Novel Ecological and Energy Saving Method
of Single-Stage Synthesis of Isoprene
K. E. BURKINВ В andВ В R. A. AKHMEDYANOVA
Kazan State Technological University,
Ul. K. Marksa 68, Kazan 420015 (Russia)
izopren_russkij@mail.ru
Keywords: isoprene, trimethylcarbinol, 1,3,5-trioxane, cation-exchange resin, isobutylene, formaldehyde, energy saving
Pages: 531–535
Abstract
The possibility of single-stage synthesis of isoprene from 1,3,5-trioxane and trimethylcarbinol in the presence of heterogeneous catalyst – strongly acidic macroporous cation-exchange resin – was established. The composition of the reaction mixture was determined by means of gas-liquid chromatography. Along with isoprene, unreacted trimethylcarbinol was detected, as well as by-products: unsaturated isoamylenic alcohols and 4,4-dimethyldioxane-1,3 – precursors of isoprene; the formation of an additional amount of isoprene during the decomposition of these compounds is possible. Optimal process conditions were chosen, providing the degree of trioxane conversion up to 99 %, selectivity of the process with respect to isoprene 65 %, and the yield of isoprene per transformed trioxane 64 %. In comparison with the existing two-stage methods of isoprene synthesis from the aqueous solution of formaldehyde and isobutylene, the proposed method allows one to decrease energy consumption and diminish the amount of waste water due to the “soft” technological conditions of the process.
UDC 54.05:542:547.315.2:504.064.043:620.9
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