Integrated butane / transmix blending system and methods

Abstract

A system is described forblending butane and transmix into PCG without exceeding predetermined regulatory limits. The system can include: (a) a gasoline stream with an associated gasoline flow rate; (b) a transmix stream in fluid; (c) a motorized pump for controlling the flow of transmix into the gasoline stream; (d) a sampler on the gasoline stream located downstream of the transmix blending point for collecting samples to be tested; (e) a butane stream in fluid communication with the gasoline stream at a butane blending point downstream of the transmix blending point; (f) a butane injection pump for controlling the flow of butane into the gasoline stream; (g) a sampler downstream of the butane blending point for sampling the resultant transmix-butane blended gasoline; (h) a distillation process analyzer; (i) a vapor pressure analyzer for analyzing samples of the transmix butane blended gasoline; and (j) a programmable logic controller.

Description

INTEGRATED BUTANE / TRANSMIX BLENDINGSYSTEM AND METHODSCROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 616,378, filed December 29, 2023, the disclosure of which is incorporated by reference herein in its entirety.TECHNICAL FIELD

[0002] Disclosed herein are systems and methods for in-line blending of butane and transmix into a gasoline stream at any point along a petroleum pipeline using an integrated system.BACKGROUND

[0003] Gasoline is distributed across the country using a network of pipelines, typically beginning at ports and refineries and ending at tank farms or storage facilities, where the gasoline can be put on trucks for final distribution. The pipeline portion of the distribution network can be used to transport many different types of fuels, such as gasoline, diesel fuel, jet fuel, propane, kerosene, etc. Because these products have specifications, shippers will provide certified analyses before they are introduced into the pipeline.

[0004] Transmix is an off-specification product. It is defined by the Environmental Protection Agency (EPA) under 40 CFR Part 1090 as any of the following mixtures of fuels that no longer meet the specifications for a fuel that can be used or sold as a fuel without further processing: (1) pipeline interface that is not cut into adjacent products; (2) mixtures produced by unintentionally combining gasoline and distillate fuels, or (3) mixtures of gasoline and distillate fuel produced from normal business operations at terminals or pipelines, such as gasoline or distillate fuel drained from a tank or drained from piping orhoses used to transfer gasoline or distillate fuel to tanks or trucks, or gasoline or distillate fuel discharged from a safety relief valve that are segregated for further processing. Any pipeline shipping multiple types of fuels (e.g., gasoline and jet fuel) will create a portion of transmix as the two products will blend at their point of contact.

[0005] Pipeline operators will measure the properties of batches moving through the pipeline to determine if transmix is present from the mixing of products. When transmix is detected, it can be directed into separate pipelines and storage tanks to isolate it from the on- specification products. When the operator measurements determine that the product flowing through the pipeline is no longer the interface transmix but instead an on- specification product, it will redirect the flow back to the appropriate pipeline or storage tanks for that product. In some aspects, the systems and methods according to the present disclosure can reduce the amount of transmix created from the product mixing within the pipeline. In some aspects, the systems and methods according to the present disclosure can quickly detect when the transmix flow has ended so that only a minor amount of on-specification product is diverted into the transmix pipeline or storage tank.

[0006] Because transmix is off specification, it is typically reprocessed before it can be used in commercial applications, which reduces its value. This processing can include separating transmix into a transmix distillate product (TDP), which is a diesel fuel blend stock produced from separated transmix, or a transmix gasoline product (TGP), which is a gasoline blendstock produced from separated transmix. The EPA regulates this processing under 40 CFR Part 1090. which defines a transmix processing facility as any facility that produces TGP or TDP from transmix by distillation or other refining processes but does not produce gasoline or diesel fuel by processing crude oil or other products. A transmix processor is anyone who owns, leases, operates, controls, or supervises a transmix processing facility.

[0007] In addition to processing, the 40 CFR Part 1090 regulations allow for blending of transmix into previously certified gasoline (PCG). PCG is that has been certified by a gasoline manufacturer as a batch of conventional gasoline, reformulated gasoline, or gasoline blendstock for oxygenate blending, as those terms are used in the regulations. A transmix blending facility is any facility that produces gasoline by blending transmix into PCG under 40 CFR § 1090.500, and a transmix blender is any person who owns, leases, operates, controls, or supervises a transmix blending facility. In some aspects, transmix blenders comply with 40 CFR § 1090.005, under which the resultant blends have a distillation endpoint not exceeding 437 degrees Fahrenheit and meet the downstream sulfur per-gallon and Reid Vapor Pressure (RVP) standards in § 1090.

[0008] The transmix blender must also follow EPA record keeping procedures and maintain and follow a written quality assurance program that complies with 40 CFR§ 1090.500(c) of the regulation. This differs depending on how the transmix and gasoline are blended. If the transmix is blended in a tank, sampling and end-point temperature testing must be done following each occasion transmix is blended. For transmix that is blended by a computer controlled in-line blending system, the transmix blender must collect and test composite samples of the resultant gasoline at least twice each calendar month during which transmix is blended. If the result for a sample collected under the quality assurance program indicates that the gasoline does not comply with the applicable standards, there are additional steps that must be taken.

