Patent Application
20240263393
The present disclosure relates to methods of using agricultural waste products and, more specifically, specific series of processes or unit operations, to create a highly viable fiber pulp suitable for creation of paper and/or suitable for an additive in paper.
As shown in
In one approach or embodiment, a method for forming fiber pulp suitable for paper and/or as an additive for pulp for making paper. In one aspect, the method includes selecting a non-homogeneous agricultural waste fiber and, optionally, treating the non-homogeneous agricultural waste fiber with anti-microbial solution and/or UV light; mechanically pre-treating, and optionally chemically pre-treating, the non-homogeneous agricultural waste fiber by dry refining and optionally pre-screening the non-homogeneous agricultural waste fiber to remove contaminants and any undesirable pulp feedstock fibers; heating or cooking the non-homogeneous agricultural waste fiber with low concentrations of sodium hydroxide and/or peroxide at low temperatures to form cooked fibers; high consistency refining of the cooked fibers to develop desired strength properties; diluting and/or rinsing the heated or cooked fibers; screening the rinsed fibers and optionally re-processing rejected fibers through chemical and refining processing; and drying the fibers to form the fiber pulp.
In another approach or embodiment, the method of the previous paragraph may be combined with one or more other features, steps, or embodiments in any combination. These option features, steps, or embodiments may include one or more of the of the following: wherein the heating is with about 1 to about 15 weight percent sodium hydroxide and at temperatures of about 15° C. to about 90° C.; and/or wherein a caustic ratio of the heating temperature to the weight percent of sodium hydroxide is about 6.5° C./percent to about 22° C./percent; and/or wherein the heating is with about 1 to about 15 weight percent hydrogen peroxide; and/or wherein no acid is used in the diluting and/or rinse step; and/or wherein the non-homogeneous agricultural waste fiber is selected from non-food portion of crops including rye, brome, bluestem, cottonwood, corn silage, alfalfa, corn stover, bamboo, hemp stalk, cotton stalk, sorghum stalk, sunflower stalk, kenaf, switchgrass, fescue, bluestem varieties, buffalo grass, king grass, alfalfa, clovers, bunker waste, bin waste, silo waste, manure, manure bunker waster, old bales, moved weed fiber, marsh vegetation, or combinations thereof; and/or wherein the non-homogeneous agricultural waste fiber is a non-digested fiber; and/or wherein the method does not use a digestor; and/or wherein the refining is to a freeness consistency of about 300 CSF to about 600 CSF as measured pursuant to TAPPI T227.
In yet another approach or embodiment, a paper pulp product including virgin and/or recycled fibers and fibers obtained from the methods of any embodiment of the previous two paragraphs is also described herein. In some embodiments, the paper pulp product includes about 20 to about 50 weight percent of the pulp fibers obtained from the method of any embodiment of this summary. In other embodiments, the paper pulp product is formed into a roll pulp, a sheet pulp, pressed block pulp, or pellets.
In yet other embodiments or approaches, the paper pulp product of the previous paragraph is produced in a manner effective to have enhanced properties, such as one or more of the following: wherein paper formed form the fiber pulp has a STFI of at least about 8 lb/in (e.g., about 8 to about 20 lb/in); and/or wherein paper formed form the fiber pulp has a scott bond of at least about 100 ft-lb/1000 (e.g., about 100 to about 250 ft-lb/1000); and/or wherein paper formed form the fiber pulp has a ring crush of at least about 60 lbf/6 inches (e.g., about 60 to about 90 lbf/6 inches); and/or wherein paper formed form the fiber pulp has a concora of at least about 40 lbf/10 flutes (e.g., about 40 to about 90 lbf/10 flutes).
In yet other embodiments, the use of paper pulp product of any embodiment of this summary or the use of paper pulp prepared by any embodiment of the methods of this summary is also described herein to achieve enhanced STFI, Scott Bond, Ring Crush, and/or concora performance such as one or more of the following: wherein paper formed form the fiber pulp has a STFI of at least about 8 lb/in (e.g., about 8 to about 20 lb/in); and/or wherein paper formed form the fiber pulp has a scott bond of at least about 100 ft-lb/1000 (e.g., about 100 to about 250 ft-lb/1000); and/or wherein paper formed form the fiber pulp has a ring crush of at least about 60 lbf/6 inches (e.g., about 60 to about 90 lbf/6 inches); and/or wherein paper formed form the fiber pulp has a concora of at least about 40 lbf/10 flutes (e.g., about 40 to about 90 lbf/10 flutes).
