US 11,873,276 B2
Fluidized bed dehydrogenation process for light olefin production
Hima Bindu Doosa, Faridabad (IN); Saravanan Subramani, Faridabad (IN); Ram Mohan Thakur, Faridabad (IN); Vineeth Venu Nath, Faridabad (IN); Kumaresan Loganathan, Faridabad (IN); Bineesh Kanattukara Vijayan, Faridabad (IN); Madhusudan Sau, Faridabad (IN); Gurpreet Singh Kapur, Faridabad (IN); and Sankara Sri Venkata Ramakumar, Faridabad (IN)
Assigned to INDIAN OIL CORPORATION LIMITED, Mumbai (IN)
Filed by Indian Oil Corporation Limited, Mumbai (IN)
Filed on Sep. 16, 2021, as Appl. No. 17/447,828.
Claims priority of application No. 202021040124 (IN), filed on Sep. 16, 2020.
Prior Publication US 2022/0081373 A1, Mar. 17, 2022
Int. Cl. C07C 5/333 (2006.01); B01J 8/24 (2006.01); B01J 8/00 (2006.01); B01J 8/18 (2006.01); B01J 38/02 (2006.01); B01J 38/06 (2006.01)
CPC C07C 5/333 (2013.01) [B01J 8/0055 (2013.01); B01J 8/1836 (2013.01); B01J 8/24 (2013.01); B01J 38/02 (2013.01); B01J 38/06 (2013.01); B01J 2208/00115 (2013.01); B01J 2208/00407 (2013.01); B01J 2208/00557 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A process for production of light olefins by dehydrogenation of alkanes in a plurality of semi-continuously operated fluidized bed reactors Ai; (i=2, . . . n) provided with a common continuously operated catalyst regenerator (D), wherein the process comprises sequential steps:
a) feeding a hot regenerated catalyst and a pre-heated diluent stream to the plurality of semi-continuously operated fluidized bed reactors;
b) pre-treating the hot regenerated catalyst by feeding a reducing gas to the plurality of semi-continuously operated fluidized bed reactors to obtain a pre-treated catalyst;
c) feeding a pre-heated alkane feed to the plurality of semi-continuously operated fluidized bed reactors for catalytic dehydrogenation in presence of the pre-treated catalyst to obtain a product mixture comprising olefins, unreacted alkanes, product gases, and a spent catalyst;
d) separating the product mixture from the spent catalyst in reactor cyclones;
e) separating remaining hydrocarbon molecules from the spent catalyst by stripping using steam, or an inert gas and recovering stripping product gas through the reactor cyclones;
f) transferring the spent catalyst to the common continuously operated catalyst regenerator (D); and,
g) reactivating the spent catalyst in the common continuously operated catalyst regenerator by burning coke deposited on spent catalyst using air, oxygen, or an oxygen containing gas,
wherein the pre-heated diluent stream and the pre-heated alkane feed are in a molar ratio in a range of 0.1 to 5,
wherein the process in each of the plurality of semi-continuously operated fluidized bed reactors begins at a different time to maintain a constant catalyst inventory with time in the common continuously operated catalyst regenerator, and to maintain a minimum catalyst inventory in each of the plurality of semi-continuously operated fluidized bed reactors by flowing steam, or an inert gas at a minimum velocity during reactivation of the spent catalyst, wherein the process occurs in a sequence wherein a slide valve of a stand pipe opens at t=0 minutes to transfer the regenerated catalyst from the common continuously operated catalyst regenerator to the semi-continuously operated fluidized bed reactor Ai−1, and wherein a slide valve of a stand pipe Bi−1 remains closed at t=0 minutes until a desired catalyst inventory is built up in the semi-continuously operated fluidized bed reactor Ai−1,
the slide valve of the stand pipe Bi opens to transfer the spent catalyst from the semi-continuously operated fluidized bed reactor Ai to the common continuously operated catalyst regenerator through a lift line Ci, wherein after regeneration, a slide valve of a stand pipe Ei opens and the hot regenerated catalyst flows into the semi-continuously operated fluidized bed reactor Ai, and wherein at the same time, the spent catalyst from the semi-continuously operated fluidized bed reactor Ai+1 flows into the common continuously operated catalyst regenerator through a slide valve of a stand pipe Bi+1 and the lift line Ci+1, where i=2, . . . n.