Processes for treating biomass

Abstract

The present disclosure provides methods for treating biowaste and similar waste sources with an acid and an oxidizing agent. The products of the process may form biogels and / or liquid fertilizers.

Description

PROCESSES FOR TREATING BIOMASSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of, and priority to, U.S. Provisional Patent Application Serial No. 63 / 603,298 filed on November 28, 2023. The entire contents of the foregoing application are incorporated by reference herein.GOVERNMENT RIGHTS

[0002] This invention was made with government support under grant number 2216585 and 2140820 awarded by the National Science Foundation. The government has certain rights in the invention.BACKGROUND

[0003] Waste and other sources of waste-products of organic origin, such as by-products from gardening, agriculture, forestry, timber industry, food processing industries and the like, have been the subject of increasing interest as possible starting materials for the production of other suitable products.

[0004] Many of the existing methods are energy demanding and require the consumption of large amounts of chemicals. Use of these chemicals may also degrade / corrode any apparatus used in the process.

[0005] Improved methods for treating organic waste sources to produce other useful materials remain desirable.SUMMARY

[0006] The present disclosure provides methods for treating biowaste and similar waste sources with nitric acid and metal -based oxidizing agents.

[0007] In aspects, the present disclosure provides methods which include contacting plant biomasses, protein biomasses, and / or mixtures as a feedstock, with nitric acid at a concentration above 30% (v / v) and one or more oxidizing agents; holding the mixture at a temperature from about 40° C to 100° C for a period of time from about 0.5 hours to about 72 hours; and separating treated fiber residues and effluent from the mixture.

[0008] In embodiments, the plant biomass includes lignocellulosic wood, non-lignocellulosic wood, lignocellulose, pure cellulose, grasses, phytoplanktons, algal celluloses, tunicate celluloses, and combinations thereof.

[0009] In other embodiments, the plant biomass is obtained from sources consisting of jute, palm tree, sugarcane bagasse, com, wheat, oat, rice, sorghum, oil palm, bamboo, spinifex, coastal bermudagrass, miscanthus, switchgrass, azolla, seaweeds, flax, hemp, ramie, kenaf stalk fiber, kenaf core, abaca, sisal, pineapple, banana leaf, banana peel, banana fiber, curaua, lotus lead stalk, roselle, seed hair fiber, cotton fiber, kapok fiber, areca nut fiber, coconut, potato, cabbage, tomato, all vegetables, rubberwood, indian screw tree, achira fiber, citrus, soybean, soybean straw, spent grain, soy hull, pea hull, grape pomace, fruit pomace, and combinations thereof.

[0010] In embodiments, the protein biomass is obtained from sources consisting of cow, chicken, fish, pig, goat, lamb, duck, turkey, prawns, crab, shrimp, lobster, mussels, oysters, scallops, clams, and combinations thereof.

[0011] In some embodiments, the protein biomass may include a mixture of cow manure, horse manure, chicken manure, pig manure, food waste, and varying combinations thereof.

[0012] In embodiments, the acid component further comprises an additional acid selected from hydrochloric acid, sulfuric acid, acetic acid, hydrobromic acid, hydrofluoric acid, and combinations thereof.

[0013] In some embodiments, the oxidizing agent component includes a metal oxide selected from Iron (II) oxide, Iron (III) oxide, Iron (II, III) oxide, titanium oxide, titanium dioxide, zirconium (II) oxide, zirconium (IV) oxide, zinc (II) oxide, copper (II) oxide, nickel (II) oxide, manganese (II) oxide, manganese (IV) oxide, cobalt oxide, molybdenum (VI) oxide, silicon dioxide, and combinations thereof.

[0014] In other embodiments, the oxidizing agent component includes a metal chloride selected from iron chlorides, aluminum chlorides, nickel chlorides, manganese chlorides, zinc chlorides, copper chlorides, cobalt chlorides, titanium chlorides, and combinations thereof.

[0015] In embodiments, the oxidizing agent component includes a metal nitrate, nitrite, and / or sulfate selected from iron (III) nitrate, iron (II) nitrate, zinc nitrate, silver nitrate, manganese (II) nitrate, iron (II) acetate, aluminum nitrate, nickel nitrate, molybdenum nitrate, potassium nitrate, potassium nitrite, manganese nitrite, iron (II) sulfate, manganese (II) sulfate, copper (II) sulfate, nickel (II) sulfate, aluminum sulfate, and combinations thereof.

[0016] In some embodiments, the oxidizing agent component includes a nitrite salt selected from potassium nitrite, calcium nitrite, magnesium nitrite, and combinations thereof.

[0017] In embodiments, the amount of the acid component used in the process of the present disclosure is from about 10 mmol to about 300 mmol per gram of biomass.

[0018] In some embodiments, the amount of the oxidizing agent used in the process of the present disclosure is from 0.05 mmol to about 60 mmol per gram of biomass.

[0019] In embodiments, the mixture of acid and oxidizing agent is at a temperature from about 40 °C to about 100 °C, for a period of time from about 0.5 hours to about 72 hours.

[0020] In some embodiments, the fibers produced by the process of the present disclosure are subjected to mechanical treatments selected from sonication, homogenization, microfluidization, cryocrushing, grinding, steam explosion, and combinations thereof, wherein the method occurs for a period from about 1 minutes to around 6 hours.

[0021] In embodiments, oxidized cellulose fibers produced by the process of the present disclosure have a mean fiber length from about 10 nm to about 10000 nm.

[0022] In embodiments, oxidized cellulose fibers produced by the process of the present disclosure have a mean nominal diameter from 2 nm to about 200 nm.

[0023] In embodiments, the weight percentage (wt%) of the gellable substrate produced by the process of the present disclosure is from about 0.5% by weight to about 10% by weight.

[0024] In embodiments, the gellable substrate produced by the process of the present disclosure has a lignin and hemicellulose content from about 2% by weight to about 20% by weight.

[0025] In embodiments, the base components or their salts used in the process of the present disclosure are selected from sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, and combinations thereof, are utilized to neutralize the produced NOP effluent.