In one approach or embodiment, novel methods are disclosed herein to prepare paper pulp from non-wood fiber sources, and preferably from a variety of different non-homogeneous fiber sources. In approaches or embodiments of the new methods, a fiber source is first prepared at a farm or at a collection site prior to utilization in the methods herein. In one approach or embodiment, the fiber sources may be one or more of agricultural waste, such as but not limited to the non-food portion of crops (such as rye, brome, bluestem, cottonwood, corn silage, alfalfa, corn stover, bamboo, hemp stalk, cotton stalk, sorghum stalk, sunflower stalk, kenaf, switchgrass, fescue, bluestem varieties, buffalo grass, king grass, alfalfa, clovers, residues from wheat, barley, oats and hops crops and the like), bunker waste, bin waste, silo waste, manure, manure bunker waster, old bales, moved weed fiber, and/or marsh vegetation. Preferably, the agricultural waste fiber is row crop stalk, including wheat, corn, barley, hops, sorghum sunflower and cotton.
Prior to use, if needed, such materials may be treated with a dilute anti-microbial solution (i.e., about 1 to about 3 weight percent peroxide) to kill mold, bacteria, and/or pathogens, and/or treated with a UV light if needed. The fiber sources, in some approaches, may be mechanically and/or dry refined at the farm to rough dimensions from about 0.010 inches to about 6 inches via dry refinement through, for example, mechanical agitation and/or abrasion to get the materials pre-cut and fibrillated to permit better permeation of the subsequent cooking solutions. In some approaches, the material may be pre-screened to remove any contaminants, if needed, to separate fines, silica, organic non-cellulosic materials, and/or any inorganic waste (e.g., twine, wire, plastics, metals, and the like).
The selected fiber is then pre-processed to a pre-determined length, preferably ranging from about 0.2 mm to about 12 mm depending on the exact fiber and application being targeted for the final pulp. Unlike most non-wood fiber processes, the methods herein create pulp from fiber sources that can have tremendous variation in the fiber source and/or cellulose type. The challenges presented from this may require different preparations and processes since differing cellulose types have very different requirements to create suitable paper pulp. The selected agricultural materials are processed, either by grinding using a rotary or belt system to reduce the fiber size. Preferably, all fiber materials will be dry screened prior to introduction to the subsequent chemical processing. Dry screening will take place to eliminate most of the dry fines and residual contaminants including silica, dirt and other non-cellulose materials.
The pre-processed fibers are then pre-treated with a combination of water and chemical application of dilute hydrogen peroxide in solution at concentrations of about 2% to about 16%. The fiber is pre-dried and agitated continuously for a period that can range from about 8 to about 48 hours in order to achieve a starting point moisture level ranging from about 5 to about 20%. Fiber is then pre-screened to remove non-fibrous materials often found in agricultural waste. Those materials are rejected and not re-introduced to the fiber system process and eventually discarded.
Next, the pre-treated fiber enters the processing environment. Rather than beginning with a pre-wash as in prior methods, the fiber is placed into an agitated chemical soak using a combination of sodium hydroxide, hydrogen peroxide, an activating agent and/or a chelant. The process is conducted at atmospheric pressure and ambient temperature (e.g., about 15° C. to about 25° C.) up to about 90° C. depending on the fiber makeup. In embodiments, the process is a continuous agitation in such solution for about 10 to about 120 minutes. The fiber then moves into a high consistency refiner chamber where it is refined to a range of 200 ml to 500 ml freeness as desired. Next, the process may be rinsed by dilution and screened. Reject materials are then re-introduced to the system to re-process through the chemical and refining stages. Preferably, no acid is used or needed in the dilution process, which means the methods use less than 0.5 weight percent acid, less than 0.25 percent weight acid, less than 0.1 percent weight acid or preferably no functional levels of acids. Any discharge to wastewater lagoons may be neutralized with very minute levels of acid prior to final discharge as needed in order to balance pH (e.g., to a pH of about 7). The methods may use about 1 to 15 weight percent caustic (e.g., sodium hydroxide) (in other approaches, about 1 to about 12 weight percent caustic or about 6 to about 12 weight percent caustic) and about 1.5 to about 15 weight percent of peroxide.
