Patent GB-767419-A (GB)
Title: Improvements in or relating to the method of making gaseous products and coke and apparatus for making same
Inventor: SCHUTTE AUGUST HENRY
IPC: C07C11/02
Filed: 1954-09-07
Abstract: <PICT:0767419/IV(b)/1> <PICT:0767419/IV(b)/2> In a process of making gaseous products from heavy residual oils wherein particulate solids are circulated through a closed system including a reaction zone, a reheating zone, and interconnecting conduits including a lift conduit, the particulate solids passing downwardly through the reaction zone in gravity-packed non-turbulent flow, a stream of heavy oil in liquid condition is injected into the particulate solids at an elevated point in the system prior to their downward movement in the reaction zone and a gas or vapour is injected or generated at a point in the lift conduit below the elevated point to effect the elevation of the particulate solids through the lift conduit to the reaction zone, the time and temperature conditions in the reaction zone being maintained such that the coke deposited on the particulate solids is dry whereby the particulate solids are capable of flowing freely through the interconnecting conduits.  As shown in Fig. 1 the contact material flows by gravity from a reactor 10 into a reheater 16 and continues to flow by gravity through the reheater to an outlet 18 for return to the reactor by line 20.  A proportion of the contact material may by-pass the reheater 16 via a size classifier 74 and line 78 and coke particles above 3/4 inch in diameter may be removed through line 76.  The reheater 16 has a series of radiant heater units 26 mounted on the upper portion of the reheater and supplied with a gaseous fuel through a manifold 28.  Combustion gases from the heater units 26 are removed through channels 32 and discharged through line 36. Reheated contact material and contact material from line 78 passes into the leg 40 of a Y-shaped member into which at 42 hydrocarbon feed preheated in a series of heat exchangers and a preheater 49 is fed, the vaporization of the hydrocarbon serves to elevate the contact material in the line 20, the amount of light stock in the feed being controlled to give the desired lifting effect.  A portion of the feed is also added through line 70 and contact material wetted with the hydrocarbon feed is discharged into reactor 10 against a streamlined adjustable baffle 72.  If necessary, steam may be introduced into the line 20 by line 52. Vapours which have a virgin gas oil character are taken from reactor 10 by line 22 and quenched at 24 with a heavy oil.  The products from the reactor are then fractionated in a tower 60, gas and gasoline are removed overhead, a light gas oil, boiling range 400-600 DEG  F., is removed at 64, a heavy product gas oil is removed at 66 and recycle bottoms at 68.  A controlled portion of the heavy product gas oil removed at 66 may be fed by line 66a into the hydrocarbon feed and the recycle bottoms are introduced into the feed through line 68a or used as quench oil at 24.  The residence time in the reactor is from 5-20 minutes.  In the typical case the reactor temperature would be 850-950 DEG  F., and the coke would be reheated to 890-965 DEG  F. In a modification in which large percentages of gaseous olefins or acetylene are obtained the contact material is circulated between reactor 115 and reheater 122 in which it is heated by combustion of a fuel gas and air admitted through the manifold 126, combustion gases are withdrawn through line 130.  Reheated material passes intermittently through valve 133 to a vessel 134 into which when valve 133 is closed, air or steam is fed through line 135 for the gas lift in line 142.  The elevated material is discharged into a receiver 110 whence it passes in part back to the reaction vessel 115 and in part to a second heater 145.  Heavy residual oil from line 116 is mixed with the solids returning to the reactor in line 112.  Steam may be admitted to the reactor through line 154 and gaseous or vaporous products are withdrawn through line 118 to be passed into a cracking vessel 150 where they are contacted with contact material from the heater 145.  In the heater 145 the contact material is heated by partial combustion with air from line 146 to between 800-1400 DEG  C. depending on the required results in the cracking vessel 150.  Combustion gases from heater 145 are led off through line 148 and may be passed by line 148a to heater 122.  The gaseous products leaving vessel 150 by line 151 contain acetylene, ethylene, propylene and lesser amounts of methane, ethane and oxides of carbon. The contact time in vessel 150 varies from 0.1 seconds to several seconds.  For maximum yields of acetylene (about 35 per cent) the average temperature in the vessel 150 will be between 1300-1400 DEG C.  Where ethylene is the desired product the average temperature will be between about 1100-1250 DEG  C., when a gas containing about 42 per cent ethylene is obtained.  At temperatures between 1832 DEG and 2012 DEG  F. a gas containing 40 per cent ethylene and 20 per cent propylene is produced.  From the vessel 150 the contact material is passed by line 160 to the heater 122.  The contact material employed is preferably coke and coke may be withdrawn from the reactor 115 by line 120.  Fresh coke feed may be added to heater 122 through line 123.  In a modification the reheating of the contact material in heater 122 may be effected by partial combustion of the contact material.  Pressures of up to 50 lbs. per sq. inch may prevail in the system but generally the pressures are near atmospheric.ALSO:<PICT:0767419/III/1> In a process of making gaseous products and coke from heavy residual oils wherein particulate solids are circulated through a closed system including a reaction zone, a reheating zone, and interconnecting conduits including a lift conduit, the particulate solids passing downwardly through the reaction zone in gravity-packed non-turbulent flow, a stream of heavy oil in liquid condition is injected into the particulate solids at an elevated point in the system prior to their downward movement in the reaction zone and a gas or vapour is injected or generated at a point in the lift conduit below the elevated point to effect the elevation of the particulate solids through the lift conduit to the reaction zone, the time and temperature conditions in the reaction zone being maintained such that the coke deposited on the particulate solids is dry whereby the particulate solids are capable of flowing freely through the interconnecting conduits. As shown in Fig. 1 the contact material flows by gravity from a reactor 10 into a reheater 16 and continues to flow by gravity through the reheater to an outlet 18 for return to the reactor by line 20.  A proportion of the contact material may by-pass the reheater 16 via a size classifier 74 and line 78 and coke particles above 3/4 inch in diameter may be removed through line 76.  The reheater 16 has a series of radiant heater units 26 mounted on the upper portion of the reheater and supplied with a gaseous fuel through a manifold 28.  Combustion gases from the heater units 26 are removed through channels 32 and discharged through line 36.  Reheated contact material and contact material from line 78 passes into the leg 40 of a Y-shaped member into which at 42 hydrocarbon feed preheated in a series of heat exchangers and a preheater 49 is fed, the vaporization of the hydrocarbon serves to elevate the contact material in the line 20, the amount of light stock in the feed being controlled to give the desired lifting effect.  A portion of the feed is also added through line 70 and contact material wetted with the hydrocarbon feed is discharged into reactor 10 against a streamlined adjustable baffle 72.  If necessary steam may be introduced into the line 20 by line 52.  Vapours which have a virgin gas oil character are taken from reactor 10 by line 22 and quenched at 24 with a heavy oil.  The products from the reactor are then fractionated in a tower 60, gas and gasoline are removed overhead, a light gas oil, boiling range 400 DEG -600 DEG F., is removed at 64, a heavy product gas oil is removed at 66 and recycle bottoms at 68. A controlled portion of the heavy product gas oil removed at 66 may be fed by line 66a into the hydrocarbon feed and the recycle bottoms are introduced into the feed through line 68a or used as quench oil at 24.  The residence time in the reactor is from 5-20 minutes.  In the typical case the reactor temperature would be 850 DEG -950 DEG F. and the coke would be reheated to 890 DEG -965 DEG F.  In order to produce maximum gas, gasoline, light distillates and coke the reactor may be run at 1000 DEG -1300 DEG F. and with a residence time in the reactor of 5-15 minutes.