U.S. patent application number 15/228070 was filed with the patent office on 2017-06-29 for processes for producing high-viscosity compounds as rheology modifiers, and compositions produced therefrom.
The applicant listed for this patent is API Intellectual Property Holdings, LLC. Invention is credited to Hisako KUREBAYASHI, Jean-Pierre MONCLIN.
Application Number | 20170183554 15/228070 |
Document ID | / |
Family ID | 57944100 |
Filed Date | 2017-06-29 |
United States Patent
Application |
20170183554 |
Kind Code |
A1 |
MONCLIN; Jean-Pierre ; et
al. |
June 29, 2017 |
PROCESSES FOR PRODUCING HIGH-VISCOSITY COMPOUNDS AS RHEOLOGY
MODIFIERS, AND COMPOSITIONS PRODUCED THEREFROM
Abstract
A process is provided for producing a biomass-derived rheology
modifier, comprising: providing a pretreated feedstock comprising
cellulose-rich solids; refining the cellulose-rich solids in a
first high-intensity refining unit, generating refined cellulose
solids; gelling the refined cellulose solids in a second
high-intensity refining unit, thereby generating gelled cellulose
solids; and homogenizing the gelled cellulose solids in a
high-shear homogenizer, thereby generating a biomass-derived
rheology modifier. The pretreated feedstock may include kraft pulp,
sulfite pulp, AVAP.RTM. pulp, soda pulp, mechanical pulp,
thermomechanical pulp, and/or chemimechanical pulp, derived from
wood or lignocellulosic biomass. The pretreated feedstock may be
GP3+.RTM. pulp, obtained from steam or hot-water extraction of
lignocellulosic biomass. These rheology modifiers may be utilized
in a wide variety of applications, including water-based or
oil-based hydraulic fracturing fluid formulations, as gelling
agents. These rheology modifiers are biodegradable, and their
production does not directly involve chemicals other than biomass
and water.
Inventors: |
MONCLIN; Jean-Pierre;
(Atlanta, GA) ; KUREBAYASHI; Hisako; (Griffin,
GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
API Intellectual Property Holdings, LLC |
Atlanta |
GA |
US |
|
|
Family ID: |
57944100 |
Appl. No.: |
15/228070 |
Filed: |
August 4, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62200952 |
Aug 4, 2015 |
|
|
|
62222611 |
Sep 23, 2015 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C09K 8/62 20130101; C04B
28/02 20130101; C08H 8/00 20130101; C08B 37/0057 20130101; C04B
2103/44 20130101; C04B 28/02 20130101; C08B 15/00 20130101; C09K
8/035 20130101; C04B 40/0064 20130101; C09K 8/90 20130101; C09K
8/68 20130101; C04B 24/38 20130101 |
International
Class: |
C09K 8/035 20060101
C09K008/035; C08B 15/00 20060101 C08B015/00; C09K 8/62 20060101
C09K008/62 |
Claims
1. A process for producing a biomass-derived rheology modifier from
cellulosic biomass, said process comprising: (a) providing a
feedstock comprising cellulosic biomass; (b) digesting said
feedstock with a reaction solution including steam and/or hot water
in a digestor under effective reaction conditions to produce a
digested stream containing cellulose-rich solids, hemicellulose
oligomers, and lignin; (c) refining said cellulose-rich solids in a
first high-intensity refining unit, thereby generating refined
cellulose solids; (d) washing said refined cellulose solids
following step (c), and/or washing said digested stream prior to
step (c) followed by said refining, thereby generating washed
refined cellulose solids; (e) gelling said washed refined cellulose
solids in a second high-intensity refining unit, thereby generating
gelled cellulose solids; and (f) homogenizing said gelled cellulose
solids in a high-shear homogenizer, thereby generating a
biomass-derived rheology modifier.
2. The process of claim 1, said process further comprising wet or
dry cleaning said feedstock prior to step (b).
3. The process of claim 1, wherein step (b) is conducted at a
digestion temperature from about 140.degree. C. to about
210.degree. C.
4. The process of claim 1, wherein step (b) is conducted for a
digestion time from about 5 minutes to about 45 minutes.
5. The process of claim 1, wherein step (b) is conducted at a
liquid/solid weight ratio from about 2 to about 6.
6. The process of claim 1, said process further comprising a
hot-blow pressure reduction of said digested stream, following step
(b).
7. The process of claim 1, said process further comprising a
cold-blow pressure reduction of said digested stream, following
step (b).
8. The process of claim 1, wherein said first high-intensity
refining unit includes disks.
9. The process of claim 1, wherein said first high-intensity
refining unit includes a conical plate.
10. The process of claim 1, wherein said first high-intensity
refining unit transfers energy to said cellulose-rich solids in an
amount from about 20 kW/ton to about 200 kW/ton (bone-dry
basis).
11. The process of claim 1, wherein washing in step (d) is
conducted at a temperature from about 18.degree. C. to about
95.degree. C.
12. The process of claim 1, wherein washing in step (d) utilizes a
pressurized screw press.
13. The process of claim 1, wherein said second high-intensity
refining unit includes disks.
14. The process of claim 1, wherein said second high-intensity
refining unit includes a conical plate.
15. The process of claim 1, wherein said second high-intensity
refining unit transfers energy to said washed refined cellulose
solids in an amount from about 20 kW/ton to about 200 kW/ton
(bone-dry basis).
16. The process of claim 1, wherein said high-shear homogenizer
transfers a shear force equivalent to a shear force produced under
a pressure from about 10,000 psig to about 25,000 psig.
17. The process of claim 1, wherein step (e) is conducted at a
different location than steps (a)-(d) and/or step (f) is conducted
at a different location than steps (a)-(e).
18. The process of claim 1, wherein said biomass-derived rheology
modifier is characterized by a particle size from about 5 microns
to about 100 microns.
19. A process for producing a biomass-derived rheology modifier
from cellulosic biomass, said process comprising: (a) providing a
pretreated feedstock comprising cellulose-rich solids; (b) refining
said cellulose-rich solids in a first high-intensity refining unit,
thereby generating refined cellulose solids; (c) optionally washing
said refined cellulose solids following step (b), and/or optionally
washing said digested stream prior to step (b) followed by said
refining, thereby generating washed refined cellulose solids; (d)
gelling said washed refined cellulose solids in a second
high-intensity refining unit, thereby generating gelled cellulose
solids; and (e) homogenizing said gelled cellulose solids in a
high-shear homogenizer, thereby generating a biomass-derived
rheology modifier.
20. The process of claim 19, wherein said pretreated feedstock is
pulp derived from wood or lignocellulosic biomass.
Description
PRIORITY DATA
[0001] This non-provisional patent application claims priority to
U.S. Provisional Patent App. No. 62/200,952, filed Aug. 4, 2015 and
to U.S. Provisional Patent App. No. 62/222,611, filed Sep. 23,
2015, each of which is hereby incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention generally relates to processes for
preparing high-viscosity cellulosic compounds from lignocellulosic
biomass.
BACKGROUND OF THE INVENTION
[0003] Biomass refining (or biorefining) has become more prevalent
in industry. Cellulose fibers and sugars, hemicellulose sugars,
lignin, syngas, and derivatives of these intermediates are being
utilized for chemical and fuel production. Indeed, we now are
observing the commercialization of integrated biorefineries that
are capable of processing incoming biomass much the same as
petroleum refineries now process crude oil. Underutilized
lignocellulosic biomass feedstocks have the potential to be much
cheaper than petroleum, on a carbon basis, as well as much better
from an environmental life-cycle standpoint.
