validation based on the degree of catalytic upgrading in form of API gravity.Overall,the work herein identifies the important parameters,such as API gravity,peak temperature,oil production rate,cumulative oil production,produced oxygen concentration,temperature distribution profile,extent of coke deposition on the catalyst surface,etc.,governing the successful operation of the THAI-CAPRI processes.In particular,this study has shown that even in the vicinities of the mobile oil zone(MOZ)where the catalytic upgrading is expected to be taking place,the catalyst surfaces are covered with high concentration of coke.This finding is in parallel to the observations reported from experiment of CAPRI process alone.Therefore,it is concluded that when experimental studies of the THAI-CAPRI processes are to be conducted,a catalyst regeneration mechanism must be put in place in order to prolong the effectiveness and thus the life of the catalyst so that proper field operation design can be made.Additionally,the study has also shown that the temperature of the MOZ is less than 306°C and that implies that an external source of heating the annular catalyst layer must be provided in order to effect the catalytic upgrading in the THAI-CAPRI processes.Thus,a new study should look at the feasibility of targeted heating(in the case of microwave)or conductive or resistive heating(in the case of electrical heating)to raise the temperature of the annular catalyst layer to that required to achieve the catalytic upgrading.
