Patent GB-743942-A (GB)
Title: Improvements in or relating to heat recovery in a gas fluidized-solids contacting operation
IPC: B01J8/00
Filed: 1953-07-10
Abstract: <PICT:0743942/IV(a)/1> In a hydroforming process in which a fluidized catalyst is contacted with a hydrocarbon vapour and the effluent vapour stream containing less than about 0.001 lbs. per cubic foot of fine catalyst is passed through a heat exchanger, the deposition of fine solids in the heat exchanger is prevented by adding extraneous non-abrasive solids of larger particle size than the fines to the effluent vapour stream prior to passage through the heat exchanger, passing cooled effluent vapour from the exchanger to a separator to remove the coarser particles, and reinjecting these particles into the vapour stream passing to the heat exchanger.  The fine solids present in the effluent stream may have an average size of less than 20 microns and the coarse solids a size of more than 80 microns.  The coarse solids may be added in an amount to increase the total solids content to at least 0.001 lbs. per cubic foot.  Smooth sand or microspheres of aluminium silicate or alumina are suitable coarse solids.  In the apparatus shown, the product stream containing catalyst fines is removed from reactor 10 through line 15 and mixed with coarse solids from line 17; the mixture passes through heat exchanger 18 where it heats the hydrocarbon feed and/or the recycle hydrogen-containing gas for the hydroforming reaction.  The coarse particles are removed in separator 30 and recycled.  The product still containing catalyst fines passes through line 33 to scrubber 35 where the fines are removed by contact with a condensed polymer fraction which is recycled through line 39.ALSO:<PICT:0743942/III/1> In a process in which a fluidized solid is contacted with a gas or vapour and the effluent gas, stream containing less than about 0.001 lbs. per cub. ft. of fine solid particles is passed through a heat exchanger, the deposition of fine solids in the heat exchanger is prevented by adding extraneous non-abrasive solids of larger particle size than the fines to the effluent gas stream prior to passage through the heat exchanger, passing cooled effluent gas from the exchanger to a separator to remove the coarser particles, and reinjecting these particles into the gas stream passing to the heat exchanger.  The fine solids present in the effluent stream may have an average size of less than 20 microns and the coarse solids a size of more than 80 microns.  The coarse solids may be added in an amount to increase the total solids content to at least 0.001 lbs. per cub. ft.  Smooth sand or microspheres of aluminium silicate or alumina are suitable coarse solids.  In the apparatus shown, hydroforming of hydrocarbons is carried out in reactor 10 and the product stream containing catalyst fines is removed through line 15 and mixed with coarse solids from line 17; the mixture passes through heat exchanger 18 where it heats the hydrocarbon feed and/or the recycle hydrogen-containing gas for the hydroforming reaction.  The coarse particles are removed in separator 30 and recycled.  The product still containing catalyst fines passes through line 33 to scrubber 35 where the fines are removed by contact with a condensed polymer fraction which is recycled through line 39. Reference is also made to the use of the process in coking and in the regeneration of catalyst used for cracking.