[0009] If the EPA regulations for transmix blending are followed, a transmix blender does not need do a full gasoline re-certification after blending. The benefit of blending transmix back into gasoline is that transmix is generally cheaper given its off-specification nature.Blending transmix with PCG allows a transmix blender to capture the margin spread betweentransmix and gasoline prices. Transmix that is not blended would otherwise generally be sold to transmix processors at a discount price.

[0010] EPA regulations also allow for the blending of regulated blendstocks like certified butane or certified pentane, into gasoline. These blendstocks have historically been blended with gasoline at different points in the gasoline distribution chain. Systems for in-line blending of butane with gasoline are described in U.S. Patent Nos. 7,631,671 and 9,207,686. These systems allow for blending of butane and gasoline at any point along a petroleum pipeline, including at the rack where it is dispensed. The systems can use commercially available components to measure RVP, flow rate, and any other process variables, along with a control unit and flow regulators, to precisely control the blending of butane and gasoline while keeping it within desired property ranges.

[0011] As with transmix, butane is generally cheaper than gasoline, which reduces the price of the resultant gasoline. Butane also has a higher RVP than gasoline, thereby increasing the volatility (ability to combust) of the resultant blend. This is a benefit during colder months when the volatility of the gasoline is lower. However, the EPA regulates the RVP of gasoline because gasoline vapor is a component of volatile organic compounds in the atmosphere. These regulations generally apply from May 1 through September 15 when the weather (and thus the gasoline) is warmer, which keeps its volatility higher, and require gasoline be certified to be within the volatility ranges. Measuring the RVP is one way of determining the vapor pressure of the gasoline.

[0012] The EPA also regulates the amount of sulfur in gasoline, which can be dependent on any blendstocks that are blended with the gasoline. Except for certain national security and hardship exceptions, all gasoline manufacturers must meet a sulfur average standard of 10.00 parts per million for each compliance period (40 CFR § 1090.205(b). and gasoline at any fuel manufacturing facility gate is subject to a maximum sulfur per-gallon standard of 80parts per million (40 CFR § 1090.205(b)). Gasoline at a downstream location can have a maximum sulfur per-gallon standard of 95 parts per million (40 CFR § 1090.205(c)).Blenders can sample and analyze sulfur content for compliance.

[0013] While separate systems exist for blending butane with gasoline and for blending transmix with gasoline, these systems are not integrated and employ separate equipment. This takes additional space and higher cost for blending. What is needed are efficient systems and methods for tightly controlled blending of both transmix and blendstocks, like butane, into the same gasoline pipeline. In some aspects, for example, the systems disclosed herein use less redundant equipment, to reduce the cost and footprint for the blending operations. It is also advantageous for such systems to operate automatically and continuously, with testing and analysis to ensure the resultant blended gasoline is within allowable parameters.SUMMARY

[0014] Disclosed herein are systems and methods for in-line blending of butane and transmix into a gasoline stream at any point on a petroleum pipeline. In some aspects, for example, the systems and methods use an integrated blending skid. In one aspect, the present disclosure provides a system for blending butane and transmix into PCG without exceeding pre-determined regulatory limits, comprising: (a) a gasoline stream with an associated gasoline flow rate; (b) a transmix stream in fluid communication with the gasoline stream at a transmix blending point; (c) a motorized pump for controlling the flow of transmix into the gasoline stream at the transmix blending point; (d) a sampler on the gasoline stream located downstream of the transmix blending point for collecting samples to be tested; (e) a butane stream in fluid communication with the gasoline stream at a butane blending point downstream of the transmix blending point; (f) a butane injection pump for controlling the flow of butane into the gasoline stream at the butane blending point; (g) a samplerdownstream of the butane blending point for sampling the resultant transmix -butane blended gasoline; (h) a distillation process analyzer for analyzing samples of the transmix-butane blended gasoline; (i) a vapor pressure analyzer for analyzing samples of the transmix-butane blended gasoline; and (j) a programmable logic controller with a target volatility value and target distillation parameters, including the final boiling point, wherein the programmable logic controller is configured to receive measured values from the vapor pressure analyzer and the distillation process analyzer, determine appropriate adjustments to the flow of transmix and butane, and communicate those adjustments to both the motorized transmix pump and the butane injection pump.

[0015] Certain aspects, for example, may include a butane tank, a transmix tank, a rack for dispensing the blended gasoline, different injection points for blending, other blendstock streams, a transmix injection meter, a butane injection meter, an additional meter installed on the gasoline pipeline between the transmix and butane injection points, additional programmable logic controllers, and additional samplers at before or after the transmix and / or butane are blended with gasoline, and additional analyzers for measuring other properties of the gasoline stream, the transmix stream, the butane stream, and / or the blended gasoline stream.

[0016] In some aspects, by combining both butane and transmix blending into an integrated skid, the systems and methods according to the present disclosure can precisely blend both products into PCG. This further reduces the cost of the gasoline, increasing revenue. In some aspects, for example, the disclosed systems and methods have the additional advantage of using less footprint for the equipment. Multiple injection configurations are possible using the systems and methods disclosed herein, including tank, truck, or pipeline blending. The systems and methods can be used without need for preprocessing of the transmix, allowing for a commercial benefit from otherwise lower pricedoff-specification product. Because transmix often has a lower RVP due to the presence of distillate components, the integrated system also allows for a potential increase of the butane injection rate in such combined installation, further lowering the cost of the resultant blended gasoline.

