Feldspar minerals are widely present in clastic reservoirs of hydrocarbon-bearing basins,where they undergo significant dissolution during burial processes.The dissolution kinetics and evolutionary trends of feldspar ...Feldspar minerals are widely present in clastic reservoirs of hydrocarbon-bearing basins,where they undergo significant dissolution during burial processes.The dissolution kinetics and evolutionary trends of feldspar under burial conditions are critical for the formation of secondary porosity and the evolution of reservoir spaces.The feldspar dissolution process is frequently associated with the precipitation and transformation of complex authigenic minerals,making it challenging to accurately determine dissolution rates under near-equilibrium conditions.This study performed experimental simulations of feldspar(K-feldspar and albite)dissolution under conditions ranging from far-from-equilibrium to near-equilibrium,with varying temperatures and pCO_(2).Under near-equilibrium conditions,scanning electron microscopy(SEM),energy-dispersive spectroscopy(EDS),and laser confocal microscopy were employed to achieve accurate quantification of the dissolution volume of feldspar samples.The dissolution rates of feldspar under near-equilibrium conditions,along with the factors influencing these rates,were systematically investigated.The results indicate that the dissolution rates of K-feldspar under near-equilibrium conditions at temperatures and pCO_(2)levels of 80℃/1 bar,120℃/4.2 bar,and 160℃/17.9 bar are 2.16695×10^(15)–8.040×10^(15),4.49288×10^(15)–1.480×10^(14),and 6.17462×10^(15)–2.496×10^(14)mol cm^(-2)s^(-1),respectively.Under the same near-equilibrium conditions,the dissolution rates of albite are 2.93294×10^(15)–1.365×10^(14),5.54499×10^(15)–2.170×10^(14),and 9.42841×10^(15)–3.074×10^(14)mol cm^(-2)s^(-1),respectively.The dissolution rates of feldspar under near-equilibrium conditions are significantly lower(1.5–2orders of magnitude at high temperatures)than those under far-equilibrium conditions.Furthermore,as the temperature increases by a gradient of 40℃,the dissolution rate only increases by only 1.5 times,which is substantially lower than the rate increase observed under far-equilibrium conditions.The discrepancy between feldspar dissolution rates under far-equilibrium conditions(L-TST)and near-equilibrium conditions increases with rising temperature.Under identical experimental conditions,the dissolution rate of albite under near-equilibrium conditions is higher than that of K-feldspar.The precipitation and transformation of secondary minerals regulate feldspar dissolution under near-equilibrium conditions by altering ion concentrations in the solution.The p H of the solution also plays a significant role in controlling feldspar dissolution under near-equilibrium conditions.This study establishes a method for quantitatively analyzing mineral dissolution using the surface morphological features of dissolved and undissolved segments of polished feldspar samples.This method avoids relying on changes in ion concentrations in the reaction solution,making it more reasonable and widely applicable.Moreover,the results provide valuable insights into feldspar dissolution kinetics under burial conditions within closed systems,enabling a more accurate assessment of the contribution of feldspar dissolution to pore formation in reservoirs.展开更多
The accumulation of discarded petroleum-based plastics causes serious environmental crises.Currently,recyclable polymers with neutrality in thermodynamics,such as polyesters,polycarbonates,and polyolefins,have been de...The accumulation of discarded petroleum-based plastics causes serious environmental crises.Currently,recyclable polymers with neutrality in thermodynamics,such as polyesters,polycarbonates,and polyolefins,have been developed as promising alternatives to traditional petroleum-based polymers.However,the chemical recycle of these polymers usually requires high energy input and expensive catalysts.Dynamic covalent bonds,such as thioester and disulfide bonds,have emerged as building blocks for constructing recyclable polymers that can be rapidly degraded/recycled under mild conditions.In this review,we introduce representative studies on recyclable polythioesters and polydisulfides with respect to their synthetic strategies,thermodynamic manipulation,physicochemical properties,and preliminary applications.We also highlight the important role of kinetic factors played in the design of recyclable polymers.Finally,major challenges,perspectives,and future opportunities in the synthesis and applications of polythioesters/polydisulfides are discussed.展开更多
