WO2004108862A1

WO2004108862A1 - Removal of drag reducer additive from fuel by treatment with selected activated carbons and graphites

Info

Publication number: WO2004108862A1
Application number: PCT/US2003/017479
Authority: WO
Inventors: John Andrew Waynick
Original assignee: Southwest Research Institute
Priority date: 2003-06-03
Filing date: 2003-06-03
Publication date: 2004-12-16
Also published as: AU2003243377A1

Abstract

The application relates to a method for selecting drag reducer additive (DRA) effectively removable by activated carbons and graphites to be used in fuel. The application also relates to effective activated carbons and graphites for removing DRA from fuel, and to a method of using effective activated carbons and graphites to remove DRA from fuel.

Description

TITLE: REMOVAL OF DRAG REDUCER ADDITIVE FROM FUEL BY

TREATMENT WITH SELECTED ACTIVATED CARBONS AND GRAPHITES Cross-reference to Related Applications

[0001] This application is a continuation-in-part application of U.S. Patent

Application No. 10/124,974, filed on April 18, 2002.

Field of the Invention

[0002] The application relates to a method for selecting drag reducer additive

(DRA) effectively removable by activated carbon to be used in fuel. The application

also relates effective activated carbons and graphites for removing DRA from fuel,

and to a method of using effective activated carbon and graphites to remove DRA from fuel.

Background

[0003] In order to move fluid through pipelines, into or out of wells, or through equipment, energy must be applied to the fluid. The energy moves the fluid, but is lost

in the form of friction. This frictional pressure drop, or drag, restricts the fluid flow,

limiting throughput and requiring greater amounts of energy for pumping.

[0004] Materials can be added to flowing fluids in order to reduce the energy lost

due to friction, or drag, thus permitting the movement of more fluid at the same differential pressure. The resulting reduction in frictional pressure drop improves

pumping efficiency, lowers energy costs, and increases profitability. Materials for

reducing drag in flowing fluids are generally known by the generic names "flow

improver" or "drag reducer additive" (sometimes referred to as "DRA"). [0005] Unfortunately, whether in the virgin form or in the sheared or partially sheared form, and despite the fact that it is intentionally added to certain fuels, drag

reducer additive nonetheless is a "contaminant" in liquid hydrocarbon fuels, and has

the potential to cause a number of problems. For example, the presence of drag reducer additive in motor gasoline, even in the sheared form, has caused increased

intake valve deposits, plugging of fuel filters, and increased combustion chamber

deposits. In diesel fuels, drag reducer additive may cause plugging of fuel filters and

strainers and increased fuel injector deposits. Drag reducer additive is prohibited in

aviation turbine fuels, although it has been observed as a contaminant due to accidental addition or other non-intentional means. The presence of drag reducer

additive in aviation turbine fuel may result in downgrading of the entire batch to non- aviation kerosene or diesel fuel, both of which generally have less market value.

[0006] Viable methods of detecting and quantifying drag reducer additive in liquid hydrocarbon fuels commonly employ gel permeation chromatography, which is time

consuming and expensive. Because of this, contaminated liquid hydrocarbon fuels

often are used, despite the potential problems if drag reducer additive is present.

Contaminated aviation turbine fuels may be diverted to other uses or returned to a refinery for reprocessing, either of which results in additional expense. Simple and inexpensive methods and materials are needed for removing drag reducer additive

from liquid hydrocarbon fuels.

Summary [0007] The application provides a method for removing drag reducer additive from a liquid hydrocarbon fuel. The method comprises providing a contaminated liquid hydrocarbon fuel comprising a concentration of a drag reducer additive, and contacting the contaminated liquid hydrocarbon fuel with a quantity of one or more of

an activated carbon or a graphite effective to substantially reduce said concentration of drag reducer additive, thereby producing a clean liquid hydrocarbon fuel.

Brief Description of the Figures

[0008] Figure 1 is a graph of % Polymer Removed vs. Carbon (activated carbons

and graphites) used to remove unsheared FLO^®XS polymer from jet fuel using the Grad Add/Stir method (described in detail below).

[0009] Figure 2 is a graph of % Polymer Removed vs. Carbon (activated carbons

and graphites) used to remove unsheared FLO^®XS polymer from jet fuel for both Grad Add/Stir and Quick Add/Stir methods using the Grad Add/Stir method.

[0010] Figure 3 is a graph of % Polymer Removed vs. Carbon (activated carbons

and graphites) used to remove sheared FLO^®XS polymer from jet fuel using the Grad

Add/Stir method.

[0011] Figure 4 is a graph of % Polymer Removed vs. Carbon (activated carbons and graphites) used to remove sheared FLO^®XS polymer from jet fuel for both Grad

Add/Stir and Quick Add/Stir methods. [0012] Figure 5 is a graph of % Polymer Removed vs. Carbon (activated carbons

and graphites) used to remove FLO ^®XS polymer from jet fuel for Unsheared vs.

Sheared FLO^®XS polymer using the Grad Add/Stir method. Detailed Description

[0013] The application provides methods for removing drag reducer additive

(DRA) from liquid hydrocarbon fuels, preferably motor gasoline or jet fuel, most

preferably jet fuel, using selected activated carbons or graphites. As used herein, the

word "contaminated" refers to the presence of DRA in the fuel, due to either intentional addition or unintentional addition.

"Liquid Hydrocarbon Fuel"

[0014] By "liquid hydrocarbon fuel" is meant any hydrocarbon that is liquid under

conditions of transport and/or storage. Suitable liquid hydrocarbon fuels include, but

are not necessarily limited to those having a boiling range of from about 150 °F to

about 750 °F, which may be used as a fuel. In one embodiment, the liquid

hydrocarbon fuel is selected from the group consisting of liquefied natural gas (LNG),

liquefied petroleum gas (LPG), motor gasoline, aviation gasoline, distillate fuels such

as diesel fuel and home heating oil, kerosene, jet fuel, No. 2 oil, residual fuel, No. 6

fuel, or bunker fuel. In a preferred embodiment, the liquid hydrocarbon fuel is

selected from the group consisting of diesel fuel, jet fuel, aviation gasoline, and motor

gasoline. In a more preferred embodiment, the liquid hydrocarbon fuel is jet fuel, at least in part due to the stringent requirements applicable to jet fuel and drag reducer

additive. The phrase "jet fuel" refers to both commercial jet fuel (Jet A, Jet A-l, and

JET B) and military jet fuel, such as JP-4, JP-5, JP-8 and the like.

"Drag Reducer Additive" [0015] The term "drag reducer additive" (i.e. DRA) is defined to mean polyolefin polymers comprising polyolefin moieties which are introduced into petroleum liquids

for the purpose of reducing fluid flow drag. The drag reducer additive may comprise other components besides the polyolefin moieties. Examples of such components

include, but are not necessarily limited to surfactant, catalyst residue, other additives,

and other byproducts from the production of the polymer. The polymer itself may

contain other non-olefin monomer units as well.

