Pyrolysis Of Propane To Acetylene Using Rotating Hydrogen Arc Plasma

Acetylene is an important chemical raw material, which has an important status in the social production. The traditional processes for preparation of acetylene have so many disadvantages, including serious pollution, high energy consumption, low yield, that have been unable to meet the needs of the society. Pyrolysis of coal and alkanes by thermal plasma is a promising technology for the preparation of acetylene. Thus. this thesis adopts a rotating arc hydrogen plasma torch for current-voltage characteristic and propane pyrolysis experiment, in order to investigate the basic law and optimize process conditions.There are two sets of plasma reactors involved in this experiment, rated power are respectively50kW and1MW. The main structure of these two reactors is similar, including constant current power supply, rotating arc plasma torch, control system, quenching device etc. The correlation formulas in data processing are also introduced in this section, including gas flow rate correction, pyrolysis gas flow calibration, propane conversion rate, calculation of specific enthalpy and so on.The current-voltage characteristics of hydrogen plasma were carried out in the two set of device. The volt-ampere characteristics of hydrogen plasma under the experimental conditions show negative characteristics, while the gas flow rate and the diameter of anode voltage have positive influence for characteristics, namely voltage increases with the increase of these two variables. In addition, magnetic induction intensity makes positive affect in the50kW device. Similarity theory equation which was used to correlate the current-voltage characteristics of those two sets of device are improved as: and the linear coefficient obtained according to this similarity theory equation is0.9958.C-H homogeneous equilibrium analysis and C-H heterogeneous equilibrium analysis are made using the Gibbs minimization free energy method. In homogeneous system, the temperature which has the maximum concentration of acetylene is2200K. In heterogeneous system, C(S) is the main component under3500K. Acetylene yield and energy consumption ratio which can be used to select better experimental conditions are showed on charts according to the material and energy balance.Pyrolysis of propane to acetylene is carried out in the1MW device, and the topic is the influence of propane content and propane enthalpy. The conversion efficiencies of propane are more than98.6%, the highest content of acetylene is12.65%, and other products are mainly methane, ethylene and so on. Both propane content and propane can impact the specific energy consumption of acetylene, and the lowest result obtained is8.85kWh/kg C2H2. The thermal efficiency of the reactor is associated with input power, and the maximum input power in this experiment is794.2kW, the highest thermal efficiency is86.5%. The highest content of acetylene according to the result is close to the theoretical calculation value in C-H homogeneous equilibrium analysis and the method for selecting better experimental conditions is suitable.