It is a challenge to make thorough but efficient experimental designs for the coupled mineral dissolution and precipitation studies in a multi-mineral system, because it is difficult to speculate the best experimental...It is a challenge to make thorough but efficient experimental designs for the coupled mineral dissolution and precipitation studies in a multi-mineral system, because it is difficult to speculate the best experimental duration, optimal sampling schedule, effects of different experimental conditions, and how to maximize the experimental outputs prior to the actual experiments. Geochemical modeling is an efficient and effective tool to assist the experimental design by virtually running all scenarios of interest for the studied system and predicting the experimental outcomes. Here we demonstrated an example of geochemical modeling assisted experimental design of coupled labradorite dissolution and calcite and clayey mineral precipitation using multiple isotope tracers. In this study, labradorite(plagioclase) was chosen as the reactant because it is both a major component and one of the most reactive minerals in basalt. Following our isotope doping studies of single minerals in the last ten years, initial solutions in the simulations were doped withmultiple isotopes(e.g., Ca and Si). Geochemical modeling results show that the use of isotope tracers gives us orders of magnitude more sensitivity than the conventional method based on concentrations and allows us to decouple dissolution and precipitation reactions at near-equilibrium condition. The simulations suggest that the precise unidirectional dissolution rates can inform us which rate laws plagioclase dissolution has followed. Calcite precipitation occurred at near-equilibrium and the multiple isotope tracer experiments would provide near-equilibrium precipitation rates, which was a challenge for the conventional concentration-based experiments. In addition, whether the precipitation of clayey phases is the rate-limiting step in some multi-mineral systems will be revealed. Overall, the modeling results of multimineral reaction kinetics will improve the understanding of the coupled dissolution–precipitation in the multi-mineral systems and the quality of geochemical modeling prediction of CO_(2) removal and storage efficacy in the basalt systems.展开更多
测定了近临界状态下甲醇-大豆油二元体系的液液相平衡数据,温度、压力范围分别为381.2～472.2 K、9.79～18.16 MPa。用PR状态方程关联了所测的液液相平衡数据。PR方程中的参数a和b采用van der Walls单流体混合规则。采用单参数van der W...测定了近临界状态下甲醇-大豆油二元体系的液液相平衡数据,温度、压力范围分别为381.2～472.2 K、9.79～18.16 MPa。用PR状态方程关联了所测的液液相平衡数据。PR方程中的参数a和b采用van der Walls单流体混合规则。采用单参数van der Waals模型计算交互参数项aij和bij,二者各包含一可调参数kij和lij。对可调参数kij和lij,采用了与温度无关和与温度有关两种处理方法,并根据实验数据估计了可调参数值。采用与温度无关的可调参数时,用PR方程关联实验数据所得均方偏差和平均偏差(按质量分数计)分别为0.0391和0.0166;采用与温度有关的可调参数时,均方偏差和平均偏差相应为0.0380和0.0162。表明PR状态方程适用于近临界状态下甲醇与大豆油的液液相平衡计算。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42222208,42488101)。
文摘Feldspar minerals are widely present in clastic reservoirs of hydrocarbon-bearing basins,where they undergo significant dissolution during burial processes.The dissolution kinetics and evolutionary trends of feldspar under burial conditions are critical for the formation of secondary porosity and the evolution of reservoir spaces.The feldspar dissolution process is frequently associated with the precipitation and transformation of complex authigenic minerals,making it challenging to accurately determine dissolution rates under near-equilibrium conditions.This study performed experimental simulations of feldspar(K-feldspar and albite)dissolution under conditions ranging from far-from-equilibrium to near-equilibrium,with varying temperatures and pCO_(2).Under near-equilibrium conditions,scanning electron microscopy(SEM),energy-dispersive spectroscopy(EDS),and laser confocal microscopy were employed to achieve accurate quantification of the dissolution volume of feldspar samples.The dissolution rates of feldspar under near-equilibrium conditions,along with the factors influencing these rates,were systematically investigated.The results indicate that the dissolution rates of K-feldspar under near-equilibrium conditions at temperatures and pCO_(2)levels of 80℃/1 bar,120℃/4.2 bar,and 160℃/17.9 bar are 2.16695×10^(15)–8.040×10^(15),4.49288×10^(15)–1.480×10^(14),and 6.17462×10^(15)–2.496×10^(14)mol cm^(-2)s^(-1),respectively.Under the same near-equilibrium conditions,the dissolution rates of albite are 2.93294×10^(15)–1.365×10^(14),5.54499×10^(15)–2.170×10^(14),and 9.42841×10^(15)–3.074×10^(14)mol cm^(-2)s^(-1),respectively.The dissolution rates of feldspar under near-equilibrium conditions are significantly lower(1.5–2orders of magnitude at high temperatures)than those under far-equilibrium conditions.Furthermore,as the temperature increases by a gradient of 40℃,the dissolution rate only increases by only 1.5 times,which is substantially lower than the rate increase observed under far-equilibrium conditions.The discrepancy between feldspar dissolution rates under far-equilibrium conditions(L-TST)and near-equilibrium conditions increases with rising temperature.Under identical experimental conditions,the dissolution rate of albite under near-equilibrium conditions is higher than that of K-feldspar.The precipitation and transformation of secondary minerals regulate feldspar dissolution under near-equilibrium conditions by altering ion concentrations in the solution.The p H of the solution also plays a significant role in controlling feldspar dissolution under near-equilibrium conditions.This study establishes a method for quantitatively analyzing mineral dissolution using the surface morphological features of dissolved and undissolved segments of polished feldspar samples.This method avoids relying on changes in ion concentrations in the reaction solution,making it more reasonable and widely applicable.Moreover,the results provide valuable insights into feldspar dissolution kinetics under burial conditions within closed systems,enabling a more accurate assessment of the contribution of feldspar dissolution to pore formation in reservoirs.
