Abstract: Isobutane in a C.sub.4 hydrocarbon feed stream is converted to methacrolein in an integrated two-step process. Isobutane is dehydrogenated in a first step to isobutylene, hydrogen, and by-products and the reaction effluent is passed directly into a second step where isobutylene is oxidized to methacrolein without significant oxidation of the hydrogen and by-products. Any normal butenes present are converted to butadiene. The methacrolein and by-products may be separated and the unreacted isobutylene and isobutane recycled to the first step. Alternatively, the effluent from the second step may be used as feed to a further oxidation step for conversion of methacrolein to methacrylic acid.

Abstract: Trivalent thallium values are extractively recovered from aqueous media containing dissolved trivalent and monovalent thallium values by contacting the aqueous medium in the presence of an alkanoic acid, having from 2 to 4 carbon atoms per molecule and having a molecular weight of at least 74 grams per gram-mol of acid, with an inert, organic, non-acidic solvent for the alkanoic acid, said solvent having limited solubility in water, to preferentially extract at least a portion of the dissolved trivalent thallium values into the organic solvent extractant and recovering an extract comprising the organic solvent containing the extracted trivalent thallium values.