[0026] In embodiments, cellulose-based biogels are produced via cross-linking with the cations in the neutralized NOP effluent selected from calcium, magnesium, iron (II), iron (III), zinc, manganese, nickel, aluminum, sodium, potassium, and combinations thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Various embodiments of the presently disclosed methods are described herein with reference to the drawings wherein:

[0028] FIG. l is a Fourier transform infrared spectra of dried palm tree leafstalk ground sample treated with 50% HNO3 and FesCri;

[0029] FIG. 2 is an FTIR spectra of dried palm tree leafstalk treated with 50% HNO3 and ground Aluminum foil;

[0030] FIG. 3 is an FTIR spectra of dried palm tree leafstalk treated with 50% HNO3 andMnO;

[0031] FIG. 4 is an FTIR spectra of dried palm tree leafstalk treated with 50% HNO3 andFeO;

[0032] FIG. 5 is an FTIR spectra of dried palm tree leafstalk treated with 50% HNO3 andFeCl2;

[0033] FIG. 6 is an FTIR spectra of dried palm tree leafstalk treated with 50% HNO3 andFeCh;

[0034] FIG. 7 is an FTIR spectra of dried palm tree leafstalk treated with 50% HNO3 and NiO;

[0035] FIG. 8 is an FTIR spectra of dried sugarcane bagasse treated with 50% HNO3 and FeO;

[0036] FIG. 9 is an FTIR spectra of dried sugarcane bagasse treated with 50% HNO3 and MnO;

[0037] FIG. 10 is an FTIR spectra of dried sugarcane bagasse treated with 50% HNO3 and NiO;

[0038] FIG. 11 is an FTIR spectra of dried potato ground biomass treated with 50% HNO3 and FeO;

[0039] FIG. 12 is an FTIR spectra of dried potato ground biomass treated with 50% HNO3 and MnO;

[0040] FIG. 13 is an FTIR spectra of dried brewer’s spent grain treated with 50% HNO3 and FeO;

[0041] FIG. 14 is an FTIR spectra of dried brewer’s spent grain treated with 50% HNO3 and MnO;

[0042] FIG. 15(a) is an FTIR spectra of dried brewer's spent grain, and dried brewer's spent grain treated with 50% HNO3 and KNO3;

[0043] FIG. 15(b) is an ICP-OES elemental analysis of the effluent produced from brewer's spent grain treated with 50% HNO3 and KNO3;

[0044] FIG. 16(a) is an FTIR spectra of dried sugarcane bagasse, and sugarcane bagasse treated with 50% HNO3 and KNO3;

[0045] FIG. 16(b) is an ICP-OES elemental analysis of the effluent produced from sugarcane bagasse treated with 50% HNO3 and KNO3;

[0046] FIG. 17(a) is an FTIR spectra of dried potato ground, and dried potato ground treated with 50% HNO3 and KN03;

[0047] FIG. 17(b) is an ICP-OES elemental analysis of the effluent produced from potato ground treated with 50% HNO3 and KNO3;

[0048] FIG. 18(a) is an FTIR spectra of dried grape pomace, and dried grape pomace treated with 50% HNO3 and KN03;

[0049] FIG. 18(b) is an ICP-OES elemental analysis of the effluent produced from grape pomace treated with 50% HNO3 and KNO3;

[0050] FIG. 19(a) is an FTIR spectra of dried jute, and dried jute treated with 50% HNO3 and KNO3;

[0051] FIG. 19(b) is an ICP-OES elemental analysis of the effluent produced from jute treated with 50% HNO3 and KNO3;

[0052] FIG. 20(a) is an FTIR spectra of dried palm tree leafstalk, and dried palm tree leafstalk treated with 50% HNO3 and KNO3;

[0053] FIG. 20(b) is an ICP-OES elemental analysis of the effluent produced from palm tree leafstalk treated with 50% HNO3 and KNO3;

[0054] FIG. 21 is an FTIR spectra of dried sorghum, and dried sorghum treated with 50% HNO3 and KNO3;

[0055] FIG. 22(a) is an FTIR spectra of dried red onion skins and dried red onion skins treated with 50% HNO3 and KNO3;

[0056] FIG. 22(b) is an ICP-OES elemental analysis of the effluent produced from red onion skins treated with 50% HNO3 and KNO3;

[0057] FIG. 23 is an FTIR spectra of dried Jute treated with 50% HNO3 and FeCh;

[0058] FIG. 24 is an FTIR spectra of dried Jute treated with 50% HNO3 and Fe(II)Ac;

[0059] FIG. 25 is an FTIR spectra of dried Jute treated with 50% HNO3 and Fe(II)O;

[0060] FIG. 26 is an FTIR spectra of dried Jute treated with 50% HNO3 and Mn(II)0;

[0061] FIG. 27 is an FTIR spectra of dried Jute treated with 50% HNO3 and FeSO4*7H2O;

[0062] FIG. 28 is an FTIR spectra of raw jute, jute treated only with 50% nitric acid, jute treated with 50% nitric acid along with KNO3, KNO2, FeSCh, Mn(NOs)2, and MnSCU;

[0063] FIG. 29 is a plot demonstrating potentiometric titration of raw jute treated only with 50% nitric acid, jute treated with 50% nitric acid along with KNO3, KNO2, FeSO4, Mn(NOj)2, and MnSO4;

[0064] FIG. 30(a) is a plot demonstrating thermogravimetric analysis (TGA) of raw jute, jute treated only with 50% nitric acid, jute treated with 50% nitric acid along with KNO3, KNO2, FeSO4, Mn(NO3)2, and MnSO4;

[0065] FIG. 30(b) show a plot demonstrating the Derivative Thermogravimetric (DTG) curve of raw jute, jute treated with 50% nitric acid, jute treated with 50% nitric acid along with KNO3, KNO2, FeSO4, Mn(NOs)2, and MnSC and a table illustrating the maximum degradation temperature for each sample, calculated from the first derivative of TGA curve as a function of temperature;

[0066] FIG. 31 is a transmission electron microscope image of jute treated with only 50% HNO3, and a plot demonstrating its width’s size distribution average;

[0067] FIG. 32 is a transmission electron microscope image of jute treated with 50% HNO3 along with KNO2, and a plot demonstrating its width’s size distribution average;

[0068] FIG. 33 is a transmission electron microscope image of jute treated with 50% HNO3 along with FeSC , and a plot demonstrating its width’s size distribution average; and

[0069] FIG. 34 is a transmission electron microscope image of jute treated with 50% HNO3 along with MnSC , and a plot demonstrating its width’s size distribution average.DETAILED DESCRIPTION

[0070] The following detailed description of embodiments of the subject matter of the present disclosure will be made in reference to the accompanying drawings. In describing the disclosure,explanation about related functions or constructions known in the art are omitted for the sake of clearness in understanding the concept of the present disclosure to avoid obscuring the recited subject matter with unnecessary detail.

