130 and depositing a matrix (e.g., carbon, phenolic resin, or any other desired matrix material) within and around the carbon fibers of the fibrous preform, and the carbonization process refers to the process of converting the fibers of the fibrous preform 130 into pure carbon fibers.

In various embodiments, a plurality of fibrous preforms 130 may be placed on top of one another with separator plates 150 and spacing stops 152 disposed between adjacent fibrous preforms 130. For example, the bottommost fibrous preform 130 may be placed on a base plate 154 at the bottom of carbonization furnace 148. A separator plate 150 may be placed on top of the bottommost fibrous preform 130. Another fibrous preform 130 may then be placed on the separator plate 150, and another separator plate 150 may be placed on that fibrous preform 130. A stack of fibrous preforms 130 and separator plates 150 may be constructed in this manner, with each fibrous preform 130 being separated from superjacent and subjacent fibrous preforms 130 by separator plates 150. Stops 152 may be placed between each of the separator plates 150. The stops 152 may comprise a height that is less than the thickness of the fibrous preform 130 prior to carbonization. Stops 152 may define a target thickness of the fibrous preform 130 after carbonization. In that regard, after the stack of fibrous preforms 130 is constructed, and before the carbonization process has started, gaps may exist between the stops 152 and adjacent separator plates 150. During carbonization, a compressive load may be applied to the fibrous preforms 130, thereby compressing the fibrous preforms 130 until stops 152 contact adjacent separator plates 150.

In various embodiments, compressive pressure may be applied to fibrous preforms 130 during the carbonization. The compressive pressure may be applied by placing a weight 156 over fibrous preforms 130, or by applying a compressive load to the fibrous preforms 130 by other suitable means. The compressive pressure may be applied along the direction of the z-fibers. It will be appreciated by those skilled in the art that the mass of weight 156 and/or the compressive force generated by weight 156 may vary depending on the size of fibrous preforms 130, the pre-carbonization fiber volume of fibrous preforms 130, the desired post-carbonization fiber volume of fibrous preforms 130, and/or the number fibrous preforms 130 being compressed. As used herein, “fiber volume” refers the percentage of the total volume of the fibrous preform that is formed by the fibers of the fibrous preform. For example, a fiber volume of 18% means the fibers of the fibrous preform form 18% of the total volume of fibrous preform. In various embodiments, after carbonization, fibrous preform 130 includes a fiber volume of between 10% and 50%. In various embodiments, after carbonization, fibrous preform 130 includes a fiber volume of between 15% and 25%. In various embodiments, fibrous preforms 130 having a low fiber volume may be desirable for the infiltration methods disclosed herein. In various embodiments, after carbonization, fibrous preform 130 may comprise a fiber volume of less than 25%. For example, in various embodiments, after carbonization, fibrous preform 130 may comprise a fiber volume of 21% or, in various embodiments, fibrous preform 130 may comprise a fiber volume of 18%.

After carbonization, fibrous preform 130, may be densified using, for example, CVI. In various embodiments, prior to densification, fibrous preform 130 is infiltrated with a slurry including a high specific heat particulate. For example, in various embodiments, fibrous preform 130 is infiltrated with a ceramic slurry (i.e., a slurry comprised of a liquid carrier and ceramic particulates). In various embodiments, the slurry infiltration process includes preparation of a slurry including a ceramic particulate (e.g., an aqueous B₄C-based slurry) and immersing the carbonized fibrous preform 130 into the slurry for a period of time sufficient for the particulate (e.g., the B₄C) to infiltrate the fibrous preform 130.