[0004] Lignocellulosic biomass is the most abundant renewable
material on the planet and has long been recognized as a potential
feedstock for producing chemicals, fuels, and materials.
Lignocellulosic biomass normally comprises primarily cellulose,
hemicellulose, and lignin. Cellulose and hemicellulose are natural
polymers of sugars, and lignin is an aromatic/aliphatic hydrocarbon
polymer reinforcing the entire biomass network. Some forms of
biomass (e.g., recycled materials) do not contain
hemicellulose.
[0005] Despite being the most available natural polymer on earth,
it is only recently that cellulose has gained prominence as a
nanostructured material, in the form of nanocrystalline cellulose
(NCC), nanofibrillar cellulose (NFC), and bacterial cellulose (BC).
Nanocellulose and microcellulose are being developed for use in a
wide variety of applications such as polymer reinforcement,
anti-microbial films, biodegradable food packaging, printing
papers, pigments and inks, paper and board packaging, barrier
films, adhesives, biocomposites, wound healing, pharmaceuticals and
drug delivery, textiles, water-soluble polymers, construction
materials, recyclable interior and structural components for the
transportation industry, rheology modifiers, low-calorie food
additives, cosmetics thickeners, pharmaceutical tablet binders,
bioactive paper, pickering stabilizers for emulsion and particle
stabilized foams, paint formulations, films for optical switching,
and detergents.
[0006] Oil and natural gas are common fossil-based resources used
for the production of transportation fuels, heat and power,
materials, chemicals, adhesives, pharmaceuticals, polymers, fibers
and other products. Since the first oil well drilled in 1859 and
the introduction of the internal combustion engine, the United
States has been a major producer and consumer of fossil
resources.
[0007] In 2010, the US produced over 2 billion barrels of oil and
26.8 trillion cubic feet of natural gas worth over $180 and $110
billion, respectively. A significant amount of this production can
be attributed to advances in horizontal drilling and hydraulic
fracturing. Previously unrecoverable deposits have been freed up
ensuring access to decades of domestic natural gas and oil.
[0008] Oil and natural gas deposits are located all across the
United States and the World. It is estimated that the total amount
of technically recoverable natural gas resources worldwide is
22,600 trillion cubic feet of which shale gas is 6,622 trillion
cubic feet or nearly 30% (World Shale Gas Resources: An Initial
Assessment of 14 Regions Outside the United States, U.S. Department
of Energy and Energy Information Administration, 2011). Wells are
drilled hundreds of meters deep in order to gain access to the
resources. Once drilled, new wells or old unproductive wells are
hydraulically fractured to stimulate production.
[0009] Drilling fluids or muds are used during the initial well
bore to cool the bit, lubricate the drill string, suspend and
transport cuttings, control hydrostatic pressure and maintain
stability. Drilling fluids are typically water-based or oil-based
but can be pneumatic. Water or oil is the main ingredient in liquid
drilling fluids. Barite, clay, polymers, thinners, surfactants,
inorganic chemicals, bridging materials, lost circulation materials
and specialized chemicals are also added to engineer drilling fluid
properties.
[0010] Hydraulic fracturing was developed in the 1940s to increase
productivity of oil and gas wells. Hydraulic fracturing creates and
maintains cracks within oil and gas formations providing a clear
path for oil and gas to flow. Fracturing can be performed in
vertical and horizontal wells. During a fracturing operation,
perforations are made through cement casing into the oil and gas
formation using explosive charges. Fracturing fluids are injected
into the well at high pressures to create new cracks while further
expanding and elongating the cracks (Hydraulic Fracturing:
Unlocking America's Natural Gas Resources, American Petroleum
Institute, 2010).
[0011] Fracturing fluids are composed primarily of water (87-94%)
and proppant such as sand (4-9%). Sand mixed with the fracturing
fluids is used to prop open formation cracks and maintain a clear
path for oil and natural gas. The remaining fracturing fluid
(0.5-3%) is composed of chemicals that aid the fracturing process.
Chemical additives are mixed into the drilling fluid depending on
the well and formation properties. Chemicals are used to dissolve
minerals, reduce friction, prevent scaling, maintain fluid
properties (viscosity, pH, etc.), eliminate bacteria (biocide),
suspend the sand, prevent precipitation of metal oxides, prevent
corrosion, stabilize fluid, formation and wellbore, thicken fluid
(gelling agent) and break down the gel (breaker).
[0012] Hydraulic fracturing fluid is made in a step-wise procedure
and carefully engineered to accomplish the fracking process. In its
most basic form, a gelling agent (typically gaur gum) is first
added to water and hydrated. Next a breaker (oxidant or enzyme) is
added which will break the gel bonds after being pumped into the
well. A crosslinking agent such as borate is then added to the
solution which immediately forms a viscous, gelled solution. The
purpose of the gel is to suspend the proppant while being pumped
into the well where it is wedged into formation fractures propping
them apart.
[0013] Eventually the fracturing fluid must be removed from the
well leaving the proppant in the fractures to maintain open
channels for oil or gas to flow through. In order to pump the
fracturing fluid out of the well and leave the proppant behind the
viscous gel must be broken down to a viscosity less than 100 cP.
Since the fracturing fluid is pumped into the well in stages,
precise amounts of breaker are mixed with the fracturing fluid to
break the entire gel solution simultaneously. Once the entire gel
is broken the fracturing fluid is pumped back to the surface where
it is stored in retention ponds or hauled away from the well for
treatment and disposal.
[0014] What are needed in the art are methods and products that
minimize environmental impact and costs of drilling, treating and
hydraulic fracturing for oil and gas. Improved compositions are
desired, including biomass-derived compositions. While
cellulose-based materials have been generally recognized as
possible components in drilling and fracturing fluids, heretofore
there has not been an economical process to provide cellulose-based
materials, with adjustable properties for different types of fluids
and additives.
SUMMARY OF THE INVENTION
[0015] The present invention addresses the aforementioned needs in
the art.
[0016] In some variations, a process is provided for producing a
biomass-derived rheology modifier from cellulosic biomass, the
process comprising:
[0017] (a) providing a feedstock comprising cellulosic biomass;
[0018] (b) digesting the feedstock with a reaction solution
including steam and/or hot water in a digestor under effective
reaction conditions to produce a digested stream containing
cellulose-rich solids, hemicellulose oligomers, and lignin;
[0019] (c) refining the cellulose-rich solids in a first
high-intensity refining unit, thereby generating refined cellulose
solids;
[0020] (d) washing the refined cellulose solids following step (c),
and/or washing the digested stream prior to step (c) followed by
the refining, thereby generating washed refined cellulose
solids;
[0021] (e) gelling the washed refined cellulose solids in a second
high-intensity refining unit, thereby generating gelled cellulose
solids; and
[0022] (f) homogenizing the gelled cellulose solids in a high-shear
homogenizer, thereby generating a biomass-derived rheology
modifier.
[0023] In some embodiments, the process further comprises wet or
dry cleaning the feedstock prior to step (b). In some embodiments,
the process further comprises reducing size of the feedstock prior
to step (b).