[0017] In one aspect, disclosed herein is a system for blending a blendstock and transmix into gasoline. The system may include (a) a gasoline pipeline; (b) a transmix pipeline in fluid communication with the gasoline pipeline at a first blending point; (c) a first pump configured to pump a flow of transmix from the transmix pipeline into the gasoline pipeline at the first blending point; (d) a first sampler on the gasoline pipeline located downstream of the first blending point; (e) a blendstock pipeline in fluid communication with the gasoline pipeline at a second blending point downstream of the first blending point; (f) a second pump configured to pump a flow of the blendstock from the blendstock pipeline into the gasoline pipeline at the second blending point; (g) a second sampler located dow nstream of the second blending point; (h) a distillation process analyzer; (i) a vapor pressure analyzer; and (j) a programmable logic controller.

[0018] In some aspects, the system may include one or more of the following features. System may include a transmix tank connected to the transmix pipeline. System may include a blendstock tank connected to the blendstock pipeline. System may include a transmix injection meter configured to measure the flow of transmix into the gasoline pipeline at the first blending point. System may include a blendstock injection meter configured to measure the flow of blendstock into the gasoline pipeline at the second blending point. System may include a sulfur analyzer. System where the sulfur analyzer is located at a same location as the distillation process analyzer or the vapor pressure analyzer. System where the sulfur analyzer is located on the transmix pipeline or the blendstock pipeline. System where the blendstock is certified butane or certified pentane. System where the blendstock is certifiedbutane. System where the gasoline is previously certified gasoline (PSG). System where the first pump is a motorized pump. System where the motorized pump is driven by a variable frequency drive motor. System where the motorized pump is an across-the-line starter motor. System where the first sampler is located upstream of the second blending point. System where the second pump is an injection pump. System where the distillation process analyzer is located downstream of the first blending point. System where the vapor pressure analyzer is a Reid vapor pressure (RVP) analyzer. System where the programmable logic controller is programmed with target parameters having a target volatility value and a final boiling point. System where the final boiling point is about 437 degrees Fahrenheit. System where the target parameters further may include a sulfur content. System where the target parameters further may include a temperature for a vapor-liquid ratio. System where the programmable logic controller is in communication with the first pump, the second pump, the distillation process analyzer, and the vapor pressure analyzer. System where the programmable logic controller is configured to receive measured values from the distillation process analyzer and the vapor pressure analyzer, determine adjustments to the flow of transmix and the flow of blendstock, and communicate the adjustments to the first pump and the second pump.

[0019] In one aspect, disclosed herein is a system for blending butane and transmix into gasoline, comprising (a) a gasoline pipeline; (b) a transmix pipeline in fluid communication with the gasoline pipeline at a transmix blending point; (c) a motorized transmix pump configured to pump a flow of transmix from the transmix pipeline into the gasoline pipeline at the transmix blending point; (d) a butane pipeline in fluid communication with the gasoline pipeline at a butane blending point downstream of the transmix blending point; (f) a butane injection pump configured to pump a flow of butane from the butane pipeline into the gasoline pipeline at the butane blending point; (g) a composite sampler; (h) a distillation process analyzer; (i) a vapor pressure analyzer; and (j) a programmable logiccontroller configured to receive measured values from the distillation process analyzer and the vapor pressure analyzer, determine appropriate adjustments to the flow of transmix and the flow of butane, and send commands to the motorized transmix pump and the butane injection pump. In some aspects, the motorized transmix pump is configured to adjust the flow of transmix based on the commands received from the programmable logic controller. In some aspects, the butane injection pump is configured to adjust the flow of butane based on the commands received from the programmable logic controller. In some aspects, the composite sampler in fluid communication with the gasoline pipeline at a first sampling point and a second sampling point, the first sampling point being located downstream of the transmix blending point and upstream of the butane blending point, and the second sampling point being located downstream of the butane blending point. In some aspects, the system may include a fast loop connecting the gasoline pipeline to the composite sampler.

[0020] In some aspects, disclosed herein is a method of blending butane and transmix into gasoline, comprising injecting a stream of transmix at a first flow rate into a stream of gasoline, injecting a stream of butane at a second flow rate into the stream of gasoline, analyzing a sample of a transmix -butane blended gasoline to measure its vapor pressure and boiling point, determining appropriate adjustments to the first flow rate and the second flow rate so as to keep the transmix-butane blended gasoline within desired property ranges, and adjusting the first flow rate and the second flow rate.

[0021] In some aspects, the method may include one or more of the following features. Method may include analyzing the sample of the transmix-butane blended gasoline to measure its sulfur content. Method may include determining a maximum flow rate of transmix and a maximum flow rate of butane that keep the transmix-butane blended gasoline within the desired property ranges. Method may include recording results from analyzing thesample of the transmix-butane blended gasoline. Implementations of the described techniques may include hardware or a computer tangible medium.

[0022] A system of one or more computers can be configured to perform particular methods by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular methods by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the methods.

[0023] When used for automatic blending, the systems and methods disclosed here involve less resources to manage. The system and methods can also provide multiple data points for the resultant blended gasoline, reducing the risk of non-compliance with applicable regulations. The systems and methods are not dependent on the availability of gasoline batch distillation data prior to blending. Blending is also adjusted for a changing final boiling point throughout the batch. In some aspects of the present disclosure, blending according to the present disclosure does not employ any “safety buffer,” which allows the blender to be able to blend a larger volume.

