Ammoniated quenching of a hydroprocessing reaction

Abstract

The disclosure provided herein describes processes for rapidly quenching an over-temperature hydroprocessing reaction utilizing a pressurized quenching agent that is rapidly released into the hydroprocessing reactor. Optimally, the quenching agent blocks acidic catalytic sites of the hydroprocessing catalyst to competitively inhibit exothermic reaction rate. Exemplary quench agents include ammonia or a chemical that is converted to ammonia under hydroprocessing conditions.

We claim: 
     
         1 . A process for quenching a catalytic hydroprocessing reaction, comprising:
 a) contacting a feedstock derived from at least one of petroleum or biomass with a hydroprocessing catalyst comprising at least on acidic catalytic active site in a reaction zone at a temperature and pressure that facilitates hydroprocessing reactions, wherein the contacting converts the feedstock to a reactor effluent comprising a liquid hydrocarbon fuel or a blending component thereof;   b) detecting a temperature condition in the reaction zone;   c) dispensing a quenching agent from a pressurized vessel to the reaction zone when the temperature condition exceeds a first predetermined threshold temperature, wherein the quenching agent binds to and blocks at least one active site of the hydroprocessing catalyst.   
     
     
         2 . The process of  claim 1 , wherein the first predetermined threshold temperature is at least 473° C. (820° F.) 
     
     
         3 . The process of  claim 1 , wherein the first predetermined threshold temperature is at least 476° C. (825° F.). 
     
     
         4 . The process of  claim 1 , wherein the first predetermined threshold temperature is at least 479° C. (830° F.). 
     
     
         5 . The process of  claim 1 , wherein the first predetermined threshold temperature is at least 482° C. (835° F.). 
     
     
         6 . The process of  claim 1 , wherein the first predetermined threshold temperature is at least 484° C. (840° F.). 
     
     
         7 . The process of  claim 1 , wherein the first predetermined threshold temperature is at least 487° C. (845° F.). 
     
     
         8 . The process of  claim 1 , wherein the first predetermined threshold temperature is at least 490° C. (850° F.). 
     
     
         9 . The process of  claim 1 , further comprising
 d) stopping a flow of water that mixes with the reactor effluent when the temperature condition in the reaction zone exceeds a second predetermined threshold temperature that is equal to or greater than the first predetermined threshold temperature, thereby increasing recycling of the quenching agent to the reaction zone via a recycling pathway.   
     
     
         10 . The process of  claim 1 , wherein the quenching agent is added to the reaction zone via one or more inlets that under normal hydroprocessing conditions allow entry of a gas comprising hydrogen to the reaction zone. 
     
     
         11 . The process of  claim 1 , wherein the quenching agent is added to the hydroprocessing reaction zone via one or more conduits that transport at least one of a recycle gas, a treat gas, and quench gas when the temperature condition is less than the first predetermined threshold temperature. 
     
     
         12 . The process of  claim 1 , wherein the quenching agent is added to the feedstock at a location upstream from the reaction zone of the hydroprocessing reactor. 
     
     
         13 . The process of  claim 1 , wherein the quenching agent is added to a pretreating reactor located upstream from the hydroprocessing reactor, wherein the pretreating reactor contains one or more catalysts for de-aromatization, de-metallization, hydrodesulfurization, hydrodenitrogenation, wherein the hydroprocessing catalyst is a hydrocracking catalyst. 
     
     
         14 . The process of  claim 1 , wherein the quenching agent is selected from the list consisting of ammonia, a chemical compound that is converted to ammonia at hydroprocessing temperatures and pressures and combinations thereof. 
     
     
         15 . The process of  claim 1 , wherein the pressurized vessel stores the quenching agent at a pressure in a range from 100 to 4000 psig.