The slurry includes sacrificial fibers. For instance, the sacrificial fibers/particulates are mixed into the slurry. The sacrificial fibers may be a polyethylene or polyester fiber such that, in response to heating to carbon CVI temperatures (e.g., 100° F. and 205° F. (38° C. and 96° C.)) will burn. In various embodiments, the preform is heated up to 1000° C. in order to cause the sacrificial fibers for burn away, or decompose. When the sacrificial fibers are burned away, or decompose, channels are formed, thus improving carbon CVI infiltration. For instance, the channels provide a pathway for the CVI to get to in. However, polyester or polyethylene fibers may be too large to incorporate directly into the B₄C slurry. Accordingly, the sacrificial fibers may be injected into the fibrous preform 130. For instance, the sacrificial fibers may be injected using a syringe or other means, prior to completing B₄C slurry infiltration. By injecting using a syringe, the sacrificial fibers may be distributed in the matrix of the boron carbide.

Slurry may include high specific heat particulate and a liquid carrier (such as, for example, water and/or alcohol). In various embodiments, slurry may further include a high specific heat particulate, a binder (e.g., a polymeric adhesive or polyvinyl acetate), and a liquid carrier (e.g., water). It will be appreciated by those skilled in the art that liquid carriers other than water may be used and that the type and/or volume of liquid carrier and/or of binder may be selected based on the composition of the high specific heat particulate. In various embodiments, slurry may be a B₄C-based slurry and may be prepared by mixing B₄C powder in water with appropriate additives, such as wetting agents and dispersants. The B₄C powder may comprise particulates having an average particle sizes from sub-micron up to about 30 microns. As used in the previous context only, “about” means±5 microns.

The slurry further includes the sacrificial fibers. The sacrificial fibers are added to the solution of the slurry. In various embodiments, the sacrificial fibers make up 5% of the slurry solution. In various embodiments, the sacrificial fibers make up 10% of the slurry solution. For instance, the sacrificial fibers make up 0.5%-10% of the slurry. The sacrificial fibers may be a micro polyester particle. The slurry solution may be loaded into the syringe. A user may then use the syringe to inject the slurry, including the sacrificial fibers, into the fibrous preform 130. The user may inject the fibrous preform 130 in a plurality of locations. For instance, the user may inject/poke the fibrous preform 130 at ten locations. In various embodiments, a bank of syringes may be provided to operate as an assembly-line system to prepare multiple fibrous preforms may be injected simultaneously with the sacrificial fibers.

Infiltration using a syringe facilitates achieving a uniform distribution of the sacrificial fibers, which in turn improves carbon CVI infiltration once the fibers are burned around during the heat-up to carbon CVI process temperature. By raising the thermal capacity of the material, more energy may be absorbed per unit mass. Accordingly, the brakes may be manufactured smaller, for instance. Further, the friction and wear characteristics may be improved.

As described previously, the process illustrated and described with respect to FIG. 3 is the emission of off gases that include but are not limited to hydrogen (H₂) and carbon dioxide (CO₂). Referring now to FIG. 4, in accordance with various embodiments, a system 400 for energy recovery of converting recovered CO₂into other products is illustrated. In various embodiments, the C/C preform production process 402 utilizes natural gas such as methane (CH₄) 403 to perform various operations in the production of the aircraft brakes. However, in various embodiments, during the C/C preform production process 402, various off gases 404, i.e. hydrocarbons, are produced. Accordingly, in system 400, the C/C preform production process 402 feeds the various off gases 404, i.e., hydrocarbons, CO₂, H₂, and nitrogen (N₂), among others, into H₂separator 406. In various embodiments, H₂separator 406 separates H₂408 from the various off gases 404 using one or more of membrane separation, pressure swing absorption (PSA), captured by solid sorbents, or cryogenic distillation, among others. In various embodiments, the H₂separator 406 feeds the H₂408 into methanization reactor 410 and feeds the remaining off gases 412, i.e. heavier hydrocarbons, as well as CO₂and N₂, among others, into burner/steam generator 414.

