The Tatoray process uses a very sim

The Tatoray process uses a very simple flow scheme consisting of a fixed-bed reactor and
a product separation section.The fresh feed to the Tatoray unit is first....with hydrogen-rich recycle gas, preheated by exchange with the hot reactor effluent,
and then raised to reaction temperature in a fired heater. The combined feed vapor is then
sent to the reactor where it is processed downflow over a fixed bed of catalyst. The reactor
effluent is then cooled by exchange with the combined feed and a product condenser
and is sent to a product separator. Hydrogen-rich gas is taken off the top of the separator,
where a small portion of it is purged to remove accumulated light ends from the recycle
gas loop. It is then mixed with makeup gas and recycled to the reactor. Liquid from the
bottom of the separator is sent to a stripper column. The overhead from the stripper is
cooled and separated into gas and liquid products. The stripper overhead gas is exported
to the fuel gas system. The overhead liquid is recycled to the Platforming unit debutanizer
column so that any benzene in this stream may be recovered to the extraction and or in
the BT separation section of the aromatics complex. The benzene and xylene products,
together with the unreacted toluene and C9
aromatics, are taken from the bottom of the
stripper and recycled to the BT fractionation section of the aromatics complex.
Because of the dealkylation reaction pathway, the reactor section of the Tatoray process
is maintained in a hydrogen atmosphere even though no net hydrogen is consumed in the
transalkylation reactions. In practice, a small amount of hydrogen is always consumed due
to the dealkylation side reactions. Hydrogen consumption increases for heavier feedstocks
since these generally contain heavier alkyl groups, typically C3 and C4.