[0024] Step (b) may be conducted at a digestion temperature from
about 140.degree. C. to about 210.degree. C., such as from about
175.degree. C. to about 195.degree. C. Step (b) may be conducted
for a digestion time from about 5 minutes to about 45 minutes, such
as from about 15 minutes to about 30 minutes. Step (b) may be
conducted at a liquid/solid weight ratio from about 2 to about 6,
such as from about 3 to about 4.
[0025] In some embodiments, the process further comprises a
hot-blow pressure reduction of the digested stream, following step
(b). Alternatively, a cold-blow pressure reduction of the digested
stream, following step (b), may be employed.
[0026] The first high-intensity refining unit may utilize disks or
a conical plate, for example. In some embodiments, the first
high-intensity refining unit transfers energy to the cellulose-rich
solids in an amount from about 20 kW/ton to about 200 kW/ton
(bone-dry basis), such as from about 75 kW/ton to about 150 kW/ton
(bone-dry basis).
[0027] In some embodiments, washing in step (d) is conducted at a
temperature from about 18.degree. C. to about 95.degree. C., such
as from about 70.degree. C. to about 80.degree. C. Washing in step
(d) may utilize a pressurized screw press.
[0028] In some embodiments, the second high-intensity refining unit
utilizes disks or a conical plate. The first and second
high-intensity refining units preferably have different patterns
with different groove and dam dimensions. In some embodiments, the
second high-intensity refining unit transfers energy to the washed
refined cellulose solids in an amount from about 20 kW/ton to about
200 kW/ton (bone-dry basis), such as from about 75 kW/ton to about
150 kW/ton (bone-dry basis).
[0029] In some embodiments, the high-shear homogenizer (or other
unit operation capable of imparting shear) transfers a shear force
equivalent to a shear force produced under a pressure from about
10,000 psig to about 25,000 psig, such as from about 16,000 psig to
about 18,000 psig.
[0030] The washed refined cellulose solids may be stored for a
period of time prior to step (e), which may be conducted at a
different location than steps (a)-(d). In some embodiments, not
step (f) is conducted at a different location than steps
(a)-(e).
[0031] The biomass-derived rheology modifier may be characterized
by a particle size from about 5 microns to about 100 microns, such
as from about 15 microns to about 50 microns.
[0032] Other variations of the invention provide a process for
producing a biomass-derived rheology modifier from cellulosic
biomass, the process comprising:
[0033] (a) providing a pretreated feedstock comprising
cellulose-rich solids;
[0034] (b) refining the cellulose-rich solids in a first
high-intensity refining unit, thereby generating refined cellulose
solids;
[0035] (c) optionally washing the refined cellulose solids
following step (b), and/or optionally washing the digested stream
prior to step (b) followed by the refining, thereby generating
washed refined cellulose solids;
[0036] (d) gelling the washed refined cellulose solids in a second
high-intensity refining unit, thereby generating gelled cellulose
solids; and
[0037] (e) homogenizing the gelled cellulose solids in a high-shear
homogenizer, thereby generating a biomass-derived rheology
modifier.
[0038] The pretreated feedstock may include kraft pulp derived from
wood or lignocellulosic biomass. The pretreated feedstock may
include sulfite pulp derived from wood or lignocellulosic biomass.
The pretreated feedstock may include soda pulp derived from wood or
lignocellulosic biomass. The pretreated feedstock may include
mechanical pulp, thermomechanical pulp, and/or chemimechanical pulp
derived from wood or lignocellulosic biomass.
[0039] In certain embodiments, the pretreated feedstock is
GP3+.RTM. pulp, such as material is obtained from steam or
hot-water extraction of lignocellulosic biomass, as described
above. In other certain embodiments, the pretreated feedstock is
AVAP.RTM. pulp, such as material obtained from fractionation of
lignocellulosic biomass in the presence of water, an acid catalyst,
and a solvent for lignin.
[0040] The present disclosure provides a water-based hydraulic
fracturing fluid formulation or additive comprising a
biomass-derived rheology modifier produced in accordance with the
processes described herein.
[0041] The present disclosure provides an oil-based hydraulic
fracturing fluid formulation or additive comprising a
biomass-derived rheology modifier produced in accordance with the
processes described herein.
[0042] The present disclosure provides a water-based drilling fluid
formulation or additive comprising a biomass-derived rheology
modifier produced in accordance with the processes described
herein.
[0043] The present disclosure provides an oil-based drilling fluid
formulation or additive comprising a biomass-derived rheology
modifier produced in accordance with the processes described
herein.
BRIEF DESCRIPTION OF THE FIGURES
[0044] FIG. 1 is a simplified block-flow diagram depicting the
process of some embodiments of the present invention.
[0045] FIG. 2 is a simplified block-flow diagram depicting the
process of some embodiments of the present invention.
[0046] FIG. 3 is a simplified block-flow diagram depicting the
process of various embodiments of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0047] This description will enable one skilled in the art to make
and use the invention, and it describes several embodiments,
adaptations, variations, alternatives, and uses of the invention.
These and other embodiments, features, and advantages of the
present invention will become more apparent to those skilled in the
art when taken with reference to the following detailed description
of the invention in conjunction with any accompanying drawings.
[0048] As used in this specification and the appended claims, the
singular forms "a," "an," and "the" include plural referents unless
the context clearly indicates otherwise. Unless defined otherwise,
all technical and scientific terms used herein have the same
meaning as is commonly understood by one of ordinary skill in the
art to which this invention belongs. All composition numbers and
ranges based on percentages are weight percentages, unless
indicated otherwise. All ranges of numbers or conditions are meant
to encompass any specific value contained within the range, rounded
to any suitable decimal point.
[0049] Unless otherwise indicated, all numbers expressing reaction
conditions, stoichiometries, concentrations of components, and so
forth used in the specification and claims are to be understood as
being modified in all instances by the term "about." Accordingly,
unless indicated to the contrary, the numerical parameters set
forth in the following specification and attached claims are
approximations that may vary depending at least upon a specific
analytical technique.
[0050] The term "comprising," which is synonymous with "including,"
"containing," or "characterized by" is inclusive or open-ended and
does not exclude additional, unrecited elements or method steps.
"Comprising" is a term of art used in claim language which means
that the named claim elements are essential, but other claim
elements may be added and still form a construct within the scope
of the claim.
[0051] As used herein, the phrase "consisting of" excludes any
element, step, or ingredient not specified in the claim. When the
phrase "consists of" (or variations thereof) appears in a clause of
the body of a claim, rather than immediately following the
preamble, it limits only the element set forth in that clause;
other elements are not excluded from the claim as a whole. As used
herein, the phrase "consisting essentially of" limits the scope of
a claim to the specified elements or method steps, plus those that
do not materially affect the basis and novel characteristic(s) of
the claimed subject matter.
[0052] With respect to the terms "comprising," "consisting of" and
"consisting essentially of," where one of these three terms is used
herein, the presently disclosed and claimed subject matter may
include the use of either of the other two terms. Thus in some
embodiments not otherwise explicitly recited, any instance of
"comprising" may be replaced by "consisting of" or, alternatively,
by "consisting essentially of."
