Analysis Of Gasoline Hydrocarbon Components

As a kind of energy source,gasoline is consumed in a large amount.During its use process,a series of environmental problems are caused because of fugitive emissions,so olefins and aromatics in gasoline hydrocarbon components are placed into the control index in order to decrease the pollution,and the quality of gasoline is improved by decreasing the content of olefins and aromatics.In order to adapt to the upgrade of gasoline quality,oil refineries pay more and more attention to the components of gasoline blending fractions,therefore,the analysis of hydrocarbon component has become the focus of the laboratory.How to quickly and accurately analyze the hydrocarbon components of gasoline has become an urgent problem to be solved.In this paper,three kinds of typical analysis methods in the laboratory,the fluorescent indicator adsorption method,chromatography monomer hydrocarbon method and multidimensional gas chromatography M3 method,were studied and optimized in detail.The operation for the fluorescent indicator adsorption method was standardized.Under the conditions of pressure of the compressed air at 40 kPa and analysis time of 60 min,the ribbon length was over 500 mm,and the interface between aromatics and olefins was clear.When the sample was analyzed for 6 times,the relative standard deviation was less than 1.7%,and the maximum and minimum relative errors were 1.4% and 0.1%,respectively.In the monomer hydrocarbon chromatography method,the retention index method was established for qualitative analysis,and the area normalization method was constructed for the quantitative analysis.The main reference peaks were confirmed according to three different analysis methods,respectively,and marked on the chromatogram.For hydrocarbon component toluene,the repeatability of the retention time could be controlled within 0.3 min,and the maximum range value for thestraight-run gasoline measured for two times was 0.1%.For the multidimensional gas chromatography M3 method,under the optimized conditions of the temperature of the olefin adsorption trap was 100?,cutting time of 3.0min for the value A,and the order of drying tubes: silica gel,molecular sieve and activated carbon,the maximum difference is 0.49% with four models(PNA,PIANO,PHONA and Winterspec MTBE model)used,less than the corresponding requirement value of 0.86%.Catalytic gasoline and final gasoline were selected as samples to be analyzed for 5 times though using the multidimensional gas chromatography M3 method,respectively,the 0.57% maximum difference between the sample and standard sample was less than the corresponding precision requirement value of 1.61%.In this paper,the research provides the technical support for reasonable selection of analysis methods,standardized operation and accurate analysis of test data.The summary of analytic characteristics of three analysis methods provides data support for the construction and optimization of the analysis methods used in the oil refinery.