Design og modellering af metanolanlæg til VEnzin-visionen Bilag

methanol requirement for this process comes from the two 2,200 tonnes (water free basis) per
day methanol plants.
Catalyst
In the 1970's, Mobil synthesised a new zeolite catalyst, which became a key element in the
MTG process. Zeolites are porous, crystalline materials with three dimensional framework
composed of AlO4 and SiO4 tetrahedra.
This catalyst, known as ZSM-5 (Figure l3) can convert methanol to hydrocarbon products
which are similar to the gasoline fraction of conventional petroleum.
ZSM-5 has an intermediate pore diameter about 6Å and a unique channel structure. There
are two sets of intersecting channels present: elliptical, l0-membcred ring channels present
and near circular (sinusoidal) channels. It is this unique combination of channel shapes and
sizes that make ZSM-5 so efficient and special in MTG conversion, producing gasoline range
molecules (C4 - C10 ) with practically no hydrocarbons above Cl0. In other words, ZSM-5
ccatalyst produces the right kind of shape and size selectivity properties suitable for gasoline
synthesis. These selectivities also give ZSM-5 a reputation for high resistance to
deactivation. Hence, a novel route to gasoline from either coal or natural gas can be achieved.
Figure 13 - Representation of the ZSM-5 catalyst
VII-Energy-D-Methanol-13