System and method for hydroprocessing high chloride feedstocks

Abstract

A system for hydroprocessing a hydrocarbon feedstock having a first stage including one or more first reactors that may receive the hydrocarbon feedstock and convert the hydrocarbon feedstock into an intermediate product. The feedstock has a total chlorine (Cl) content greater than 3 parts per million weight (ppmw), and the intermediate product includes hydrogen chloride (HCl), ammonia (NH 3 ), and an ammonium salt. The system also includes a heating system having a plurality of heat exchangers arranged in a loop and having a heat transfer fluid that may recover and dispense heat to one or more fluids in the first stage. At least one heat exchanger of the plurality of heat exchangers is disposed between the first stage and a separation section, and the at least one heat exchanger may maintain a temperature of the intermediate product above a desublimation temperature of ammonia with hydrogen halide.

We claim: 
     
         1 . A system for hydroprocessing a hydrocarbon feedstock, comprising:
 a first stage comprising one or more first reactors and configured to receive the hydrocarbon feedstock and to convert the hydrocarbon feedstock into an intermediate product, wherein the feedstock has a total chlorine (Cl) content greater than 3 parts per million weight (ppmw), and wherein the intermediate product comprises hydrogen halide, ammonia (NH 3 ) and an ammonium salt;   a heating system comprising a plurality of heat exchangers arranged in a loop and having a heat transfer fluid configured to recover and dispense heat to one or more fluids in the first stage, wherein at least one heat exchanger of the plurality of heat exchangers is disposed between the one or more first reactors and a separation section, and wherein the at least one heat exchanger is configured to maintain a temperature of the intermediate product above a desublimation temperature of ammonia and hydrogen halide.   
     
     
         2 . The system of  claim 1 , comprising a separation system disposed within the separation section and configured to receive the intermediate product and to separate the intermediate product into an aqueous stream and the first hydrocarbon liquid. 
     
     
         3 . The system of  claim 2 , comprising a first conduit extending between and fluidly coupling the first stage and the separation system, a second conduit extending between and fluidly coupling the separation system and the first conduit, wherein the second conduit is configured to inject an quench fluid generated in the separation system into the first conduit downstream of the at least one heat exchanger of the plurality of heat exchangers, and wherein the first conduit comprises the intermediate product. 
     
     
         4 . The system of  claim 3 , wherein the quench fluid comprises a wash water stream, a wash oil stream, or both. 
     
     
         5 . The system of  claim 1 , wherein the one or more first reactors comprises a di-olefin saturation reactor, a demetallization reactor, and a hydrotreating reactor, and wherein the hydrotreating reactor is configured to generate the intermediate product. 
     
     
         6 . The system of  claim 5 , wherein another heat exchanger of the plurality of heat exchangers is disposed between the di-olefin saturation reactor and the demetallization reactor, and wherein this heat exchanger is configured to transfer heat to an effluent with a reduced di-olefins content generated in the di-olefin saturation reactor. 
     
     
         7 . The system of  claim 1 , wherein the ammonium salt is ammonium chloride, ammonium bi-sulfide, ammonium halide, and combinations thereof. 
     
     
         8 . The system of  claim 7 , wherein the intermediate product comprises hydrogen chloride (HCl) and, wherein a product of partial vapor pressures of the HCl and the NH 3  in the intermediate product is above 100,000 Pa 2 . 
     
     
         9 . The system of  claim 1 , wherein the heating system comprises a fluid vessel configured to contain the heat transfer fluid and a heater disposed between the fluid vessel and the at least one heat exchanger, wherein the heater is configured to heat the heat transfer fluid upstream of the at least one heat exchanger. 
     
     
         10 . The system of  claim 1 , wherein the feedstock is a liquid hydrocarbon derived from fossil, biomass, post-consumer products, solid plastic waste, and combinations thereof. 
     
