Abstract: A fluidized bed reactor operating under countercurrent gas-solid flow conditions wherein the reactor is supplied with horizontal baffles having separate passages through which the gas and the solid flow, such that the ascending gas leaves the baffle in a point higher than the point in which the descending solid leaves the same baffle, and the use of the reactor to perform reactions under countercurrent flow conditions while maintaining gas and solids flows of at least 70% of flooding conditions.

Abstract: Disclosed are devices for introducing and uniformly distributing spent catalyst into a regenerator bed of a fluid catalytic cracking unit. Also disclosed are devices for collecting and discharging regenerated catalyst from the regenerator bed. The devices provide more uniform contacting of the spent catalyst particles with regeneration gas and consequently more efficient and complete regeneration.

Abstract: A method and apparatus for passivating the adverse catalytic effects of metal contaminated hydrocarbon feedstocks is described. The method is directed at the use of control means to regulate the residence time of the catalyst in the passivation zone and to regulate the reducing gas flow rate to the passivation zone.

Abstract: The invention relates to a system for the discharge and/or distribution of a gas from a source of the gas, and more specifically relates to such a system which enables gas from a source to be discharged and/or distributed to at least two gas-utilizing units irrespective of the operational status of each unit. The gas from the source is conducted from a manifold to each unit via respective conduits. Each conduit has a valve having a maximum closed position, in which the valve is open to a predetermined minimum degree exceeding zero, and a maximum opened position, in which it is open to a predetermined extent set by the maximum gas capacity of the respective unit. One valve maintains a gas flow delivery pressure to its respective unit not exceeding a selected maximum pressure. The other valve maintains a gas flow-rate corresponding to the gas-requirement of its respective unit.

Abstract: Apparatus wherein spent, coked catalyst is admixed with combustion air externally of the regenerator and then introduced into the lower portion of a dense phase fluidized bed of said regenerator via an inlet. The inlet is characterized as an annulus, annular area or zone around a regenerated catalyst standpipe from which regenerated catalyst is removed from the regenerator and recycled to the reactor. Generally from about 3 percent to about 20 percent, preferably from about 5 percent to about 10 percent, of the total air introduced into the regenerator is introduced in this manner and balance of the air, which is in itself sufficient for complete combustion, is introduced via a separate air inlet into the regenerator.

Abstract: The present invention is for a continuous system wherein spent catalyst is removed from a regeneration vessel, while fresh catalyst is added in order to maintain proper catalyst activity in a hydrocarbon processive system. The withdrawal of the spent catalyst must be achieved at a steady flow rate which is compatible with the introduction of fresh catalyst of the hydrocarbon processing system. This flow rate is controlled by a downstream pressure and venting control in the spent catalyst hopper stage acting in conjunction with a novel flow restriction zone in a discharge conduit.

Abstract: A minor portion of the regeneration gas used to regenerate spent fluid catalytic cracking catalyst is employed to combust volatile hydrocarbons in mixture with said spent catalyst prior to said mixture entering the regeneration zone. This serves to reduce and/or minimize transverse oxygen gradients in the dense phase catalyst bed and in the effluent gases therefrom such that excessive or undesirable afterburning in the dilute catalyst phase can be minimized or eliminated.

Abstract: A minor portion of the regeneration gas used to regenerate spent fluid catalytic cracking catalyst is introduced into the regeneration zone in the localized area of the terminus of the spent catalyst line so as to combust the volatile hydrocarbons in mixture with the spent catalyst being transferred from the reaction zone to the regeneration zone. This serves to reduce and/or minimize transverse oxygen gradients in both the dense phase catalyst bed and in the effluent gases therefrom such that excessive or undesirable afterburning in the dilute catalyst phase can be minimized or eliminated.

Abstract: A method for controlling the oxides of nitrogen concentration in the exit flue gas from the regeneration zone of a catalytic cracking unit employing carbon monoxide combustion promoters which comprises monitoring the oxides of nitrogen concentration in the exit flue gas and adjusting the concentration of combustion promoter present in the regeneration zone to maintain the oxides of nitrogen concentration below a predetermined limit.

Abstract: A minor portion of the regeneration gas used to regenerate spent fluid catalytic cracking catalyst is passed into a distribution means located at the interface between the dense phase catalyst bed and the dilute catalyst phase in the regeneration zone of a fluid catalytic cracking process to combust, at said interface, the carbon monoxide formed in said bed to carbon dioxide. In a preferred embodiment, the level of the dense phase bed can be adjusted to vary the amount of catalyst entrained in the dilute catalyst phase such that the distribution means will be partially submerged. This serves to provide a simple and convenient method to absorb the heat released by the oxidation of carbon monoxide, thereby minimizing or eliminating excessive or undesirable afterburning in the dilute catalyst phase and in equipment downstream thereof.

