Dechlorination of crude oil is an effective way to alleviate corrosion in refinery units,and the critical process is the removal of organochlorine which can be efficiently removed through nucleophilic substitution rea...Dechlorination of crude oil is an effective way to alleviate corrosion in refinery units,and the critical process is the removal of organochlorine which can be efficiently removed through nucleophilic substitution reaction catalyzed by phase transfer.Herein,seven typical chlorinated alkanes were selected as model compounds to study the mechanism of dechlorination of crude oil by phase transfer catalyst in the nucleophilic substitution method,and a new dechlorination reagent using hexamethyl quaternary ammonium hydroxide(HMQAH)with two quaternary ammonium groups as phase transfer catalyst,ethylenediamine as nucleophile and ethanol as solvent was developed.The results show that the dechlorinating performance of the dechlorination reagent on the model compounds decreases in the following order:epichlorohydrin>1,2-dichlorobutane>1,2-dichloroethane>1,3-dichloropropane>2-chloropropane>1-chlorobutane>chloroisobutane.Meanwhile the results of the reaction kinetics show that epichlorohydrin with epoxy structure has the lowest activation energy in the process of nucleophilic substitution reaction by the phase transfer catalyst which makes it easier to be removed by the dechlorination reagent.The removal rate of epichlorohydrin can reach up to 99.4%.The optimal dechlorination reagent used ethylenediamine as nucleophile,ethanol as solvent and HMQAH as phase transfer catalyst.The dechlorinating rate of the Iranian crude oil reached 71.6%under conditions covering a reaction temperature of 95℃,a reaction time of 90 minutes,a dechlorination reagent dosage of 1000μg/g,and a phase transfer reagent/nucleophile molar ratio of 6:1.In addition,the mechanism of phase transfer in nucleophilic substitution reaction of chloroalkanes was investigated in the paper.展开更多
The influencing factors of the equipment support activity process have the characteristics of nonlinearity, high dimension, many constraints, random uncertainty and fuzzy uncertainty. Monte Carlo method can solve the ...The influencing factors of the equipment support activity process have the characteristics of nonlinearity, high dimension, many constraints, random uncertainty and fuzzy uncertainty. Monte Carlo method can solve the above problems commendably. This paper analyzes the main equipment support activity process and establishes the sampling plan and simulation model of the medium maintenance process based on Monte Carlo method, and the simulation result verifies a fact that the medium maintenance time can be effectively reduced when parallel operation on some procedures is used. It has a practical value and can give good advice to achieve the capability of equipment supportability.展开更多
Time for single vehicle combat preparation(TSVCP) is an important characteristic parameter for the operational support feature of armored vehicle. During the development phase, how to validate the TSVCP of armored veh...Time for single vehicle combat preparation(TSVCP) is an important characteristic parameter for the operational support feature of armored vehicle. During the development phase, how to validate the TSVCP of armored vehicle through analytic method is a difficult issue in analysis and validation of vehicle supportability.This paper uses Monte Carlo approach and builds a working model for single vehicle combat preparation(SVCP)of armored vehicle, thus realizes the prediction and analysis of the TSVCP of armored vehicle, and finally validates the effectiveness of the approach by example.展开更多
基金We acknowledge the financial support from the Joint Fund by the National Natural Science Foundation of China and PetroChina(Project U1862204).
文摘Dechlorination of crude oil is an effective way to alleviate corrosion in refinery units,and the critical process is the removal of organochlorine which can be efficiently removed through nucleophilic substitution reaction catalyzed by phase transfer.Herein,seven typical chlorinated alkanes were selected as model compounds to study the mechanism of dechlorination of crude oil by phase transfer catalyst in the nucleophilic substitution method,and a new dechlorination reagent using hexamethyl quaternary ammonium hydroxide(HMQAH)with two quaternary ammonium groups as phase transfer catalyst,ethylenediamine as nucleophile and ethanol as solvent was developed.The results show that the dechlorinating performance of the dechlorination reagent on the model compounds decreases in the following order:epichlorohydrin>1,2-dichlorobutane>1,2-dichloroethane>1,3-dichloropropane>2-chloropropane>1-chlorobutane>chloroisobutane.Meanwhile the results of the reaction kinetics show that epichlorohydrin with epoxy structure has the lowest activation energy in the process of nucleophilic substitution reaction by the phase transfer catalyst which makes it easier to be removed by the dechlorination reagent.The removal rate of epichlorohydrin can reach up to 99.4%.The optimal dechlorination reagent used ethylenediamine as nucleophile,ethanol as solvent and HMQAH as phase transfer catalyst.The dechlorinating rate of the Iranian crude oil reached 71.6%under conditions covering a reaction temperature of 95℃,a reaction time of 90 minutes,a dechlorination reagent dosage of 1000μg/g,and a phase transfer reagent/nucleophile molar ratio of 6:1.In addition,the mechanism of phase transfer in nucleophilic substitution reaction of chloroalkanes was investigated in the paper.
基金the Special Research Fund for the Research on Armored Vehicle Supportability Requirement Analysis(No.51319050302)
文摘The influencing factors of the equipment support activity process have the characteristics of nonlinearity, high dimension, many constraints, random uncertainty and fuzzy uncertainty. Monte Carlo method can solve the above problems commendably. This paper analyzes the main equipment support activity process and establishes the sampling plan and simulation model of the medium maintenance process based on Monte Carlo method, and the simulation result verifies a fact that the medium maintenance time can be effectively reduced when parallel operation on some procedures is used. It has a practical value and can give good advice to achieve the capability of equipment supportability.
文摘Time for single vehicle combat preparation(TSVCP) is an important characteristic parameter for the operational support feature of armored vehicle. During the development phase, how to validate the TSVCP of armored vehicle through analytic method is a difficult issue in analysis and validation of vehicle supportability.This paper uses Monte Carlo approach and builds a working model for single vehicle combat preparation(SVCP)of armored vehicle, thus realizes the prediction and analysis of the TSVCP of armored vehicle, and finally validates the effectiveness of the approach by example.