[0053] Some variations are premised on the discovery of a
surprisingly simple process for converting lignocellulosic biomass
into fermentable sugars. Biomass may be subjected to a steam or
hot-water soak to dissolved hemicelluloses, with or without acetic
acid recycle. This step is followed by mechanical refining, such as
in a hot-blow refiner, of the cellulose-rich (and lignin-rich)
solids. The refined solids are then enzymatically hydrolyzed to
generate sugars. A stripping step for removing fermentation
inhibitors in the hydrolysate may be included.
[0054] Certain exemplary embodiments of the invention will now be
described. These embodiments are not intended to limit the scope of
the invention as claimed. The order of steps may be varied, some
steps may be omitted, and/or other steps may be added. Reference
herein to first step, second step, etc. is for illustration
purposes only. In the drawings, dotted lines denote optional
streams or units.
[0055] Some variations of the present invention are premised on
relatively simple processes to generate high-viscosity compounds
made from cellulosic biomass. The high-viscosity compounds will act
as rheology modifiers when mixed in small proportions with
different fluids, such as drilling fluids, paints, etc.
[0056] In hydraulic fracturing fluid formulations, particularly
water-based formulations but also for oil-based formulations, these
compositions will function as gelling agents. Easy mixing and
handling allows for customization for each reservoir
characteristics. Several properties of these rheology modifiers
present strong advantages when compared to current available
products on the market. Some of these properties are higher thermal
stability, strong shear thinning, thixotropic qualities, and water
solubility. Another important property of these new compounds is
that they are biodegradable, and their production does not directly
involve any chemicals other than biomass and water.
[0057] Generally, the feedstock could be "residue biomass" with
high cellulose content, typically between 25% and 75% on biomass
weight, but not limited. In some cases, wood pulp may be used as
the starting feedstock. Some embodiments employ the following
steps:
[0058] 1. After dry and/or wet cleaning, the biomass is reduced in
size, typically using a set of knives, a shredder, a hammer mill,
or a combination of these.
[0059] 2. Then the cleaned and size-reduced biomass is submitted to
a hot-water treatment allowing the extraction of solubilized
compounds. This thermal treatment is made continuously or in batch,
subjecting the biomass with pressurized steam or liquid hot water
at a temperature between 140.degree. C. and 210.degree. C., such as
between 175.degree. C. and 195.degree. C. during a period of time
between 5 minutes and 45 minutes, such as between 15 minutes and 30
minutes. The ratio of liquid (water and condensed steam) to solid
(bone dry biomass) is between 2 to 1 to 6 to 1, such as between 3
to 1 to 3.5 to 1. This step could be referred to as "cooking,"
"digesting," "deconstruction," or "fractionation," for example.
[0060] 3. Following there may be a "blow" (i.e. pressure reduction)
which may be a gradual pressure reduction referred to as a "cold
blow." If it is a sudden pressure reduction, this may be referred
to as a "hot blow."
[0061] 4. Next there is a stage of additional size reduction with
the purpose of increasing the specific surface of the fiber by
mechanical fiber cutting using a "high intensity pulp refiner"
which may include a conical plate or disks. During this stage,
there is a need for energy transfer to the pulp between 20 kw/ton
BD and 200 kw/ton BD, preferably between 75 kw/ton BD and 150
kw/ton BD.
[0062] 5. A pulp washing operation may be inserted either between
the blow stage and the high-intensity refiner or following the
high-intensity pulp refiner. The pulp washing is to separate the
pulp (the solid fraction) and the steam-water solubilized product
during the thermal treatment, i.e. the liquid fraction. This may be
achieved in a batch process or in a continuous operation. In either
case, the pulp is further washed with water. Washing water may be
at a temperature between 18.degree. C. and 95.degree. C.,
preferably between 70.degree. C. and 80.degree. C., for
example.
[0063] 6. Following the optional water wash, which may be either
countercurrent or cocurrent, the pulp may be either directed to the
high-intensity pulp refiner or to a storage bin. Countercurrent
continuous pulp washing preferably will be made immediately after
the hot blow, using one or more of several commercially available
solid-liquid separation systems, such as a pressurized screw
press.
[0064] 7. Next, the pulp is sent to a second disk refiner, to
strongly transform the defibrillation of the pulp until a gel-type
product is generated by gelation. During this stage, there is a
need for energy transfer to the pulp between 20 kw/ton BD and 200
kw/ton BD, preferably between 75 kw/ton BD and 150 kw/ton BD. The
configuration of the plates for the first refiner ("high-intensity
pulp refiner") and the second one ("second disk refiner")
preferably includes different patterns with different groove and
dam dimensions ratios.
[0065] 8. Next the gel-type product is sent to a unit operation
containing a high-shear homogenizer, where high-intensity shear is
applied similar to an equivalent shear produced under 10,000 psig
and 25,000 psig, such as between 16,000 psig and 18,000 psig.
[0066] This process creates high-viscosity compounds with sizes
generally between 1 micron and 100 microns, such as between 15
micron and 50 microns. These new compounds produced without any
chemicals (other than biomass and water) may be used as rheology
modifiers and, being based on cellulose, are biodegradable.
[0067] The process presents several advantages. The design allows
the process to be fully integrated in one line from the startup
with the biomass through production of the high-viscosity
compounds. Or the process may be separated in several modules
located in different geographical sites.
[0068] In some variations, a process is provided for producing a
biomass-derived rheology modifier from cellulosic biomass, the
process comprising:
[0069] (a) providing a feedstock comprising cellulosic biomass;
[0070] (b) digesting the feedstock with a reaction solution
including steam and/or hot water in a digestor under effective
reaction conditions to produce a digested stream containing
cellulose-rich solids, hemicellulose oligomers, and lignin;
[0071] (c) refining the cellulose-rich solids in a first
high-intensity refining unit, thereby generating refined cellulose
solids;
[0072] (d) washing the refined cellulose solids following step (c)
(as shown in FIG. 1), and/or washing the digested stream prior to
step (c) followed by the refining (as shown in FIG. 2), thereby
generating washed refined cellulose solids;
[0073] (e) gelling the washed refined cellulose solids in a second
high-intensity refining unit, thereby generating gelled cellulose
solids; and
[0074] (f) homogenizing the gelled cellulose solids in a high-shear
homogenizer, thereby generating a biomass-derived rheology
modifier.
[0075] The biomass feedstock may be selected from hardwoods,
softwoods, forest residues, agricultural residues (such as
sugarcane bagasse), industrial wastes, consumer wastes, or
combinations thereof. In any of these processes, the feedstock may
include sucrose. In some embodiments with sucrose present in the
feedstock, a majority of the sucrose is recovered as part of the
fermentable sugars.
[0076] Some embodiments of the invention enable processing of
"agricultural residues," which for present purposes is meant to
include lignocellulosic biomass associated with food crops, annual
grasses, energy crops, or other annually renewable feedstocks.
Exemplary agricultural residues include, but are not limited to,
corn stover, corn fiber, wheat straw, sugarcane bagasse, rice
straw, oat straw, barley straw, miscanthus, energy cane, or
combinations thereof. In certain embodiments, the agricultural
residue is sugarcane bagasse, energy cane bagasse, sugarcane straw,
or energy cane straw.
[0077] In some embodiments, the process further comprises wet or
dry cleaning the feedstock prior to step (b). In some embodiments,
the process further comprises reducing size of the feedstock prior
to step (b). The process may include size reduction, hot-water
soaking, dewatering, steaming, or other operations, upstream of the
digestor.
