Analysis of the Future Petrochemical Industry Consumption in Chinese Energy Structure Based on Lotka-Volterra Model

China is the one of the only several countries of which energy consumption are coal-dominated in the world. China's current coal production accounts for about a quarter of world production. Energy demand forecast is the basis and prerequisite for the development of energy development strategy and planning. We regard the whole energy demand as an ecological circle, and different types of energy are regarded as a population in the ecosphere. By studying the interaction and development of the population, we forecast the changes in entire ecosystem and even the evolution of the ecosystem. Therefore, for the energy consumption structure forecast, we assume that the three populations are coal consumption, oil consumption and natural gas consumption. Population growth is forecasted by population competition analysis. The three kinds of resources in the competition environment will also have their own impact coefficient at the same time. By using the model, we calculate that coal, oil and natural gas consumption accounted for the proportion of total energy consumption are 62.5%, 29.2% and 8.3% by 2020, respectively. The proportion of total energy consumption of coal declines from 70% in 2008 to around 65%, but it is still a high ratio. Coal consumption is responsible for about 90% of total SO2 emissions, 60% of total NOX emissions and 85% of total CO2 emissions. Oil is mainstream energy in the world, but the prevailing rate in energy consumption is not high in China. In order to increase the ratio of oil, the petrochemical industry capacity needs to be enhanced, and the process needs to continue to improve. The results of the model predictions can help policy makers with better decision, as well as provide some management advice.