Abstract: Unsaturated nitriles, particularly acrylonitrile or methacrylonitrile, are produced in a process which integrates dehydrogenation of an alkane, particularly propane or isobutane, to the corresponding olefin, followed by ammoxidation of the olefin in the dehydrogenation reactor effluent to the corresponding nitrile. After recovery of the nitrile product, the residual gases are processed to remove hydrogen, oxygen, and carbon oxides, after which the gases are recycled to the dehydrogenation reactor. By operating with relatively low conversion of olefin to nitrile in each pass, the overall efficiency of the process is improved despite the need to recirculate substantial amounts of unreacted hydrocarbons.

Abstract: Unsaturated nitriles, particularly acrylonitrile, are produced in a process which integrates dehydrogenation of an alkane, particularly propane, to the corresponding olefin, followed by ammoxidation of the olefin in the dehydrogenation reactor effluent to the corresponding nitrile. After recovery of the nitrile product, the residual gases are processed to remove hydrogen, oxygen, and carbon oxides, after which the gases are recycled to the dehydrogenation reactor. By operating with relatively low conversion of olefin to nitrile in each pass, the overall efficiency of the process is improved despite the need to recirculate substantial amounts of unreacted hydrocarbons.

Abstract: In the carbonylation of alkyl esters in the presence of a Group VIII noble metal catalyst to produce a reaction mixture comprising volatile components and the non-volatile Group VIII noble metal catalyst, and the volatile components are separated from the catalyst, catalyst activity is maintained by providing a partial pressure of hydrogen of at least 10 psi during the separation of the volatile products. A partial pressure of at least 15 psi of carbon monoxide is also preferably provided, particularly when a metal promoter for the Group VIII noble metal catalyst is present, during such separation.