[0024] Other aspects and advantages of the disclosed systems and methods will be apparent from the following description and figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is a diagram of an automated blending system.

[0026] FIG. 2 is a diagram of one aspect of the integrated system of the present disclosure, which can blend both transmix and butane into a gasoline stream.DETAILED DESCRIPTION

[0027] 1. Introduction

[0028] This disclosure describes systems and methods for blending butane and transmix into previously certified gasoline (PCG) without exceeding predetermined regulatory limits. This section describes certain general terminology and specific terms that are referred to in later sections of the disclosure.

[0029] Throughout this specification and claims, the following definitions, general statements, and illustrations are applicable.

[0030] The patents, published applications, and scientific literature referred to herein establish the knowledge of those with skill in the art and are hereby incorporated by reference in their entireties to the same extent as if each were specifically and individually indicated to be incorporated by reference. Any conflict between any reference cited herein and the specific teachings of this specification shall be resolved in favor of the latter. Likewise, any conflict between an art-understood definition of a word or phrase and a definition of the word or phrase as specifically taught in this specification shall be resolved in favor of the latter.

[0031] As used herein, whether in a transitional phrase or in the body of a claim, the terms “comprise(s)” and “comprising” are to be interpreted as having an open-ended meaning. That is, the terms are to be interpreted synonymously with the phrases “having at least” or “including at least.” When used in the context of a process, the term “comprising” means that the process includes at least the recited steps, but may include additional steps. When used in the context of a composition, the term “comprising” means that the composition includes at least the recited features or components, but may also include additional features or components.

[0032] The terms “consists essentially of’ or “consisting essentially of have a partially closed meaning, that is, they do not permit inclusion of steps or features or componentswhich would substantially change the essential characteristics of a process or composition; for example, steps or features or components which would significantly interfere with the desired properties of the compounds or compositions described herein, i.e., the process or composition is limited to the specified steps or materials and those which do not materially affect the basic and novel characteristics of the process or composition.

[0033] The terms “consists of’ and “consists” are closed terminology and allow only for the inclusion of the recited steps or features or components.

[0034] Also, as used herein, the terms “has,” “have,” “having,” or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.

[0035] As used herein, the singular forms “a” and “an” specifically also encompass the plural forms of the terms to which they refer, unless the content clearly dictates otherwise. Conversely, a term in its plural form may also encompass the singular form of the term, unless the content clearly dictates otherwise. Where only one item is intended, the phrase “only one” or similar language is used.

[0036] Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more.”

[0037] Furthermore, as used herein, the term “set” is intended to include one or more items (e.g., related items, unrelated items, a combination of related and unrelated items, and / or the like), and may be used interchangeably with “one or more.”

[0038] The term “about” is used herein to mean approximately, in the region of, roughly, or around. When the term “about” is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. Ingeneral, the term “about” or “approximately” is used herein to modify a numerical value above and below the stated value by a variance of 20%.

[0039] As used herein, the recitation of a numerical range for a variable is intended to convey that the variable can be equal to any values within that range. Thus, for a variable which is inherently discrete, the variable can be equal to any integer value of the numerical range, including the end-points of the range. Similarly, for a variable which is inherently continuous, the variable can be equal to any value of the numerical range, including the endpoints of the range. As an example, a variable which is described as having values between 0 and 2, can be 0, 1 or 2 for variables that are inherently discrete, and can be 0.0, 0.1, 0.01, 0.001, or any other value for variables that are inherently continuous.

[0040] Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and / or,” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of’).

[0041] ‘Blendstock” means any liquid compound or mixture of compounds (not including fuel or fuel additive) that is used or intended for use as a component of a fuel. 0 42] “Butane” means an organic compound with the formula C;H?.;.

[0043] ‘Certified butane” means butane that is certified to meet the following per-gallon standards: (a) butane content: minimum 85 volume percent; (b) benzene content: maximum 0.03 volume percent; (c) sulfur content: maximum 10 ppm; and (d) chemical composition: be composed solely of carbon, hydrogen, oxygen, nitrogen, and sulfur.

[0044] “Certified pentane” means pentane that is certified to meet the following per- gallon standards: (a) pentane content: minimum 95 volume percent: (b) benzene content: maximum 0.03 volume percent; (c) sulfur content: maximum 10 ppm; (d) chemical composition: be composed solely of carbon, hydrogen, oxygen, nitrogen, and sulfur.

[0045] ‘Conventional gasoline” (CG) means gasoline that is not certified to meet the requirements for reformulated gasoline.

[0046] ‘Diesel fuel” means any of the following: (1) any fuel commonly or commercially known as diesel fuel; (2) any fuel (including nonpetroleum diesel fuel or a fuel blend that contains nonpetroleum diesel fuel) that is intended or used to power a vehicle or engine that is designed to operate using diesel fuel; or (3) any fuel that conforms to the specifications of ASTM D975 (incorporated by reference in 40 CFR § 1090.95) and is made available for use in a vehicle or engine designed to operate using diesel fuel.

[0047] ‘Distillate fuel” means diesel fuel and other petroleum fuels with a T90 temperature below 700 °F that can be used in vehicles or engines that are designed to operate using diesel fuel. For example, diesel fuel and jet fuel are distillate fuels. Natural gas, ;iquefied petroleum gas, and gasoline are not distillate fuels.

