The BASF-process for production of acetylene by partial oxidation of gaseous hydrocarbons

Abstract

Summary The growing demand for acetylene and the increasing availability of methane made it desirable to open ways for transforming methane to acetylene. By thermodynamical calculation it was found that: 1. Methane has to be brought to high temperatures; 2. A great reaction-enthalpy has to be brought in; 3. The reaction mixture has to be quenched fast enough to preserve the acetylene formed from decomposition into carbon and hydrogen. An advantageous way to bring in the reaction-enthalpy seemed to be a coupling of the endo-thermic reaction with an exothermic oxidation process. In order to quench the acetylene formed fast enough the reaction had to be in the form of a flame reaction of pre-mixed gases. The chemical-engineering problem was: 1. To mix hydrocarbon and oxygen preheated to ~ 600°C while preventing the stabilization of a flame at the point of mixing; 2. To bring the mixture to the reaction zone without any premature reactions; 3. To stabilize a stationary flame at the entrance of the reaction zone; 4. To concentrate the flame zone in a small space in order to cool the reaction mixture by injection of water after a residence time short in relation to the life-span of acetylene at the flame-temperature. A burner, capacity 8 tons acetylene daily, was designed for these operations. Next the acetylene formed had to be separated as pure and completely as possible from the gas mixture resulting from the flame reaction, which contained about 8½% acetylene. A wash with a selective solvent was used for that purpose. By the use of rectification columns between wash zone and degassing zone and by using a mixture of water and selective organic solvent as a working solvent it was possible to separate the burner gas by only one circuit of the solvent into acetylene of the purity needed for chemical processes, and into a stream of higher acetylene homologues containing only small amounts of acetylene, and a lean gas containing only traces of acetylene.