With the advancement of oilfield extraction technology,since oil-water emulsions in waxy crude oil are prone to be deposited on the pipe wall,increasing the difficulty of crude oil extraction.In this paper,the mesosco...With the advancement of oilfield extraction technology,since oil-water emulsions in waxy crude oil are prone to be deposited on the pipe wall,increasing the difficulty of crude oil extraction.In this paper,the mesoscopic dissipative particle dynamics method is used to study themechanism of the crystallization and deposition adsorbed on thewall.The results show that in the absence of water molecules,the paraffin molecules near the substrate are deposited on themetallic surface with a horizontalmorphology,while the paraffin molecules close to the fluid side are arranged in a vertical column morphology.In the emulsified system,more water molecules will be absorbed on the metallic substrate than paraffin molecules,which obstructed the direct interaction between paraffin molecules and solid surface.Therefore,the addition of watermolecules hinders the crystallization of wax near the substrate.Perversely,on the fluid side,water molecules promote the formation of paraffin crystallization.The research in this paper reveals the crystallization mechanism of paraffin wax in oil-water emulsions in the pipeline from the microscopic scale,which provides theoretical support for improving the recovery of wax-containing crude oil and enhancing the transport efficiency.展开更多
Researches have shown that Raphia hookeri gum could be used as a binder in pharmaceutical formulations and gums in general have been used as emulsifiers in liquid paraffin emulsion but nothing has been heard of Raphia...Researches have shown that Raphia hookeri gum could be used as a binder in pharmaceutical formulations and gums in general have been used as emulsifiers in liquid paraffin emulsion but nothing has been heard of Raphia hookeri in liquid paraffin emulsion as an emulsifier.This work was aimed at evaluating the emulsifying properties of Raphia gum in liquid paraffin emulsion.Two separate preparations containing different concentrations(1,2,3,5 and 10%w/v)of Raphia gum and acacia gum respectively were prepared.Five liquid paraffin emulsions(200 mL each)were also prepared using 60 mL liquid paraffin as the oil phase and 6 g of the various combinations of Raphia gum and Tween 80 as emulsifier blend at ratio 1:5,1:2,1:1,2:1 and 5:1.The preparations were assessed using density,viscosity and stability after 5 days of storage as evaluation parameters.By increasing the concentration of Raphia and Acacia gum,the density of emulsion formed increased.The ranking of the density was 10%>5%>3%>2%>1%.The viscosity of emulsion increased as the concentration of the gum increased.The viscosity which plays a role in the stability of emulsion increased as the concentration of gum increased.The ranking of viscosity was 10%>5%>3%>2%>1%.The stability of the emulsion was measured by the level of creaming and cracking.Emulsion containing 2%w/v of Raphia gum with a creaming index of 23%was more stable compared to the emulsion containing 3%w/v acacia gum with creaming index of 29.9%.The viscosity and stability of emulsion containing emulsifier blends of Raphia and Tween 80 increased with increase in the concentration of Raphia gum.Emulsion containing 3%w/v Raphia gum with no creaming was more stable than emulsion containing 1%w/v emulsifier blend.Raphia gum is suitable for use at a concentration of 2%w/v as an emulsifier in 50 mL of liquid paraffin emulsion competing alternatively to standard acacia gum for emulsification as against Afzelia africana in our previous research which was suitable for use at a concentration of 3%w/v as an emulsifier in 30%v/v liquid paraffin emulsion.展开更多
基金sponsored by Natural Science Foundation of Xinjiang Uygur Autonomous Region,Grant No.2023D01C197Performance Incentive Guidance Project of Chongqing Scientific Research Institutions(cstc2022jxjl20016).
文摘With the advancement of oilfield extraction technology,since oil-water emulsions in waxy crude oil are prone to be deposited on the pipe wall,increasing the difficulty of crude oil extraction.In this paper,the mesoscopic dissipative particle dynamics method is used to study themechanism of the crystallization and deposition adsorbed on thewall.The results show that in the absence of water molecules,the paraffin molecules near the substrate are deposited on themetallic surface with a horizontalmorphology,while the paraffin molecules close to the fluid side are arranged in a vertical column morphology.In the emulsified system,more water molecules will be absorbed on the metallic substrate than paraffin molecules,which obstructed the direct interaction between paraffin molecules and solid surface.Therefore,the addition of watermolecules hinders the crystallization of wax near the substrate.Perversely,on the fluid side,water molecules promote the formation of paraffin crystallization.The research in this paper reveals the crystallization mechanism of paraffin wax in oil-water emulsions in the pipeline from the microscopic scale,which provides theoretical support for improving the recovery of wax-containing crude oil and enhancing the transport efficiency.
文摘Researches have shown that Raphia hookeri gum could be used as a binder in pharmaceutical formulations and gums in general have been used as emulsifiers in liquid paraffin emulsion but nothing has been heard of Raphia hookeri in liquid paraffin emulsion as an emulsifier.This work was aimed at evaluating the emulsifying properties of Raphia gum in liquid paraffin emulsion.Two separate preparations containing different concentrations(1,2,3,5 and 10%w/v)of Raphia gum and acacia gum respectively were prepared.Five liquid paraffin emulsions(200 mL each)were also prepared using 60 mL liquid paraffin as the oil phase and 6 g of the various combinations of Raphia gum and Tween 80 as emulsifier blend at ratio 1:5,1:2,1:1,2:1 and 5:1.The preparations were assessed using density,viscosity and stability after 5 days of storage as evaluation parameters.By increasing the concentration of Raphia and Acacia gum,the density of emulsion formed increased.The ranking of the density was 10%>5%>3%>2%>1%.The viscosity of emulsion increased as the concentration of the gum increased.The viscosity which plays a role in the stability of emulsion increased as the concentration of gum increased.The ranking of viscosity was 10%>5%>3%>2%>1%.The stability of the emulsion was measured by the level of creaming and cracking.Emulsion containing 2%w/v of Raphia gum with a creaming index of 23%was more stable compared to the emulsion containing 3%w/v acacia gum with creaming index of 29.9%.The viscosity and stability of emulsion containing emulsifier blends of Raphia and Tween 80 increased with increase in the concentration of Raphia gum.Emulsion containing 3%w/v Raphia gum with no creaming was more stable than emulsion containing 1%w/v emulsifier blend.Raphia gum is suitable for use at a concentration of 2%w/v as an emulsifier in 50 mL of liquid paraffin emulsion competing alternatively to standard acacia gum for emulsification as against Afzelia africana in our previous research which was suitable for use at a concentration of 3%w/v as an emulsifier in 30%v/v liquid paraffin emulsion.