In embodiments, the fibers are then screened, and rejected fibers are re-circulated back to the soak processing to continue treatment. This is common in this process with varied material sources, as certain woodier fiber sources, such as corn stover, bamboo, hemp stalk, cotton stalk, sorghum stalk and sunflower stalk will take longer to soften adequately compared to the variety of grasses often present including kenaf, switchgrass, fescue, bluestem varieties, buffalo grass, king grass, alfalfa and clovers. In embodiments, screening herein may be with a at least a 0.010 inch flat screen (or equivalent).
Accepted fibers are further thickened and dewatered and then dried for preparation into a variety of output options including roll pulp, sheet pulp, pressed blocks and pellets. The resulting fiber can be introduced into paper mills at a stage post-refinement, usually in a collection mixing tank prior to final slurry introduction into the headbox of a paper machine. The resulting fibers herein may be an additive used along with virgin fibers and/or recycled fibers (such as OCC or old corrugated cardboard). In approaches, the resultant fibers from the methods herein may be blended with virgin or recycled fibers in a papermaking process at about 20 to about 50 weight percent, and preferably about 20 to about 40 weight percent of the fibers as processed via the methods herein.
As shown in
In some embodiments, the methods pull the slurry via screw or other induction into a refiner to get to a certain CSF range (about 300 ml to about 500 ml). This process uses a high consistency refining of between 25 and 35% in order to significantly lower water and energy usage per input ton of fiber by up to 85%. The methods then screen and move rejects to re-soak, and acceptable product to dewatering. In some embodiment, the methods may use a unique dewatering and rinse unit operations, such as using dilution and optionally very dilute organic acid to help neutralize a little but the chemicals as they rinse out to the wastewater channel. If formed, any black liquor may be recycled to make up delignification chemical solution, requiring no evaporation or burning. In approaches, the wastewater production output is low, such as about 25 gal/min of expulsion in a 150,000 tpy plant, and all effluent is benign and able to be treated in an aerated lagoon system. In some approaches, the methods herein may also incorporate unique dewatering systems, such as vertical fall presses after a screw press, then use of a forced air screen (such as, for instance, over 0.025 mm holes) to pelletization/brick forming which will enable about a 20 to 25% moisture content fiber and the pellet process force evaporates it to a 5 to 15% average moisture content and very freight friendly format. In other approaches, the drying process may be unique to the methods herein, suitably using a press, vertical dewatering press, or optionally forced air drying (at speeds up to about 200 mph) and then utilizing systems to form pellets or make rolls/lap.
As shown in the Examples below, the pulp formed by the methods herein (inventive agricultural fibers) can be combined as an additive (optionally with virgin or recycled fiber such as OCC or old corrugated cardboard) in making paper. As used herein and unless indicated otherwise, the following test methods were used in the Examples that follow:
The Concora Corrugating Medium Test measures the crushing resistance of a fluted strip of corrugating medium, and provides a means of estimating the potential flat crush resistance of a corrugated board. As used herein, the test can be run according to TAPPI T809. The method may use a laboratory fluter to prepare a fluted strip of board medium. The flutes of this strip are then held in position with a piece of adhesive tape. The prepared, fluted test-piece is placed in the compression tester and the compressive force at failure is measured. Unless specified otherwise, the test involves 10 flutes.
The ring crush test is used to determine a ring crush resistance of a paper string formed into a ring with a set length and width. The test is performed to ISO 12192 and TAPPI T822 standards.
The short-span compression test is used to evaluate the compressive strength of paper and evaluated according to ISO 9895, DIN 54514, or TAPPI T826 standards.
The burst gest evaluated the maximum resistance of a specimen to increase pressure. Tests can be performed according to ISO 2758 or ISO 2759 on a ZwickRoell or equivalent burst tester.
The Porosity test evaluates the openness of papers and conducted by TAPPI T460 using a Gurley or equivalent porosity tester. The instrument measures porosity by forcing air through the sheet and measuring the rate of flow. More open sheets allow air to pass through the sheet more rapidly. The units for Gurley Porosity is seconds/100 cc3.
Tensile strength can be measured through one or more of ASTM D828, TAPPI T220, TAPPI T456, and/or TAPPI T494.
Peak load may be evaluated through one or more of uses standards TAPPI T 838 and TAPPI T 839 TAPPI T 898 can determine the edgewise compressive strength, parallel to the flutes, of a short column of single, double, or triple-wall corrugated fiberboard, in a neckdown, non-reinforced, loading edge configuration
Pulp freeness or CSF is an evaluation to measure the rate at which a dilute suspension of pulp (3 g of pulp in 1 liter of water) may be drained and may be evaluated using TAPPI T227.
