Thermodynamical Investigation Of Microbial Degradation Aviation Kerosene

Microbial degradation of petroleum hydrocarbon is one of Microbe Enhanced Oil Recovery (MEOR) mechanisms. Petroleum bacteria can degrade long chain alkane into short chain alkane and change the petroleum composition, which carry out the biotechnologicalonversation of petroleum chemicals and obtain high-quality petrol .Onthe other hand, microbiological deterioration play an important role in the respect of environmental protection. Therefore, how to improve the effect of microbial degradation is the main purpose of this study. The qualities of surface active agent forming micelle and the formation of microemulsion have been studied by microcalorimetric method.Critical micelle concentration (cmc) can be used to measure the surface activity of surface active agent. When the concentration of surface active agent is close to cmc, the qualities of surface active agent will change strikingly. A lot of studies of surface active agent related to the determination of cmc. Surface tension method is difficult in determination of crne. It is easy to determined cmc by calorimetry, moreover, calorimetry doesn抰 destroy phase equilibrium and obtains many information constant at the same time. In this paper, the critical micelle concentration of ionic surface active agent and non-ionic surface agent atIidifferent temperature have been determined by using a 2277 thermal ?activity monitor. Phase Separation model and Mass Action model havebeen used to calculate cmc and related thermodynamic data. Under the experiment condition, the solution or dilution process of ionic surface agent absorb heat, while non-ionic surface active agent release heat. With the improvement of temperature, the micelle formation heat of ionic surface agent drop simply, while that of non-ionic surface active agent raise simply, some almost change linearly. The average aggregation number of surfactant N and micelle formation constant K are obtained in this paper. The results show that the surface activity of ionic surface active agent improve and its cmc drop with adding inorganic salts. But the effect of inorganic salts for non-ionic surface active agent is very liftle.Pseudoternary phase diagrams of microemulsion were made by means of microcalorimetric method in the paper. The results show that the microstructure of the middle-phase microemulsion undergoes the change from 0/W to bieontinuous to W/0. The change of standard free energy ArG~?, for alcohol to transfer from the oil continuous phase to the interfaeial membranes was also calculated. According to ArG~I~ the change of enthalpy and entropy in this process also can be calculated. These studies provide guidance for making a thorough investigation and study of microemulsion.The growth power-time curves of four strains of petroleum bacteria, I, LI, K, and P in the microernulsion system of Tween8O/alcohol/aviation kerosene/water have been determined by using the 2277 thermal activityIimonitor. Logistic equation has been used to calculate the growth rate constant. The results show that the growth rate constant of petroleum bacteria increase. It prove that microernulsion formation can enlarge the contact area between oil phase and aqueous solution ,which promote the growth metabolism of petroleum bacteria and improve the effect of microbial degradation of aviation kerosene.The qualities of surface active agent and microemulsion were studied at a different angle. It contacts microbial degradation with formation microemulsion .The studies in this paper give out very important guidance for MIEOR.