TOLUE HYDRODEALKYLATION PROCESSToluene hydrodealkylation or toluene hydrodealkylation (HDA) is a process used to produce benzene. The reaction occurs as: Toluene + H2 Benzene + CH4. The process requires toluene and hydrogen as the main reactor. Next, toluene and hydrogen are converted in a catalyst-filled reactor to produce benzene and methane. This reaction is exothermic and the operating conditions are 500°C to 660°C and 20 to 60 bars of pressure. This process begins by mixing fresh toluene with a stream of unreacted recycled toluene, and mixing is carried out in a storage tank. Then the toluene is pumped to combine with a stream of mixed hydrogen and fresh hydrogen gas. The mixture of toluene and hydrogen is preheated before being introduced into the heater or oven. In the oven, the flow is heated to 600 0C, then introduced into the reactor. Basically, the main reactions occur in the reactor. The hydrodealkylation process of toluene C7H8 + H2 C6H6 + CH4 is an irreversible process and requires a catalyst. The catalyst used in this process consists of molybdenum or chromium oxides, platinum or platinum oxides, silica or alumina. The minor reversible side reaction is: 2 Benzene Diphenyl + H2. The catalytic process occurs at lower temperature and provides higher selectivity but requires frequent catalyst regeneration. Next, the products are cooled and fed into a pair of separators that separate unreacted hydrogen. The unreacted hydrogen is compressed and recycled to the feed and the reactor. The products leaving the separators are heated before being introduced into a distillation column where the toluene is separated from the flow and recycled to the middle of the paper...... temperature of 112 0C also and a pressure of 2.5 bars . Cooling water is used to condense the steam leaving the column. The remaining methane and hydrogen are separated in a reflux drum where the steam stream is combined with other gas streams. The overhead waters from the first and second separators are combined to form combustible gas. The liquid flow leaving the bottom of the reflux drum is pumped at a pressure of 3.3 bars to relieve the pressure. The pump flow is separated into two flows. One stream must feed plate one of the column and the other stream is cooled to 38°C in a heat exchanger. Then the cooled product stream is sent to storage. The advantages of this process are: Higher reaction efficiency Reduced hydrogen consumption Higher conversions Lower operating temperature Higher liquid yield Open to advances in catalysis Clean operations Good selectivity