Abstract:
The present invention provides a method of producing a synthesis gas from a regeneration of spent cracking catalyst. The method includes introducing a spent cracking catalyst into a first regeneration zone I a presence of a first oxygen and carbon dioxide atmosphere and at a first regeneration temperature. For example, a temperature that does not exceed about 1400 DEG F, ad more preferable a temperature that ranges from about 1150 DEG F to about 1400 DEG F, may be used as the first regeneration temperature. The method further includes introducing the spent cracking catalyst from the first regeneration zone into a second regeneration zone in a presence of a second oxygen and carbo dioxide atmosphere, and producing a synthesis gas from cracking deposits located on the spent cracking catalyst within the second regeneration zone at a second regeneration temperature substantially grater than said first regeneration temperature. In a preferred embodiment, the second regeneration temperature ranges from about 1500 DEG F to about 1800 DEG F, and in a related embodiment is about 1800 DEG F.
Abstract:
The present invention features a system and method for circulating catalyst between a reactor system and a regenerator system. A circulating catalyst system includes a reactor system, a regenerator system, and a distribution unit. The reactor system and regenerator system are adapted to exchange catalyst. The regeneration system preferably includes a regeneration zone adapted for the contact of catalyst with a regeneration gas. The system and method are adapted so that more than one regeneration gas may contact catalyst. The distribution unit is adapted to control the percentage of catalyst contacting each regeneration gas. Thus, the distribution unit is adapted to select the percentages so as to maintain the reactor system and regeneration system under a heat balance regime. Heat is preferably transferred from the regenerator system to the reactor system by an exchange of catalyst.
Abstract:
A continuous regenerator for the two-stage regeneration of hot coked fluid catalytic cracking catalyst, and a method for regenerating coked catalyst by combustion with air and with reduced emissions of nitrogen oxides, or with reduced emissions of any two or more of the pollutants which include nitrogen oxides, sulfur oxides and carbon monoxide.
Abstract:
La présente invention décrit une zone de combustion d'une unité catalytique régénérative en vue de la régénération en continue du catalyseur, la dite zone de combustion ayant une forme annulaire et étant divisée en au moins deux étages de combustion, chaque étage étant divisé en un nombre N de secteurs radiaux, sensiblement égaux, le catalyseur s'écoulant de manière gravitaire d'un secteur du premier étage de combustion au secteur situé à l'aplomb du second étage de combustion au moyen de jambes de descente, et la circulation du gaz de combustion étant telle que le gaz de combustion parcourt successivement tous les secteurs du premier étage de combustion dans un ordre quelconque, puis tous les secteurs du second étage de combustion dans un ordre quelconque.
Abstract:
A process is disclosed for simultaneously heating and cooling spent FCC catalyst during regeneration in a high efficiency FCC regenerator using a fast fluidized bed coke combustor (50). The coke combustor (50) burns coke from the spent catalyst in a turbulent or fast fluidized bed (52), and discharges catalyst and flue gas up into a dilute phase transport riser (56), where the catalyst is separated from the flue gas and flows to a bubbling dense bed (75) of catalyst. The coke combustor (50) is heated by recyling hot catalyst from the bubbling dense bed (75) and simultaneously cooled by a backmixed heat exchanger (203). Catalyst flows from the combustor (50) to the heat exchanger (203), and is displaced back into the combustor (50) by adding air to the catalyst in the cooler (203). Heating promotes rapid coke combustion, while cooling reduces thermal and hydrothermal deactivation of the spent catalyst. High superficial vapor velocities in the heat exchanger (203) promote heat transfer without disrupting flow in the fast fluidized bed coke combustor (50), and without increasing catalyst traffic in the flue gas above the bubbling dense bed (75).
Abstract:
Catalyst regenerators and methods of their use are provided. A method includes combusting coke from the catalyst in a second stage regenerator to produce a second flue gas, where the second stage regenerator includes a second combustion chamber and a top having a top cross-sectional area. The coke is partially combusted from the catalyst in a first stage regenerator with a first combustion chamber having a first combustion chamber cross-sectional area greater than the top cross-sectional area. The first stage regenerator is positioned above the top of the second stage regenerator. The first combustion chamber includes a cylindrical section directly over the top and an annular section surrounding the cylindrical section. The second flue gas is vented into the first stage regenerator through a vent tube, and a portion of the second flue gas is dispersed into the annular section of the first combustion chamber.
Abstract:
A catalyst regenerator (100) has a first section (110) and a second section (120) and is operated such that carbon from a carbon-contaminated catalyst (140) is converted to carbon monoxide in the first section (110) and that carbon monoxide is converted to carbon dioxide in the second section (120). The residence time of the oxygen-containing gas in the first and second sections (110, 120) is regulated in preferred configurations by the shape (e.g., diameter) of the first and second sections (110, 120).
Abstract:
In a process for controlled, multi-stage regeneration of FCC catalyst, a modified high efficiency catalyst regenerator (80), with a fast fluidized bed coke combustor (62), dilute phase transport riser (83), and second fluidized bed (82) regenerates the catalyst in at least two stages. The primary stage of regeneration is in the coke combustor (62), whereas a second stage catalyst regeneration occurs in the second fluidized bed (82). The amount of combustion air added to, and conditions in, the coke combustor (62) are controlled to limit CO combustion, while the second stage of regeneration, in the second fluidized bed (82), achieves complete CO combustion. Controlled multi-stage regeneration reduces steaming or deactivation of a catalyst during regeneration, increase coke burning capacity, and reduces NOx emissions.
Abstract:
Disclosed is an apparatus (50) and process for prolonging the residence time of catalyst in a chamber (54) for regenerating catalyst. Spent catalyst, perhaps from an FCC reactor (10), is introduced into a chamber (54) of a regeneration vessel (50) between lower and higher combustion gas distributors (66, 72). The velocity of gas from the lower distributor is insufficient to entrain catalyst from the bed, and gas from the higher distributor when combined with gas rising from the lower distributor is sufficient to generate a fast fluidized flow condition. The second distributor elevates the location of the transition from turbulent bed to fast fluidized conditions.