MTDP-3 (toluene disproportionation) advantages

Lower costs and debottlenecks
MTDP-3 can debottleneck operations and lower the costs of producing mixed xylenes. Its high space velocity and low H2/hydrocarbon mole ratio can permit increases in throughput without reactor and/or compressor replacement. Additionally, it can reduce operating costs by requiring less hydrogen than competing technologies.

Retrofits into existing reactors
MTDP-3 incorporates ExxonMobil's expertise in ZSM-5 technology and is readily adaptable into existing radial-flow and conventional-flow reactors.

High-purity benzene co-product
Another advantage of the MTDP-3 process is that benzene co-product does not have to be extracted to meet commercial benzene specifications. The MTDP-3 benzene co-product purity exceeds 99.90 wt% via simple fractionation.

Simple fixed-bed process
The process flow (shown) is typical for a vapor-phase reaction in a fixed-bed reactor. Toluene feed with a limited amount of C9 aromatics is combined with a hydrogen-rich recycle gas. It is preheated and passed through a catalyst bed. Disproportionation occurs here, at a moderate temperature and pressure, to produce equilibrium-mixed xylenes and benzene. By-product yields are small.

Reactor effluent is cooled by heat exchange and the liquid products are separated from the recycle gas. The separated liquid is stripped to remove the light ends and then fractionated to recover the benzene product and the mixed xylenes. Unreacted toluene is recycled to extinction.

MTDP-3 technologies flow chart describes the process flow of chemical through the manufacturing process
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MTDP-3 process can debottleneck operations and lower costs of producing mixed xylenes.