Abstract:
The present invention provides a novel system and method for sulphur and metal removal from crude oil and all liquid fuel fractions to biofuels by means of ultrasonic cavitation to enhance chemical reactions of said contaminants with sodium or potassium methylate and a water/fluoride mix in separate stages obtaining a solid form which is filtered out by the use of a centrifuge system. The resulting fuel is molecularly stable and cleaner than regular fuels.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention pertains mostly to the petrochemical sector. It relates to systems and methods for contaminant reduction in hydrocarbons and biofuels, mainly focused on the significant reduction of sulphur, and metals embedded in the fuel molecules, therefor improving fuel characteristics in the process. 
       BACKGROUND OF THE INVENTION 
       [0002]    With decreasing reserves of light crude oil we have been led to extract lower quality crudes (sour crudes) which are high in sulphur and metals. The costs associated with de-contaminating, or elevating this crude to International fuel standards is much higher, requiring in some cases the purchase of lighter crudes to reduce contaminants in general due to a lack of cost effective technologies to completely eliminate or significantly reduce these contaminants. The petroleum industry is always looking for more economical ways to crack, distil, refine and improve on fuel characteristics. Recent environmental requirements for fuels to exceed EPA standards, and having the rest of the World focusing on the reduction of these contaminants as well, have prompted the industry to explore new methods to reduce these non-desired elements or substances in the least expensive manner. 
         [0003]    The conventional process used in the petroleum industry for Sulphur reduction is known as hydrolysis. The hydrocarbon is reacted in one or more vessels, incorporating a hydrolysis catalyst and an absorption stage to trap the reacted sulphur. This occurs under high temperature and pressure conditions with sophisticated equipment and requires extensive footprint and energy resources. 
         [0004]    Also, hydrocracking is a process used in the oil industry to convert low quality raw materials into higher-value fuel. This process is the best way to obtain a diesel fuel with lower sulphur content and aromatics. Normally the hydrocracking process is carried out using two suspended bed catalytic packed reactors that operate at high pressure and temperature. In the first reactor the molecule is ruptured, releasing sulfur and nitrogen, then the liquid fraction enters the second reactor where it is hydroisomerized and cracked. The hydrocracking process allows a variety of liquid fuels with certain undesirable characteristics to conform to existing environmental requirements. 
         [0005]    These conventional processes have a high demand in energy and require large spaces for the process to take place, aside from the use of catalysts and other consumables which require periodical exchange or replacement. All this represents an added cost for the industry, especially now that we have to work with heavier fractions of sour crude oil. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides a novel system and method for sulphur and metal removal from crude oil and all liquid fuel fractions. 
         [0007]    According to an aspect of the invention, the system is a lower energy/power/heat consumption system. 
         [0008]    According to another aspect of the invention, the method removes sulphur, zinc and silica by reacting with sodium methylate. 
         [0009]    According to another aspect of the invention, the method removes sulphur, zinc and silica by reacting with potassium methylate. 
         [0010]    According to another aspect of the invention, the method removes heavy metals by reacting with water. 
         [0011]    According to still another aspect of the invention, the method improves the API index. 
         [0012]    According to yet another aspect of the invention, the method creates cleaner fuels. 
         [0013]    According to another aspect of the invention, the method can be applied to biofuels as well as hydrocarbon fuels. 
         [0014]    According to yet another aspect of the invention, the method reduces associated system maintenance due to a cleaner combustion process. 
         [0015]    According to yet another aspect of the invention, the method increases the volume of the treated fuel. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Further features and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying figures showing illustrative embodiments of the invention, in which: 
           [0017]      FIG. 1  illustrates the sulfur and heavy metal removal system, according to an embodiment of the present invention. 
           [0018]      FIG. 2  illustrates a dosing, mixing and cavitation configuration, according to an embodiment of the present invention. 
           [0019]      FIG. 3  illustrates an isometric view of the sulfur and heavy metal removal system, according to an embodiment of the present invention. 
           [0020]      FIG. 4  illustrates a hydrodynamic cavitation reactor system, according to a preferred embodiment of the invention. 
           [0021]      FIG. 5  illustrates an isometric view of water and methylate tank system, according to an embodiment of the present invention. 
           [0022]      FIG. 6  illustrates a treated fuel pressure release tank, according to an embodiment of the present invention. 
