FremgangsmÕte og innretning for fremstilling av mettede karboksylsyrer med en til fire karbonatomer

摘要

In a process for the production of 1-4C saturated carboxylic acids by gas-phase oxidation of 4C (un)saturated hydrocarbons at 100-400 degrees C and 1.2-51 x 10<5> Pa in presence of water vapor and catalyst and with partial recycling of acid-depleted reaction gas in a loop circuit, the crude acid is extracted from the gas leaving the reactor by counter-current washing. An Independent claim is also included for apparatus for this process, comprising a mixer, a reactor with a cooling circuit, a gas cooler for the main outgoing gas stream (with cooling circuit) and a recycling loop containing: (a) a line to remove small amounts of off-gas (to maintain steady-state conditions in the loop) and (b) a counter-current scrubbing system comprising an absorption column with cooler(s), a feed pipe for a suitable scrubbing solvent, a tube for removing crude acid for further work-up and a tube for recycling residual reaction gas to the mixer via a pump.