[0071] Previous methods for treating biomass to produce carboxycellulose or caboxylated cellulose nanofibers include those disclosed in U.S. Patent No. 10,894,838, the entire disclosure of which is incorporated by reference herein and generally relates to a Nitro-Oxidation Process (NOP) to generate oxidized cellulose fibers (containing both nanofibers and macrofibers) from unutilized biomass and includes various advantages, such as simplicity, cost-effectiveness, less- chemically oriented, and low energy and water consumption.. The most conventional methods used to extract cellulose from biomass often involve multiple steps such as alkaline treatment (e.g., NaOH, KOH, etc.), chemical pulping, and subsequent chemical modification processes (e.g., sulfuric acid hydrolysis, TEMPO oxidation). Generally, these steps are required to remove non-cellulosic components (primarily lignin and hemicellulose) from the biomass. In addition, previous methods for the extraction and oxidation of cellulose use 65% (w / w) nitric acid, which can be challenging in regards to large scale manufacturing due to toxic acid handling.

[0072] The present disclosure provides methods for simultaneously producing cellulose biogels and liquid fertilizers directly from plant biomass (e.g., lignocellulose wood, nonlignocellulose wood, lignocellulose, pure cellulose, grasses, phytoplanktons, algal celluloses, tunicate celluloses, and combinations thereof), protein biomass (e.g., cow, chicken, fish, pig, goat, lamb, duck, turkey, prawns, crab, shrimp, lobster, mussels, oysters, scallops, clams, and combinations thereof), food waste, and / or animal waste. In this disclosure, several new oxidizing agents, including metal oxides, metal chlorides, metal nitrates, and metal nitrites, are introduced with nitric acid to defibrillate and oxidize the raw biomass in a one-step process. Inembodiments, following the disclosed process, there is zero by-product waste. The resultant oxidized fibers and effluent can be used in diverse applications such as liquid biofertilizers, biogels, wastewater adsorbents, packaging, coating, and biomedical applications, etc.

[0073] As noted above, suitable sources of the biomass used in the process of the present disclosure include plant biomass, protein biomass, animal waste, food waste, combinations thereof, and the like.

[0074] In some embodiments, examples of suitable plant biomass sources include jute, palm tree, sugarcane bagasse, corn, wheat, oat, rice, sorghum, oil palm, bamboo, spinifex, coastal bermudagrass, miscanthus, switchgrass, azolla, seaweeds, flax, hemp, ramie, kenaf stalk fiber, kenaf core, abaca, sisal, pineapple, banana leaf, banana peel, banana fiber, curaua, lotus lead stalk, roselle, seed hair fiber, cotton fiber, kapok fiber, areca nut fiber, coconut, potato, cabbage, tomato, all vegetables, rubberwood, indian screw tree, achira fiber, citrus, soybean, soybean straw, spent grain, soy hull, pea hull, grape pomace, fruit pomace, and combinations thereof.

[0075] Examples of suitable protein biomass sources include cow, chicken, fish, pig, goat, lamb, duck, turkey, prawns, crab, shrimp, lobster, mussels, oysters, scallops, clams, and combinations thereof.

[0076] Suitable animal wastes which may be used as a biomass source in accordance with the present disclosure include cow manure, horse manure, chicken manure, pig manure, and combinations thereof.

[0077] Food waste which may be used as a biomass source in accordance with the present disclosure may be of any origin and may be combined with any of the above sources of biomass, including plant biomass, protein biomass, animal waste, and the like.

[0078] In embodiments, biogel materials and a nutrient-rich potential fertilizing effluent may be produced by combining different catalytic amounts of metal -based oxidizing agents with a suitable acid, in embodiments nitric acid. The method of the present disclosure avoids the need for high amounts of NaNCh or KNO2 or their related inorganic compound as a primary oxidizing agent. This is desirable as a high amount of sodium ions in the effluent can reduce the efficacy of plant fertilization. Furthermore, reducing the amount of oxidizing agents will decrease upscaling costs by at least twenty-five percent.

[0079] The methods of the present disclosure include the extraction and oxidation of untreated biomass feedstocks to produce biogels and a nitrogen rich effluent, by utilizing nitric acid and catalytic amounts of oxidizing agents. The effluent produced from these metal catalystbased reactions can serve as macro- and micro-nutrients for plants.

[0080] However, in accordance with the present disclosure, no harsh pretreatment of raw biomass is required, rendering the process less energy intensive and more cost-effective. All of the processing occurs in one step, which starts via the reaction of biomass waste as a feedstock source with the reaction ingredients. In embodiments, the reaction ingredients used to treat the biomass include nitric acid (HNO3) at a desired concentration. While the disclosure describes the use of HNO3 in detail, other acids may be used, including hydrochloric acid (HC1), sulfuric acid (H2SO4), acetic acid (CH3COOH), hydrobromic acid (HBr), hydrofluoric acid (HF). In some embodiments, combinations of the foregoing acids may be used.

[0081] The acid used in the process of the present disclosure may be at a concentration from about 5 mmol to about 500 mmol per gram of biomass, in embodiments from about 10 mmol to about 300 mmol per gram of biomass.

[0082] In addition, a catalytic amount of an oxidizing agent is combined with the above acids in treating the biomass feedstock. Suitable oxidizing agents include, in embodiments, metal oxides, metal chlorides, metal nitrates, metal nitrites, nitrite salts, combinations thereof, and the like.