In various embodiments, the burner/steam generator 414 burns the remaining off gases 412 utilizing air 416 to generate steam 418 from incoming water (H₂O) 420. In various embodiments, the steam 418 may be utilized to operate other components of the C/C preform production process 402. During the operations performed by the burner/steam generator 414, in addition to generating the steam 418, the burner/steam generator 414 generates byproducts 422, such as such as CO₂, H₂O, and N₂, among others, which the burner/steam generator 414 feeds into separator 424. Separator 424 may operate to separate the CO₂426 from the byproducts 422, which is fed into methanization reactor 410, to separate the N₂428 from the byproducts 422, which may be released into the atmosphere, and to separate the H₂O 430 from the byproducts 422, which may be fed into the burner/steam generator 414 along with H₂O 420. The separator 424 may one or more of absorption, adsorption, cryogenic distillation, captured by solid sorbents or solvents such as mono-ethanol amine (MEA), or membrane separation, among others for the separation process.

In various embodiments, the methanization reactor 410 utilizes the incoming H₂408 and CO₂426 to perform a methanization process in order to produce methane (CH₄) 432, which is fed into the C/C preform production process 402 or another system to perform various operations in the production the aircraft brakes, such as heat generation. In various embodiments, in the production of CH₄432, the methanization reactor 410 also produces heat and/or steam 434 in the form of a gas exhaust and/or steam exhaust, which is fed into heat recovery unit 440. In various embodiments, the heat recovery unit 440 may operate to utilize the heat and/or steam 434 to generate energy 442, i.e. heat, via thermal transfer to another fluid that, once heated, may be utilized as a heat transfer fluid. In various embodiments, the heat recovery unit 440 may feed the energy 442, i.e. the heat transfer fluid, via a closed loop process, to separator 424 in order for separator 424 to utilize the provided heat to separate the CO₂426 from the byproducts 422, which is fed into methanization reactor 410, to separate the N₂428 from the byproducts 422, which may be released into the atmosphere, and to separate the H₂O 430 from the byproducts 422, which may be fed into the burner/steam generator 414 along with H₂O 420. In various embodiments, the heat recovery unit 440 may operate to utilize the heat and/or steam 434 to generate energy 444, i.e. heat, via thermal transfer to another fluid that, once heated, may be utilized as a heat transfer fluid. In various embodiments, the heat recovery unit 440 may feed the energy 444, i.e. the heat transfer fluid, via a closed loop process, to the C/C preform production process 402 in order that the C/C preform production process 402 uses the heat for performing various operations in the production of the aircraft brakes.

In various embodiments, rather than using the heat and/or steam 434 to heat, via thermal transfer, another fluid, i.e. the heat transfer fluid, in various embodiments, the heat recovery unit 440 may feed the heat and/or steam 434 as energy 442, via a closed loop process, to separator 424 in order for separator 424 to separate the CO₂426 from the byproducts 422, which is fed into methanization reactor 410, to separate the N₂428 from the byproducts 422, which may be released into the atmosphere, and to separate the H₂O 430 from the byproducts 422, which may be fed into the burner/steam generator 414 along with H₂O 420. In various embodiments, rather than the heat recovery unit 440 using the heat and/or steam 434 to heat, via thermal transfer, another fluid, i.e. the heat transfer fluid, in various embodiments, the heat recovery unit 440 may feed the heat and/or steam 434 as energy 444, via a closed loop process, to the C/C preform production process 402 for use in performing various operations in the production of the aircraft brakes.

In various embodiments, the heat recovery unit 440 may operate to utilize the heat and/or steam 434 to operate a turbine of an electric generator, thereby producing energy 442, i.e. electricity. In various embodiments, the heat recovery unit 440 may feed the energy 442, i.e. the electricity, to separator 424 in order for separator 424 to utilize the energy 442 to produce electric heat to separate the CO₂426 from the byproducts 422, which is fed into methanization reactor 410, to separate the N₂428 from the byproducts 422, which may be released into the atmosphere, and to separate the H₂O 430 from the byproducts 422, which may be fed into the burner/steam generator 414 along with H₂O 420. In various embodiments, the heat recovery unit 440 may operate to utilize the heat and/or steam 434 to operate a turbine of an electric generator, thereby producing energy 444, i.e. electricity. In various embodiments, the heat recovery unit 440 may feed the energy 444, i.e. the electricity, to the C/C preform production process 402 to utilize the energy 442 to produce electric heat in order that the C/C preform production process 402 uses the heat for performing various operations in the production of the aircraft brakes.