[0078] Step (b) may be conducted at a digestion temperature from
about 140.degree. C. to about 210.degree. C., such as from about
175.degree. C. to about 195.degree. C. Step (b) may be conducted
for a digestion time from about 5 minutes to about 45 minutes, such
as from about 15 minutes to about 30 minutes. Step (b) may be
conducted at a liquid/solid weight ratio from about 2 to about 6,
such as about 3, 3.5, 4, 4.5, or 5.
[0079] In some embodiments, the reaction solution comprises steam
in saturated, superheated, or supersaturated form. In some
embodiments, the reaction solution comprises hot water.
[0080] The pressure in the pressurized vessel may be adjusted to
maintain the aqueous liquor as a liquid, a vapor, or a combination
thereof. Exemplary pressures are about 1 atm to about 30 atm, such
as about 3 atm, 5 atm, 10 atm, or 15 atm.
[0081] The solid-phase residence time for the digestor (pressurized
extraction vessel) may vary from about 2 minutes to about 4 hours,
such as about 5 minutes to about 1 hour. In certain embodiments,
the digestor residence time is controlled to be about 5 to 15
minutes, such as 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 minutes.
The liquid-phase residence time for the digestor may vary from
about 2 minutes to about 4 hours, such as about 5 minutes to about
1 hour. The vapor-phase residence time for the digestor may vary
from about 1 minute to about 2 hours, for example, such as about 3
minutes to about 30 minutes. The solid-phase, liquid-phase, and
vapor-phase residence times may all be about the same, or they may
be independently controlled according to reactor-engineering
principles (e.g., recycling and internal recirculation
strategies).
[0082] In some embodiments, the process further comprises a
hot-blow pressure reduction of the digested stream, following step
(b). Alternatively, a cold-blow pressure reduction of the digested
stream, following step (b), may be employed.
[0083] To reduce pressure, a blow tank may be situated between the
digestor and the refining unit. In some embodiments, vapor is
separated from the blow tank, and heat is recovered from at least
some of the vapor. Optionally, at least some of the vapor is
compressed and returned to the digestor, and/or at least some of
the vapor is purged from the process. Note that "blow tank" should
be broadly construed to include not only a tank but any other
apparatus or equipment capable of allowing a pressure reduction in
the process stream. Thus a blow tank (or blow means) may be a tank,
vessel, section of pipe, valve, separation device, or other
unit.
[0084] Each mechanical refiner may be selected from the group
consisting of a hot-blow refiner, a hot-stock refiner, a disk
refiner, a conical refiner, a cylindrical refiner, an in-line
defibrator, a homogenizer, and combinations thereof. Mechanically
treating (refining) may employ one or more known techniques such
as, but by no means limited to, milling, grinding, beating,
sonicating, or any other means to reduce cellulose particle size.
Such refiners are well-known in the industry and include, without
limitation, Valley beaters, single disk refiners, double disk
refiners, conical refiners, including both wide angle and narrow
angle, cylindrical refiners, homogenizers, microfluidizers, and
other similar milling or grinding apparatus. See, for example,
Smook, Handbook for Pulp & Paper Technologists, Tappi Press,
1992.
[0085] The refining may be conducted at a wide range of solids
concentrations (consistency), including from about 2% to about 50%
consistency, such as about 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%,
12%, 15%, 20%, 30%, 35%, or 40% consistency.
[0086] Each mechanical refiner may be configured to transfer from
about 20 to about 200 kW/ton (i.e., kW refining power per ton
fiber, based on the solid phase that is converted to the refined
stream). In certain embodiments, the mechanical refiner is
configured to transfer from about 75 to about 150 kW refining power
per ton fiber. For example, a mechanical refiner with plates may be
adjusted by changing the plate type, gap, speed, etc. to achieve
these power inputs.
[0087] The extent of mechanical treatment may be monitored during
the process by any of several means. Certain optical instruments
can provide continuous data relating to the fiber length
distributions and % fines, either of which may be used to define
endpoints for the mechanical treatment step. The time, temperature,
and pressure may vary during mechanical treatment. For example, in
some embodiments, sonication for a time from about 5 minutes to 2
hours, at ambient temperature and pressure, may be utilized.
[0088] In some embodiments, a portion of the cellulose-rich solids
is converted to fibrillated and/or gelled while the remainder of
the cellulose-rich solids is not fibrillated and/or gelled. In
various embodiments, about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%,
90%, 95%, 99%, or substantially all of the cellulose-rich solids
are fibrillated and/or gelled.
[0089] The first high-intensity refining unit may utilize disks or
a conical plate, for example. In some embodiments, the first
high-intensity refining unit transfers energy to the cellulose-rich
solids in an amount from about 20 kW/ton to about 200 kW/ton
(bone-dry basis), such as from about 75 kW/ton to about 150 kW/ton
(bone-dry basis).
[0090] In some embodiments, washing in step (d) is conducted at a
temperature from about 18.degree. C. to about 95.degree. C., such
as from about 70.degree. C. to about 80.degree. C. Washing in step
(d) may utilize a pressurized screw press.
[0091] In some embodiments, the second high-intensity refining unit
utilizes disks or a conical plate. The first and second
high-intensity refining units preferably have different patterns
with different groove and dam dimensions. In some embodiments, the
second high-intensity refining unit transfers energy to the washed
refined cellulose solids in an amount from about 20 kW/ton to about
200 kW/ton (bone-dry basis), such as from about 75 kW/ton to about
150 kW/ton (bone-dry basis).
[0092] In some embodiments, the high-shear homogenizer (or other
unit operation capable of imparting shear) transfers a shear force
equivalent to a shear force produced under a pressure from about
1,000 psig to about 50,000 psig, such as about 10,000 psig to about
25,000 psig, such as about 15,000 psig to about 20,000 psig or
16,000 psig to 18,000 psig.
[0093] In some embodiments, the high-shear homogenizer (or other
unit operation capable of imparting shear) utilizes a shear rate of
about 100,000 s.sup.-1, 500,000 s.sup.-1, 1,000,000 s.sup.-1,
2,000,000 s.sup.-1, 3,000,000 s.sup.-1, 4,000,000 s.sup.-1,
5,000,000 s.sup.-1, 6,000,000 s.sup.-1, 7,000,000 s.sup.-1,
8,000,000 s.sup.-1, 9,000,000 s.sup.-1, or 10,000,000 s.sup.-1 or
higher.
[0094] The washed refined cellulose solids may be stored for a
period of time prior to step (e), which may be conducted at a
different location than steps (a)-(d). In some embodiments, not
step (f) is conducted at a different location than steps
(a)-(e).
[0095] The biomass-derived rheology modifier may be characterized
by a particle size (e.g., fiber or fibril length or effective
length) from about 1 microns to about 100 microns, such as from
about 1 micron to about 50 microns. In certain embodiments, a
majority (such as about 50%, 60%, 70%, 80%, 90%, or 95%) of the
particles are in the size (length) range of 10-20 microns. The
biomass-derived rheology modifier may include particles smaller
than 5 microns, such as 4, 3, 2, 1 microns or less in length (i.e.
nanoparticles). Particles larger than 100 microns in length, such
as 150, 200, 250, 300, 400, 500 microns or greater, may be present.