[0048] ‘Gasoline” means any of the following: (1) any fuel commonly or commercially known as gasoline, including gasoline before oxygenate blending (BOB); (2) any fuel intended or used to power a vehicle or engine designed to operate on gasoline; (3) any fuel that conforms to the specifications of ASTM D4814 (incorporated by reference in 40 CFR § 1090.95) and is made available for use in a vehicle or engine designed to operate on gasoline.

[0049] ‘Gasoline before oxygenate blending” (BOB) means gasoline for which a gasoline manufacturer has accounted for oxygenate added downstream under 40 CFR § 1090.710.

[0050] “Jet fuel” means any distillate fuel used, intended for use, or made available for use in aircraft.

[0051] “Oxygenate” means a liquid compound that consists of one or more oxygenated compounds.

[0052] “Pentane” means an organic compound with the formula C5H12.

[0053] “Pipeline interface” means the mixture between different fuels and products that abut each other during shipment by a refined petroleum products pipeline system.

[0054] “Pipeline operator” means any person who owns, leases, operates, controls, or supervises a pipeline that transports fuel, fuel additive, or regulated blendstock.

[0055] “Previously certified gasoline” (PCG) means conventional gasoline, reformulated gasoline, or gasoline before oxygenate blending that has been certified as a batch by a gasoline manufacturer.

[0056] ‘Reformulated gasoline” (RFG) means gasoline that is certified under 40 CFR§ 1090.1000(b) and that meets each of the standards and requirements in 40 CFR § 1090.220.

[0057] ‘Transmix” means any of the following mixtures of fuels, which no longer meet the specifications for a fuel that can be used or sold as a fuel without further processing: (1) pipeline interface that is not cut into the adjacent products; (2) mixtures produced by unintentionally combining gasoline and distillate fuels; or (3) mixtures of gasoline and distillate fuel produced from normal business operations at terminals or pipelines, such as gasoline or distillate fuel drained from a tank or drained from piping or hoses used to transfer gasoline or distillate fuel to tanks or trucks, or gasoline or distillate fuel discharged from a safety relief valve that are segregated for further processing.

[0058] ‘Transmix distillate product” (TDP) means the diesel fuel blendstock that is produced when transmix is separated into blendstocks at a transmix processing facility.

[0059] “Transmix gasoline product” (TGP) means the gasoline blendstock that is produced when transmix is separated into blendstocks at a transmix processing facility.

[0060] “Transmix processing facility” means any facility that produces TGP or TDP from transmix by distillation or other refining processes, but does not produce gasoline or diesel fuel by processing crude oil or other products.

[0061] ‘Transmix processor” means any person who owns, leases, operates, controls, or supervises a transmix processing facility.

[0062] 2. Systems and Methods for Blending Butane and Transmix

[0063] In some aspect, disclosed herein are systems for in-line blending of butane with gasoline while monitoring the RVP and other physical properties both upstream and downstream of the blend point. Referring to FIG. 1, this is a schematic of an exemplary7butane blending system that can be used at the final distribution end point. By blending at this location, the blender can blend the maximum allowable amount of butane while remaining within regulatory parameters, thus decreasing the cost of the gasoline. The blending skid in FIG. 1 includes a butane pipeline 100 that interfaces a gasoline pipeline 101 carrying a gasoline batch. The flow rate of butane pipeline 100 is controlled by butane injection pump 103. The system further includes fast loop 107 and composite sampler 108 downstream of the butane blending interface 105, for sampling the butane-blended gasoline. The system also includes distillation process analyzer 109 and RVP analyzer 110. Distillation process analyzer 109 measures multiple distillation parameters of the butane-blended gasoline to ensure those are in compliance. The RVP analyzer 110 measures the vapor pressure (and in some configurations, the temperature for a vapor-liquid ratio of 20) of the butane-blended gasoline to ensure it is within the applicable regulations. Programmable logic controller 106 receives these measurements and, based on pre-set or determined minimum and maximum limits for those properties, can communicate adjustments to butane injection pump 103 to change the blend ratio.

[0064] In one aspect, the present disclosure relates to a system for blending transmix and butane into a gasoline stream using an integrated skid. In another aspect, the present disclosure provides a system for blending butane and transmix into PCG without exceeding pre-determined regulatory limits, comprising: (a) a gasoline stream with an associatedgasoline flow rate; (b) a transmix stream in fluid communication with the gasoline stream at a transmix blending point; (c) a motorized pump for controlling the flow of transmix into the gasoline stream at the transmix blending point; (d) a sampler on the gasoline stream located downstream of the transmix blending point for collecting samples to be tested, optionally for compliance with distillation requirements; (e) a butane stream in fluid communication with the gasoline stream at a butane blending point downstream of the transmix blending point; (f) a butane injection pump for controlling the flow of butane into the gasoline stream at the butane blending point; (g) a sampler downstream of the butane blending point for sampling the resultant transmix -butane blended gasoline; (h) a distillation process analyzer for analyzing samples of the transmix -butane blended gasoline; (i) a vapor pressure analyzer for analyzing samples of the transmix -butane blended gasoline; and (j) a programmable logic controller with target volatility values for butane blending and target final boiling point values for transmix blending, wherein the programmable logic controller is configured to receive measured values from the vapor pressure analyzer and the distillation process analyzer, perform calculations, determine appropriate adjustments to the flow of transmix and butane, and communicate those adjustments to both the motorized transmix pump and the butane injection pump.

