Multi-step processing in a microstructured flow reactor: direct nitration of propane–a proof of principle

Abstract

The vapor phase nitration of propane was successfully investigated in a multi-step microstructured reactor. The concept integrates heating, evaporation of reactants, the reaction channel, and the quenching and cooling of the product mixture; all done in a reactor with one plate. The nitration of propane with evaporated nitric acid was carried out at 380°C–450°C. This radical chain reaction was subsequently quenched, in a fast manner due to the high surface-to-volume ratio of the reaction channel. Therefore, the conversion of propane was deliberately kept low (approx. 2%) but at favor of selectivity for 2-nitropropane which increases remarkably. The harsh reaction conditions require a sophisticated microreactor concept, the use of an exceptional construction material, that is, an uncommon stainless steel alloy, as well as a process design which avoids NOx release into the environment.

Keywords

• gas-phase
• micro reactor
• nitration
• nitro alkanes