Abstract: Hydrocarbon conversion catalysts which have become deactivated by the deposition of coke and metal contaminants such as nickel, iron, vanadium, etc., are regenerated under conditions which include temperatures in excess of 1300.degree. F. and the periodic use of an amount of oxygen which is in excess of that required to completely burn the coke to CO.sub.2. In a hydrocarbon conversion process whereby a metal-contaminated heavy feed is contacted at conversion conditions with a cracking catalyst to produce lower boiling hydrocarbon products and a spent catalyst having coke and said metal contaminant deposited thereon and wherein said spent catalyst is reactivated in a regeneration zone at elevated temperatures in the presence of O.sub.2 to produce a regenerated catalyst and a flue gas containing more than 2 vol. % CO, the improvement which comprises periodically increasing the amount of O.sub.2 introduced into said regeneration zone at a temperature in excess of 1300.degree. F. so that the level of O.sub.

Abstract: An improved method for regenerating a catalytic cracking catalyst which comprises the steps of (1) increasing the temperature of the regeneration zone dense phase catalyst bed to a desired level above that normally employed during the regeneration so as to accelerate the rate of carbon conversion, (2) reducing the coke make in the reaction zone while maintaining the elevated temperature obtained in step (1) so as to increase the oxygen concentration in said regeneration zone so as to establish low levels of carbon monoxide in the flue gas and (3) reducing the temperature of the regeneration zone dense phase catalyst bed below the elevated temperature obtained in steps (1) and (2) while maintaining low levels of carbon monoxide in the flue gas. According to this invention, the flue gas may contain less than 0.05 volume %, preferably less than 0.02 volume %, carbon monoxide and, as such, may be discharged directly to the atmosphere with no discernable effect upon ambient air quality.

Abstract: Noxious emissions produced in the process of regenerating catalysts employed in the catalytic cracking of hydrocarbons are reduced by burning the coke on the spent catalyst in a regenerator operated at a temperature greater than 1200.degree. F. to produce flue gas containing less than 2.0 vol.

Abstract: An open shrouded trickle valve for use in processes such as those adapted for fluid cat crackers and particularly for use in a cyclone dipleg to eliminate the shroud normally employed. The valve is connected at the exit of the dipleg to provide a seal so that the collected solids can be returned directly to the bed and comprises a flapper plate which is disposed to prevent backflow of gas up the exit opening when solids flow is interrupted or when a bubble of gas passing through the bed is directed up the dipleg thereby preventing direct loss of solids out of the cyclones. Situated a fixed distance behind the flapper plate is a flat baffle plate disposed in a vertical position and wider than the flapper plate, which serves to protect the flapper plate by preventing local disturbances such as passing bubbles from affecting its position with respect to the exit opening.

Abstract: The catalyst circulation rate in a fluid catalytic cracking process is regulated by using a low pressure drop valve means in the spent catalyst circuit of said process in conjunction with a control riser in said circuit. More particularly, a reduced catalyst circulation rate may be obtained in a fluid catalytic cracking process, the spent catalyst circulation rate in said process being controlled by the injection of variable amounts of a control gas into the control riser so as to cause density variations therein, by employing a low pressure drop valve means in the spent catalyst circuit of said process such that the pressure drop across said valve means reduces the pressure drop across the riser and consequently the density within said riser. The reduction in density within the riser results in a lowering of the catalyst circulation rate.

Abstract: Steam coils having two different pressure levels are provided in a bed of carbon-contaminated catalyst undergoing regeneration by combustion with an oxygen-containing gas to control the temperature.

Abstract: An improved method for the regeneration of catalytic cracking catalyst wherein a regeneration flue gas having a reduced concentration of carbon monoxide, preferably less than 0.05 vol. %, and a regenerated catalyst having a reduced residual carbon content, preferably less than 0.1 wt. %, are obtained by first burning coke from the coke-contaminated catayst at an elevated temperature such that when the coke burned is substantially completely converted to carbon dioxide, the temperature of the fluidized bed in the regeneration zone may then be reduced to a desired operating level while maintaining substantially complete conversion of the carbon to carbon dioxide. This is accomplished by regulating the amount of coke deposited on the catalyst in the reaction zone and adjusting the catalyst circulation rate. Effluent gas from the regeneration zone may be discharged directly to the atmosphere with no discernible effect upon ambient air quality.

Abstract: Process and apparatus for hydrocarbon conversion, such as, fluid catalytic cracking, in which finely divided catalyst is circulated from a catalyst regeneration vessel through a standpipe connected by an angle bend to a vertically inclined conduit which in turn is connected to a straight vertical transferline riser reaction zone into a gas-solids disengaging and stripping vessel without the necessity of a variable orifice flow control valve. Separated spent and stripped catalyst flows from the disengaging-stripping vessel to the regeneration vessel through an external conduit.

Abstract: Regeneration of spent catalyst contaminated by a carbonaceous deposit is conducted by contacting the spent catalyst with a hot flue gas emanating from a first dense phase regeneration zone. The heated spent catalyst is then contacted countercurrently with an oxygen-containing gas in the first dense phase regeneration zone to produce partially regenerated catalyst which is subsequently contacted concurrently with an oxygen-containing gas in a second dense phase regeneration zone. The regenerator includes a standpipe section disposed within the regeneration vessel in concentric relation to the vertical axis thereof with a cylindrical baffle disposed around an upper portion of the standpipe section. The baffle has at least one orifice at its lower portion for direct passage of catalyst from the fluidized bed into the annular zone between the baffle and the standpipe.