           [0023]      FIG. 7  illustrates a heat exchanger, according to an embodiment of the present invention. 
           [0024]      FIG. 8  illustrates a dosing and mixing unit, according to an embodiment of the present invention. 
       
    
    
       [0025]    Throughout the figures, the same reference numbers and characters, unless otherwise stated, are used to denote like elements, components, portions or features of the illustrated embodiments. The subject invention will be described in detail in conjunction with the accompanying figures, in view of the illustrative embodiments. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    The method of the present invention, is based on the use of a mixing and dosing station, followed by an ultrasonic cavitation reactor coupled with a 300 atm. high pressure system in the presence of 5% Sodium or Potassium Methylate additives in one stage to react with the sulfur, zinc, and silica content in the fuel producing sulfates and salts that are collected in their solid form in a centrifuge filter station, and 20% water with 0.5% fluoride, on a secondary stage, that reacts with certain metals (Mercury Hg, Cadmium Cd, Lead Pb, and Vanadium) which are bonded to the fluoride molecules and removed in their solid form via centrifuge filtering station, ostensibly improving overall physical-chemical characteristics of the fuel during the process. Regardless of the fuel enhanced by the method, the resulting fuel will also have better characteristics, since polymeric molecules are broken and rearranged due to ultrasound enhanced chemical reactions, so that characteristics such as, for example, API in the case of crude oil, and flash point, Cetane level, and heating value in the case of diesel are substantially improved, among other treated fuels and improvements. 
         [0027]    An ultrasonic cavitation reactor is a device which reproduces the cavitation phenomenon or cavitation bubbles in the liquid; here a fluid is subjected to a strong change of pressure with the aim of achieving a phase shift among other functions. In the reactor, pressure reached is equal to the vapor pressure of the fluid, causing the formation of cavitation bubbles known as cavities. These reactors provide the formation of cavities, which in turn implode generating high frequency pulses (ultrasonic waves) that shock the fluid causing the rupture and reorganization of the polymer chains in the fuel therefore allowing for new bonds to be attained with the introduced additives. 
         [0028]    During the process of the present invention, the molecular rupture of the polymer chains forms what we call a “temporary active binding center”, also known as radical, which is ready to combine chemically with the methylate molecules in the first stage and fluoride in the second stage. These active binding sites are joined with the desired molecules to react with the contaminant in the fuel, therefore disrupting the original bonds within the fuel before it is treated. 
         [0029]    Any polymer chain fluid that is submitted to this strong pressure change suffers rupture and reorganization of its molecules. When the rupture occurs, unstable molecular “active” sites are formed and become available to be combined in situ with other molecules (additives). The formation of these active sites is what makes possible the reorganization and recombination of the fuel&#39;s molecules therefore improving the fuel&#39;s overall quality and characteristics, as well as the removal of unwanted contaminants. 
         [0030]    Molecular rupture caused by the process of the present invention is used to liberate the undesired contaminating molecules and reacting them with methylate and fluoride to create new bonds that are easily removed from the stream. Since we must dilute fluoride in water, the excess H2O forms a new polymer chain in the fuel containing hydrogen and oxygen within its final structure. This process improves the treated fuels, increasing the volume of the finished product by the determined percentage, enhancing features and characteristics while remaining molecularly_stable. 
         [0031]    The physics and chemistry behind the process of the present invention is based on studies of the induced sono-chemical reactions on inorganic and organic material after being submitted to ultrasound. In the process of the present invention, the ultrasound energy is supplied by the formation of cavities in the fluid due to the change in pressure induced by the ultrasonic cavitation reactor. The high inlet pressure is violently reduced inside the reactor, causing a thermodynamic change which is used to aid in the formation of cavities within the fluid (cavitation bubbles). When the fluid returns to its initial conditions the cavities then collapse and release a large amount of energy which is absorbed by the fluid rupturing its molecular structure and reorganizing the molecules in a more orderly and stable form for combustion. The intensity in which we create the cavities or cavitation bubbles within the fluid is a function of the system&#39;s pressure which also determines the frequency and the intensity of the shock wave that causes the molecular rupture. 
         [0032]    During the phenomenon of creation and subsequent collapse of cavities or cavitation bubbles, the process of the present invention reaches up to 500 atmospheres of localized pressure and hundreds of degrees in temperature, which rupture all polymer chain liquid fluid molecules. This same energy is used to form new polymer chains that are more stable, allow us to remove undesired elements or compounds in the fuel and also results in a fuel with better properties for combustion. 
