Crude oil blending to reduce organic-based fouling of pre-heat train exchangers and furnaces

Abstract

A high solvent power (HSP) crude oil is added to a blend of incompatible oils to proactively address the potential for fouling heat exchange equipment. The HSP component dissolves asphaltene precipitates before coking affects heat exchange surfaces. An HSP oil is also flushed through heat exchange equipment to remove any deposits and/or precipitates on a regular maintenance schedule before coking can affect heat exchange surfaces.

1 . A process for blending petroleum crude oils that reduces organic-based fouling of heat exchange equipment, comprising:
 blending two or more crude oils that have a proportion of the oils that precipitate asphaltenes; and   adding a high solvent power (HSP) crude oil defined as a crude oil having a solubility blending number (SBN) greater than 80 to dissolve the precipitated asphaltenes.   
   
   
       2 . The process of  claim 1 , wherein the HSP crude oil comprises at least 5% by volume of the blend. 
   
   
       3 . The process of  claim 1 , wherein the HSP crude oil comprises at least 50% by volume of the blend. 
   
   
       4 . The process of  claim 1 , wherein the HSP crude oil has an SBN greater than 100. 
   
   
       5 . The process of  claim 1 , wherein the HSP crude oil has an SBN greater than 120. 
   
   
       6 . The process of  claim 1 , wherein the step of blending the two or more crude oils includes:
 determining the insolubility number (I n ) for the two or more crude oils,   determining the solubility blending number (SBN) for the two or more crude oils, and   combining the two or more crude oils into a blend such that the SBN/I n  ratio is less than 1.3 and the delta of SBN−I n  is less than 10 such that the blend has a high fouling tendency.   
   
   
       7 . The process of  claim 1 , wherein any component of the two or more petroleum oils is an unprocessed crude oil or a processed oil derived from petroleum. 
   
   
       8 . The process of  claim 1 , further comprising feeding the blended crude oils including the HSP oil in a refining process. 
   
   
       9 . The process of  claim 1 , further comprising feeding the blended crude oils including the HSP oil through a heat exchanger. 
   
   
       10 . The process of  claim 9 , wherein the heat exchanger is a pre-heat train exchanger or furnace. 
   
   
       11 . The process of  claim 9 , wherein feeding the blended crude oils through a heat exchanger includes feeding the blend according to a periodic schedule. 
   
   
       12 . The process of  claim 9 , wherein feeding the blended crude oils through a heat exchanger includes contacting a surface of the heat exchanger for at least 30 minutes with the blended crude oils. 
   
   
       13 . The process of  claim 9 , wherein feeding the blended crude oils through a heat exchanger includes contacting a surface of the heat exchanger for at least 24 hours with the blended crude oils. 
   
   
       14 . The process of  claim 9 , wherein feeding the blended crude oils through a heat exchanger includes contacting a surface of the heat exchanger for a period of between one to five days with the blended crude oils. 
   
   
       15 . A process for treating a heat exchange surface in a heat exchanger used for effecting thermal exchange on a process fluid comprising asphaltenic compounds, comprising:
 flushing the heat exchanger by feeding a stream of high solvent power (HSP) crude oil having a solubility blending number (SBN) of at least 80 through a heat exchanger to dissolve asphaltenic compounds precipitated from the process fluid; and   repeating the flush on a periodic basis to prevent prolonged exposure of deposited asphaltenes and waxes to heated surfaces of the heat exchanger.   
   
   
       16 . The process of  claim 15 , wherein flushing the heat exchanger with the HSP crude oil stream occurs at least four times per year. 
   
   
       17 . The process of  claim 15 , wherein flushing the heat exchanger with the HSP crude oil occurs at least six times per year. 
   
   
       18 . The process of  claim 15 , wherein flushing the heat exchanger with the HSP crude oil occurs every month. 
   
   
       19 . The process of  claim 15 , wherein feeding the stream includes contacting heated surfaces of the heat exchange surface for a period of time of at least 30 minutes. 
   
   
       20 . The process of  claim 15 , wherein feeding the stream includes contacting heated surfaces of the heat exchange surface for a period of time of at least 24 hours. 
   
   
       21 . The process of  claim 15 , wherein feeding the stream includes contacting heated surfaces of the heat exchange surface for a period of time of between one to five days. 
   
   
       22 . The process of  claim 15 , wherein the process fluid includes a blend of two or more incompatible crude oils. 
   
   
       23 . The process of  claim 15 , wherein the stream of HSP crude oil is a blend of an HSP crude oil at 5% by volume and at least two incompatible crude oils. 
   
   
       24 . The process of  claim 15 , wherein the stream of HSP crude oil is a blend of an HSP crude oil at 50% by volume and at least two incompatible crude oils. 
   
   
       25 . The process of  claim 15 , wherein the flushing occurs on-line in a refinery. 
   
   
       26 . The process of  claim 15 , wherein the heat exchanger includes an entire pre-heat train. 
   
   
       27 . The process of  claim 15 , wherein the heat exchanger is a component of a pre-heat train. 
   
   
       28 . The process of  claim 15 , wherein the HSP crude oil has an SBN of at least 100. 
   
   
       29 . The process of  claim 15 , wherein the HSP crude oil has an SBN of at least 120.