[0016] In a preferred embodiment, the drag reducer additive includes, but is not

necessarily limited to, non-polar long-chain polyolefin polymers, generally referred to

as "polyalphaolefins," having a "peak" molecular weight sufficiently high to allow the

polymers to reduce fluid flow drag. Suitable polyalphaolefins are believed to have a

molecular weight of about 1 million Daltons or more, more preferably about 10

million Daltons or more, most preferably about 25 million Daltons or more. The

"peak" molecular weight refers to the peak that typically is measured as the drag

reducer is eluted and detected during gel permeation chromatography.

[0017] Suitable polyalphaolefins comprise polymerized linear alpha olefin (LAO)

monomers having from about 2 to about 40 carbon atoms, preferably from about 2 to

about 30 carbon atoms, more preferably from about 4 to about 20 carbon atoms, most

preferably from about 6 to about 12 carbon atoms. An especially preferred embodiment for a DRA which is effectively removable by the activated carbons

and/or graphites described herein comprises at least two different LAO's, preferably

having from about 6 to about 12 carbon atoms, the number of carbon atoms of the "at

least two different LAO's" differing by 6. [0018] Polyalphaolefins having relatively high molecular weights are required to

impart good drag reduction. Suitable polyalpha olefins "are made by a variety of

processes, including but not necessarily limited to solution polymerization and bulk

polymerization. Bulk polymerization is said to produce "ultra-high molecular weight polyolefin drag reducers [that] are significantly larger (molecular weight basis) than

the best molecular weights made by solution polymerization." See U.S. Patent No.

5,504,132. Preferred DRA's for removal according to the process described herein

are made by solution polymerization.

[0019] Without limiting the invention to a specific theory or mechanism of action,

the very large polyalpha olefins made by bulk polymerization may be more difficult to

adsorb onto and retain on the carbonaceous removal agents. In contrast, the polyalpha

olefins made by solution polymerization may be more readily adsorbable onto the

removal agents, and more readily retained by the removal agents.

[0020] Drag reducer additives are generally unsheared, partially sheared, or fully sheared. An additive that is fully sheared is one that is degraded in molecular weight

to the maximum extent possible using high shear devices such as pumps, static

mixers, etc. Commercially available drag reducer additives include, but are not

necessarily limited to, CDR ^® Flow Improver and REFINED POWER ™,

manufactured by Conoco Specialty Products, Inc., EN-660 Flow Improver,

manufactured by Energy 2000 LLC, and FLO ^®XS and FLO ^®XL, manufactured by

Baker Petrolite. In a preferred embodiment, the drag reducer additive is FLO^®XS and

equivalents thereof. [0021] The exact mechanism by which a drag reducer additive reduces drag in flowing liquid hydrocarbons is not completely known. However, a drag reducer

additive apparently alters the turbulent flow regime of the liquid hydrocarbons. In a pipeline, this flow regime is comprised of at least three regions. At the center of the

pipe is a turbulent core, which is the largest region and includes most of the fluid in the pipe. This is the zone of eddy currents and random motions for which turbulent

flow is named. Nearest to the pipe line wall is the laminar sublayer. In this zone, the fluid moves laterally in "sheets". Between the laminar layer and the turbulent core

lies the "buffer zone". It appears that much of the turbulence which exists in turbulent

flow develops when a portion of the laminar sublayer, called a "streak", moves up to

the buffer zone, where it begins to vortex and oscillate, finally breaking up and

throwing fluid into the core. This ejection of fluid into the core is called a "burst".

The burst creates the turbulence in the core, and energy is wasted in different

directions. Drag reducer additive appears to interfere with the bursting process and

prevent or reduce the degree of turbulence by stretching in the flow, absorbing the

energy in the streak, and thereby preventing bursts.

[0022] As liquids containing drag reducer additive travel through pumps, pipelines

and other equipment, the drag reducer additive typically degrades through shearing

action, resulting in a reduction in the molecular weight of the drag reducer additive. The degraded drag reducer additive is generally sheared or partially sheared drag

reducer additive. Upon reaching the ultimate destination, liquid hydrocarbon fuels

that have been shipped using drag reducer additive may contain a significant amount of drag reducer additive, including that in the sheared and partially sheared form.

Removal Agents for Removing DRA from Fuels

[0023] The present application is based on the surprising finding that selected

activated carbons and graphites, particularly selected graphites, are much more

effective than others as removal agents for binding and removing drag reducer

additive from fuels, preferably motor gasoline and jet fuels, most preferably jet fuels.

The superiority has been demonstrated in unsheared DRA known as Baker Petrolite

FLO^®XS.

[0024] Without limiting the application to a particular theory or mechanism of

operation, the more active removal agents are believed to comprise ducts or pores

having a hydrophobic/hydrophilic property that provides a chemical attraction to

pendant groups on the drag reducer additive. The chemical attraction is believed to

bring the pendant groups on the drag reducer additive into proximity and orientation

with the pore surface of the agent, thereby immobilizing the pendant groups. Because

many pendant groups on a given drag reducer molecule are simultaneously

immobilized, the drag reducer molecule is strongly immobilized.

[0025] Without limiting the claims to a particular mechanism or theory of action,

the effective activated carbons and graphites are believed to be porous materials

comprising pores having a hydrophobic/hydrophilic property that is compatible with

or provides a chemical attraction to pendant groups of the particular drag reducer

additive. The specific activated carbons and graphites may be in the form of crushed

particles or granules, powder, cylinders, globules, fibers, or honeycombs. Preferred agents are in the form of particles or granules. Most preferred agents are in powder or granule form.

Activated Carbons

[0026] Suitable activated carbons are commercially available, for example, from

AUchem Industries, Inc., Beta Chemicals, Calgon, Coyne Chemical Co., Elf Atochem North America, Inc. (Performance Products), R. W. Greef & Co, Inc., Kingshine

Chemical Co., Ltd., Mays Chemical Co., Inc., Mitsubishi International Corp.

(Industrial Specialty Chemicals Div.), Spectrum Chemical Mfg. Corp., Norit and

others. When added (in increments with agitation) to a fuel mixture containing a

preferred unsheared drag reducer additive of about 8-12 ppm polymer concentration,

more preferably about 9-11 ppm polymer concentration, most preferably about 10

ppm polymer concentration, suitable activated carbons attain a % polymer removal of

about 20% or more; preferably about 30% or more; more preferably at least about

40% or more, at about lg activated carbon/100 ml fuel. This equates to a %

adsorption capacity of about 0.014% or more, preferably about 0.02% or more, most

preferably about 0.03% or more. When added (in increments with agitation) to a fuel

mixture containing a preferred sheared drag reducer additive of about 8-12 ppm

polymer concentration, more preferably about 9-11 ppm polymer concentration, most preferably about 10 ppm polymer concentration, suitable activated carbons attain a %

polymer removal of about 20% or more; preferably about 25% or more; more

preferably about 30% or more, at about lg activated carbon/100 ml fuel. This equates

to a % adsorption capacity of about 0.018% or more, preferably about 0.025% or more, more preferably about 0.03% or more.

