Patent Application
20230357988
The present invention is related to a process for providing cellulose and nanocellulose from terrestrial-based and marine-based biomasses.
Biomasses may be a major feedstock to industries like the pulp and paper industries, plastics including films for food packaging, pharmaceuticals, water treatment, cosmetics, and the like.
Biomasses may be terrestrial-based (land-based) or may be marine-based. Exemplary terrestrial-based biomasses include wood, wood residues and non-wood materials derived from plants like hemp, various grasses, corn, and sugar cane. Exemplary marine-based biomasses include macroalgae, namely seaweed and kelp.
Both terrestrial-based and marine-based biomasses are a potential source of cellulose and its derivatives such as cellulose esters, ethers, cellulose fibers, microcrystalline cellulose and nanocellulose. Terrestrial-based biomasses are socalled lignocelluloses. In order to break down and separate lignocelluloses into its cellulose, hemicellulose and lignin constituents, Kraft pulping is the historic process used. Kraft pulping includes using a hot reaction mixture that comprises hydrogen sulfide. The process tends to be slow, require high levels of energy because of the heat, and there is a noxious sulfur odor caused by the reaction mixture. Moreover, much of the waste is in liquid form and is substantial and potentially hazardous.
Seaweed is another potential source of cellulose. Cellulose is present in the cell walls of seaweed along with various polysaccharides such as xylem, mannan and galactan, alginic acid, agar, and carageean. In contrast to plant-based sources of cellulose, absent from seaweed cell walls is lignin or lignin is only present in very small amounts. Thus, the use of harsh chemicals to separate cellulose from the other components of seaweed may be avoided. Seaweed is also a source of alginic acid which may be converted to sodium alginate. Moreover, the source of seaweed as a raw material is somewhat limitless in that algae has a high growth rate which affords mass/farm production, and there is a need at many beaches to harvest natural seaweed because of it being invasive.
Of particular interest is to utilize non-wood-based cellulose or seaweed cellulose to provide a source of nanocellulose which may be transformed into cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs). Examples of this are provided in Extraction and Modification of Cellulose Nanofibers Derived From Biomass for Environmental Application, Menon et al, RSC Adv. 2017.7.42750-42773; Seaweed-Based Cellulose: Application, and Future Perspectives, Baghel, et al., Carbohydrate Polymer, vol 267; 2021; Article No. 118241; Preliminary Study on Nanocellulose Production in Local Seaweeds, Zaini, et al., and International STEM Journal, Volume 2 No. 1, June 2021, 36-42; the disclosures of which are incorporated by reference in their entireties.
It should be appreciated that this Summary is provided to introduce a selection of concepts in a simplified form, the concepts being further described below in the Details Description. This Summary is not intended to identify key features or essential features of this disclosure, nor is it intended to limit the scope of the invention.
The present invention provides a process for treating a biomass. In one embodiment, the biomass may be from terrestrial-based (land-based) biomasses (e.g., hemp) or from marine-based biomasses (e.g., seaweed). The process may separate components such as cellulose, hemicellulose, lignin and/or alginic acid from the biomass. The process may include reducing the size of the biomass to provide the biomass in a fiber form and a suitable size for processing. The biomass fibers may then be subjected to a solution comprising a basic composition (e.g., sodium hydroxide) and an oxidation agent (e.g., hydrogen peroxide) to pulp the fibers. The chemical treatment is conducted at temperatures of less than 95° C. and often at ambient temperature (24° C. to 26° C.). The pulped fibers may substantially be cellulose and are separated from the basic/oxidation agent solution along with an extract of the biomass. The cellulose pulped fibers may be dried and formed into paper grade pulp. The resulting pulp may then be subjected to the basic solution and oxidizing agent a second time. For the terrestrial-based biomasses, the resulting product may be separated into a cellulose rich dissolving grade pulp and an extract high in lignin. For the marine-based biomasses, the resulting product may be separated into a cellulosic-rich pulp and an extract high in alginic acid/sodium alginate.
The foregoing and other aspects of the present invention will now be described in more detail with respect to the description and methodologies provided herein. It should be appreciated that the invention can be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the embodiments of the invention and the appended claims, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Also, as used herein, “and/or” refers to and encompasses any and all possible combinations of one or more of the associated listed items.
