Desulfurization processes and systems utilizing hydrodynamic cavitation

Abstract

Processes and systems associated with hydrodynamic cavitation-catalyzed oxidation of sulfur-containing substances in a fluid are described. In one example method, cavitation bubbles are produced in a mixture of a carbonaceous fluid and one or more oxidants by hydrodynamic cavitation. Collapse of the cavitation bubbles may catalyze or partially catalyze oxidation of the sulfur-containing substances. The sulfur-containing substances may be removed from the mixture based, at least in part, on their oxidized state. An example system includes a device configured to mix a carbonaceous fluid and one or more oxidants, at least one cavitation chamber configured to produce cavitation bubbles in the mixture, and at least one elevated pressure zone configured to collapse the cavitation bubbles, thereby catalyzing oxidation of the sulfur-containing substances.

1 . A method for oxidation of sulfur-containing substances in a carbonaceous fluid, the method comprising: 
 producing hydrodynamic cavitation in a mixture of the fluid and an oxidant, the hydrodynamic cavitation initiating one or more chemical reactions that, at least in part, oxidize at least some of the sulfur-containing substances.    
   
   
       2 . The method of  claim 1 , where producing hydrodynamic cavitation includes flowing the mixture through one or more locally-constricted areas of a flow-through chamber to produce cavitation bubbles.  
   
   
       3 . The method of  claim 2 , where flowing the mixture through the one or more locally-constricted areas of the flow-through chamber produces one or more localized areas of low pressure in the mixture.  
   
   
       4 . The method of  claim 2 , where flowing the mixture through the one or more locally-constricted areas of the flow-through chamber includes one or more of, flowing the mixture through the same flow-through chamber more than one time, and flowing the mixture through multiple flow-through chambers that are in fluid communication with one another.  
   
   
       5 . The method of  claim 2 , where producing hydrodynamic cavitation includes collapsing the cavitation bubbles to produce one or more of, local high-shear conditions, shockwaves, ultraviolet light, and heating conditions, thereby at least partially catalyzing an oxidation reaction.  
   
   
       6 . The method of  claim 5 , where the oxidation reaction occurs in one or more of, a first area that includes cavitation bubbles that are collapsing, have collapsed, or are collapsing and have collapsed, and a second area that includes an area surrounding the first area that includes cavitation bubbles that have not collapsed.  
   
   
       7 . The method of  claim 1 , where the carbonaceous fluid includes petroleum-based substances.  
   
   
       8 . The method of  claim 7 , where the oxidation of sulfur-containing substances occurs under conditions where the petroleum-based substances are not oxidized.  
   
   
       9 . A method, comprising: 
 introducing one or more oxidizing agents into a solution containing one or more sulfur-containing compounds to produce a mixture;    creating cavitation bubbles in the mixture using hydrodynamic cavitation; and    collapsing the cavitation bubbles, thereby at least partially catalyzing one or more oxidation reactions that at least partially oxidize at least some of the sulfur-containing compounds.    
   
   
       10 . The method of  claim 9 , where using hydrodynamic cavitation includes flowing the mixture through one or more locally-constricted areas of a flow-through chamber.  
   
   
       11 . The method of  claim 10 , where the one or more oxidizing agents are introduced into the solution containing one or more sulfur-containing compounds at the one or more locally-constricted areas of the flow-through chamber.  
   
   
       12 . The method of  claim 9 , where the mixture is produced by pre-mixing the one or more oxidizing agents and the solution containing one or more sulfur-containing compounds.  
   
   
       13 . The method of  claim 9 , where the mixture is produced in one or more of, a mixing reactor, and a pump.  
   
   
       14 . The method of  claim 9 , where the one or more oxidizing agents include hydroperoxides.  
   
   
       15 . The method of  claim 9  where the one or more oxidizing agents include one or more of, organic peroxy acids, inorganic peroxy acids, and peroxy salts.  
   
   
       16 . The method of  claim 9 , where the one or more oxidizing agents include hydrogen peroxide and water.  
   
   
       17 . The method of  claim 9 , including introducing one or more catalysts into one or more of, the oxidizing agents, the solution containing one or more sulfur-containing compounds, and the mixture.  
   
   
       18 . The method of  claim 9 , where the solution containing the one or more sulfur-containing compounds includes one or more of, liquid hydrocarbons, solid hydrocarbons, and liquefied hydrocarbons.  
   
