The Synthesis And Properties Of The Supported Reverse Demulsifier

ASP?Alkaline/Surfactant/Polymer?flooding technique is an EOR technique which has been found to enhance oil recovery by over 20%.However,disadvantages identified during the application process of the ASP flooding technique,such as difficulties in treating the produced water from ASP flooding due to the use of alkali,surfactant,and polymer in the injected water in ASP flooding technology,limited its further application in the field.There is no mature technology for the treatment of produced water from ASP flooding,and the key to solve the problem is to de-emulsify.In this study,a novelsilica gel-supported reverse demulsifier was synthesized,and the performance of demulsification and adsorption can be provided.The reverse demulsifier ployether polyquaternium?PPA?was grafted on the surface of silica gel particals,the composite SiO₂@PPA demulsifier was prepared and characterized.The effects of reaction temperature,reaction time,the amount of reactants and the dosage of catalyst on the conversion rate of synthetic products were investigated.The microstructure and pore structure of SiO₂ were characterized through SEM and BET,SiO₂@PPA was synthesized and characterized using FTIR,1H-NMR,XPS and SEM.PPA shows a better demulsification capability of 85.48% when the dosage of PPA is 50 mg L-1,n?epoxy ether?: n?methyl ether?=3:1,the reaction time was 1h and the reaction temeperature was 30?.Due to the PPA with excellent interfacial diffusion performance,it can be adsorbed to the oil-water interface to replace the surfactant molecule for ASP flooding to reduce the film intensity between oil droplets.Meanwhile,it can neutralize the negative surface charge of oil droplets to reduce the electrostatic repulsion.Thus the oil droplets can be coalesced to accelerate oil-water separation,and the performance of the system is better than that of poly quaternary ammonium salt cationic reverse demulsifier X71.When the reaction temeperature at 30 oC,the dosage was 1.5 g/L and the reaction time was 90 min,the adsorption efficiency of MPS-SiO₂ was about 46.8%When the reaction temeperature at 30 oC,the dosage was 1.5 g/L and the reaction time was 90 min,the the SiO₂@PPA exhibited a high removal capacity of 91.6%.The adsorption capacity of carrier particles of SiO₂@PPA was about 301 mg g-1 and is six times higher than granular activated carbon?GAC?.The carrier particles of SiO₂@PPA have small particle size and large pore area and SiO₂@PPA has the function of demulsification and adsorption.SiO₂@PPA can be applied to remove of oil from oil-in-water emulsions.Analysis of fitting the equilibrium data kinetic model of carrier particles of SiO₂@PPA showed that the fitting results of the pseudo second order model presented a better compliance.A higher reaction temperature was found to increase the reaction rate constants,suggesting that the reaction of oil droplets removed by carrier particles of SiO₂@PPA may be endothermic.Meanwhile,analysis of fitting the equilibrium data equilibrium model showed that Langmuir isotherm might be more useful to simulate the adsorption process.Thermodynamic studies showed that the adsorption process was ?G<0 and ?H>0,indicating that the adsorption of oil droplets by carrier particles of SiO₂@PPA was a spontaneous and endothermic process.