[0083] Exemplary metal oxides which may be used in the present disclosure include Iron (II) oxide, Iron (III) oxide, Iron (II, III) oxide, titanium oxide, titanium dioxide, zirconium (II) oxide, zirconium (IV) oxide, zinc (II) oxide, copper (II) oxide, nickel (II) oxide, manganese (II) oxide, manganese (IV) oxide, cobalt oxide, molybdenum (VI) oxide, silicon dioxide, and combinations thereof.

[0084] Exemplary metal chlorides which may be used in the present disclosure include iron chlorides, aluminum chlorides, nickel chlorides, manganese chlorides, zinc chlorides, copper chlorides, cobalt chlorides, titanium chlorides, and combinations thereof.

[0085] Exemplary metal nitrates, nitrites, and / or sulfates which may be used in the present disclosure include iron (III) nitrate, iron (II) nitrate, zinc nitrate, silver nitrate, manganese (II) nitrate, iron (II) acetate, aluminum nitrate, nickel nitrate, molybdenum nitrate, potassium nitrate, potassium nitrite, manganese nitrite, iron (II) sulfate, manganese (II) sulfate, copper (II) sulfate, nickel (II) sulfate, aluminum sulfate, and combinations thereof.

[0086] Exemplary nitrite salts which may be used in the present disclosure include potassium nitrite, calcium nitrite, magnesium nitrite, and combinations thereof.

[0087] The concentration of the oxidizing agent used in the present disclosure may be from about 0.05 mmol to about 60 mmol per gram of biomass, in embodiments 0.10 mmol to about 100 mmol per gram of biomass.

[0088] The acid and oxidizing agent may be contacted with the biomass feedstock at a temperature from about 25 °C to about 140 °C, in embodiments from about 30 °C to about 120 °C, in yet other embodiments from about 40 °C to about 100 °C. The nitric acid and optional potassium nitrite may be contacted with the biowaste for a period of time from about 0.5 hours to about 72 hours, in embodiments from about 2 hours to about 24 hours, in yet other embodiments from about 6 hours to about 9 hours.

[0089] Whether the process produces a biogel fertilizer (i.e., a combination of biogel and fertilizer), or functionalized cellulose nanofibers, sometimes referred to herein as nitro-oxidized cellulose nanofibers (NOCNF), will be dependent on the biomass being treated. For example, for forming biogel fertilizers, the biomass to be treated may include animal waste or food waste, combinations thereof, and the like.

[0090] Where the biomass source includes fibrous cellulosic materials, the process of the present disclosure produces biodegradable and sustainably sourced charged micro- and nanocellulose extracted from the fibers within the biowaste source. The charged micro- and nanocellulose may be functionalized micro- or nanofibers or, in some embodiments, a biogel. Ionic gelation of nanocellulose suspension produces a biogel.

[0091] For forming the NOCNF, the starting biomass should be a fibrous plant-based biomass. In embodiments, the NOCNF may also be in the form of a biogel, suitable for a myriad of applications, including but not limited to plants as a fertilizer, as a soilless growth medium, or as a water remediation material.

[0092] Where the product of the process of the present disclosure is fibrous, the fibers may be subjected to mechanical treatments such as sonication, homogenization, cryocrushing, grinding, steam explosion, and combination thereof. These additional processing steps may occur for asuitable period of time, in embodiments from about 1 minute to about 360 min, in other embodiments from about 0.5 hours to about 4 hours.

[0093] Fibers produced by the methods of the present disclosure may include oxidized cellulose fibers having a mean fiber length from about 10 nm to about 10000 nm, in embodiments from about 100 nm to about 1000 nm. These fibers may have a mean nominal diameter from 2 nm to about 200 nm, in embodiments from about 5 nm to about 100 nm.

[0094] Where the biomass source does not include fibrous materials, the result of the above processes / treatments of biomass with acid and oxidizing agent is a liquid biowaste effluent. The effluent, which includes essential nutrients such as nitrogen, may be used as a fertilizer.

[0095] In embodiments, the oxidized cellulose fibers thus produced may be utilized to form a gellable substrate. The weight percentage (wt%) of the fiber suspension in the gellable substrate may be from about 0.5% by weight to about 20% by weight, in embodiments from about 2% by weight to about 10% by weight. In some embodiments, the gellable substrate may include lignin and hemicellulose, with the lignin and hemicellulose present in an amount from about 2% by weight to about 20% by weight.

[0096] In embodiments, the effluent recovered from the process of the present disclosure may be treated with a base and / or its salt to neutralize the effluent. Suitable base components or their salts include sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, and combinations thereof.

[0097] In other embodiments, cellulose-based biogels produced by the disclosed process may be subjected to a cross-linking step by contacting the recovered materials with cations. Suitable cations used for cross-linking include calcium, magnesium, iron (II), iron (III), zinc, manganese, nickel, aluminum, sodium, potassium, and combinations thereof.

[0098] As noted above, the biogels produced as a result of the disclosed processes may be utilized as fertilizers or soilless plant growth medium. Nanocellulose derived from the nitrooxidation process provides a relatively accessible, low cost, and an environmentally friendly methodology for the upcycling of biowaste into valuable materials for use in a myriad of agricultural applications including water purification, soilless growth media, and NPK fertilizer. The process of the present disclosure provides a cost-effective, simple, environmentally friendly process to treat wastewater and similar waste sources for future use as fertilizer or soil free growth materials.

[0099] Advantages of the methods disclosed herein include, but are not limited to:• Using a little amount of oxidizing agent will make the process both sustainable and less expensive (may decrease the price of the process by at least 10-25%, depending on the chosen oxidant).• The process may be used to treat various biomasses, such as agricultural organic wastes, food waste, lignocellulosic wood or non-wood biomasses, animal wastes, etc. Moreover, the process can occur fairly quickly, in embodiments from about 6 hours to about 9 hours.• The effluent produced from the disclosed process is rich in essential macro (e.g., potassium) and micro (e.g., iron and manganese) nutrients required for plant growth, making the process a closed-loop system.• The present process utilizes the acid and a smaller amount of the oxidizing agent in a one-step process. Therefore, no additional pretreatment steps (e.g., alkaline treatment, chemical pulping, etc.) are required, making the process less energyintensive, less time-consuming, and more cost-effective.• The present process allows better upcy cling of biomass since the chemical ratio in this process is much lower than the chemical ratio previously used for sodium nitrite.• Products and effluent generated from the disclosed can be used in diverse applications, such as liquid biofertilizers, biogels, wastewater adsorbents, food packaging, biomedical applications, etc. Using food waste and agricultural waste in the disclosed process results in a closed-loop system where the biowastes treated by the process can be used to regrow crops or plants (from plant to plant).