   
       19 . The method of  claim 18 , where the liquid hydrocarbons include one or more of, crude oil, diesel fuel, gasoline, kerosene, and petroleum fractions.  
   
   
       20 . The method of  claim 18 , where the solid hydrocarbons include coal.  
   
   
       21 . The method of  claim 18 , where the liquefied hydrocarbons include liquefied petroleum gas.  
   
   
       22 . The method of  claim 9  where the sulfur-containing compounds include one or more of, mercaptans (thiols), sulfides, disulfides, and thiophenes.  
   
   
       23 . The method of  claim 9 , where the one or more oxidation reactions produce one or more of, sulfoxides, and sulfones, of at least some of the sulfur-containing compounds.  
   
   
       24 . The method of  claim 9 , including removing the at least partially-oxidized sulfur-containing compounds from the mixture.  
   
   
       25 . The method of  claim 24 , where removing the at lease partially oxidized sulfur-containing compounds includes one or more of, adsorption, decomposition, distillation, and extraction.  
   
   
       26 . The method of  claim 9 , including extracting the at least partially-oxidized sulfur-containing compounds with a substantially polar solvent.  
   
   
       27 . The method of  claim 26 , where the substantially polar solvent includes one or more of, methanol, acetonitrite, dimethyl sulfoxide, a furan, a chlorinated hydrocarbon, a trialkylphosphate, and N-methylpyrrolidone.  
   
   
       28 . A method for removing sulfur-containing compounds from a petroleum-based fluid containing one or more sulfur-containing compounds that are substantially apolar, comprising: 
 flowing the petroleum-based fluid and one or more oxidants into one or more of, a mixing tank, and a pump;    mixing the petroleum-based fluid and the one or more oxidants in one or more of, the mixing tank, and the pump, to produce a mixture;    flowing the mixture from one or more of, the mixing tank, and the pump, into at least one local constriction of flow in a flow-through chamber;    generating cavitation bubbles within the at least one local constriction of flow;    collapsing the cavitation bubbles in one or more elevated pressure zones, thereby generating one or more of, local high-shear conditions, shockwaves, ultraviolet light, and heating conditions, that at least partially catalyze oxidation of at least some of the substantially apolar sulfur-containing compounds to substantially polar sulfur-containing compounds including one or more of, sulfoxides and sulfones;    extracting the substantially polar sulfur-containing compounds from the mixture using a substantially polar solvent that is not miscible with the mixture, the extracting leaving a product having a lower concentration of sulfur-containing compounds than the petroleum-based fluid.    
   
   
       29 . The method of  claim 28 , including recirculating the mixture that contains one or more of, sulfoxides and sulfones, back through one or more of, the mixing tank, the pump, and the flow-through chamber.  
   
   
       30 . The method of  claim 28  including flowing one or more catalysts into the petroleum-based fluid.  
   
   
       31 . The method of  claim 30 , where the one or more catalysts include one or more of, molybdenum, copper, iron, vanadium, and nickel.  
   
   
       32 . The method of  claim 30 , where the one or more catalysts include formic acid.  
   
   
       33 . A product made by the method of  claim 28 .  
   
   
       34 . A system, comprising: 
 a mixing device into which a carbonaceous fluid containing sulfur-containing substances and one or more oxidizing agents can flow, the device configured to mix the carbonaceous fluid and the one or more oxidizing agents to produce a mixture;    at least one cavitation chamber in fluid communication with the mixing device and into which the mixture can flow, the cavitation chamber including one or more locally-constricted areas configured to produce a localized area of low pressure as the mixture flows through the at least one cavitation chamber, thereby producing cavitation bubbles in the mixture; and    at least one elevated-pressure zone configured to collapse the cavitation bubbles, thereby producing one or more of, local shearing conditions, shockwaves, ultraviolet light, and local heating, capable of catalyzing or partially catalyzing a chemical reaction that oxidizes at least some of the sulfur-containing substances.    
   
   
       35 . The system of  claim 34 , where the mixing device includes one or more of, a mixing tank, and a pump.  
   
   
       36 . A system, comprising: 
 means for producing a mixture of a fluid containing sulfur-containing substances and one or more oxidizing agents; and    means for producing cavitation bubbles in the mixture by hydrodynamic cavitation.    
   
   
       37 . The system of  claim 36 , comprising means for collapsing the cavitation bubbles.