[0027] Commercially viable activated carbons, which have been demonstrated to be

suitable to remove Baker Petrolite FLO^® XS and equivalents thereof include, but are

not necessarily limited to, CALGON ADP, CALGON COLORSORB, CALGON

WPX, NORIT A SUPRA, NORIT CA 1, NORIT FGD, NORIT HDB, SXO

POWDER, and CARBON 5565. Preferred activated carbons demonstrated to be

useful for removing Balcer Petrolite FLO^® XS and equivalents thereof include, but are

not necessarily limited to CALGON WPX, NORIT A SUPRA, NORIT CA1, NORIT

FGD, NORIT HDB, SXO POWDER and CARBON 5565. Most preferred activated

carbons demonstrated to be useful for removing Balcer Petrolite FLO^® XS and

equivalents thereof include, but are not necessarily limited to NORIT A SUPRA,

NORIT CAl, NORIT FGD, and NORIT HDB.

Preferred Graphites [0028] Most preferred carbonaceous materials are graphites. Graphite is a

crystalline form of carbon found as a naturally occurring mineral in many locations

around the world. Graphite can be amorphous ("amorphous graphite"). Graphite

also can have a perfect basal cleavage which, coupled with its extreme softness, gives

it an oily, slippery feel, such graphites include, but are not necessarily limited to

natural graphite, synthetic graphite, and expanded graphite. Each of these graphite

types is commercially available in various forms, including, crystalline lumps,

crystalline large flakes, crystalline medium flakes, crystalline small flakes, and

powder form. Artificial graphite can be manufactured from petroleum coke and is primarily used to make electrodes. The virgin by-product of such electrode production has a carbon content as high as 99.9%, and can be a relatively inexpensive source of graphite agent, to highly refined natural graphite. Suitable candidate

graphites are commercially available, for example, from Asbury Carbons, Inc., Asbury, NJ; Superior Graphite Co., Chicago, IL; Stanford Materials Corporation,

Aliso Viejo, CA; and others.

[0029] Preferred graphites comprise graphite powders or granular graphite

particulates. The granular graphite particulates have an average diameter of from about 0.01 microns to about 10,000 microns; preferably from about 0.1 microns to about 1,000 microns; most preferably about 1 micron to about 100 microns. Preferred graphites have a porosity sufficient to provide an adsorption capacity of about 0.01

wt.% or more, preferably about 0.03 wt.% or more, most preferably about 0.04 wt%,

when added to a preferred drag reducer additive. Suitable and preferred graphites are commercially available from Superior Graphite Company. Preferred graphite

products comprise, but are not necessarily limited to, purified carbon, natural graphite, silica (crystalline quartz), and synthetic graphite.

[0030] When added (in increments with agitation) to a fuel mixture containing a preferred unsheared drag reducer additive of about 8-12 ppm polymer concentration,

more preferably about 9-11 ppm polymer concentration, most preferably about 10

ppm polymer concentration, suitable graphites attain a % polymer removal of about

30% or more; preferably about 40% or more; more preferably at least about 50% or more, at about lg activated carbon/100 ml fuel. This equates to a % adsorption capacity of about 0.02% or more, more preferably about 0.03% or more, most

preferably about 0.04% or more. When added (in increments with agitation) to a fuel mixture containing a preferred sheared drag reducer additive of about 8-12 ppm

polymer concentration, more preferably about 9-11 ppm polymer concentration, most

preferably about 10 ppm polymer concentration, suitable graphites attain a % polymer

removal of at least about 25%; more suitably at least about 30%; most suitably at least

about 35%, at about lg activated carbon/ 100 ml fuel. This equates to a % adsorption

capacity of about 0.02%, more preferably about 0.025%, most preferably about

0.03%.

[0031] Graphites that demonstrated commercial viability for adsorbing unsheared

and sheared BAKER PETROLITE FLO^® XS and equivalents included GRAPHITE 2126, GRAPHITE 2139, GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5526,

GRAPHITE 5539, GRAPHITE 9026, GRAPHITE 9039, and GRAPHITE GA-17,

available from Superior Graphite Co. The foregoing graphites exhibited an adsorption

capacity for unsheared and sheared BAKER PETROLITE FLO^® XS of about 0.01

wt% or more.

[0032] Preferred commercially available graphites for adsorbing unsheared BAKER

PETROLITE FLO^® XS and equivalents included GRAPHITE 2126, GRAPHITE

2139, GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5539, GRAPHITE 9039, and GRAPHITE GA-17. The foregoing graphites exhibited an adsorptioncapacity for unsheared BAKER PETROLITE FLO^® XS of about 0.02 wt% or more. Preferred

commercially available graphites for adsorbing sheared BAKER PETROLITE FLO ©^' XS and equivalents included GRAPHITE 2126, GRAPHITE 2139, GRAPHITE

3726, GRAPHITE 3739, GRAPHITE 9026, and GRAPHITE 9039. The foregoing

graphites exhibited an adsorptioncapacity for sheared BAKER PETROLITE FLO^® XS of about 0.018 wt% or more.

[0033] Even more' preferred commercially available graphites for adsorbing unsheared BAKER PETROLITE FLO^® XS and equivalents included GRAPHITE

2139, GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5539, GRAPHITE 9039, and

GRAPHITE GA-17. The foregoing graphites exhibited an adsorptioncapacity for

unsheared BAKER PETROLITE FLO^® XS of about 0.03 wt% or more.

[0034] Most prefeπ-ed graphites, particularly for adsorbing unsheared BAKER

PETROLITE FLO^® XS and equivalents thereof, include but are not necessarily

limited to GRAPHITE 2139 and GRAPHITE 3739. The foregoing graphites

exhibited an adsorptioncapacity for unsheared BAKER PETROLITE FLO^® XS of about 0.04 wt% or more. Most preferred graphites, particularly for adsorbing sheared

BAKER PETROLITE FLO^® XS and equivalents thereof, include but are not

necessarily limited to GRAPHITE 3726 and GRAPHITE 3739. The foregoing

graphites exhibited an adsorptioncapacity for sheared BAKER PETROLITE FLO^® XS

of about 0.025 wt% or more.

Removal of Drag Reducer Additive From Liquid Hydrocarbon Fuels

[0035] It may be desirable simply to subject all of a given fuel at a given storage or

transport site to a DRA removal procedure. This would be particularly effective if all

the DRA in use was removable by carbonaceous materials. In fact, it would even be most preferable to use as DRA in fuels only materials known to be removable by carbonaceous materials. Or it may be desirable to test for the presence of DRA before incurring the expense of removal.