[0100] In summary, the process of the present disclosure can be used to treat different kinds of plant biomasses, protein biomasses, and mixtures. These types of reactions produce a nitrogen rich effluent and robust biogel materials. The process of the present disclosure results in the degradation of non-cellulosic components and chemical modification of the biomass to generate reliable, safe, and valuable materials that can find its applications in a variety of areas. These types of reactions produce a nitrogen rich effluent and robust biogel materials. In embodiments, the resulting biogel and the effluent formed by this process may be used as a soilless growth medium and a fertilizer, respectively.

[0101] Several embodiments of the disclosure are described below with reference to the following non-limiting Examples. The Examples are intended to be illustrative only and are not intended to limit the scope of the present disclosure. As used herein, “room temperature” refers to a temperature of from about 20 °C to about 30 °C. Also, parts and percentages, such as solution percentages, are by weight unless otherwise indicated.EXAMPLES

[0102] For the Examples set forth below, the following general process was followed. First, the raw biomass was oven dried at 60 °C until consistent weight was measured (e.g., 12 hours).

[0103] About 20 grams of each raw biomass was immersed in a 3000 mL 2-neck round bottom flask. About 280 ml cone. HNO3 (50% v / v) and a determined concentration of oxidant (from 0.0063 to 0.18991 mol) were then added into the flask under continuous stirring (~ 240 rpm) to start the reaction.

[0104] A stopper was loosely parafdmed around the neck of the flask. The reaction was conducted at 50 °C for 9 hours and a stopper was placed in the flask. After the 9 hours reaction, the effluent was collected, and the resulting fibers were washed several times with distilled water until pH was about 3.0.

[0105] For characterization, oxidized cellulose fibers were freeze dried. The yield of the obtained cellulose was calculated as the ratio between the weight of the freeze dried cellulose and the dried weight of raw biomass was calculated using Equation (1):Yield (%) = Dried cellulose weight in g) / Dried raw biomass weight in g) * 100 (1)

[0106] Potentiometric titration was conducted using a potentiometric titrator (HI 902, HANNA Instrument) to quantitatively assess the carboxyl (COOH) group content of the oxidized nanocellulose. In this method, 0.5 grams of the freeze-dried cellulose fibers were mixed with 70 mL of deionized water. Subsequently, 5 mL of 0.1 M HNO3 and 5 mL of 0.01 M NaCl were added to the mixture, and the solution was stirred overnight to ensure homogenous distribution. Titration was conducted by gradually introducing a 0.05 M NaOH solution at a rate of 2 mL / min.A Blank solution was prepared using 5 mL of 0.01 M NaCl and 5 mL of 0.1 M HNO3 to establish the equivalence point for the blank sample. The difference in volume between the blankand the sample indicated the volume of NaOH solution exclusively consumed by the fibers. The degree of oxidation (DO) of nanofibers was calculated using Equation (2):DO (mmol / g) = (V_NaOH xM_NaOH) / W_sample x 100 (2)

[0107] In Equation (2) where V is the NaOH volume added (1), M is the NaOH concentration (mol), and W is the cellulose fiber mass (grams). Fourier-transform infrared (FTIR) spectrometer in the attenuated total reflectance (ATR) mode (Nicol et™ iS™ 10 FTIR Spectrometer, Thermo Scientific) was employed to analyze the chemical functional groups and verify the presence of carboxyl groups on the surface of the produced oxidized micro- and nanofibers.

[0108] Inductively coupled plasma optical emission spectroscopy (ICP-OES) was conducted to investigate the element / nutrient composition of the produced NOP effluent.

[0109] The thermal properties of the selected samples were examined using a thermogravimetric analyzer (TA instruments Q50). Approximately 5 mg of the freeze-dried samples were placed in a platinum crucible. The measurement was conducted in a temperature range from 25 °C to 800 °C at a heating rate of 10 °C min ' under a nitrogen atmosphere with a flow rate of 10 mL min The onset of thermal degradation and the maximum degradation temperatures were determined using DTG curves.

[0110] The microstructure of selected samples was analyzed using transmission electron microscopy (TEM) (JEOL, JEM-1400, Japan)). Prior to imaging, the 0.01 wt% CNF suspensions were vortexed for 10 min. A drop of the diluted suspension was deposited onto a carbon-coated copper grid and subsequently stained with 2% (w / v) uranyl acetate for 5 min. The sample was then air-dried at room temperature. TEM images were captured at an accelerating voltage of 120 kV.EXAMPLE 1

[0111] 20 grams of dried ground palm tree biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.32 grams (0.014 mol) of FesC were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0.