The term “about,” as used herein when referring to a measurable value such as an amount of a compound, dose, time, temperature, and the like, is meant to encompass variations of 20%, 10%, 5%, 1%, 0.5%, or even 0.1% of the specified amount. Unless otherwise defined, all terms, including technical and scientific terms used in the description, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
As used herein, the terms “comprise,” “comprises,” “comprising,” “include,” “includes” and “including” specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
As used herein, the term “consists essentially of” (and grammatical variants thereof), as applied to the compositions and methods of the present invention, means that the compositions/methods may contain additional components so long as the additional components do not materially alter the composition/method. The term “materially alter,” as applied to a composition/method, refers to an increase or decrease in the effectiveness of the composition/method of at least about 20% or more.
All patents, patent applications and publications referred to herein are incorporated by reference in their entirety. In case of a conflict in terminology, the present specification is controlling.
The term terrestrial-based or land-based plant biomass include lignocellulosic materials, and may be wood (both hardwood and softwood), particle board, forestry wastes, sawdust, wood chips, and non-wood based such as grasses, switchgrass, miscanthus, cord grass, cotton gin mote, reed canary grass, grain residues, rice hulls, oat hulls, pea hulls, wheat chaff and hulls, barley hulls, cocoa pod husks, peanut hulls, cotton linters, silage, canola straw, wheat straw, barley straw, oat straw, rice straw, jute, hemp, flax, kudzu, bamboo, sisal, abaca, sorghum, corn cobs, corn stover, soybean stover, corn fiber, alfalfa, hay, tomato leaves, coconut hair, sugar bagasse and sugar processing residues, beet pulp, banana fibers, agave bagasse, and agricultural and industrial wastes or mixtures or blends of any of these.
The term “marine-based biomass” includes “macro algae” including red, green, and brown seaweed and kelp.
The present invention provides a process for treating terrestrial-based or marine-based biomasses to isolate or separate components such as cellulose, hemicellulose, lignin and/or alginic acid from the above biomasses. The process may include reducing the size of the biomass to provide the biomass in a fiber or chopped form and a suitable size for processing. By providing the biomass in this form, the fibers are initially opened up by chopping, cutting, fraying or attrition. A refiner or disk mill may be used. Residual moisture from the biomass, particularly if seaweed may be removed before or after reducing the size.
The biomass fibers may be subjected to an apparatus to mechanically internally fibrillate the fibers often over a short time frame of less than about 10 seconds. The phrase “mechanically internally fibrillate” is intended to mean a process or treatment in which the bonds between the tiny fibrils and microfibrils of a plant cell walls are destroyed and allows penetration of water into the space between the fibrils to fluidize or make flowable the biomass fibers. Internal fibrillation allows the fibers to be able to form bonds during the pulping process while maintaining strength.
In one embodiment, the fibrillation may be accomplished using a 1.5# Voith Valley Beater available from Voith Group, Heidenheim, Germany, already dried, using a screw press. A dried biomass may also be rehydrated and pressed through the equipment again. In another embodiment, the biomass fibers may be mechanically internally fibrillated over a short time frame of less than about 10 seconds. Such an apparatus is described, for example, in WO 93/25584, WO 94/03497, and U.S. Pat. No. 4,016,353,the disclosures of which are incorporated by reference in their entireties and is available from Kadant Black Clawson, Lebanon, Ohio. In yet another embodiment, the fibers may be subjected to high frequency pulses and shear forces such as described in U.S. Pat. Nos. 9,421,477, 10,981,083 and 11,174,355, the disclosures of which are incorporated herein by reference in their entireties.
The present invention provides a process for treating terrestrial-based and marine-based biomasses. The process may include removing residual moisture from the biomass, particularly if seaweed. The biomass may be subjected to a basic solution. The biomass may then be heated to a temperature of about 130° F. to about 150° F. for about 30 to 50 minutes. The biomass is then subjected to an oxidation agent for about 40 to 90 minutes. The first-pass biomass, pulp and the liquid extract may be separated. The first pass biomass pulp may then be subjected to a second pass. Namely, the biomass may then be heated to a temperature of about 130° F. to about 150° F. for about 30 to 50 minutes. The biomass is then subjected to an oxidation agent for about 40 to 90 minutes.