[0036] Once preferred carbonaceous materials, preferably graphite removal agents have been identified, the activated carbon and/or graphite(s) may be used to remove the drag reducer additive from a given liquid hydrocarbon fuel, preferably motor gasoline or jet fuel, most preferably jet fuel. Alternately, a given sample of

hydrocarbon fuel is analyzed for DRA by gel permeation chromatography (GPC).

[0037] When it is desired to remove DRA from a given fuel, one or more effective

carbonaceous materials, preferably selected activated carbons, more preferably graphite(s) are incorporated into a system for filtering the DRA/fuel mixture and for

removing drag reducer additive from that mixture. The filter may be in any suitable

form and may be installed in a variety of locations. Suitable locations include, but are

not necessarily limited to a pipeline to a fuel terminal, a delivery system between a

fuel terminal and a tanker truck, a delivery system between two different tanker trucks, a delivery system from a tanker truck to a storage tank or to an engine, and, actually as a component of the engine, itself. In one embodiment, the filter comprises a component of a fuel delivery system from a tanker truck to a jet engine. The filter

may be used in substantially any type of delivery system. In each method, the graphites may or may not be heated. Heating removes any water, if any is adsorbed on

the graphite.

[0038] Due to the difficulty in providing for incremental addition and agitation in most commercial situations, it may be preferred to simply pass the liquid hydrocarbon

fuel through a bed of the carbonaceous materials, preferably selected activated carbons, more preferably graphite(s), until the removal rate is so low that the carbonaceous materials must be replaced. In one embodiment, the filtering system

provides for agitation of the DRA/fuel mixture as incremental additions of a given carbonaceous material, preferably a selected activated carbon(s), more preferably graphite(s) are added to the DRA/fuel mixture. This procedure is sometimes herein referred to as the "gradual addition and stirring" method or "Grad Add/Stir" method.

This is a preferred method for more viscous hydrocarbon fuels such as jet fuel.

[0039] Civilian aircraft generally are serviced in hangers at airports. Military aircraft are serviced on the flight line, where a row of aircraft are parked away from a

maintenance terminal and nearer to the runway, to be ready for mobilization. The distance from the flight line to the maintenance terminals may be as much as one mile. Servicing of aircraft, particularly military aircraft, typically is performed by shuttling

service vehicles out to the flight line from the maintenance terminal where they

perform the requisite service. Periodically, the servicing vehicles return to the maintenance terminal to themselves be refueled or for other servicing.

[0040] An example of how the system would be incorporated into a known fuel

delivery system is described in U.S. Patent Application No. 10/124,974, filed on April 18, 2002, incorporated herein by reference. Briefly, the fuel delivery system comprises: (1) a tank of a refueling truck, (2) a transfer hose, (3) a bracket for storing the hose, (4) a manual pump, (5) a filter device, (6) a drain connected to the transfer hose at one end, and (7) a shutoff valve. The filter device comprising the removal agent of the present application may be inserted either in series or in parallel with these one-way filters. Preferably, a filter device, such as a canister or cartridge of the removal agent(s), is placed downstream of the one-way filters in order to improve efficiency and longevity of the operation.

[0041] The application will be better understood with reference to the following examples, which are illustrative only:

EXAMPLE 1 [0042] The Grad Add/Stir method was used in this example. About 100 ml of jet fuel comprising about 8.36 ppm of FLO^® XS - unsheared DRA (manufactured by

Baker Petrolite) was stirred with a magnetic stir bar, to create a moderate vortex.

Increments of about 0.02 to about 0.1 gram of a removal agent were placed in the agitating DRA/jet fuel mixture, while stirring, until a total of about 1.0 g had been added. The stirring was continued for approximately two to three minutes. The

sample was allowed to settle for about 5 minutes. The carbon was removed from the mixture by filtration with a Whatman 8 micron filter. The mixture was then tested for

polymer concentration.

[0043] The polymer adsorption of removal agents increased with graphite as

compared to activated carbon. Table 1 (in Example 2) summarizes the % DRA

adsorbed for both an activated carbon group (34 samples), and a graphite group (9 samples). FIG. 1 is a graphical representation of the effectiveness of graphites to remove unsheared DRA from jet fuel. Table 1 further summarizes the % adsorption capacity for both an activated carbon group, and a graphite group. For unsheared

DRA, the % adsorption capacity of a given carbon = (0.000678)*(% polymer removed). This formula is derived using the initial polymer concentration, volume of DRA/fuel used in the experiment, weight of carbon used in the experiment, and density of the DRA/fuel used.

[0044] As shown in FIG. 1, graphites are more effective at removing unsheared polymer than activated carbons. The highest removal effectiveness of the 43 removal

agents tested was 58.20 % (with "Graphite 3739"), provided by Superior Graphite

Company, which corresponds to a polymer adsorption capacity of 0.04 %(wt).

EXAMPLE 2 [0045] The Quick Add/Stir method was used in this example. About 100 ml of jet fuel comprising about 8.36 ppm of FLO^® XS - unsheared DRA (manufactured by

Once the removal agent had cooled, about 1.0 g of the removal agent was placed in

the agitating DRA/jet fuel mixture, while stirring. The stirring was continued for approximately two to three minutes. The sample was allowed to settle for about 5 minutes. The carbon was removed from the mixture by filtration with a Whatman 8

micron filter. The mixture was then tested for polymer concentration. [0046] The polymer adsorption of removal agents increased with graphite as

compared to activated carbon. Table 1 summarizes the % DRA adsorbed for both an

activated carbon group (7 samples), and a graphite group (1 sample). The highest removal effectiveness of the 8 removal agents tested was 49.90 % (with "Graphite 3739"), which corresponds to a polymer adsorption capacity of 0.034 %(wt). FIG. 2 compares the effectiveness of removing DRA using the Grad Add/Stir and Quick

Add/Stir methods for the 8 commonly tested removal agents. The Grad Add/Stir method gave superior results in 5 of the 8 carbons tested. The Quick Add/Stir method

gave superior results in 3 of the 8 carbons tested. FIG. 2 further demonstrates that

graphite is more effective at DRA removal than activated carbon, regardless of the method employed.

[0047] The removal agents listed in Table 1 are derived from numerous sources, including wood, coconut and other shells, peat, bituminous coal, lignite coal, and

anthracite coal. Each carbon source material differs in surface area, pore size, density,

and strength characteristics.

Table 1

[0048] Based on the foregoing, a gradual or incremental add/stir procedure is more efficient in removing DRA from more viscous hydrocarbon fuels, such as jet fuel.

