Energy Conservation And Optimization Of Biomass Pyrolysis Process

Biomass is a new type energy which can instead of petrochemical, it is an effective and viable economic route to develop and utilize the biomass. The fast pyrolysis conditions are difficult to control and the heat utilization of process is very low. Biomass fuels Production rate, the heat utilization are decided by fast pyrolysis conditions. In this paper, aiming at the existing problems of fast pyrolysis, it proposes a thermal cracking process which has high efficient energy use. It makes simulation and optimization to the energy use of cracking process and ultimately achieves the goal of saving energy and reducing consumption. This article’s main content is as follows:On the basis of the existing process data, it analyzes the changes in the relationship between minimum temperature difference and the hot utilities, cold utilities, heat exchanger area, total cost. The selection of optimal heat transfer temperature difference should consider a variety of factors, such as the total cost and the cost of hot and cold utilities, at last, it determines the minimum heat transfer temperature difference value is10. When the minimum heat transfer temperature difference value is10, it can obtained the combination graph, the simulation results show that:the system needs a minimum amount of heating is54kw, the minimum amount of cooling is230kw, the largest amount of heat recovery is100kw, pinch average temperature value is212℃.Biomass pyrolysis process is analyzed by using pinch technology. The heat of original cold and hot logistics is taken away by cold and heat public works. The original process is improved by pinch analysis method and new heat exchanger network is obtained. This heat exchanger network can match the hot and cold logistics reasonably, so it can reduces the consumption of hot and cold utilities and achieves the goal of saving energy and reducing consumption. Before heat exchanging, the hot and cold utilities respectively needs155.2kw,330kw. After matching logistics, hot utilities only needs53kw, cold utilities needs227.8kw,102kw’s quantities of hot and cold utilities is saved. The calculation result is similar to the simulation outcome. It calculates the heat load and heat transfer area of each heat exchanger through simulation.The three link method is used to analyze the process’s three links, including energy utilization link, energy conversion and transmission link, energy recovery link. This method provides a theoretical model which can analyze and optimize the process system energy use. The simplification of complex analysis process is conducive to conduct a comprehensive and scientific analysis and calculation to overall energy use. The analysis shows:the energy consumption of pump and fan are very less,the consumption of electrical is only15kw. The main energy consumption of this device is cracking furnace, it consumes361.9kw’s fuel. In energy recovery link, heat exchange equipment takes a lot of cooling utilities, energy consumption of the total cooling water is216kw. Through analyzing the process energy-using situation, it can be obtained that pyrolysis process energy consumption are mainly fuel,air and water. Fuel gas accounts for43%of the total energy, cooling water accounts for26%, the consumption of cooling water volume is very large.It saves the amount of hot and cold utilities and achieves the purpose of energy saving through to analyze and improve the process’s energy use.