基金supported by the National Natural Science Foundation of China (22125101)the fellowship of the China Postdoctoral Science Foundation Funded Project (2020M680193)the China Postdoctoral Science Special Foundation Funded Project (2021T140008)
文摘The accumulation of discarded petroleum-based plastics causes serious environmental crises.Currently,recyclable polymers with neutrality in thermodynamics,such as polyesters,polycarbonates,and polyolefins,have been developed as promising alternatives to traditional petroleum-based polymers.However,the chemical recycle of these polymers usually requires high energy input and expensive catalysts.Dynamic covalent bonds,such as thioester and disulfide bonds,have emerged as building blocks for constructing recyclable polymers that can be rapidly degraded/recycled under mild conditions.In this review,we introduce representative studies on recyclable polythioesters and polydisulfides with respect to their synthetic strategies,thermodynamic manipulation,physicochemical properties,and preliminary applications.We also highlight the important role of kinetic factors played in the design of recyclable polymers.Finally,major challenges,perspectives,and future opportunities in the synthesis and applications of polythioesters/polydisulfides are discussed.
基金partially supported by U.S. National Science Foundation grants EAR-2221907partly sponsored by agencies of the United States Government。
文摘It is a challenge to make thorough but efficient experimental designs for the coupled mineral dissolution and precipitation studies in a multi-mineral system, because it is difficult to speculate the best experimental duration, optimal sampling schedule, effects of different experimental conditions, and how to maximize the experimental outputs prior to the actual experiments. Geochemical modeling is an efficient and effective tool to assist the experimental design by virtually running all scenarios of interest for the studied system and predicting the experimental outcomes. Here we demonstrated an example of geochemical modeling assisted experimental design of coupled labradorite dissolution and calcite and clayey mineral precipitation using multiple isotope tracers. In this study, labradorite(plagioclase) was chosen as the reactant because it is both a major component and one of the most reactive minerals in basalt. Following our isotope doping studies of single minerals in the last ten years, initial solutions in the simulations were doped withmultiple isotopes(e.g., Ca and Si). Geochemical modeling results show that the use of isotope tracers gives us orders of magnitude more sensitivity than the conventional method based on concentrations and allows us to decouple dissolution and precipitation reactions at near-equilibrium condition. The simulations suggest that the precise unidirectional dissolution rates can inform us which rate laws plagioclase dissolution has followed. Calcite precipitation occurred at near-equilibrium and the multiple isotope tracer experiments would provide near-equilibrium precipitation rates, which was a challenge for the conventional concentration-based experiments. In addition, whether the precipitation of clayey phases is the rate-limiting step in some multi-mineral systems will be revealed. Overall, the modeling results of multimineral reaction kinetics will improve the understanding of the coupled dissolution–precipitation in the multi-mineral systems and the quality of geochemical modeling prediction of CO_(2) removal and storage efficacy in the basalt systems.
文摘测定了近临界状态下甲醇-大豆油二元体系的液液相平衡数据,温度、压力范围分别为381.2～472.2 K、9.79～18.16 MPa。用PR状态方程关联了所测的液液相平衡数据。PR方程中的参数a和b采用van der Walls单流体混合规则。采用单参数van der Waals模型计算交互参数项aij和bij,二者各包含一可调参数kij和lij。对可调参数kij和lij,采用了与温度无关和与温度有关两种处理方法,并根据实验数据估计了可调参数值。采用与温度无关的可调参数时,用PR方程关联实验数据所得均方偏差和平均偏差(按质量分数计)分别为0.0391和0.0166;采用与温度有关的可调参数时,均方偏差和平均偏差相应为0.0380和0.0162。表明PR状态方程适用于近临界状态下甲醇与大豆油的液液相平衡计算。
