A new technology for the production of isoprene from isobutene-containing C4 fractions and formaldehyde: Prospects for industrial reconstruction

The industrially implemented process of isoprene production from isobutene-containing C 4 fractions and formaldehyde, which includes the gas-phase high-temperature decomposition of an intermediate, 4,4-dimethyl-1,3-dioxane, is expensive and obsolete. We propose a new technology that requires the same precursors and allows for a reduction in the cost of isoprene by a factor of at least 1.5. It features the concurrent liquid-phase decomposition of intermediate products in a column reactor in the presence of an aqueous solution of phosphoric acid at a moderate temperature (∼160°C), and is convenient for reconstructing existing production lines.