EXAMPLE 3 [0049] The Grad Add/Stir method was used in this example. About 100 ml of jet

fuel comprising about 8.36 ppm of FLO^® XS - sheared DRA (manufactured by Baker

Petrolite) was stirred with a magnetic stir bar, to create a moderate vortex. Increments of about 0.02 to about 0.1 gram of a removal agent were placed in the agitating

DRA/jet fuel mixture, while stirring, until a total of about 1.0 g had been added. The

stirring was continued for approximately two to three minutes. The sample was

allowed to settle for about 5 minutes. The carbon was removed from the mixture by

filtration with a Whatman 8 micron filter. The mixture was then tested for polymer

concentration.

[0050] The polymer adsorption of removal agents increased with graphite as compared to activated carbon. Table 2 (in Example 4) summarizes the % DRA adsorbed for both an activated carbon group (34 samples), and a graphite group (9

samples). FIG. 3 is a graphical representation of the effectiveness of graphites to remove sheared DRA from jet fuel. Table 2 further summarizes the % adsorption

capacity for both an activated carbon group, and a graphite group. For sheared DRA, the % adsorption capacity of a given carbon = (0.000857)*(% polymer removed). This formula is derived using the initial polymer concentration, volume of DRA/fuel

used in the experiment, weight of carbon used in the experiment, and density of the DRA/fuel used.

[0051] As shown in FIG. 3, graphites are more effective at removing sheared polymer than activated carbons. The highest removal effectiveness of the 43 removal

agents tested was 36.30% (with "Graphite 3739"), which corresponds to a polymer adsorption capacity of 0.031 %(wt).

EXAMPLE 4

[0052] The Quick Add/Stir method was used in this example. About 100 ml of jet

fuel comprising about 8.36 ppm of FLO^® XS - sheared DRA was stirred with a magnetic stir bar, to create a moderate vortex. Once the removal agent had cooled, about 1.0 g of the removal agent was placed in the agitating DRA/jet fuel mixture, while stirring. The stirring was continued for approximately two to three minutes.

The sample was allowed to settle for about 5 minutes. The carbon was removed from

the mixture by filtration with a Whatman 8 micron filter. The mixture was then tested

for polymer concentration.

[0053] The polymer adsorption of removal agents increased with graphite as

compared to activated carbon. Table 2 summarizes the % DRA adsorbed for both an activated carbon group (7 samples), and a graphite group (1 sample). The highest removal effectiveness of the 8 removal agents tested was 42.10 % (with "Graphite

3739"), which corresponds to a polymer adsorption capacity of 0.040 %(wt). FIG. 4

compares the effectiveness of removing DRA using the Grad Add/Stir and Quick

Add/Stir methods for the 8 commonly tested removal agents. The Grad Add/Stir

method gave superior results in 5 of the 8 carbons tested. The Quick Add/Stir method gave superior results in 3 of the 8 carbons tested. FIG. 4 further demonstrates that

[0054] FIG. 5 demonstrates the effectiveness of the removal agents to remove both sheared and unsheared FLO^® XS from jet fuel. All removal agents perform better removing unsheared polymer over sheared polymer. Only the most effective removal agents at removing unsheared polymer were effective at removing sheared polymer.

Table 2

[0055] Persons of ordinary skill in the art will recognize that many modifications may be made to the present application without departing from the spirit and scope of the present application. The embodiment described herein is meant to be illustrative only and should not be taken as limiting the application.

Claims

We claim: 1. A method of removing drag reducer additive from a liquid hydrocarbon fuel, said method comprising:

providing a contaminated liquid hydrocarbon fuel comprising a concentration of a drag reducer additive (DRA); contacting said contaminated liquid hydrocarbon fuel with a quantity of one or

more graphite effective to substantially reduce said concentration of

DRA, said contacting occurring under conditions effective to produce a clean liquid hydrocarbon fuel.

2. The method of claim 1 wherein said graphite comprises a graphite powder.

3. The method of claim 1 wherein said graphite comprises a particulate

having an average diameter of from about 1 micron to about 100 microns.

4. The method of claim 1 wherein said graphite comprises an adsorption

capacity for said DRA of about 0.01 wt.% or more at from about 8 to about 12 ppm

DRA concentration and at about lg activated carbon/100 ml fuel, said DRA being selected from the group consisting of sheared and unsheared DRA.

5. The method of claim 1 wherein said graphite comprises an adsorption capacity for DRA of about 0.02 wt.% or more at from about 8 to about 12 ppm DRA

concentration and at about lg activated carbon/100 ml fuel, said DRA being selected

from the group consisting of sheared and unsheared DRA.

6. The method of claim 1 wherein said graphite comprises an adsorption capacity for sheared DRA of about 0.025 wt.% or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

7. The method of claim 1 wherein said graphite comprises an adsorption capacity for unsheared DRA of about 0.04 wt.% or more at from about 8 to about 12

ppm DRA concentration and at about lg activated carbon/100 ml fuel.

8. The method of claim 1 wherein said graphite produces a % polymer

removal for unsheared DRA of about 25% or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

9. The method of claim 1 wherein said graphite produces a % polymer

removal for DRA of about 30% or more at from about 8 to about 12 ppm DRA

from the group consisting of sheared and unsheared DRA.

10. The method of claim 1 wherein said graphite produces a % polymer

removal for sheared DRA of about 35% or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

11. The method of claim 1 wherein said graphite produces a % DRA

removal for unsheared DRA of about 40% or more at about lg activated carbon/100

ml fuel.

12. The method of claim 1 wherein said graphite produces a % DRA removal for unsheared DRA of about 50% or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

13. The method of claim 1 wherein said graphite is selected from the group consisting of GRAPHITE 2126, GRAPHITE 2139, GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5526, GRAPHITE 5539, GRAPHTTE 9026, GRAPHTTE 9039, and GRAPHTTE GA-17.

14. The method of claim 1 wherein said graphite is selected from the group consisting of GRAPHITE 2126, GRAPHITE 2139, GRAPHITE 3726, GRAPHTTE 3739, GRAPHITE 5539, GRAPHTTE 9039, and GRAPHITE GA-17.

15. The method of claim 1 wherein said graphite is selected from the group

consisting of GRAPHITE 2139, GRAPHITE 3726, GRAPHITE 3739, GRAPHITE

5539, GRAPHTTE 9039, and GRAPHITE GA-17.

16. The method of claim 1 wherein said graphite is selected from the group consisting of GRAPHTTE 2139 and GRAPHITE 3739.

17. A method of removing drag reducer additive from a liquid

hydrocarbon fuel, said method comprising:

providing a contaminated liquid hydrocarbon fuel comprising a concentration

of a drag reducer additive (DRA);

contacting said contaminated liquid hydrocarbon fuel with a quantity of one or more activated carbon effective to having an adsorption capacity for DRA of about 0.014 or more at from about 8 to about 12 ppm DRA

concentration and at about lg activated carbon/100 ml fuel, said DRA

being sheared or unsheared, said contacting occurring under conditions

effective to produce a clean liquid hydrocarbon fuel.