In various embodiments, the heat recovery unit 440 using the heat and/or steam 434 to operate a turbine of an electric generator, thereby producing energy 442, 444, i.e. electricity, any excess energy, 446, i.e. electricity, may be fed into other processes within a plant where the C/C preform production process 402 operates or sold as excess energy to an electric provider via an electric grid. In various embodiments, excess steam 448 of the heat and/or steam 434 may then be condensed to generate H₂O 438, which may be fed into the burner/steam generator 414 along with H₂O 420 and H₂O 430. In various embodiments, the condensing may be performed by the heat recovery unit 440 in response the heat recovery unit 440 is able to remove enough heat from the heat and/or steam 434. In various embodiments, in response the heat recovery unit 440 not being able to remove enough heat from the heat and/or steam 434, then the excess steam 448 may be fed to condenser 436. In various embodiments, the condenser 436 condenses the excess steam 448. Accordingly, system 400 provides for CO₂emission recovery by converting the recovered CO₂into other products that may be utilized by the C/C preform production process 402.

Referring now to FIG. 5, in accordance with various embodiments, a system 500 for energy recovery of converting recovered CO₂into other products is illustrated. In various embodiments, the C/C preform production process 502 utilizes natural gases such as methane (CH₄) 503 to perform various operation in the production the aircraft brakes. However, in various embodiments, during the C/C preform production process 502 various off gases 504, i.e. hydrocarbons, are produced. Accordingly, in system 500, the C/C preform production process 502 feeds the various off gases 504, i.e., hydrocarbons, CO₂, H₂, and nitrogen (N₂), among others, into burner/steam generator 514. In various embodiments, the burner/steam generator 514 burns the various off gases 504 utilizing air 516 to generate steam 518 from incoming water (H₂O) 520. In various embodiments, the steam 518 may be utilized to operate other components of the C/C preform production process 502. During the operations performed by the burner/steam generator 514, in addition to generating the steam 518, the burner/steam generator 514 generates byproducts 522, such as CO₂, H₂O, and N₂, among others, which the burner/steam generator 514 feeds into separator 524. Separator 524 may operate to separate the CO₂526 from the byproducts 522, which is fed into methanization reactor 510, to separate the N₂528 from the byproducts 522, which may be released into the atmosphere, and to separate the H₂O 530 from the byproducts 522, which may be fed into the burner/steam generator 514 along with H₂O 420. The separator 524 may be one or more of absorption, adsorption, cryogenic distillation, captured by solid sorbents or solvents such as mono-ethanol amine (MEA), or membrane separation, among others for the separation process.

In various embodiments, the methanization reactor 510 utilizes the incoming H₂508 provided via green H₂supply 540 and CO₂526 to perform a methanization process in order to produce methane (CH₄) 532, which is fed into the C/C preform production process 502 or another system to perform various operations in the production the aircraft brakes, such as heat generation. In various embodiments, green H₂supply 540 may be H₂generated sustainably via electrolysis from a green H₂supply device, such as a solar generator or wind generator. In various embodiments, in the production of CH₄532, the methanization reactor 510 also produces heat and/or steam 534 in the form of a gas exhaust and/or steam exhaust, which is fed into heat recovery unit 540. In various embodiments, the heat recovery unit 540 may operate to utilize the heat and/or steam 534 to generate energy 542, i.e. heat, via thermal transfer, another fluid that, once heated, may be utilized as a heat transfer fluid. In various embodiments, the heat recovery unit 540 may feed the energy 542, i.e. the heat transfer fluid, via a closed loop process, to separator 524 in order for separator 524 to utilize the provided heat to separate the CO₂526 from the byproducts 522, which is fed into methanization reactor 510, to separate the N₂528 from the byproducts 522, which may be released into the atmosphere, and to separate the H₂O 530 from the byproducts 522, which may be fed into the burner/steam generator 514 along with H₂O 520. In various embodiments, the heat recovery unit 540 may operate to utilize the heat and/or steam 534 to generate energy 544, i.e. heat, via thermal transfer, another fluid that, once heated, may be utilized as a heat transfer fluid. In various embodiments, the heat recovery unit 540 may feed the energy 544, i.e. the heat transfer fluid, via a closed loop process, to the C/C preform production process 502 in order that the C/C preform production process 502 uses the heat for performing various operations in the production of the aircraft brakes.