[0112] The obtained oxidized micro- and nanofibers were characterized following the above- mentioned methods. The yield of cellulose fibers obtained was about 19% and the DO was 1.07 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 1, which showed a peak around 1732 cm’1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 2

[0113] 20 grams of dried ground palm tree biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.038 grams (0.014 mol) of ground aluminum foil were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 25% and the DO was 0.96 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 2, which showed a peak around 1711 cm’1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 3

[0114] 20 grams of dried ground palm tree biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.099 grams (0.014 mol) of MnO were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 21% and the DO was 0.92 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 3, which showed a peak around 1732 cm'1that corresponds to - C=O of carboxyl stretching of cellulose.EXAMPLE 4

[0115] 20 grams of dried ground palm tree biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.1 grams (0.014 mol) of FeO were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 22% and the DO was 1.14 mmol / g. The FTIR spectrum of the fibers isset forth in FIG. 4, which showed a peak showed a peak around 1713 cm’1that corresponds to - C=O of carboxyl stretching of cellulose.EXAMPLE 5

[0116] 20 grams of dried ground palm tree biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0. 177 grams (0.014 mol) of FeCL were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached at ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 21% and the DO was 0.84 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 5, which showed a peak around 1732 cm’1that corresponds to - C=O of carboxyl stretching of cellulose.EXAMPLE 6

[0117] 20 grams of dried ground palm tree biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.226 grams (0.014 mol) of FeCL were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield ofcellulose fibers obtained was about 24% and the DO was 0.7 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 6, which showed a peak around 1732 cm'1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 7

[0118] 20 grams of dried ground palm tree biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50%, v / v) and 0.104 grams (0.014 mol) of NiO were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 25% and the DO was 0.78 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 7, which showed a peak around 1731 cm'1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 8

[0119] 20 grams of dried ground sugarcane bagasse biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.1 grams (0.014 mol) of FeO were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro-and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 31% and the DO was 1.49 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 8, which showed a peak around 1731 cm'1that corresponds to - C=O of carboxyl stretching of cellulose.EXAMPLE 9

[0120] 20 grams of dried ground sugarcane bagasse biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.099 grams (0.014 mol) of MnO were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 33% and the DO was 1.07 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 9, which showed a peak around 1728 cm'1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 10

[0121] 20 grams of dried ground sugarcane bagasse biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.104 grams (0.014 mol) of NiO were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers werecollected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 31% and the DO was 1.28 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 10, which showed a peak around 1731 cm’1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 11

[0122] 20 grams of dried ground potato biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentratedHNCh (50% v / v) and 0.1 grams (0.014 mol) of FeO were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 3.5% and the DO was 1.07 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 11, which showed a peak around 1731 cm’1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 12

[0123] 20 grams of dried ground potato biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.099 grams (0.014 mol) of MnO were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected andwashed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 4% and the DO was 1.61 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 12, which showed a peak around 1729 cm’1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 13

[0124] 20 grams of dried raw brewer's spent grain biomass was added in a 1-neck round bottom flask (3.0 1). 280 ml of concentrated HNO3 (50% v / v) and 0.1 grams (0.014 mol) of FeO were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 14.0% and the DO was 0.57 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 13, which showed a peak around 1707 cm’1that corresponds to - C=O of carboxyl stretching of cellulose.EXAMPLE 14

[0125] 20 grams of dried raw brewer's spent grain biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.099 grams (0.014 mol) of MnO were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers werecollected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 14.0% and the DO was 0.77 mmol / g. The FTIR spectrum of the fibers is set forth in FIG. 14, which showed a peak around 1708 cm’1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 15

[0126] 20 grams of dried raw brewer's spent grain biomass was added in a 2-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.064 grams (0.0063 mol) of KNO3 were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. To maintain the pressure inside the flask, both mouths of the round bottom flask were covered with a stopper and loosely parafilmed. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the abovementioned methods. The yield of cellulose fibers obtained was about 14.0% and the DO was 0.98 mmol / g. FTIR spectra of FIG. 15(a) showed that compared to the raw biomass, a new peak appeared at 1707 cm’1that corresponds to -C=O of carboxyl stretching of cellulose after treatment. ICP-OES elemental analysis of the effluent produced from spent grain treated with 50% HNO3 (v / v) and KNO3 is shown in FIG. 15(b).EXAMPLE 16

[0127] 20 grams of dried raw sugarcane bagasse biomass was added in a 2-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.064 grams (0.0063 mol) of KNO3 were then added at once into the flask under continuous stirring and the reaction was initiated at 50°C for 9 hours. To maintain the pressure inside the flask, both mouths of the round bottom flask were covered with a stopper and loosely parafilmed. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the abovementioned methods. The yield of cellulose fibers obtained was about 14.0% and the DO was 1.20 mmol / g. FTIR spectra of FIG. 16(a) showed that compared to the raw biomass, a new peak appeared at 1724 cm’1that corresponds to -C=O of carboxyl stretching of cellulose after treatment. ICP-OES elemental analysis of the effluent produced from sugarcane bagasse treated with 50% (v / v) HNO3 and KNO3 is shown in FIG. 16(b).EXAMPLE 17

[0128] 20 grams of dried ground raw potato biomass was added in a 2-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.064 grams (0.0063 mol) of KNO3 were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. To maintain the pressure inside the flask, both mouths of the round bottom flask were covered with a stopper and loosely parafilmed. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the abovementioned methods. The yield of cellulose fibers obtained was about 4.19% and the DO was 1.29 mmol / g. FTIR spectra of FIG. 17(a) showed that compared to the raw biomass, a new peak appeared at 1724 cm’1that corresponds to -C=O of carboxyl stretching of cellulose after treatment. ICP-OES elemental analysis of the effluent produced from potato ground treated with 50% HNO3 (v / v) and KNO3 is shown in FIG. 17(b).EXAMPLE 18

[0129] 20 grams of dried raw grape pomace biomass was added in a 2-neck round bottom flask (3.0 L). 280 ml of concentrated. HNO3 (50% v / v) and 0.064 grams (0.0063 mol) of KNO3 were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. To maintain the pressure inside the flask, both mouths of the round bottom flask were covered with a stopper and loosely parafilmed. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the abovementioned methods. The yield of cellulose fibers obtained was about 17.28% and the DO was 0.92 mmol / g. FTIR spectra of FIG. 18(a) showed that compared to the raw biomass, a new peak appeared at 1712 cm'1that corresponds to -C=O of carboxyl stretching of cellulose after treatment. ICP-OES elemental analysis of the effluent produced from grape pomace treated with 50% HNO3 (v / v) and KNO3 is shown in FIG. 18(b).EXAMPLE 19