         [0033]    Based on the above explanation, it is clear that the reactions happen due to a local increase in the temperature, pressure and the formation of molecular radicals. All of these chemical and physical changes are due to the rupture of the fluid molecular links caused by the collapse of the cavitation bubbles created during the process of cavitation. Depending on the nature of the liquid being cavitated, different effects can be obtained such as: radical creation, depolymerization, Lysis, liquid emulsions, rupture of solid particles, and acceleration of chemical reactions, among others. 
         [0034]      FIG. 1  illustrates an embodiment of the present invention used to remove fuel contaminants such as sulfur, zinc, silica, mercury, lead, among others, as well as fuel volume increase. The system improves fuels to produce less polluting fuels as well as increasing its final volume. The system comprises a first stage dosing, mixing, and ultrasonic cavitation station  110 , a centrifuge filtering system  112 , and a heat exchanger  109 . The dosing and mixing station receives fuel from fuel tank  101  which is preheated by a heater  109 , as well as methylate from storage tank  102  by means of pumps  141 , 142 . Before arriving at the station  110  the various liquids travel through a check valve  121 , 122  and each flow is controlled by volume through an adjustable control flow valve  131 , 132 . At the dosing and mixing station in  110  liquids are kept for ten minutes (10 min.) while a micro emulsion is obtained. After this, the mixture passes through a high-pressure pump where the fluid reaches a high pressure of 300 atmospheres. At this high pressure, the fluid enters the ultrasonic cavitation reactor in  110  where cavitation bubbles form and the depolymerization and the desired reactions take place. After the mixture has been cavitated under the mentioned pre-established pressure, the treated fuel is stored in the insulated storage tank  103  for pressure release. The treated fuel is then pumped through pump  111  and filtered through the centrifuge  112  to remove the resulting solids. The fuel is then ready to move to the second stage for metal removal. The second stage system comprises a dosing, mixing, and ultrasonic cavitation station  113 , a centrifuge filtering system  115 , and a heat exchanger  106 . The dosing and mixing station receives fuel from fuel tank  103  which has been treated at the first stage, as well water/fluoride from storage tank  104  by means of pumps  143 , 144 . Before arriving at the station  113  the various liquids travel through a check valve  123 , 124  and each flow is controlled by volume through an adjustable control flow valve  133 , 134 . At the dosing and mixing station in  113  liquids are kept for ten minutes (10 min.) while a micro emulsion is obtained. After this, the mixture passes through a high-pressure pump where the fluid reaches a high pressure of 300 atmospheres. At this high pressure, the fluid enters the ultrasonic cavitation reactor in  113  where cavitation bubbles form and the depolymerization and the desired reactions take place. After the mixture has been cavitated under the mentioned pre-established pressure, the treated fuel is stored in the insulated storage tank  105  for pressure release. The treated fuel is then pumped through pump  114  and filtered through the centrifuge  115  to remove the resulting solids. The final clean fuel goes through a heat exchanger  106 , before exiting through outlet  107 , to remove the temperature increase that results from the cavitation by means of the recycling of the closed loop system  108 . 
         [0035]      FIG. 2  illustrates the dosing, mixing, and cavitation station  110 , 113  from  FIG. 1  comprising two mixing tanks  221 , 222 , which receive water/fluoride or methylate through pipe  201 , and preheated fuel from pipe  202 . The mixing that takes place in the tanks  221 , 222  occurs by recirculating with a high pressure pump  231 , 232 . Mixing takes place for a pre-determined amount of time as stated above, at such time a computer-controlled valve  241 , 242  is opened, allowing the mixed fluid to enter the ultrasonic cavitation reactor  261 . After the mixture has been cavitated under pre-established pressure, the chemically treated fuel is sent through a pipe  270  to the insulated storage tank. 