In various embodiments, rather than using the heat and/or steam 534 to heat, via thermal transfer, another fluid, i.e. the heat transfer fluid, in various embodiments, the heat recovery unit 540 may feed the heat and/or steam 534 as energy 542, via a closed loop process, to separator 524 in order for separator 524 to separate the CO₂526 from the byproducts 522, which is fed into methanization reactor 510, to separate the N₂528 from the byproducts 522, which may be released into the atmosphere, and to separate the H₂O 530 from the byproducts 522, which may be fed into the burner/steam generator 514 along with H₂O 520. In various embodiments, rather than the heat recovery unit 540 using the heat and/or steam 534 to heat, via thermal transfer, another fluid, i.e. the heat transfer fluid, in various embodiments, the heat recovery unit 540 may feed the heat and/or steam 534 as energy 544, via a closed loop process, to the C/C preform production process 502 for use in performing various operations in the production of the aircraft brakes.

In various embodiments, the heat recovery unit 540 may operate to utilize the heat and/or steam 534 to operate a turbine of an electric generator, thereby producing energy 542, i.e. electricity. In various embodiments, the heat recovery unit 540 may feed the energy 542, i.e. the electricity, to separator 524 in order for separator 524 to utilize the energy 542 to produce electric heat to separate the CO₂526 from the byproducts 522, which is fed into methanization reactor 510, to separate the N₂528 from the byproducts 522, which may be released into the atmosphere, and to separate the H₂O 530 from the byproducts 522, which may be fed into the burner/steam generator 514 along with H₂O 520. In various embodiments, the heat recovery unit 540 may operate to utilize the heat and/or steam 534 to operate a turbine of an electric generator, thereby producing energy 544, i.e. electricity. In various embodiments, the heat recovery unit 540 may feed the energy 544, i.e. the electricity, to the C/C preform production process 502 to utilize the energy 542 to produce electric heat in order that the C/C preform production process 502 uses the heat for performing various operations in the production of the aircraft brakes.

In various embodiments, the heat recovery unit 540 using the heat and/or steam 534 to operate a turbine of an electric generator, thereby producing energy 542, 544, i.e. electricity, any excess energy, 546, i.e. electricity, may be fed into other processes within a plant where the C/C preform production process 502 operates or sold as excess energy to an electric provider via an electric grid. In various embodiments, excess steam 548 of the heat and/or steam 534 may then be condensed to generate H₂O 538, which may be fed into the burner/steam generator 514 along with H₂O 520 and H₂O 530. In various embodiments, the condensing may be performed by the heat recovery unit 540 in response the heat recovery unit 540 is able to remove enough heat from the heat and/or steam 534. In various embodiments, in response the heat recovery unit 540 not being able to remove enough heat from the heat and/or steam 534, then the excess steam 548 may be fed to condenser 536. In various embodiments, the condenser 536 condenses the excess steam 548. Accordingly, system 500 provides for CO₂emission recovery by converting the recovered CO₂into other products that may be utilized by the C/C preform production process 502.

Referring now to FIG. 6, in accordance with various embodiments, a system 600 for energy recovery of converting recovered CO₂into other products is illustrated. In various embodiments, the C/C preform production process 602 utilizes natural gases such as methane (CH₄) 603 to perform various operations in the production of aircraft brakes. However, in various embodiments, during the C/C preform production process 602 various off gases 604, i.e. hydrocarbons, are produced. Accordingly, in system 600, the C/C preform production process 602 feeds the various off gases 604, i.e., hydrocarbons, CO₂, H₂, and nitrogen (N₂), among others, into H₂separator 606. In various embodiments, H₂separator 606 separates H₂608 from the various off gases 604 using one or more of membrane separation, pressure swing absorption (PSA), captured by solid sorbents, or cryogenic distillation, among others. In various embodiments, the H₂separator 606 feeds the H₂608 into methanization reactor 610 and feeds the remaining off gases 612, i.e. heavier hydrocarbons, as well as CO₂and N₂, among others, into burner/steam generator 614.

