Removal of organic silicon compounds from refinery hydrocarbon streams

Abstract

A method, process, and system are disclosed for removing silicon-containing compounds from refinery hydrocarbon streams using alkaline treatment. The refinery stream, which may originate from units such as a crude stream, delayed coker, or other process unit, is contacted with an alkaline agent, such as a solid or an aqueous solution of sodium hydroxide, potassium hydroxide, or an amine. This treatment extracts at least a portion of the silicon-containing compounds, including organic silicon species, from the hydrocarbon stream. The process may be applied to whole streams or specific fractions such as LPG, naphtha, kerosene, diesel, or coker gas oil. Following alkaline treatment, the hydrocarbon stream may be directed to a hydrotreating unit, where reduced silicon content reduces catalyst poisoning.

What is claimed is: 
     
         1 . A method of extracting silicon-containing compounds from a refinery stream, the method comprising:
 contacting a refinery stream with an alkaline agent, wherein the refinery stream comprises a mixture of hydrocarbons and silicon-containing compounds,   wherein the alkaline agent extracts the silicon-containing compounds from the refinery stream.   
     
     
         2 . The method of  claim 1 , wherein the refinery hydrocarbon stream comprising the silicon-containing compound is separated into two or more fractions before contacting with the alkaline agent. 
     
     
         3 . The method of  claim 2 , wherein the two or more fractions comprise a liquefied petroleum gas (LPG) fraction, a naphtha fraction, a kerosene fraction, a diesel fraction, coker gas oil, or a combination of two or more thereof. 
     
     
         4 . The method of  claim 1 , wherein the alkaline agent comprises a solid, a powder, or an aqueous solution. 
     
     
         5 . The method of  claim 1 , wherein the alkaline agent is within an alkaline scrubbing bed, a packed bed, or a trayed column. 
     
     
         6 . The method of  claim 1 , wherein the silicon-containing compound is an organic silicon-containing compound. 
     
     
         7 . A process for extracting a silicon-containing compound from a refinery hydrocarbon stream, the process comprising:
 providing a refinery hydrocarbon stream from an upstream process unit, wherein the refinery hydrocarbon stream comprises a silicon-containing compound; and   contacting the refinery hydrocarbon stream comprising the silicon-containing compound with an alkaline agent in an alkaline bed, thereby extracting at least a portion of the silicon-containing compound from the refinery hydrocarbon stream; and   hydrotreating the refinery hydrocarbon stream after the contacting.   
     
     
         8 . The process of  claim 7 , wherein the upstream process unit is a delayed coker unit. 
     
     
         9 . The process of  claim 7 , wherein the refinery hydrocarbon stream comprising the silicon-containing compound is separated into two or more fractions before passing through the alkaline bed. 
     
     
         10 . The process of  claim 9 , wherein the two or more fractions comprise an LPG fraction, a naphtha, a kerosene fraction, a diesel fraction, coker gas oil, or a combination of two or more thereof. 
     
     
         11 . The process of  claim 7 , wherein the alkaline bed comprises a solid, a powder, or an aqueous solution. 
     
     
         12 . The process of  claim 7 , wherein the silicon-containing compound is an organic silicon-containing compound. 
     
     
         13 . The process of  claim 7 , wherein an alkaline agent is circulated within the alkaline bed to maintain a concentration of the alkaline agent throughout the process. 
     
     
         14 . The process of  claim 7 , wherein the alkaline bed is an alkaline scrubbing bed, a packed bed, or a trayed column. 
     
     
         15 . A system for extracting a silicon-containing compound from a refinery hydrocarbon stream, the system comprising:
 an upstream process unit,   an alkaline bed, and   a hydrotreater,   wherein, the alkaline bed is upstream of the hydrotreater, and   wherein the alkaline bed is configured to receive a refinery hydrocarbon stream comprising the silicon-containing compound from the upstream process unit such that the refinery hydrocarbon stream comprising the silicon-containing compound contacts the alkaline bed, thereby removing the silicon-containing compound from the refinery hydrocarbon stream before hydrotreating.   
     
     
         16 . The system of  claim 15  further comprising a distillation unit upstream of the alkaline bed. 
     
     
         17 . The system of  claim 15 , wherein the upstream process unit is a delayed coker unit. 
     
     
         18 . The system of  claim 15 , wherein the alkaline bed comprises an alkaline agent, and the alkaline agent is provided as a solid, a powder, or an aqueous solution. 
     
     
         19 . The system of  claim 15 , wherein the silicon-containing compound is an organic silicon-containing compound. 
     
     
         20 . The system of  claim 15 , wherein the alkaline bed is an alkaline scrubbing bed, an amine bed, a packed bed, or a trayed column.