[0065] Referring to Fig. 2, this is a schematic illustration showing an exemplary diagram of the above-discussed aspect. The blending skid contains the butane blending components from the butane blending skid shown in FIG. 1, including butane injection pump 203. fast loop 207. composite sampler 208, distillation process analyzer 209. RVP analyzer 210. and programmable logic controller 206. The butane blending components can be used to continuously in-line blend butane into gasoline pipeline 201 at butane blending interface 205.

[0066] The schematic in FIG. 2 further includes components for blending transmix into gasoline pipeline 201. Transmix tank 211 is connected to gasoline pipeline 201 throughtransmix pipeline 216 at transmix blending interface 213. The system includes a motorized pump 212, which controls the flow of transmix through transmix pipeline 216. In one aspect, as depicted in FIG. 2, the motor for the pump is a variable frequency drive. In other aspects, the motor can be an across the line starter or other commercially available motor for driving the pump. In some aspects, for example, the system can include transmix injection meter 214 or other measurement meter and control valve for regulating the flow of transmix into the gasoline stream at the transmix blending point. Motorized pump 212 receives commands from programmable logic controller 206, which is discussed in more detail herein.Programmable logic controller 206 can communicate with motorized pump 212 to adjust the flow of transmix into gasoline pipeline 201 at transmix blending interface 213. In some aspects, for example, only one programmable logic controller is used to communicate with both motorized pump 212 and butane injection pump 203, to reduce the equipment that is needed.

[0067] In operation, the blending skid blends transmix from transmix tank 211 into gasoline pipeline 201. The transmix-blended gasoline is sampled at point 215 using composite sampler 208. This sampling is done before any injection of butane into the transmix-blended gasoline because the transmix blender must ensure that the final boiling point of the transmix-blended gasoline does not exceed 437 degrees Fahrenheit, per the applicable regulatory framework. These samples can be tested with a lab analyzer at least twice a month to verify compliance. Composite sampler 208 can also be used to test butane properties if needed, using fast loop 207, which takes samples downstream of butane blending interface 205.

[0068] After blending gasoline with transmix at transmix blending interface 213 and sampling the resultant blend with composite sampler 208. butane can be blended with the transmix-blended gasoline at butane blending interface 205. Butane from butane tank 204 isblended into gasoline pipeline 201 at butane blending interface 205, using butane pipeline 200. Downstream of butane blending interface 205, the transmix-butane-blended gasoline is sampled using fast loop 207. These samples are then sent to both distillation process analyzer 209 and RVP analyzer 210 for analysis.

[0069] In some aspects, for example, distillation process analyzer is a PAC MicroDist analyzer. In some aspects, for example, distillation process analyzer is of other commercially available brands, including for example a Bartec™ brand analyzer. Distillation process analyzer 209 determines multiple distillation points of the transmix-butane-blended gasoline to control butane injection, as well as the final boiling point to control the injection of transmix into the gasoline before the butane injection point. This is done because under EPA regulations, a transmix blender must ensure that the resultant blended gasoline does not exceed a final boiling point of 437 degrees Fahrenheit.

[0070] In some aspects, for example, RVP analyzer 210 is an ERAVAP™ brand analyzer. In some aspects, for example, RVP analyzer 210 is of other commercially available brands, including Bartec™, Grabner™, or ORB™. RVP analyzer 210 determines the vapor pressure of the transmix-butane-blended gasoline and, in some configurations if desired, can determine the temperature for a vapor-liquid ratio of 20. This is carried out because vapor pressure of gasoline is regulated. Butane has a higher vapor pressure than gasoline and therefore can increase the RVP of the butane-blended gasoline.

[0071] Both RVP analyzer 210 and distillation process analyzer 209 communicate their measured analysis to programmable logic controller 206. In some aspects, for example, programmable logic controller 206 is an Allen Bradley™ brand programmable logic controller. In some aspects, for example, programmable logic controller 206 is of other types or brands. Programmable logic controller 206 can be set with a fixed maximum vapor pressure, depending on the applicable regulation, certain distillation points, temperature for avapor-liquid ratio of 20, and any predetermined final boiling point. Any type of information processing unit can be used in place of a programmable logic controller so long as it can receive information from the analyzers and meters and send commands to the respective pumps. In some aspects, for example, distillation process analyzer 209 is placed downstream of transmix blending interface 213 because transmix may not have a linear effect on the final boiling point of the gasoline blend.