The width of the particles may be less than 1 micron, such as about
0.1 to about 1 microns. In various embodiments, regardless of the
particle length, the average width of the particles is from about
0.1 to about 10 microns, or about 0.5 to about 5 microns. In some
embodiments, particles are separated based on particle sizes or
ranges of sizes, by known separation techniques (e.g., filtering,
screening, flocculation, centrifugation, settling, etc.).
[0096] Some variations of this disclosure are premised on the
concept of integrating a product tank, vessel, reactor, or other
unit operation with a rotary positive-displacement pump, for
conveying nanocellulose precursor material. The rotary
positive-displacement pump is in material communication with the
integrated vessel so that material can be readily transferred to
the pump, similar to the benefits from an open-hopper arrangement
in the pump.
[0097] In some embodiments, "rotor-stator"-type rotary
positive-displacement pumps are utilized. These pumps are
characterized by two conveying elements to cause a sequence of
motion. The eccentric input screw features a circular cross section
and performs an oscillating rotary motion (the rotor). The
stationary second pumping element, the stator, features an internal
screw of the same geometric dimensions but with double the number
of helices. Due to the different number of helices and the
different pitches of the conveying elements, cavities are formed
that alternatingly open and close steadily with the rotary motion
of the rotor. As an example, a "Range BT" pump supplied by Seepex
GmbH (Bottrop, Germany) may be employed.
[0098] In certain variations, a rotary positive-displacement pump
feeds material into another unit for mechanical refining (e.g.,
disk refining or microfluidization). A vessel may be physically
integrated (in material communication) with the pump. Such vessel
may be a tank, reactor, separator, washer, and so on. The material
may be received into such vessel continuously, semi-continuously,
simulated-continuously, or batch-wise. The vessel may include some
type of level control, such as ultrasonic level measurement to
maintain optimum operation of the pump. The fill level may be
measured via an ultrasonic detector and transferred to a product
feed control via a transducer, for example.
[0099] Other variations of the invention provide a process for
producing a biomass-derived rheology modifier from cellulosic
biomass, the process comprising (e.g., see FIG. 3):
[0100] (a) providing a pretreated feedstock comprising cellulosic
biomass;
[0101] (b) refining the cellulose-rich solids in a first
high-intensity refining unit, thereby generating refined cellulose
solids;
[0102] (c) optionally washing the refined cellulose solids
following step (b), and/or optionally washing the digested stream
prior to step (b) followed by the refining, thereby generating
washed refined cellulose solids;
[0103] (d) gelling the washed refined cellulose solids in a second
high-intensity refining unit, thereby generating gelled cellulose
solids; and
[0104] (e) homogenizing the gelled cellulose solids in a high-shear
homogenizer, thereby generating a biomass-derived rheology
modifier.
[0105] The pretreated feedstock may include kraft pulp derived from
wood or lignocellulosic biomass. The pretreated feedstock may
include sulfite pulp derived from wood or lignocellulosic biomass.
The pretreated feedstock may include soda pulp derived from wood or
lignocellulosic biomass. The pretreated feedstock may include
mechanical pulp, thermomechanical pulp, and/or chemimechanical pulp
derived from wood or lignocellulosic biomass.
[0106] In certain embodiments, the pretreated feedstock is
GP3+.RTM. pulp, such as material is obtained from steam or
hot-water extraction of lignocellulosic biomass, as described
above. In other certain embodiments, the pretreated feedstock is
AVAP.RTM. pulp, such as material obtained from fractionation of
lignocellulosic biomass in the presence of water, an acid catalyst,
and a solvent for lignin.
[0107] The rheology modifier compounds are primarily
cellulose-based polymers, with some microcrystalline shape like
nanocellulose including some of the initial biomass lignin in the
structure. In some embodiments, the compound properties are
predominantly hydrophilic, allowing a strong stability of
water-based drilling fluid and water-based fracking fluids. In some
embodiments with lignin content and suitable high-intensity
refining, the compounds are hydrophobic, moderately hydrophobic, or
a combination of hydrophilic and hydrophobic.
[0108] The present disclosure provides a water-based hydraulic
fracturing fluid formulation or additive comprising a
biomass-derived rheology modifier produced in accordance with the
processes described herein.
[0109] The present disclosure provides an oil-based hydraulic
fracturing fluid formulation or additive comprising a
biomass-derived rheology modifier produced in accordance with the
processes described herein.
[0110] The present disclosure provides a water-based drilling fluid
formulation or additive comprising a biomass-derived rheology
modifier produced in accordance with the processes described
herein.
[0111] The present disclosure provides an oil-based drilling fluid
formulation or additive comprising a biomass-derived rheology
modifier produced in accordance with the processes described
herein.
[0112] The process may further include removal of one or more
fermentation inhibitors (such as acetic acid or furfural) by
stripping. This stripping may be conducted by treating the
hydrolyzed cellulose stream, prior to fermentation. Alternatively,
or additionally, the stripping may be conducted on a stream
following digestion, such as in the blow line.
[0113] The process in some embodiments further comprises a step of
fermenting the fermentable sugars, contained in the liquid phase
derived from the initial digestion, to a dilute fermentation
product. The process further may comprise concentration and
purification of the fermentation product. The fermentation product
may be selected from ethanol, n-butanol, 1,4-butanediol, succinic
acid, lactic acid, or combinations thereof. Also, a solid stream
containing lignin may be removed, either prior to fermentation or
downstream of fermentation.
[0114] A step may include conditioning of hydrolysate to remove
some or most of the volatile acids and other fermentation
inhibitors. The evaporation may include flashing or stripping to
remove sulfur dioxide, if present, prior to removal of volatile
acids. The evaporation step is preferably performed below the
acetic acid dissociation pH of 4.8, and most preferably a pH
selected from about 1 to about 2.5. In some embodiments, additional
evaporation steps may be employed. These additional evaporation
steps may be conducted at different conditions (e.g., temperature,
pressure, and pH) relative to the first evaporation step.
[0115] In some embodiments, some or all of the organic acids
evaporated may be recycled, as vapor or condensate, to the first
step (cooking step) to assist in the removal of hemicelluloses or
minerals from the biomass. This recycle of organic acids, such as
acetic acid, may be optimized along with process conditions that
may vary depending on the amount recycled, to improve the cooking
effectiveness.
[0116] A step may include recovering fermentable sugars, which may
be stored, transported, or processed. A step may include fermenting
the fermentable sugars to a co-product (the primary product being
rheology modifiers).
[0117] A step may include preparing solid residuals (containing
lignin) for combustion. This step may include refining, milling,
fluidizing, compacting, and/or pelletizing the dried, extracted
biomass. The solid residuals may be fed to a boiler in the form of
fine powder, loose fiber, pellets, briquettes, extrudates, or any
other suitable form. Using known equipment, solid residuals may be
extruded through a pressurized chamber to form uniformly sized
pellets or briquettes.
[0118] Following fermentation, residual solids (such as
distillation bottoms) may be recovered, or burned in solid or
slurry form, or recycled to be combined into the biomass pellets.
Use of the fermentation residual solids may require further removal
of minerals. Generally, any leftover solids may be used for
burning, after concentration of the distillation bottoms.
[0119] Alternatively, or additionally, the process may include
recovering the residual solids as a fermentation co-product in
solid, liquid, or slurry form. The fermentation co-product may be
used as a fertilizer or fertilizer component, since it will
typically be rich in potassium, nitrogen, and/or phosphorous.
[0120] The process may be continuous, semi-continuous, or batch.