In various embodiments, the burner/steam generator 614 burns the remaining off gases 612 utilizing air 616 to generate steam 618 from incoming water (H₂O) 620. In various embodiments, the steam 618 may be utilized to operate other components of the C/C preform production process 602. During the operations performed by the burner/steam generator 614, in addition to generating the steam 618, the burner/steam generator 614 generates byproducts 622, such as such as CO₂, H₂O, and N₂, among others, which the burner/steam generator 614 feeds into separator 624. Separator 624 may operate to separate the CO₂626 from the byproducts 622, which is fed into methanization reactor 610, to separate the N₂628 from the byproducts 622, which may be released into the atmosphere, and to separate the H₂O 630 from the byproducts 622, which may be fed into the burner/steam generator 614 along with H₂O 620. The separator 624 may one or more of absorption, adsorption, cryogenic distillation, captured by solid sorbents or solvents such as mono-ethanol amine (MEA), or membrane separation, among others for the separation process.

In various embodiments, the methanization reactor 610 utilizes the incoming H₂608, which may be supplemented by green H₂supply 640, and CO₂626 to perform a methanization process in order to produce methane (CH₄) 632, which is fed into the C/C preform production process 602 or another system to perform various operation in the production the aircraft brakes, such as heat generation. In various embodiments, green H₂supply 640 may be H₂generated sustainably via electrolysis from a green H₂supply device, such as a solar generator or wind generator. In various embodiments, in the production of CH₄632, the methanization reactor 610 also produces heat and/or steam 634 in the form of a gas exhaust and/or steam exhaust, which is fed into heat recovery unit 640. In various embodiments, the heat recovery unit 640 may operate to utilize the heat and/or steam 634 to generate energy 642, i.e. heat, via thermal transfer, another fluid that, once heated, may be utilized as a heat transfer fluid. In various embodiments, the heat recovery unit 640 may feed the energy 642, i.e. the heat transfer fluid, via a closed loop process, to separator 624 in order for separator 624 to utilize the provided heat to separate the CO₂626 from the byproducts 622, which is fed into methanization reactor 610, to separate the N₂628 from the byproducts 622, which may be released into the atmosphere, and to separate the H₂O 630 from the byproducts 622, which may be fed into the burner/steam generator 614 along with H₂O 620. In various embodiments, the heat recovery unit 640 may operate to utilize the heat and/or steam 634 to generate energy 644, i.e. heat, via thermal transfer, another fluid that, once heated, may be utilized as a heat transfer fluid. In various embodiments, the heat recovery unit 640 may feed the energy 644, i.e. the heat transfer fluid, via a closed loop process, to the C/C preform production process 602 in order that the C/C preform production process 602 uses the heat for performing various operations in the production of the aircraft brakes.

In various embodiments, rather than using the heat and/or steam 634 to heat, via thermal transfer, another fluid, i.e. the heat transfer fluid, in various embodiments, the heat recovery unit 640 may feed the heat and/or steam 634 as energy 642, via a closed loop process, to separator 624 in order for separator 624 to separate the CO₂626 from the byproducts 622, which is fed into methanization reactor 610, to separate the N₂628 from the byproducts 622, which may be released into the atmosphere, and to separate the H₂O 630 from the byproducts 622, which may be fed into the burner/steam generator 614 along with H₂O 620. In various embodiments, rather than the heat recovery unit 640 using the heat and/or steam 634 to heat, via thermal transfer, another fluid, i.e. the heat transfer fluid, in various embodiments, the heat recovery unit