Lebedev process 2 CH3-CH2OH =====> CH2=CH2-CH2=CH2 + 2 H2O + H2 catalyst : mix of various metal oxide / doped zeolit / .... temperature 450°c
Ostromisslensky process CH3-CH2OH + CH3-CHO ====> CH2=CH2-CH2=CH2 +2H2O
process description :
1,3-Butadiene (BD), the monomer of synthetic rubbers and polymers, is one of the most important unsaturated hydrocarbons. There are two methods of BD production: Lebedev - conversion of ethanol (EtOH) over one catalyst in one reactor, and Ostromisslensky - conversion of a mixture of EtOH and acetaldehyde (AA), which is produced over a catalyst in the first reactor and then converted to BD over another catalyst in the second reactor.
Tantalum-containing
SiBEA zeolite with isolated framework mononuclear Ta(V) doped with Ag,
Cu and Zn were prepared and characterized by XRD, XPS, DR UV-VIS and
FTIR (with pyridine, 2,6-di-tert-butylpyridine, pyrrole and deuterated
chloroform). The conversion of ethanol as renewable raw material into
1,3-butadiene by Lebedev method over these zeolite catalysts was
investigated. The doping of TaSiBEA with Ag, Cu and Zn changes its
catalytic properties in ethanol conversion into 1,3-butadiene as a
result of modification of acid-base properties with formation of
additional dehydrogenation sites. Such modification allows accelerating
ethanol dehydrogenation to acetaldehyde and subsequent steps of the
ethanol-to-butadiene process. Ethanol conversion and butadiene
selectivity over the catalysts increase in the order: TaSiBEA <
ZnTaSiBEA < AgTaSiBEA < CuTaSiBEA. Higher selectivity to
butadiene (73 %) was achieved over CuTaSiBEA (at 88% ethanol
conversion, T = 598 К, WHSV = 0.5 h-1).