[0130] 20 grams of dried ground raw jute biomass was added in a 2-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.064 grams (0.0063 mol) of KNO3 were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. To maintain the pressure inside the flask, both mouths of the round bottom flask were covered with a stopper and loosely parafilmed. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the abovementioned methods. The yield of cellulose fibers obtained was about 52.19%, and the DO was 1.38 mmol / g. FTIR spectraof FIG. 19(a) showed that compared to the raw biomass, a new peak appeared at 1728 cm'1that corresponds to -C=O of carboxyl stretching of cellulose after treatment. ICP-OES elemental analysis of the effluent produced from jute treated with 50% HNO3 (v / v) and KNO3 is shown in FIG. 19(b).EXAMPLE 20

[0131] 20 grams of dried raw palm tree leafstalk biomass was added in a 2-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.064 grams (0.0063 mol) of KNO3 were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. To maintain the pressure inside the flask, both mouths of the round bottom flask were covered with a stopper and loosely parafilmed. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the abovementioned methods. The yield of cellulose fibers obtained was about 21.84%, and the DO was 1.45 mmol / g. FTIR spectra of FIG. 20(a) showed that compared to the raw biomass, a new peak appeared at 1732 cm'1that corresponds to -C=O of carboxyl stretching of cellulose after treatment. ICP-OES elemental analysis of the effluent produced from palm tree leafstalk treated with 50% HNO3 (v / v) and KNO3 is shown in FIG. 20(b).EXAMPLE 21

[0132] 20 grams of dried ground raw sorghum biomass was added in a 2-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.064 grams (0.0063 mol) of KNO3 were then added at once into the flask under continuous stirring and the reaction was initiated at50 °C for 9 hours. To maintain the pressure inside the flask, both mouths of the round bottom flask were covered with a stopper and loosely parafdmed. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached -3.0. The obtained oxidized micro- and nanofibers were characterized following the abovementioned methods. The yield of cellulose fibers obtained was about 37.35%, and the DO was 1.16 mmol / g. FTIR spectra (FIG. 21) showed that compared to the raw biomass, a new peak appeared at 1719 cm'1that corresponds to -C=O of carboxyl stretching of cellulose after treatment.EXAMPLE 22

[0133] 20 grams of dried ground red onion skins biomass was added in a 2-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.064 grams (0.0063 mol) of KNO3 were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. To maintain the pressure inside the flask, both mouths of the round bottom flask were covered with a stopper and loosely parafilmed. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached -3.0. The obtained oxidized micro- and nanofibers were characterized following the abovementioned methods. The yield of cellulose fibers obtained was about 20.14%, and the DO was 1.68 mmol / g. FTIR spectra of FIG. 22(a) showed that compared to the raw biomass, a new peak appeared at 1727 cm'1that corresponds to -C=O of carboxyl stretching of cellulose after treatment. ICP-OES elemental analysis of the effluent produced from red onion skins treated with 50% HNO3 (v / v) and KNO3 is shown in FIG. 22(b).EXAMPLE 23

[0134] 20 grams of dried ground raw sugarcane bagasse biomass was added in a 2-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.064 grams (0.0063 mol) of KNO3 were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. To maintain the pressure inside the flask, both mouths of the round bottom flask were covered with a stopper and loosely parafilmed. At the end of the reaction, the effluent was collected and neutralized with base to pH ~5.5-6.0. In parallel, the fibers were collected and washed several times with distilled water until pH reached ~3.0. After neutralization with base to pH ~5.5-6.0, the fibers were homogenized using high-pressure homogenizer and then cross-linked with the abovementioned neutralized effluent, which is initially diluted to two, five, ten or twenty times with DI water to prepare cellulose-based biogels.EXAMPLE 24

[0135] 20 grams of dried raw grape pomace biomass was added in a 2-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.064 grams (0.0063 mol) of KNO3 were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. To maintain the pressure inside the flask, both mouths of the round bottom flask were covered with a stopper and loosely parafilmed. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. After neutralization with base to pH~5.5-6.0, the fibers were homogenized using high-pressure homogenizer and then cross-linked with the abovementioned neutralized effluent derived fromsugarcane bagasse treated with 50% HNO3 (v / v) and KNO3 (Example 23), which is initially diluted to two, five, ten or twenty times with DI water to prepare cellulose-based biogels.EXAMPLE 25

[0136] 20 grams of dried raw brewer's spent grain biomass was added in a 2-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.064 grams (0.0063 mol) of KNO3 were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. To maintain the pressure inside the flask, both mouths of the round bottom flask were covered with a stopper and loosely parafilmed. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. After neutralization with base to pH~5.5-6.0, the fibers were homogenized using high-pressure homogenizer and then cross-linked with the abovementioned neutralized effluent derived from sugarcane bagasse treated with 50% HNO3 (v / v) and KNO3 (Example 23), which is initially diluted to two, five, ten or twenty times with DI water to prepare cellulose-based biogels.EXAMPLE 26

[0137] 20 grams of dried raw jute ground biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 1.76 grams (0.014 mol) of FeCh were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulosefibers obtained was about 41%, and the DO was 1 .26 mmol / g. FTIR spectrum (FIG. 23) showed a peak around 1725 cm'1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 27

[0138] 20 grams of dried raw jute ground biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 2.42 grams (0.014 mol) of iron (II) acetate were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 44 %, and the DO was 1.05 mmol / g. FTIR spectrum (FIG. 24) showed a peak around 1732 cm'1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 28

[0139] 20 grams of dried raw jute ground biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 1 gram (0.014 mol) of iron (II) oxide were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield ofcellulose fibers obtained was about 42 %, and the DO was 1 .2 mmol / g. FTIR spectrum (FIG. 25) showed a peak around 1731 cm’1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 29

[0140] 20 grams of dried raw jute ground biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 0.5 grams (0.007 mol) of manganese (II) oxide were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 44%, and the DO was 1.38 mmol / g. FTIR spectrum (FIG. 26) showed a peak around 1725 cm’1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 30

[0141] 20 grams of dried raw jute ground biomass was added in a 1-neck round bottom flask (3.0 L). 280 ml of concentrated HNO3 (50% v / v) and 3.86 grams (0.014 mol) of iron (II) sulfate heptahydrate were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. Theyield of cellulose fibers obtained was about 42%, and the DO was 1 .33 mmol / g. FTIR spectrum (FIG. 27) showed a peak around 1726 cm'1that corresponds to -C=O of carboxyl stretching of cellulose.EXAMPLE 31