[0072] Programmable logic controller 206 receives the measured distillation points, including the final boiling point from distillation process analyzer 209 and will communicate adjustments to motorized pump 212 as needed. These adjustments will increase or decrease the flow of transmix into gasoline pipeline 201 at gasoline blending interface 213 to ensure that the transmix -blended gasoline stays in compliance with final boiling point regulations. RVP Analyzer 210 also communicates its measured vapor pressure to programmable logic controller 206. Depending on the RVP value, the distillation points (other than the final boiling point), and the temperature for a vapor-liquid ratio of 20 (which are affected by butane injection), the programmable logic controller 206 can communicate with butane injection pump 203 to increase or decrease the amount of butane blended into gasoline pipeline 201 at butane blending interface 205. This is to ensure the vapor pressure, distillation parameters, and the temperature for a vapor-liquid ratio of 20 of the butane- blended gasoline do not exceed the allowable amounts. In some aspects, for example, the sampling and adjustment loop is placed downstream of butane blending interface 205 because, depending on the transmix properties, blending transmix prior to the butane blending may reduce the vapor pressure of the gasoline, thereby allowing additional butane to be blended. Placing RVP analyzer 210 downstream of the butane blending allows the effects of blending both the transmix and butane to be measured.

[0073] The result of FIG. 2 is a system that can continuously and automatically blend both transmix and butane into gasoline, allowing blenders to decrease the cost of the gasoline by the maximum amount feasible. By continuously measuring these properties, the blender can also ensure compliance with all laws and regulations that may be applicable. The integrated nature of the system further allows the blender to use less resources and space to perform the blending operations.

[0074] While FIG. 2 shows one configuration, the integrated blending skid can be practiced in other configurations not shown. For example, there can be different or multiple injection points for transmix and / or butane into the gasoline pipeline, or an additional meter installed on the gasoline pipeline between the transmix and butane injection points. Additionally, other blendstocks could be used in addition to, or instead of, butane. While FIG. 1 shows an RVP analyzer and a distillation process analyzer, other analyzers could be included to measure various physical properties including but not limited to the sulfur content of the gasoline both pre- and post- blending with transmix and / or butane. For example, a sulfur analyzer can be included at the same location as the distillation process analyzer and RVP analyzer. Alternatively, a sulfur analyzer can be placed on the transmix or butane pipelines to measure the sulfur content of the to-be-blended transmix and / or butane. The programmable logic controller can also be configured to have a maximum allowed sulfur amount and adjust the flow of butane and / or transmix to stay within the sulfur limits, depending on which input has a sulfur value higher than the allowable value for the resultant blended gasoline.

[0075] 3. Programmable Logic Controller

[0076] The exemplary systems described above may use a programmable logic controller or other computing device for electronic control of mechanical components. A programmable logic controller is only one example of a computing device or programmabledevice, is not intended to suggest any limitation as to scope of use or functionality of the system and / or their possible architectures.

[0077] In general, an example computing device to at least assist in controlling the blending systems can include one or more processors or processing units, one or more memory components, and a bus that allows the various components and devices to communicate with each other, and can include local data storage, among other components.

[0078] Memory generally represents one or more volatile data storage media. Memory components can include volatile media, such as random access memory (RAM), and / or nonvolatile media, such as read only memory (ROM), flash memory, and so forth.

[0079] Bus represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. Bus can include wired and / or wireless buses.

[0080] Local data storage can include fixed media (e.g., RAM, ROM, a fixed hard drive, etc.) as well as removable media (e.g., a flash memory drive, a removable hard drive, optical disks, magnetic disks, and so forth).

[0081] A user interface device can also communicate via a user interface (UI) controller, which can connect with the UI device either directly or through the bus.

[0082] A network interface can communicate outside of the computing device via a connected network, and in some implementations can communicate with hardware.

[0083] A media drive / interface accepts removable tangible media, such as flash drives, optical disks, removable hard drives, software products, etc. Logic, computing instructions, or a software program comprising elements of the sharpening controller can reside on removable media readable by the media drive / interface.

[0084] One or more input / output devices can allow a user to enter commands and information to example device, and also allow information to be presented to the user and / or other components or devices. Examples of input devices include keyboard, a cursor control device (e.g., a mouse), a microphone, a scanner, and so forth. Examples of output devices include a display device (e.g., a monitor or projector), speakers, a printer, a network card, and so forth.

[0085] Various methods of blending can be implemented in software or program modules, or in pure computing hardware. Software generally includes routines, programs, objects, components, data structures, and so forth that perform particular tasks or implement particular abstract data types. An implementation of these modules and techniques can be stored on or transmitted across some form of tangible computer readable media. Computer readable media can be any available data storage medium or media that is tangible and can be accessed by a computing device. Computer readable media can thus comprise computer storage media.

[0086] “Computer storage media” designates tangible media, and includes volatile and non-volatile, removable and non-removable tangible media implemented for storage of information such as computer readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other tangible medium which can be used to store the desired information, and which can be accessed by a computer.

[0087] 4. Conclusion

[0088] The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the implementations to the precise form disclosed. Modificationscan be made in light of the above disclosure or can be acquired from practice of the implementations. Those skilled in the art will appreciate that there are other embodiments of the disclosed systems and methods that overcome the disadvantages of the prior art discussed herein and fulfill the needs unmet by the prior art.

[0089] The descriptions and figures herein are exemplary in nature. Although particular combinations of features are recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various implementations. In fact, many of these features can be combined in ways not specifically recited in the claims and / or disclosed in the specification. In other words, as disclosed herein, many features can be taken and combined with other features disclosed herein to arrive at other embodiments. No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such.

[0090] Although each dependent claim listed below may directly depend on only one claim, the disclosure of various implementations includes each dependent claim in combination with every other claim in the claim set.