18. The method of claim 17 wherein said activated carbon has an adsorption capacity for sheared DRA of 0.018% or more.

19. The method of claim 17 wherein said activated carbon has an adsorption capacity for DRA of about 0.020% or more, said DRA being selected from the group consisting of sheared and unsheared DRA.

20. The method of claim 17 wherein said activated carbon has an adsorptioncapacity for DRA of 0.025%, said DRA being selected from the group consisting of sheared and unsheared DRA.

21. The method of claim 17 wherein said activated carbon has an

adsorptioncapacity for DRA of about 0.030%, said DRA being selected from the

group consisting of sheared and unsheared DRA.

22. The method of claim 17 wherein said activated carbon comprises an

activated carbon powder.

23. The method of claim 17 wherein said activated carbon comprises a

particulate having an average diameter of from about 1 micron to about 100 microns.

24. The method of claim 17 wherein said activated carbon produces a %

polymer removal for DRA of about 20% or more at from about 8 to about 12 ppm

DRA concentration and at about lg activated carbon/100 ml fuel, said DRA being

selected from the group consisting of sheared and unsheared DRA.

25. The method of claim 17 wherein said activated carbon produces a %

polymer removal for unsheared DRA of about 30% or more at from about 8 to about

12 ppm DRA concentration and at about lg activated carbon/100 ml fuel, said DRA

being selected from the group consisting of sheared and unsheared DRA.

26. The method of claim 17 wherein said activated carbon produces a % polymer removal for unsheared DRA of about 40% or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

27. The method of claim 17 wherein said activated carbon is selected from the group consisting of CALGON ADP, CALGON COLORSORB, CALGON WPX,

NORIT A SUPRA, NORIT CA 1, NORTTN FGD, NORTT HDB, SXO POWDER, and CARBON 5565.

28. The method of claim 17 wherein said activated carbon is selected from the group consisting of CALGON WPX, NORIT A SUPRA, NORTT CAl , NORIT

FGD, NORIT HDB , SXO POWDER and CARBON 5565.

29. The method of claim 17 wherein said activated carbon is selected from

the group consisting of NORIT A SUPRA, NORIT CAl, NORIT FGD, and NORIT HDB.

30. A method of removing drag reducer additive from a liquid hydrocarbon fuel, said method comprising:

providing a contaminated liquid hydrocarbon fuel comprising a concentration of a drag reducer additive (DRA), said DRA comprising

polyalphaolefin produced by solution polymerization;

contacting said contaminated liquid hydrocarbon fuel with a quantity of removal agent under conditions effective to produce a clean liquid

hydrocarbon fuel, said removal agent being selected from the group

consisting of one or more graphite and one or more activated carbon having an adsorptioncapacity for said DRA of about 0.014 or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

31. The method of claim 30 wherein said graphite comprises an adsorption capacity for DRA of about 0.02 wt.% or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel, said DRA being selected from the group consisting of sheared and unsheared DRA.

32. The method of claim 30 wherein said graphite comprises an

adsorptioncapacity for unsheared DRA of about 0.04 wt.% or more at from about 8 to

about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

33. The method of claim 30 wherein said graphite produces a % polymer removal for unsheared DRA of about 25% or more at from about 8 to about 12 ppm

DRA concentration and at about lg activated carbon/100 ml fuel.

34. The method of claim 30 wherein said graphite produces a % polymer

removal for DRA of about 30% or more at from about 8 to about 12 ppm DRA

from the group consisting of sheared and unsheared DRA.

35. The method of claim 30 wherein said graphite produces a % DRA removal for unsheared DRA of about 40% or more at about lg activated carbon/100 ml fuel.

36. The method of claim 30 wherein said graphite produces a % DRA

removal for unsheared DRA of about 50% or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

37. The method of claim 30 wherein said removal agent comprises graphite selected from the group consisting of GRAPHITE 2126, GRAPHITE 2139,

GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5526, GRAPHTTE 5539, GRAPHITE 9026, GRAPHTTE 9039, and GRAPHTTE GA-17.

38. The method of claim 30 wherein said removal agent comprises

graphite selected from the group consisting of GRAPHITE 2126, GRAPHITE 2139,

GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5539, GRAPHITE 9039, and GRAPHITE GA-17.

39. The method of claim 30 wherein said removal agent comprises

graphite selected from the group consisting of GRAPHITE 2139, GRAPHITE 3726,

GRAPHTTE 3739, GRAPHTTE 5539, GRAPHITE 9039, and GRAPHITE GA-17.

40. The method of claim 30 wherein said removal agent comprises graphite selected from the group consisting of GRAPHITE 2139 and GRAPHITE

3739.

41. The method of claim 30 wherein said removal agent is activated carbon selected from the group consisting of CALGON ADP, CALGON COLORSORB ,

CALGON WPX, NORTT A SUPRA, NORIT CA 1 , NORTTN FGD, NORIT HDB,

SXO POWDER, and CARBON 5565.

42. The method of claim 30 wherein said removal agent is activated carbon

selected from the group consisting of CALGON WPX, NORTT A SUPRA, NORIT

CAl, NORTT FGD, NORIT HDB, SXO POWDER and CARBON 5565.

43. The method of claim 30 wherein said removal agent is activated carbon selected from the group consisting of NORIT A SUPRA, NORIT CAl , NORIT FGD, and NORIT HDB.

44. A method of removing drag reducer additive from a liquid hydrocarbon fuel, said method comprising:

providing a contaminated liquid hydrocarbon fuel comprising a concentration

of a drag reducer additive (DRA) comprising polymerized linear alpha

olefin (LAO) monomers having from about 6 to about 12 carbon

atoms, wherein said LAO monomers comprise two different LAO's

which differ in number of carbon atoms by 6; contacting said contaminated liquid hydrocarbon fuel with a quantity of a removal agent under conditions effective to produce a clean liquid

hydrocarbon fuel, said removal agent being selected from the group

consisting of one or more graphite and one or more activated carbon

having an adsorptioncapacity for said DRA of about 0.014 or more at

from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

45. The method of claim 44 wherein said graphite comprises an adsorption capacity for DRA of about 0.02 wt.% or more at from about 8 to about 12 ppm DRA

from the group consisting of sheared and unsheared DRA.

46. The method of claim 44 wherein said graphite comprises an adsorption capacity for unsheared DRA of about 0.04 wt.% or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

47. The method of claim 44 wherein said graphite produces a % polymer removal for unsheared DRA of about 25% or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

48. The method of claim 44 wherein said graphite produces a % polymer removal for DRA of about 30% or more at from about 8 to about 12 ppm DRA

concentration and at about lg activated carbon/100 ml fuel, said DRA being selected from the group consisting of sheared and unsheared DRA.

49. The method of claim 44 wherein said graphite produces a % DRA

removal for unsheared DRA of about 40% or more at about lg activated carbon/100

ml fuel.

