Selective polymerization of butene means that only isobutylene is completely polymerized, butene-1 and butene-2 are not polymerized or a small amount of polymerization under the action of catalyst.
Butene is an important chemical raw material, mainly comes from the C4 mixed fraction produced by catalytic cracking unit of the refinery and the C4 mixed fraction from the by-product of ethylene production. Among them, more than 90% isobutene is used in MTBE production in China; butene-1 can be dehydrogenated to make butadiene, it is also possible to hydrate it to butanol and further to produc methyl ethyl ketone, it can also be oxidized to produce maleic anhydride or acetic acid,
high purity butene-1 is mainly used in the production of linear polyethylene resin or polybutene resin; butene-2 is the best raw material for alkylated gasoline and can also be used as butadiene.
As the boiling point of isobutylene and butene-1 is close to each other with a difference of 0.6, it is difficult to separate by rectification. At present, isobutene and butene-1 are mostly separated by MTBE devices. But the promotion and implementation of domestic vehicle ethanol gasoline policy , MTBE will no longer be used as a gasoline additive, a large number of MTBE production units will be discontinued.
The selective polymerization of butene is used to produce isooctene effectively and butene-1 butene-2 can be well separated.
1， Adaptable raw material
The C4 component of isobutene
2，Physicochemical properties of catalysts
Item | Index |
Appearance | Brown-reddish brown globes |
Diameter，mm | 2.5-3.0 |
Bulk density，kg/L | 0.5-0.6 |
Intensity，N/cm | ≥30 |
BET，m2/g | >350 |
3，Process condition
Item | Value |
Reaction temperature，℃ | 80-130 |
Reaction pressure，MPa | 2.0-3.0 |
Butene volume SV，h-1 | 0.5-1.5 |
4，Technical flow diagram
5 ，Process characteristics
Remission of reaction conditions, high isobutene conversion rate, a small amount of butene-1 conversion, butene-2 hardly converts, dimerization is the main product.