Claims

What is claimed is:

1. A system for blending a blendstock and transmix into gasoline, the system comprising:(a) a gasoline pipeline;(b) a transmix pipeline in fluid communication with the gasoline pipeline at a first blending point;(c) a first pump configured to pump a flow of transmix from the transmix pipeline into the gasoline pipeline at the first blending point;(d) a first sampler on the gasoline pipeline located downstream of the first blending point;(e) a blendstock pipeline in fluid communication with the gasoline pipeline at a second blending point downstream of the first blending point;(f) a second pump configured to pump a flow of the blendstock from the blendstock pipeline into the gasoline pipeline at the second blending point;(g) a second sampler located downstream of the second blending point;(h) a distillation process analyzer;(i) a vapor pressure analyzer; and(j) a programmable logic controller.

2. The system of claim 1, further comprising a transmix tank connected to the transmix pipeline.

3. The system of claim 1, further comprising a blendstock tank connected to the blendstock pipeline.

4. The system of claim 1, further comprising a transmix injection meter configured to measure the flow of transmix into the gasoline pipeline at the first blending point.

5. The system of claim 1, further comprising a blendstock injection meter configured to measure the flow of blendstock into the gasoline pipeline at the second blending point.

6. The system of claim 1, further comprising a sulfur analyzer.

7. The system of claim 6, wherein the sulfur analyzer is located at a same location as the distillation process analyzer or the vapor pressure analyzer.

8. The system of claim 6, wherein the sulfur analyzer is located on the transmix pipeline or the blendstock pipeline.

9. The system of claim 1, wherein the blendstock is certified butane or certified pentane.

10. The system of claim 9, wherein the blendstock is certified butane.

11. The system of claim 1, wherein the gasoline is previously certified gasoline (PSG).

12. The system of claim 1, wherein the first pump is a motorized pump.

13. The system of claim 12, wherein the motorized pump is driven by a variable frequency drive motor.

14. The system of claim 12, wherein the motorized pump is an across-the-line starter motor.

15. The system of claim 1, wherein the first sampler is located upstream of the second blending point.

16. The system of claim 1, wherein the second pump is an injection pump.

17. The system of claim 1, wherein the distillation process analyzer is located downstream of the first blending point.

18. The system of claim 1, wherein the vapor pressure analyzer is a Reid vapor pressure (RVP) analyzer.

19. The system of claim 1, wherein the programmable logic controller is programmed with target parameters comprising a target volatility value and a final boiling point.

20. The system of claim 19, wherein the final boiling point is about 437 degrees Fahrenheit.

21. The system of claim 19, wherein the target parameters further comprise a sulfur content.

22. The system of claim 19, wherein the target parameters further comprise a temperature for a vapor-liquid ratio.

23. The system of claim 1, wherein the programmable logic controller is in communication with the first pump, the second pump, the distillation process analyzer, and the vapor pressure analyzer.

24. The system of claim 23, wherein the programmable logic controller is configured to receive measured values from the distillation process analyzer and the vapor pressure analyzer, determine adjustments to the flow of transmix and the flow of blendstock, and communicate the adjustments to the first pump and the second pump.

5. A system for blending butane and transmix into gasoline, the system comprising:(a) a gasoline pipeline;(b) a transmix pipeline in fluid communication with the gasoline pipeline at a transmix blending point;(c) a motorized transmix pump configured to pump a flow of transmix from the transmix pipeline into the gasoline pipeline at the transmix blending point;(d) a butane pipeline in fluid communication with the gasoline pipeline at a butane blending point downstream of the transmix blending point;(f) a butane injection pump configured to pump a flow of butane from the butane pipeline into the gasoline pipeline at the butane blending point;(g) a composite sampler;(h) a distillation process analyzer;(i) a vapor pressure analyzer; and(j) a programmable logic controller configured to receive measured values from the distillation process analyzer and the vapor pressure analyzer, determine appropriate adjustments to the flow of transmix and the flow of butane, and send commands to the motorized transmix pump and the butane injection pump; wherein the motorized transmix pump is configured to adjust the flow of transmix based on the commands received from the programmable logic controller; wherein the butane injection pump is configured to adjust the flow of butane based on the commands received from the programmable logic controller; and wherein the composite sampler in fluid communication with the gasoline pipeline at a first sampling point and a second sampling point, the first sampling point being located downstream of the transmix blending point and upstream of the butaneblending point, and the second sampling point being located downstream of the butane blending point.

26. The system of claim 25, further comprising a fast loop connecting the gasoline pipeline to the composite sampler.

27. A method of blending butane and transmix into gasoline, the method comprising: injecting a stream of transmix at a first flow rate into a stream of gasoline; injecting a stream of butane at a second flow rate into the stream of gasoline; analyzing a sample of a transmix-butane blended gasoline to measure its vapor pressure and boiling point; determining appropriate adjustments to the first flow rate and the second flow rate so as to keep the transmix-butane blended gasoline within desired property ranges; and adjusting the first flow rate and the second flow rate.

28. The method of claim 27, further comprising: analyzing the sample of the transmix-butane blended gasoline to measure its sulfur content.

29. The method of claim 27, further comprising: determining a maximum flow rate of transmix and a maximum flow rate of butane that keep the transmix-butane blended gasoline within the desired property ranges.

30. The method of claim 27, further comprising: recording results from analyzing the sample of the transmix-butane blended gasoline.

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