A Study Of The Numerical Simulation On The Distribution Of The Hydrocarbon Molecules's Pyrolysis Products

With the cracking materials being heavier, components of the cracking materials are becoming more complex, and the cracking reaction is complex, so far these made there is no better evaluate more accurate method of the hydrocarbons cracking of raw materials in the impact of the product of vinyl, expect sophisticated experiments. This paper discussed systems analysis and quantitative analysis method about the distribution of the pyrolysis products of hydrocarbon raw materials with different molecular size and structure by the numerical simulation method. First, using the pervious two-dimensional hydrocarbon steam pyrolysis process model, choose the raw material hydrocarbon molecules in the two-dimensional model, and make comparative analysis of the calculation results; second, using the molecular simulation technique, by optimizing received information of the molecular structure we analyzed and judged the effect of the different size and structure of hydrocarbon molecules for the main product of pyrolysis.The simulation results show that the size and structure of hydrocarbon molecules affect the yield of their cracking objective product. The pyrolysis of different hydrocarbons structure get ethylene, propylene, butadiene which have different yield apparently; N-paraffin is being thermal cracking reaction, there are much difference when by hydrocarbon which the number of C lower than 4. when the number of C is more than 4, the difference ethylene propylene butadiene are produced hydrocarbon focuses on the odd and even the number of C, The smaller the molecule, the bigger the difference ; as isoparaffin the site of substituting group make lots of influence on the yield of ethylene propylene butadiene are produced hydrocarbon; as cyclanes which the number of C lower than 7,the cracking reaction of 5-cyclanes has much difference, while 6-has little; compared the impact of temperature and hydrocarbon type on the three propylene yield in pyrolysis products, we can see that the influence of the hydrocarbon molecular structure was much larger than the temperature.Using Hyperchem molecular simulation software, and according to bond length data parameter analysis and judgment , the pyrolysis products distribution law of hydrocarbon molecules was consistent with the pyrolysis product distribution in two-dimensional model results. This shows that by using molecular simulation software to predict the hydrocarbon molecules pyrolysis distribution was feasible.