The basic solution may be any aqueous solution, alkaline metal hydroxide, carbonate, phosphate, or borate. In one embodiment, the alkaline metal hydroxide is sodium hydroxide, sodium carbonate or sodium borate. Mixtures or blends of the hydroxides, carbonates, phosphates, and borates may be used. The pH may be from about 7.0 to about 13.0 and sometimes may be from about 9.0 to about 12.0.
Suitable oxidation agents may include hydrogen peroxide. Other oxidation agents may include sodium peroxide, calcium peroxide, magnesium peroxide and sodium percarbonate. Typically about 1 to about 5 percent NaOH to H2O and about 5 to about 20 percent hydrogen peroxide to NaOH/H2O mixture may be used and in some embodiments may be 2 to 4 percent NaOH to H2O and 7 to 10 percent hydrogen peroxide to NaOH/H2O mixture.
The treated pulp is then separated to separate a solid cellulose pulp portion from a liquid extract portion. Although the inventors not wishing to be bound by any one theory, the inventors believe that the second pass results in the biomass pulp being mercerized and the cellulose being converted to nanocellulose such as cellulose nanofibers (CNF) and cellulose nanocrystals (CNC). Such treatment of biomass reduces the adulteration of the desired components, namely cellulose, lignin and alginic acid/sodium alginate.
After the two passes of subjecting to a basic solution and an oxidizing agent, the biomass cellulosic-rich pulp may be bleached with a bleaching solution such as sodium hypochlorite, elemental chlorine, chlorine dioxide and oxygen. A catalyst may also be included with the basic/oxidation agent solution. In one embodiment, the catalyst may be a transition metal catalyst such as iron, manganese, and cobalt.
In yet another alternate embodiment, the cellulose fibers may be converted to nanocellulose and nanocellulose fibers by acidifying the pulp by contacting the pulp with an acidifying agent. An exemplary acidifying agent is sulfuric acid. Alternatively, the cellulosic-rich pulp may be contacted with a coenzymes such as Novozymes Cellic® CTec 3.
Plant biomass comprises three major components, namely hemicellulose, cellulose, and lignin. Hemicellulose is a polysaccharide comprising the pentose and hexose sugars xylon, glucuronoxylan, arabinoxylan, glucomannan, and xyloglucan. The sugars are highly substituted with acetic acid, and because of its branched structure, hemicellulose is amorphous. Hemicellulose may be easily cleaved via hydrolysis. In contrast, cellulose (alpha cellulose) is a polysaccharide of glucose sugars bonded together by ß-glycosidic linkages to form lengthy linear chains. Hydrogen bonding can occur between cellulose chains and results in a rigid crystalline structure which is resistant to cleavage. Lignin is a polymer of phenolic molecules and is hydrophobic. It provides structural integrity to plants, i.e., it is the glue that maintains the plant intact. The biomass may include lesser components such as sugars, lipids, proteins, ash, pectins and cutin, and other materials obtained from the leaves, stems, flowers, buds, roots, tubers, seeds, nuts, fruit, and the like of a plant.
The cellulose pulp from treatment of a terrestrial-based biomass may be dissolving grade pulp, namely pulp having an alpha cellulose content greater than about 90 percent. The cellulose pulp may also be formed into a pulp slurry suitable for papermaking and paper conversion, namely for forming a paper article of manufacture. In one embodiment, the pulp slurry comprises pulp, water, optionally starch and optionally a biomass extract such as separated from the pulped fibers added back to the slurry. Exemplary starch sources include corn, potato, waxy maize, wheat, and tapioca. The starch may be cationic, anionic, or amphoteric, and often have high levels of amylopectin. The starch may include a hydrolysis aid (e.g., hydrogen peroxide).
In one embodiment, the terrestrial-based biomass extract high in lignin may have a wide variety of uses and may be modified such as described in US. Pat. No. 11,174,355, the disclosure of which is incorporated by reference herein in its entirety, and be applied to the paper article of manufacture as a coating to strengthen the article of manufacture made from the pulp. Such extracts may also provide barrier properties related to the transport of moisture and gases. The extracts may be blended with biopolymers to improve performance. The coating may be accomplished by extrusion coating, spray coating, curtain coating, size press coating, bar coating and dip coating.