When continuous or semi-continuous, the stripping column may be
operated countercurrently, cocurrently, or a combination
thereof.
[0121] The process may further comprise bleaching the
cellulose-rich solids prior to a refining step and/or as part of
refining. Alternatively, or additionally, the process may further
comprise bleaching the refined material, the gelled material, or
the homogenized material. Any known bleaching technology or
sequence may be employed, including enzymatic bleaching.
[0122] Rheology modifiers as provided herein may be incorporated
into drilling fluids, drilling fluid additives, fracturing fluids,
and fracturing fluid additives. The rheology modifiers may be
present in a wide variety of concentrations, such as from about
0.001 wt % to about 10 wt % or higher, e.g. about 0.01 wt %, 0.05
wt %, 0.1 wt %, 0.5 wt %, 1 wt %, or 2 wt %.
[0123] The invention, in some variations, is related to a group of
cellulosic compounds which could be used in different applications.
One of the applications is to use them as product enhancers of
drilling fluids. The rheology modifiers may serve one or more
functions in drilling fluids. For example, the rheology modifier
may serve as a gelling agent to increase viscosity, or a
viscosifier in general. The rheology modifier may serve as a
friction reducer. Also, rheology modifiers may be a drilling
polymer, displacing other polymers or adding to them.
[0124] Drilling fluids are fluids used in drilling in the natural
gas and oil industries, as well as other industries that use large
drilling equipment. The drilling fluids are used to lubricate,
provide hydrostatic pressure, keep the drill cool, and keep the
hole as clean as possible of drill cuttings. Rheology modifiers
provided herein are suitable as additives to these drilling
fluids.
[0125] In some embodiments, these rheology modifier compositions
provide one or more of the following functions or advantages:
[0126] Polymeric viscosifiers [0127] Predictable shear thinning
[0128] Rheology modifiers to enhance drilling efficiency [0129]
Provide increased viscosity of the fracturing fluid [0130] Provide
lower friction loss which will increase the rate of penetration by
reducing the injection pressure hence enhance reducing fracking
time [0131] Shear thinning [0132] Gelling agents [0133] Linear gels
[0134] Stable crosslinked products [0135] Friction reducers [0136]
Provide improved performance of proppant transport, and for well
cleanup [0137] Biodegradable [0138] Produced from biomass
[0139] In some embodiments, enzymes can be used as a "breaker" with
the compositions, to break down rheology modifiers after some
period of time or under certain conditions (e.g., temperature or
pH).
[0140] In some embodiments, lignosulfonates are incorporated for
enhanced lubricity in drilling applications. Also, the ability of
lignosulfonates to reduce the viscosity of mineral slurries can be
beneficial in oil drilling muds.
[0141] In some embodiments, native lignin or non-sulfonated lignin,
or non-sulfonated lignin derivatives, are incorporated into the
compositions.
[0142] Some embodiments provide a drilling fluid additive
comprising rheology modifiers.
[0143] Some embodiments provide a drilling fluid additive
comprising rheology modifiers, wherein the additive further
comprises lignosulfonates.
[0144] Some embodiments provide a drilling fluid additive
comprising rheology modifiers, wherein the additive further
comprises non-sulfonated lignin.
[0145] Some embodiments provide a drilling fluid additive
comprising rheology modifiers, wherein the additive further
comprises a crosslinking agent.
[0146] Some embodiments provide a drilling fluid additive
comprising crosslinked rheology modifiers and lignosulfonates.
[0147] Some embodiments provide drilling fluids comprising the
drilling fluid additives as disclosed. The drilling fluid may be a
water-based drilling fluid, an oil-based drilling fluid, or a
hybrid water-based/oil-based drilling fluid.
[0148] In various embodiments, the drilling fluid further comprises
one or more of a biomass-derived weighting material, a
biomass-derived filtration-control agent, a biomass-derived
rheology-control agent, a biomass-derived pH-control agent, a
biomass-derived lost-circulation material, a biomass-derived
surface-activity modifier, a biomass-derived lubricant, and a
biomass-derived flocculant, and/or a biomass-derived
stabilizer.
[0149] In some variations, the invention provides a method of using
a drilling fluid additive, the method comprising combining a
drilling fluid additive as disclosed into a base fluid to generate
a drilling fluid. In some variations, the invention provides a
method comprising introducing a disclosed drilling fluid additive
directly or indirectly into a geological formation.
[0150] In some variations, a method of drilling includes
introducing a drilling fluid additive directly or indirectly into a
geological formation, wherein the drilling fluid additive includes
an enzyme for degelling under effective conditions. In related
variations, a method of drilling includes introducing a drilling
fluid additive directly or indirectly into a geological formation,
and then later introducing an enzyme for degelling under effective
conditions.
[0151] Some variations provide a process for producing a drilling
fluid additive, the process comprising refining biomass under
effective pretreatment conditions and refining conditions to
generate a drilling fluid additive as disclosed. In some
embodiments, the effective pretreatment conditions include the
generation of lignosulfonic acids. Optionally, at least a portion
of the lignosulfonic acids are not removed and remain present in
the drilling fluid additive. In certain embodiments, the drilling
fluid additive comprises a liquid slurry derived from the process.
For example, the slurry may contain rheology modifiers derived from
the biomass as well as water and pretreatment chemicals (such as
acids, solvents, etc.).
[0152] Another application of these compositions is to use them as
product enhancers of hydraulic fracturing fluids. Improvement in
this purpose are particularly due to their impact in friction
reduction, in improved pumping of proppants at a higher rate, at
reduced pressure and predictable viscosity at high temperatures.
Additionally, these products are fully biodegradable; they are
produced from biomass, and are less susceptible to biofouling as
could be other products like galactomannan derivatives.
[0153] Rheology modifiers may be crosslinked for robust gelling in
fracking fluids. In some embodiments, crosslinking of rheology
modifiers gives a stronger gel with more hydration.
[0154] Biomass-derived ash (from the biomass structure) or sand
(from washing) may be used as a proppant, to displace mined
silica.
[0155] The present invention, in other variations, provides
fracturing fluid additives.
[0156] Some embodiments provide a fracturing fluid additive
comprising rheology modifiers.
[0157] Some embodiments provide a fracturing fluid additive
comprising rheology modifiers, wherein the additive further
comprises lignosulfonates.
[0158] Some embodiments provide a fracturing fluid additive
comprising rheology modifiers, wherein the additive further
comprises non-sulfonated lignin.
[0159] Some embodiments provide a fracturing fluid additive
comprising rheology modifiers, wherein the additive further
comprises a crosslinking agent.
[0160] Some embodiments provide a fracturing fluid additive
comprising crosslinked rheology modifiers and lignosulfonates.
[0161] Some embodiments provide a fracturing fluid comprising the
fracturing fluid additive as disclosed. The fracturing fluid may be
a water-based fracturing fluid, an oil-based fracturing fluid, or a
hybrid water-based/oil-based fracturing fluid.
