Patent GB-795839-A (GB)
Title: Improvements in hydroforming
IPC: C10G35/14
Filed: 1956-07-24
Abstract: In a hydroforming process in a system comprising a reaction zone and a catalyst regeneration zone, catalyst being in a fluidized bed in each zone, the hot products from the reaction zone are split into two parts and heat exchanged in separate heat exchangers with the naphtha feed and the hydrogen-containing gas, and the naphtha feed is further preheated by passing in heat exchange with the fluidized catalyst bed in the regeneration zone before passing to the reaction zone. Naphtha feed enters by line 3 and is partially heated to about 700 DEG  F. by heat exchange with part of the products of the reforming zone in heat exchanger 4. It then passes by line 5 to the coil 6 which is immersed in the fluidized bed of catalyst in the catalyst regenerator 2 where the feed is heated to the desired temperature preferably not above thermal cracking temperatures of 900-950 DEG  F. Thence the naphtha is fed to the reactor 1 by line 7.  The hydrogen for the reactor is taken from the product gas which is separated from liquid products in the separation drum 8 and recycled by line 9, any excess being removed by line 24.  The recycle gas is preheated partially, to 600-700 DEG  F., by heat exchange with part of the product in heat exchanger 12 and then to 1100-1400 DEG  F. in the furnace 14.  The gas then picks up regnerated catalyst from line 49 and passes to the reactor.  Products from the reactor are split, part passing by line 18 and part by line 21 to heat naphtha feed and recycle gas respectively, then through the condenser 20 and liquid and gases are separated in the separation drum 8. Catalyst is withdrawn from the fluidized bed of the reactor by line 30 into the stripper 31 where volatile material is removed by nitrogen or steam passed in by line 32.  Catalyst is withdrawn by standpipe 34 into line 35 into which sufficient air is introduced to carry the catalyst to regenerator 2.  Further air or oxygen-containing gas for the regeneration is supplied by line 39. Combustion products leave the regenerator by line 40. Regenerated catalyst is led by line 43 into the stripper 46 where undesirable water, and oxides of carbon <PICT:0795839/IV (b)/1> are removed by a stripping gas.  Catalyst is returned to the reactor by feeding it by line 49 into the recycle gas line 16. The temperature of the naphtha feed is controlled in two ways, (1) the amount of heat applied in heat exchanger 4 may be controlled by the proportion of product passing through line 18, depending on the valve V which may be automatically controlled according to the temperature of the heated feed by the control TRC in line 7, (2) the amount of heat applied in the regenerator is controlled by the degree of immersion of the heat-exchange coil in the regenerator depending on the level of the catalyst bed, this level being maintained at a constant predetermined level by control of the valve in line 43 by level control LRC and the level may be changed when the range of temperature control given by valve V is insufficient.  Similarly the level of the catalyst bed in the reactor is maintained constant by automatic control of the valve in line 16 by control LRC associated with the reactor fluidized bed and the temperature by control of the amount of regenerated catalyst flowing through the valve in line 49 controlled by control TRC in the reactor.  The temperature of the recycle gas is controlled by the amount of fuel and air fed to the furnace 14 by a temperature responsive control TRC2.ALSO:In a fluidized hydroforming process the hot products are split into two streams which are used respectively to heat the naphtha feed and the hydrogen-containing gas by heat exchange and the naphtha feed is further heated by heat exchange with hot fluidized catalyst in a catalyst regeneration zone.  The degree of immersion of the heating coils in the regeneration zone may be varied responsive to the temperature of the heated naphtha which is thereby heated to a constant temperature.  Hot regenerated catalyst may also be returned to the reaction zone at a rate controlled by the temperature in the reaction zone to maintain that temperature at the desired value.