The isolated pulp may be utilized to make a wide variety of paper articles of manufacture including coated and uncoated paper-based products, for example tissue, board, printing, and specialty papers. The isolated dissolving grade pulp may be used to make various textiles and used in the manufacture of viscose (rayon). End products may include clothing, non-wovens (e.g. for filters and hygiene products), and cellophane.
The pulp may be blended with virgin pulp or with pulp from a wide variety of biomasses using the present invention. For example, pulp based on a marine-based biomass may be blended with virgin pulp or with pulp from a land-based plant biomass treated according to the present invention. Often the blend between virgin pulp and the biomass pulp is between 50 to 95 percent virgin pulp to 5 to 50 percent biomass pulp, and often the amount of the virgin pulp is greater than 80 percent of the blend.
Marine-based biomasses comprises cellulosic, other carbohydrates such as galactins, fucoidan, laminarin, xylene, mannan, lipids and alginates (e.g. alginic acid). The seaweed may be in the form of green, red, and brown species of seaweed with Sargassum spp being of particular interest. The marine-based cellulose and liquid extract in the form of sodium alginate may be separated.
Cellulosic pulp, cellulose nanofibers and cellulose nanocrystals may be provided using the process of the invention and have improved mechanical properties, film-forming properties, absorbance properties, and the like. The cellulose pulp of the invention may be converted to nanocellulose by acid hydrolysis ultrasonically, or enzymatic hydrolysis such as described in “Nanocellulose Prepared by Acid Hydrolysis of Isolated Cellulose From Sugarcane Bagasse”, Wulandari et al, 2016 IOP Conf. Ser.: Mater. Sci. Eng. 107 012045 of the cellulose pulp. For example, a 50 percent solution of sulfuric acid may be used. Cellulose nanofibers are also known as “nanofibrillated cellulose”, “cellulose microfibril”, “microfibrillated cellulose”, “cellulose nanofibril” or “nanofibrillar cellulose”. Cellulose nanofiber may be characterized as the long, flexible and entangle nanocellulose having a diameter of 1 to 100 nm to 500 to 2000 nm in length. The cellulose nanofibers have a high surface area and highly extensive hydroxyl groups available for surface modification.
With respect to actual uses, in the area of paper and paperboard manufacture, nanocelluloses provided by the invention are expected to enhance the fiber-fiber bond strength and, hence, have a strong reinforcement effect on paper materials. Nanocellulose has been reported to improve the mechanical properties of thermosetting resins, starch-based matrixes, soy protein, rubber latex, and polylactides. Nanocellulose may be used as a low-calorie replacement for carbohydrate additives used as thickeners, flavour carriers, and suspension stabilizers in a wide variety of food products. Nanocellulose have improved absorption properties. Thus, nanocellulose may be used as a super water absorbent material (e.g. for incontinence pads) or used in combination with other super absorbent polymers, non-woven products, and as antimicrobial films. The use of nanocellulose in cosmetics and pharmaceuticals has also been suggested. Interactive materials may be mixed with nanocellulose to enable the creation of new interactive fibers, films, aerogels, hydrogels, and papers. For example, nanocellulose mixed with conducting polymers may have improved electronic and ionic conductivity. Filaments spun from a mix of nanocellulose, and carbon nanotubes show good conductivity and mechanical properties.
In one embodiment, lignin may be added to, or contacted with, cellulose nanofibers to provide a reinforced fiber having mechanical and strength properties similar to Kevlor® and carbon fibers. Other additives with or without addition of lignin may be added and the cellulose nanofibers or cellulose nanocrystals may act as a carrier or a delivery system for various additives.
With respect to sodium alginate, it may be added to nanocellulose to form biodegradable films and coatings. These films and coatings may be modified by the addition to, or blending with, other polyomas. Sodium alginate may be used as a carrier for pharmaceuticals and nutraceuticals. Sodium alginate may be used with or without nanocellulose as a food additive.
The invention now will be described in additional detail, by way of example only with reference to the following examples.