[0162] The fracturing fluid may further include, in addition to a
disclosed fracturing fluid additive, one or more of a
biomass-derived acid (such as acetic acid, formic acid, levulinic
acid, and/or lignosulfonic acid), a biomass-derived corrosion
inhibitor (such as lignin or a lignin derivative), a
biomass-derived friction reducer (such as lignosulfonate or a
lignosulfonate derivative), a biomass-derived clay-control agent, a
biomass-derived crosslinking agent, a biomass-derived scale
inhibitor, a biomass-derived breaker, a biomass-derived
iron-control agent, a biomass-derived biocide (e.g., biomass
hydrolysate), and/or a biorefinery-derived source of recycled or
recovered water. Typically, the fracturing fluid carries, includes,
or is intended to be combined with a proppant, which may be a
biomass-derived proppant (such as ash contained in the structure of
biomass and/or sand, ash, or dirt collected with biomass).
[0163] Some variations of the invention provide a method of using a
fracturing fluid additive, the method comprising combining a
disclosed fracturing fluid additive into a base fluid to generate a
fracturing fluid. Some methods include introducing a fracturing
fluid additive directly or indirectly into a geological
formation.
[0164] In some variations, a process for producing a fracturing
fluid additive comprises refining biomass under effective
pretreatment conditions and refining conditions to generate a
fracturing fluid additive as disclosed. In some embodiments, the
pretreatment conditions include the generation of lignosulfonic
acids, which optionally are not entirely removed and are present in
the fracturing fluid additive. In some embodiments, the fracturing
fluid additive comprises a liquid slurry derived from the process.
For example, the slurry may contain rheology modifiers derived from
the biomass as well as water and pretreatment chemicals (e.g.,
solvents, acids, bases, and so on).
[0165] The rheology modifiers of some embodiments are characterized
by an average cellulose degree of polymerization from about 100 to
about 2000, such as from about 400 to about 1200 or from about 500
to about 800. In certain embodiments, the rheology modifiers are
free of enzymes.
[0166] The present disclosure, while directed to rheology modifiers
for use as additives and various compositions, is not limited to
rheology modifiers. The material produced by the multiple refining
steps (following biomass pretreatment) as disclosed, may be used in
a wide variety of applications. For example, the rheology modifier
may be incorporated into product selected from the group consisting
of a structural object, a foam, an aerogel, a polymer composite, a
carbon composite, a film, a coating, a coating precursor, a current
or voltage carrier, a filter, a membrane, a catalyst, a catalyst
substrate, a coating additive, a paint additive, an adhesive
additive, a cement additive, a paper coating, a thickening agent, a
rheological modifier, an additive for a drilling fluid, and
combinations or derivatives thereof.
[0167] Some embodiments provide products with applications for
sensors, catalysts, antimicrobial materials, current carrying and
energy storage capabilities. Cellulose crystals have the capacity
to assist in the synthesis of metallic and semiconducting
chains.
[0168] Some embodiments provide composites containing refined
cellulose and a carbon-containing material, such as (but not
limited to) lignin, graphite, graphene, or carbon aerogels.
[0169] Cellulose crystals may be coupled with the stabilizing
properties of surfactants and exploited for the fabrication of
architectures of various semiconducting materials.
[0170] The reactive surface of --OH side groups in refined
cellulose facilitates grafting chemical species to achieve
different surface properties. Surface functionalization allows the
tailoring of particle surface chemistry to facilitate
self-assembly, controlled dispersion within a wide range of matrix
polymers, and control of both the particle-particle and
particle-matrix bond strength. Composites may be transparent, have
tensile strengths greater than cast iron, and have very low
coefficient of thermal expansion. Potential applications include,
but are not limited to, barrier films, antimicrobial films,
transparent films, flexible displays, reinforcing fillers for
polymers, biomedical implants, pharmaceuticals, drug delivery,
fibers and textiles, templates for electronic components,
separation membranes, batteries, supercapacitors, electroactive
polymers, and many others.
[0171] Other applications suitable to the present invention include
reinforced polymers, high-strength spun fibers and textiles,
advanced composite materials, films for barrier and other
properties, additives for coatings, paints, lacquers and adhesives,
switchable optical devices, pharmaceuticals and drug delivery
systems, bone replacement and tooth repair, improved paper,
packaging and building products, additives for foods and cosmetics,
catalysts, and hydrogels.
[0172] Aerospace and transportation composites may benefit from
these rheology modifiers. Automotive applications include cellulose
composites with polypropylene, polyamide (e.g. Nylons), or
polyesters (e.g. PBT).
[0173] Rheology modifiers provided herein may be suitable as
strength-enhancing additives for renewable and biodegradable
composites. The cellulosic fibrillar structures may function as a
binder between two organic phases for improved fracture toughness
and prevention of crack formation for application in packaging,
construction materials, appliances, and renewable fibers.
[0174] Rheology modifiers provided herein are may be as transparent
and dimensional stable strength-enhancing additives and substrates
for application in flexible displays, flexible circuits, printable
electronics, and flexible solar panels. Cellulose is incorporated
into the substrate-sheets are formed by vacuum filtration, dried
under pressure and calandered, for example. In a sheet structure,
cellulose acts as a glue between the filler aggregates. The formed
calandered sheets are smooth and flexible.
[0175] Rheology modifiers provided herein may be suitable for
composite and cement additives allowing for crack reduction and
increased toughness and strength. Foamed, cellular
cellulose-concrete hybrid materials allow for lightweight
structures with increased crack reduction and strength.
[0176] Strength enhancement with cellulose increases both the
binding area and binding strength for application in high strength,
high bulk, high filler content paper and board with enhanced
moisture and oxygen barrier properties. The pulp and paper industry
in particular may benefit from rheology modifiers provided
herein.
[0177] Porous cellulose may be used for cellular bioplastics,
insulation and plastics and bioactive membranes and filters. Highly
porous cellulose materials are generally of high interest in the
manufacturing of filtration media as well as for biomedical
applications, e.g., in dialysis membranes.
[0178] Rheology modifiers provided herein may be suitable as
additives to improve the durability of paint, protecting paints and
varnishes from attrition caused by UV radiation.
[0179] Rheology modifiers provided herein are suitable as
thickening agents in food and cosmetics products. Rheology
modifiers can be used as a thixotropic, biodegradable,
dimensionally stable thickener (stable against temperature and salt
addition). Rheology modifiers materials provided herein may be
suitable as a Pickering stabilizer for emulsions and particle
stabilized foam.
[0180] The large surface area of these rheology modifiers in
combination with their biodegradability makes them attractive
materials for highly porous, mechanically stable aerogels.
[0181] In this detailed description, reference has been made to
multiple embodiments of the invention and non-limiting examples
relating to how the invention can be understood and practiced.
Other embodiments that do not provide all of the features and
advantages set forth herein may be utilized, without departing from
the spirit and scope of the present invention. This invention
incorporates routine experimentation and optimization of the
methods and systems described herein. Such modifications and
variations are considered to be within the scope of the invention
defined by the claims.
[0182] All publications, patents, and patent applications cited in
this specification are herein incorporated by reference in their
entirety as if each publication, patent, or patent application were
specifically and individually put forth herein.
[0183] Where methods and steps described above indicate certain
events occurring in certain order, those of ordinary skill in the
art will recognize that the ordering of certain steps may be
modified and that such modifications are in accordance with the
variations of the invention. Additionally, certain of the steps may
be performed concurrently in a parallel process when possible, as
well as performed sequentially.
[0184] Therefore, to the extent there are variations of the
invention, which are within the spirit of the disclosure or
equivalent to the inventions found in the appended claims, it is
the intent that this patent will cover those variations as well.
The present invention shall only be limited by what is claimed.
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