Laser-powered homogeneous and heterogeneous pyrolysis of 2-nitropropane

Abstract

The pyrolysis of 2-nitropropane has been studied under both homogeneous conditions (using a continuous-wave CO₂ laser and sensitized by sulphur hexafluoride) and heterogeneous conditions (pulsed pyrolysis) at temperatures in the range 820–1210 K. A comparison of both decompositions is aided by the determination of spatial temperature profiles and the effective temperature in the laser-driven reaction by using calculations of the temperature distribution, thermocouple techniques and elimination of ethyl acetate as a ‘chemical thermometer’. The main process in the laser-driven decomposition is the clean decomposition into propene and nitrous acid occurring via C—N bond fission. In heterogeneous pyrolysis additional products such as 2-nitropropene, acetonitrile and acetone are formed. The high yield of 2-nitropropene at 820 K indicates a unique route to this compound.