180 grams of pressed hemp is mixed in an insulated stainless vessel with 32 grams of NaOH and 800 ml water and placed in a 140° F. heated oven for 30 minutes. The kettle is removed, and 60 ml of 12 percent HOOH is added to the kettle and covered for one hour. An additional 60 ml of 12 percent HOOH is added to the kettle and covered for an additional hour. Hemp pulp is removed from the kettle and screen washed. Screen washed hemp pulp is pressed using a Sampson screw press. Hemp pulp and Hemp liquid extract are separated and collected in separate containers.
Hemp pulp from first processing steps is mixed in an insulated stainless vessel with 32 grams of NaOH and 800 ml water and placed in a 140° F. heated oven for 30 minutes. The kettle is removed, and 60 ml of 12 percent HOOH is added to the kettle and covered for one hour. An additional 60 ml of 12 percent HOOH is added to the kettle and covered for an additional hour. Hemp pulp is removed from the kettle and screen washed. Screen washed hemp pulp is pressed using a Sampson screw press. Hemp cellulosic pulp and Hemp liquid extract were separated, collected in separate containers.
Hemp cellulosic pulp is put in a glass container and mixed with 1500 ml H20 225 ml (7.5% sodium hypochlorite concentration) to bleach the pulp. The glass container is placed in a 140° F. heated oven for 30 minutes. Hemp-based cellulosic pulp was removed from the glass container and screen washed. A vacuum is then applied to the cellulosic pulp to remove as much water from the exterior of the nanosized capillary pores of the cellulosic pulp.
SEMS of the hemp-based dissolving grade pulp are done at a HV of 25.0 KV, WD of 9.3 mm and magnification of 5000x. The SEM of
180 grams of screw-pressed sargassum is mixed in an insulated stainless vessel with 16 grams of NaOH and 800 ml water and placed in a 140° F. heated oven for 30 minutes. The kettle is removed, and 40 ml of 12 percent HOOH is added to the kettle and covered for one hour. An additional 40 ml of 12 percent HOOH is added to the kettle and covered for an additional hour at room temperature. Sargassum pulp is removed from the kettle and screen washed. Screen washed sargassum pulp is pressed using an Omega Model 8006 screw press. Sargassum pulp and Sargassum liquid extract are separated and collected in separate containers.
Sargassum pulp from first processing steps is mixed in an insulated stainless vessel with 16 grams of NaOH and 800 ml water and placed in a 140° F. heated oven for 30 minutes. The kettle is removed, and 30 ml of 12 percent HOOH is added to the kettle and covered for one hour at room temperature. An additional 30 ml of 12 percent HOOH is added to the kettle and covered for an additional hour at room temperature. Sargassum pulp is removed from the kettle and screen washed. Screen washed sargassum pulp is pressed using an Omega Model 8006 screw press. Sargassum cellulosic pulp and Sargassum liquid extract (in the form of sodium alginate) were separated, collected in separate containers.
Sargassum cellulosic pulp is put in a glass container and mixed with 1500 ml H20 225 ml (7.5% sodium hypochlorite concentration). The glass container is placed in a 140° F. heated oven for 30 minutes. Sargassum-based cellulosic pulp was removed from the glass container and screen washed. A vacuum is then applied to the cellulosic pulp to remove as much water from the exterior of the nanosized capillary pores of the cellulosic pulp.
SEMs of the sargassum-based cellulosic pulp are done at HV of 10.0 KV, WD of 10.3 mm and magnification of 2000x. The SEM of
Although the present approach has been illustrated and described herein with reference to preferred embodiments and specific examples thereof, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples may perform similar functions and/or achieve like results. All such equivalent embodiments and examples are within the spirit and scope of the present approach.
The present application claims priority to and is a continuation-in-part of PCT/US2023/010765 filed Jan. 13, 2023 which claims priority to U.S. Provisional Application No. 63/299,465 filed Jan. 14, 2022 and U.S. Provisional Application No. 63/341,040 filed May 12, 2022, and further claims priority to U.S. Provisional Application No. 63/461,959 filed Apr. 26, 2023, the disclosures of which are incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 63461959 | Apr 2023 | US | |
| 63299465 | Jan 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2023/010765 | Jan 2023 | WO |
| Child | 18220587 | US |