50. The method of claim 44 wherein said graphite produces a % DRA removal for unsheared DRA of about 50% or more at from about 8 to about 12 ppm

DRA concentration and at about lg activated carbon/100 ml fuel.

51. The method of claim 44 wherein said removal agent comprises

graphite selected from the group consisting of GRAPHITE 2126, GRAPHITE 2139,

GRAPHITE 3726, GRAPHTTE 3739, GRAPHITE 5526, GRAPHITE 5539, GRAPHITE 9026, GRAPHITE 9039, and GRAPHTTE GA-17.

52. The method of claim 44 wherein said removal agent comprises

graphite selected from the group consisting of GRAPHITE 2126, GRAPHITE 2139,

GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5539, GRAPHITE 9039, and GRAPHITE GA-17.

53. The method of claim 44 wherein said removal agent comprises graphite selected from the group consisting of GRAPHITE 2139, GRAPHITE 3726,

GRAPHITE 3739, GRAPHITE 5539, GRAPHITE 9039, and GRAPHITE GA-17.

54. The method of claim 44 wherein said removal agent comprises

graphite selected from the group consisting of GRAPHTTE 2139 and GRAPHITE

3739.

55. The method of claim 44 wherein said removal agent is activated carbon

selected from the group consisting of CALGON ADP, CALGON COLORSORB , CALGON WPX, NORIT A SUPRA, NORIT CA 1 , NORITN FGD, NORIT HDB ,

SXO POWDER, and CARBON 5565.

56. The method of claim 44 wherein said removal agent is activated carbon

selected from the group consisting of CALGON WPX, NORIT A SUPRA, NORTT

CAl, NORIT FGD, NORTT HDB, SXO POWDER and CARBON 5565.

57. The method of claim 44 wherein said removal agent is activated carbon selected from the group consisting of NORIT A SUPRA, NORIT CAl , NORIT FGD, and NORIT HDB.

58. A method of removing drag reducer additive from a liquid hydrocarbon

fuel, said method comprising: providing a contaminated liquid hydrocarbon fuel comprising a concentration

of a drag reducer additive (DRA) comprising polymerized linear alpha

olefin (LAO) monomers having from about 2 to about 40 carbon atoms;

contacting said contaminated liquid hydrocarbon fuel with a quantity of a removal agent under conditions effective to produce a clean liquid hydrocarbon fuel, said removal agent being selected from the group consisting of one or more graphite and one or more activated carbon having an adsorptioncapacity for said DRA of about 0.014 or more at from about 8 to about 12 ppm DRA concentration and at about lg

activated carbon/100 ml fuel.

59. The method of claim 58 wherein said LAO monomers have from about

2 to about 30 carbon atoms.

60. The method of claim 58 wherein said LAO monomers have from about 4 to about 20 carbon atoms.

61. The method of claim 58 wherein said LAO monomers have from about

6 to about 12 carbon atoms.

62. The method of claim 58 wherein said graphite comprises an adsorption capacity for DRA of about 0.02 wt.% or more at from about 8 to about 12 ppm DRA

from the group consisting of sheared and unsheared DRA.

63. The method of claim 58 wherein said graphite comprises an adsorptioncapacity for unsheared DRA of about 0.04 wt.% or more at from about 8 to

about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

64. The method of claim 58 wherein said graphite produces a % polymer removal for unsheared DRA of about 25% or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel.

65. The method of claim 58 wherein said graphite produces a % polymer

removal for DRA of about 30% or more at from about 8 to about 12 ppm DRA concentration and at about lg activated carbon/100 ml fuel, said DRA being selected

from the group consisting of sheared and unsheared DRA.

66. The method of claim 58 wherein said graphite produces a % DRA

removal for unsheared DRA of about 40% or more at about lg activated carbon/100 ml fuel.

67. The method of claim 58 wherein said graphite produces a % DRA

removal for unsheared DRA of about 50% or more at from about 8 to about 12 ppm

DRA concentration and at about lg activated carbon/100 ml fuel.

68. The method of claim 58 wherein said graphite comprises an adsorption capacity for DRA of about 0.02 wt.% or more at from about 8 to about 12 ppm DRA

from the group consisting of sheared and unsheared DRA.

69. The method of claim 58 wherein said graphite produces a % polymer

removal for DRA of about 30% or more at from about 8 to about 12 ppm DRA

from the group consisting of sheared and unsheared DRA.

70. The method of claim 58 wherein said removal agent comprises

graphite selected from the group consisting of GRAPHITE 2126, GRAPHITE 2139, GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5526, GRAPHITE 5539, GRAPHITE 9026, GRAPHITE 9039, and GRAPHITE GA-17.

71. The method of claim 58 wherein said removal agent comprises

graphite selected from the group consisting of GRAPHITE 2126, GRAPHTTE 2139, GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5539, GRAPHITE 9039, and GRAPHITE GA-17.

72. The method of claim 58 wherein said removal agent comprises graphite selected from the group consisting of GRAPHITE 2139, GRAPHITE 3726,

GRAPHITE 3739, GRAPHITE 5539, GRAPHITE 9039, and GRAPHTTE GA-17.

73. The method of claim 58 wherein said removal agent comprises graphite selected from the group consisting of GRAPHITE 2139 and GRAPHITE

3739.

74. The method of claim 58 wherein said removal agent is activated carbon

selected from the group consisting of CALGON ADP, CALGON COLORSORB,

CALGON WPX, NORIT A SUPRA, NORIT CA 1 , NORITN FGD, NORIT HDB , SXO POWDER, and CARBON 5565.

75. The method of claim 58 wherein said removal agent is activated carbon

selected from the group consisting of CALGON WPX, NORIT A SUPRA, NORIT CAl, NORIT FGD, NORTT HDB, SXO POWDER and CARBON 5565.

76. The method of claim 58 wherein said removal agent is activated carbon

selected from the group consisting of NORTT A SUPRA, NORIT CAl , NORIT FGD,

and NORIT HDB.

77. The method of claim 58 wherein said removal agent comprises graphite selected from the group consisting of GRAPHITE 2126, GRAPHTTE 2139, GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5526, GRAPHTTE 5539, GRAPHTTE 9026, GRAPHITE 9039, and GRAPHITE GA-17.

78. The method of claim 58 wherein said removal agent comprises graphite selected from the group consisting of GRAPHITE 2139 and GRAPHTTE

3739.

79. The method of claim 58 wherein said removal agent is activated carbon

selected from the group consisting of CALGON ADP, CALGON COLORSORB,

CALGON WPX, NORIT A SUPRA, NORIT CA 1, NORITN FGD, NORIT HDB,

SXO POWDER, and CARBON 5565.

80. The method of claim 58 wherein said removal agent is activated carbon

selected from the group consisting of NORIT A SUPRA, NORIT CAl , NORIT FGD, and NORIT HDB.