         [0036]    The illustration shown in  FIG. 3  is an isometric representation for the embodiment of the present invention used to remove fuel contaminants such as sulfur, zinc, silica, mercury, lead, among others, as well as fuel volume increase. The system improves fuels to produce less polluting fuels as well as increasing its final volume. The system comprises a first stage dosing and, mixing station  310  and an ultrasonic cavitation reactor  310   a,  a centrifuge filtering system  312 , and a heat exchanger  309 . The dosing and mixing station receives fuel from fuel tank  301  which is preheated by a heater  309 , as well as methylate from storage tank  302  by means of pumps  341 , 342 . At the dosing and mixing station  310  liquids are kept for ten minutes (10 min.) while a micro emulsion is obtained. After this, the mixture passes through a high-pressure pump where the fluid reaches a high pressure of 300 atmospheres. At this high pressure, the fluid enters the ultrasonic cavitation reactor  310   a  where cavitation bubbles form and the depolymerization and the desired reactions take place. After the mixture has been cavitated under the mentioned pre-established pressure, the treated fuel is stored in the insulated storage tank  303  for pressure release. The treated fuel is then pumped through pump  311  and filtered through the centrifuge  312  to remove the resulting solids. The fuel is then ready to move to the second stage for metal removal. The second stage system comprises a dosing and mixing station  313 , an ultrasonic cavitation reactor  313   a,  a centrifuge filtering system  315 , and a heat exchanger  306 . The dosing and mixing station receives fuel from fuel tank  303  which has been treated at the first stage, as well water/fluoride from storage tank  304  by means of pumps  343 , 344 . At the dosing and mixing station  313  liquids are kept for ten minutes (10 min.) while a micro emulsion is obtained. After this, the mixture passes through a high-pressure pump where the fluid reaches a high pressure of 300 atmospheres. At this high pressure, the fluid enters the ultrasonic cavitation reactor  313   a  where cavitation bubbles form and the depolymerization and the desired reactions take place. After the mixture has been cavitated under the mentioned pre-established pressure, the treated fuel is stored in the insulated storage tank  305  for pressure release. The treated fuel is then pumped through pump  314  and filtered through the centrifuge  315  to remove the resulting solids. The final clean fuel goes through a heat exchanger  306 , before exiting through outlet  307 . 
         [0037]      FIG. 4  illustrates an ultrasonic cavitation reactor of the present invention. In a preferred embodiment the hydrodynamic cavitation reactor is made from stainless steel. The system comprises a high pressure pump  401  set at 300 atmospheres, a cavitation valve  402 , a Schedule 40 SS 1″ diameter pipe  403 , all contained in one module, specifically the valve  402  contains the following zones; liquid entrance zone  404 , a cavitation bubble formation zone  405 , and a shock zone  406  where the molecular rupture and reorganization occurs. 
         [0038]      FIG. 5  illustrates a water/fluoride and methylate storage tank of the present invention. In a preferred embodiment the water and methylate storage tank is made from stainless steel. The system comprises an entrance pipe connector  501 , a cylindrical tank, among other shapes  502 , an exit pipe connector  503 , and a support frame  504  when deemed necessary. 
         [0039]      FIG. 6  illustrates a fuel storage tank of the present invention. In a preferred embodiment the fuel storage tank is made from stainless steel. The system comprises an entrance pipe connector  601 , a cylindrical tank, among other shapes  604 , an exit pipe connector  605 , and a support frame when deemed necessary. 
         [0040]    In a preferred embodiment the heat exchanger is a shell and tube type heat exchanger as illustrated in  FIG. 7 . In a preferred embodiment the heat exchanger is made from stainless steel. The system comprises a cooling liquid entrance pipe connector  701 , a temperature sensor  702 , a treated fuel entrance pipe connector  703 , a cooling liquid exit pipe connector  704 , a treated fuel exit pipe connector  705 , and four baffles  706  to ensure proper heat exchange between fluids. 
         [0041]      FIG. 8  illustrates the dosing and mixing station of the present invention. In a preferred embodiment the dosing and mixing station is made from stainless steel. The system comprises a water or methylate entrance pipe connector  801 , a fuel entrance pipe connector  802 , and an extra connector  803  which is used for cleaning, a cylindrical tank, among other available shapes  805 , a mixed fuel/water or fuel/methylate emulsion exit pipe connector  804 , all held together with a steel frame. 
         [0042]    Although the present invention has been described herein with reference to the foregoing exemplary embodiment, this embodiment does not serve to limit the scope of the present invention. Accordingly, those skilled in the art to which the present invention pertains will appreciate that various modifications are possible, without departing from the technical spirit of the present invention.