STFI evaluates the compression strength of linerboard and corrugating medium using instruments from, for instance, Taber, Gurley and/or L&W or the equivalent. The test is run according to TAPPI T526
Scott bond or the Scott Plybond test measures the internal bonding strength of paper, using a lifting motion that is somewhat similar to peeling. A pendulum strikes an aluminum angle bar that has been taped to the paper. If the paper has high internal bond strength, the energy in the pendulum is absorbed to a greater degree. This test is run according to TAPPI Test Method T569.
The following examples are illustrative of exemplary embodiments of the disclosure. In these examples, as well as elsewhere in this application, all ratios, parts, and percentages are by weight unless otherwise indicated. It is intended that these examples are being presented for the purpose of illustration only and are not intended to limit the scope of the invention disclosed herein.
The fiber testing results of paper prepared using the methods of the present disclosure (e.g., Inventive Agricultural Fibers or Ag Fibers or Ag residue herein) have been overwhelmingly positive showing marked improvement in several areas, including burst, STFI, Concora, and Scott Bond as set forth herein. The impact on the strength attributes of both burst and STFI is highly unusual, as traditionally these parameters are inversely related. Specifically, performance has increased in a range for each characteristic, and the general improvements are reflected in results of Table 1 below and shown in
Additionally, results have been recorded in testing against various substrates and independently verified. A series of results from the testing show dramatic improvements in paper mill testing, which are reflected in the graphs of
In
In a graph from an integrated mill laboratory showing various improvements versus baseline on the burst strength of the Inventive agricultural fibers as an additive is shown in
Tensile strength or TES was evaluated on inventive agriculture fibers and blends with OCC from the paper mill laboratory as shown in
Peak Load trial data showing improvement in performance is shown in
Dramatic testing results on Short Span Compression testing from an integrated paper mill laboratory is shown in
Ring crush testing of inventive agriculture samples are shown in
It is noted that, as used in this specification and the appended claims, the singular forms a,” “an,” and “the,” include plural referents unless expressly and unequivocally limited to one referent. Thus, for example, reference to “an antioxidant” includes two or more different antioxidants. As used herein, the term “include” and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.
For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values 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 can vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
It is to be understood that each component, compound, substituent or parameter disclosed herein is to be interpreted as being disclosed for use alone or in combination with one or more of each and every other component, compound, substituent or parameter disclosed herein.
It is further understood that each range disclosed herein is to be interpreted as a disclosure of each specific value within the disclosed range that has the same number of significant digits. Thus, for example, a range from 1 to 4 is to be interpreted as an express disclosure of the values 1, 2, 3 and 4 as well as any range of such values.
It is further understood that each lower limit of each range disclosed herein is to be interpreted as disclosed in combination with each upper limit of each range and each specific value within each range disclosed herein for the same component, compounds, substituent or parameter. Thus, this disclosure to be interpreted as a disclosure of all ranges derived by combining each lower limit of each range with each upper limit of each range or with each specific value within each range, or by combining each upper limit of each range with each specific value within each range. That is, it is also further understood that any range between the endpoint values within the broad range is also discussed herein. Thus, a range from 1 to 4 also means a range from 1 to 3, 1 to 2, 2 to 4, 2 to 3, and so forth.
Furthermore, specific amounts/values of a component, compound, substituent or parameter disclosed in the description or an example is to be interpreted as a disclosure of either a lower or an upper limit of a range and thus can be combined with any other lower or upper limit of a range or specific amount/value for the same component, compound, substituent or parameter disclosed elsewhere in the application to form a range for that component, compound, substituent or parameter.
It is to be understood that throughout the present disclosure, the terms “comprises,” “includes,” “contains,” etc. are considered open-ended and include any element, step, or ingredient not explicitly listed. The phrase “consists essentially of” is meant to include any expressly listed element, step, or ingredient and any additional elements, steps, or ingredients that do not materially affect the basic and novel aspects of the invention. The present disclosure also contemplates that any composition described using the terms, “comprises,” “includes,” “contains,” is also to be interpreted as including a disclosure of the same composition “consisting essentially of” or “consisting of” the specifically listed components thereof.
While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or can be presently unforeseen can arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they can be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.
This application claims the benefit of U.S. Provisional Application 63/479,622 filed on Jan. 12, 2023, the entire contents of which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63479622 | Jan 2023 | US |