81. The method of any of claims 1 and 2-80 wherein the liquid

hydrocarbon fuel has a boiling range of from about 150 °F to about 750 °F.

82. The method of any of claims 1 and 2-80 wherein said liquid

hydrocarbon fuel is selected from the group consisting of liquefied natural gas (LNG), liquefied petroleum gas (LPG), motor gasoline, aviation gasoline, distillate fuels such as diesel fuel and home heating oil, kerosene, jet fuel, No. 2 oil, residual fuel, No. 6

fuel, or bunker fuel.

83. The method of claims 1 and 2-80 wherein the liquid hydrocarbon fuel is selected from the group consisting of diesel fuel, jet fuel, aviation gasoline, and motor gasoline.

84. The method of claims 1 and 2-80 wherein the liquid hydrocarbon fuel is jet fuel.

85. The method of any of claims 1 and 2-80 wherein the DRA is FLO ^® XS .

86. The method of claim 84 wherein the DRA is FLO ^® XS .

87. The method of any of claims 1 and 2-80 wherein said conditions comprise adding said quantity of said one or more effective graphites to said contaminated liquid hydrocarbon fuel in increments with agitation.

88. The method of claim 81 wherein said conditions comprise adding said

quantity of said one or more effective graphites to said contaminated liquid

hydrocarbon fuel in increments with agitation.

89. The method of claim 82 wherein said conditions comprise adding said

quantity of said one or more effective graphites to said contaminated liquid

hydrocarbon fuel in increments with agitation.

90. The method of claim 83 wherein said conditions comprise adding said quantity of said one or more effective graphites to said contaminated liquid

hydrocarbon fuel in increments with agitation.

91. The method of claim 84 wherein said conditions comprise adding said quantity of said one or more effective graphites to said contaminated liquid

hydrocarbon fuel in increments with agitation.

92. The method of claim 85 wherein said conditions comprise adding said quantity of said one or more effective graphites to said contaminated liquid hydrocarbon fuel in increments with agitation.

93. The method of claim 86 wherein said conditions comprise adding said quantity of said one or more effective graphites to said contaminated liquid

hydrocarbon fuel in increments with agitation.

94. The method of claim 87 wherein said conditions comprise adding said

quantity of said one or more effective graphites to said contaminated liquid hydrocarbon fuel in increments with agitation.

95. A method for selecting a drag reducer additive for a liquid hydrocarbon

fuel comprising:

providing one or more samples of liquid hydrocarbon fuel comprising a single candidate DRA; and,

determining whether said single candidate DRA is removed from said liquid

hydrocarbon fuel by a removal agent selected from the group

consisting of a graphite and an activated carbon having an

adsorptioncapacity for DRA of about 0.014 or more at from about 8 to

about 12 ppm DRA concentration and at about lg activated carbon/100

ml fuel; and, selecting as said DRA only candidates which are removed from said liquid

hydrocarbon fuel by said removal agent.

96. The method of claim 95 wherein said liquid hydrocarbon fuel in said

samples is jet fuel.

97. The method of claims 95 and 96 wherein said removal agent is activated carbon selected from the group consisting of CALGON ADP, CALGON COLORSORB, CALGON WPX, NORIT A SUPRA, NOR T CA 1, NORITN FGD, NORTT HDB , SXO POWDER, and CARBON 5565.

98. The method of claims 95 and 96 wherein said removal agent is

activated carbon selected from the group consisting of CALGON WPX, NORTT A

SUPRA, NORTT CAl, NORTT FGD, NORTT HDB, SXO POWDER and CARBON

5565.

99. The method of claims 95 and 96 wherein said removal agent is

activated carbon selected from the group consisting of NORIT A SUPRA, NORIT

CAl, NORTT FGD, and NORIT HDB.

100. The method of claims 95 and 96 wherein said removal agent is graphite

selected from the group consisting of GRAPHITE 2126, GRAPHITE 2139, GRAPHTTE 3726, GRAPHITE 3739, GRAPHTTE 5526, GRAPHITE 5539,

GRAPHITE 9026, GRAPHITE 9039, and GRAPHITE GA-17.

101. The method of claims 95 and 96 wherein said removal agent is graphite

selected from the group consisting of GRAPHITE 2126, GRAPHITE 2139,

GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5539, GRAPHITE 9039, and

GRAPHITE GA-17.

102. The method of claims 95 and 96 wherein said removal agent is graphite

selected from the group consisting of GRAPHTTE 2139, GRAPHTTE 3726,

GRAPHITE 3739, GRAPHITE 5539, GRAPHITE 9039, and GRAPHITE GA-17.

103. The method of claims 95 and 96 wherein said removal agent comprises GRAPHITE 2139 104. The method of claims 95 and 96 wherein said removal agent comprises

and GRAPHITE 3739.

105. A removal agent for removing drag reducer from a liquid hydrocarbon fuel, the removal agent comprising activated carbon selected from the group

consisting of CALGON ADP, CALGON COLORSORB, CALGON WPX, NORIT A

SUPRA, NORTT CA 1, NORITN FGD, NORTT HDB, SXO POWDER, and

CARBON 5565.

106. A removal agent for removing drag reducer from a liquid hydrocarbon fuel, the removal agent comprising activated carbon selected from the group

consisting of CALGON WPX, NORIT A SUPRA, NORIT CAl , NORIT FGD,

NORTT HDB, SXO POWDER and CARBON 5565.

107. A removal agent for removing drag reducer from a liquid hydrocarbon

fuel, the removal agent comprising activated carbon selected from the group

consisting of NORTT A SUPRA, NORIT CAl , NORTT FGD, and NORIT HDB .

108. A removal agent for removing drag reducer from a liquid hydrocarbon

fuel, the removal agent comprising graphite selected from the group consisting of

GRAPHITE 2126, GRAPHITE 2139, GRAPHITE 3726, GRAPHITE 3739,

GRAPHITE 5526, GRAPHITE 5539, GRAPHITE 9026, GRAPHITE 9039, and

GRAPHITE GA-17.

109. A removal agent for removing drag reducer from a liquid hydrocarbon fuel, the removal agent comprising graphite selected from the group consisting of GRAPHITE 2126, GRAPHITE 2139, GRAPHITE 3726, GRAPHITE 3739, GRAPHTTE 5539, GRAPHITE 9039, and GRAPHTTE GA-17.

110. A removal agent for removing drag reducer from a liquid hydrocarbon fuel, the removal agent comprising graphite selected from the group consisting of

GRAPHITE 2139, GRAPHITE 3726, GRAPHITE 3739, GRAPHITE 5539, GRAPHITE 9039, and GRAPHITE GA-17.

111. A removal agent for removing drag reducer from a liquid hydrocarbon

GRAPHITE 2139 and GRAPHTTE 3739.