     
         11 . The system of  claim 1 , comprising a second stage disposed downstream of and fluidly coupled to the first stage, the second stage comprising one or more second reactors configured to receive a first hydrocarbon liquid product derived from the intermediate product and to generate a second hydrocarbon liquid product, wherein the first hydrocarbon liquid and the second hydrocarbon liquid are substantially free of chlorides. 
     
     
         12 . A process for hydroprocessing a hydrocarbon feedstock, comprising:
 feeding a feedstock to a first stage of a hydroprocessing system, wherein the first stage comprises one or more reactors and is configured to convert the hydrocarbon feedstock into an intermediate product having hydrogen halide, ammonia (NH 3 ), and an ammonium salt, wherein the hydrocarbon feedstock has a total chlorine (Cl) content greater than 3 parts per million weight (ppmw); and   cooling the intermediate product through a first heat exchanger disposed between the one or more reactors and a separation section of the hydroprocessing system to generate a cooled intermediate product, wherein the first heat exchanger comprises a heat transfer fluid configured to recover heat from the intermediate product, and wherein a temperature of the cooled intermediate product is above a deposition temperature of the ammonium salt.   
     
     
         13 . The process of  claim 12 , comprising quenching the cooled intermediate product to decrease the temperature to below the deposition temperature of the ammonium salt. 
     
     
         14 . The process of  claim 13 , wherein quenching the cooled intermediate product comprises injecting a quench fluid into a flow of the intermediate product, and wherein the quench fluid is generated in a separation system disposed within the separation section and fluidly coupled to the first stage. 
     
     
         15 . The process of  claim 14 , wherein the quench fluid is a wash water stream, a wash oil stream, or both. 
     
     
         16 . The process of  claim 15 , wherein at least a portion of the wash oil is derived from an effluent generated in the separation system. 
     
     
         17 . The process of  claim 12 , wherein the ammonium salt is ammonium chloride, ammonium bi-sulfide, ammonium halide, and combinations thereof. 
     
     
         18 . The process of  claim 17 , wherein the intermediate product comprises hydrogen chloride (HCl) and a product of partial vapor pressures of the HCl and the NH 3  in the intermediate product is above 100,000 Pa 2 . 
     
     
         19 . The process of  claim 12 , wherein conversion of the hydrocarbon feedstock into the intermediate product comprises selective saturation of di-olefins to generate a first effluent, demetallization of the first effluent to generate a second demetallized effluent, and hydrotreatment of the second demetallized effluent to generate the intermediate product. 
     
     
         20 . The process of  claim 19 , wherein the first effluent is heated through a second heat exchanger comprising the heat transfer fluid, and wherein the second heat exchanger is fluidly coupled to the first heat exchanger in a loop configuration. 
     
     
         21 . The process of  claim 12 , generating a first hydrocarbon liquid product from the intermediate product in the separation section, feeding the first hydrocarbon liquid product to a second comprising one or more second reactors configured to generate a second hydrocarbon liquid product from the first hydrocarbon liquid product, wherein the first hydrocarbon liquid and the second hydrocarbon liquid are substantially free of chlorides. 
     
     
         22 . A process for hydroprocessing a hydrocarbon feedstock, comprising:
 cooling a hydrocarbon product having a first temperature through a first heat exchanger disposed between a first stage and a second stage of a hydroprocessing system to generate a cooled hydrocarbon product, wherein the hydrocarbon product is output from a hydrotreater and comprises hydrogen halide, ammonia (NH 3 ), and an ammonium salt, wherein the first heat exchanger comprises a heat transfer fluid configured to recover heat from the hydrocarbon product and generate a cooled hydrocarbon product having a second temperature, and wherein the second temperature is less than the first temperature and above a deposition temperature of the ammonium salt.   
     
     
         23 . The process of  claim 22 , comprising quenching the cooled hydrocarbon product with a quench fluid provided by a separation system disposed between the first stage and the second stage to generate a quenched hydrocarbon product having a third temperature, wherein the third temperature is below the deposition temperature of the ammonium salt. 
     
     
         24 . The process of  claim 23 , wherein the quench fluid is a wash water stream, a wash oil stream, or both.