[0142] 6.66 grams of dried raw jute ground biomass was added in a 1-neck round bottom flask (1.0 L). 93.35 ml of concentrated HNOs (50% v / v) was then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. The reaction was quenched by adding about 2 / 3 L of water. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 54%, and the DO was 1.48 mmol / g (FIG. 29). FTIR spectrum (FIG. 28) showed a peak around 1726 cm'1that corresponds to -C=O of carboxyl stretching of cellulose. The maximum decomposition temperature for this sample was 308°C (FIG. 30(b)). TEM images showed an average width of 5.70 nm (FIG. 31).EXAMPLE 32

[0143] 6.66 grams of dried raw jute ground biomass was added in a 1-neck round bottom flask (1 .0 L). 93.35 ml of concentrated HNO3 (50% v / v) along with 0.468 grams (4.63 mmol) of potassium nitrate were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. The reaction was quenched byadding about 2 / 3 L of water. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 55%, and the DO was 1.43 mmol / g (FIG. 29). FTIR spectrum (FIG. 28) showed a peak around 1726 cm'1that corresponds to -C=O of carboxyl stretching of cellulose. The maximum decomposition temperature for this sample was 310°C (FIG. 30(b)).EXAMPLE 33

[0144] 6.66 grams of dried raw jute ground biomass was added in a 1-neck round bottom flask (1.0 L). 93.35 ml of concentrated HNO3 (50% v / v) along with 0.394 grams (4.63 mmol) of potassium nitrite were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. The reaction was quenched by adding about 2 / 3 L of water. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 54%, and the DO was 1.57 mmol / g (FIG. 29). FTIR spectrum (FIG. 28) showed a peak around 1726 cm1that corresponds to -C=O of carboxyl stretching of cellulose. The maximum decomposition temperature for this sample was 304°C (FIG. 30). TEM images showed an average width of 5.32 nm (FIG. 32).EXAMPLE 34

[0145] 6.66 grams of dried raw jute ground biomass was added in a 1-neck round bottom flask (1.0 L). 93.35 ml of concentrated HNO3 (50% v / v) along with 1.29 grams (4.63 mmol) of iron(ii) sulfate heptahydrate were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. The reaction was quenched by adding about 2 / 3 L of water. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 55%, and the DO was 1.48 mmol / g (FIG. 29). FTIR spectrum (FIG. 28) showed a peak around 1726 cm'1that corresponds to -C=O of carboxyl stretching of cellulose. The maximum decomposition temperature for this sample was 305°C (FIG. 30). TEM images showed an average width of 6.39 nm (FIG. 33).EXAMPLE 35

[0146] 6.66 grams of dried raw jute ground biomass was added in a 1-neck round bottom flask (1.0 L). 93.35 ml of concentrated HNO3 (50% v / v) along with 1.162 grams (4.63 mmol) of manganese(ii) nitrate tetrahydrate were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. The reaction was quenched by adding about 2 / 3 L of water. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield ofcellulose fibers obtained was about 54%, and the DO was 1 .28 mmol / g (FIG. 29). FTIR spectrum (FIG. 28) showed a peak around 1726 cm'1that corresponds to -C=O of carboxyl stretching of cellulose. The maximum decomposition temperature for this sample was 311°C (FIG. 30).EXAMPLE 36

[0147] 6.66 grams of dried raw jute ground biomass was added in a 1-neck round bottom flask (1.0 L). 93.35 ml of concentrated HNO3 (50% v / v) along with 0.783 grams (4.63 mmol) of manganese(ii) sulfate monohydrate were then added at once into the flask under continuous stirring and the reaction was initiated at 50 °C for 9 hours. The round bottom flask was covered with a stopper and loosely parafilmed so pressure can decrease if necessary. The reaction was quenched by adding about 2 / 3 L of water. At the end of the reaction, the fibers were collected and washed several times with distilled water until pH reached ~3.0. The obtained oxidized micro- and nanofibers were characterized following the above-mentioned methods. The yield of cellulose fibers obtained was about 54%, and the DO was 1.37 mmol / g (FIG. 29). FTIR spectrum (FIG. 28) showed a peak around 1726 cm'1that corresponds to -C=O of carboxyl stretching of cellulose. The maximum decomposition temperature for this sample was 310°C (FIG. 30). TEM images showed an average width of 4.52 nm (FIG. 34).

Claims

WHAT IS CLAIMED IS:

1. A method comprising:Contacting plant biomasses, protein biomasses, and / or mixtures as a feedstock, with nitric acid at a concentration above 30% v / v and one or more oxidizing agents; holding the mixture at a temperature from about 40° C to 100° C for a period of time from about 0.5 hours to about 72 hours; and separating the treated fiber residues and effluent.

2. The method of claim 1, wherein the plant biomass includes lignocellulose wood, non-lignocellulose wood, lignocellulose, pure cellulose, grasses, phytoplanktons, algal celluloses, tunicate celluloses, and combinations thereof.

3. The method of claim 1, wherein the plant biomass is obtained from sources including jute, palm tree, sugarcane bagasse, com, wheat, oat, rice, sorghum, oil palm, bamboo, spinifex, coastal bermudagrass, miscanthus, switchgrass, azolla, seaweeds, flax, hemp, ramie, kenaf stalk fiber, kenaf core, abaca, sisal, pineapple, banana leaf, banana peel, banana fiber, curaua, lotus lead stalk, roselle, seed hair fiber, cotton fiber, kapok fiber, areca nut fiber, coconut, potato, cabbage, tomato, all vegetables, rubberwood, indian screw tree, achira fiber, citrus, soybean, soybean straw, spent grain, soy hull, pea hull, grape pomace, fruit pomace, and combinations thereof.

4. The method of claim 1, wherein the protein biomass is obtained from sources including cow, chicken, fish, pig, goat, lamb, duck, turkey, prawns, crab, lobster, shrimp, mussels, oysters, scallops, clams, and combinations thereof.

5. The method of claim 1, wherein the mixture includes cow manure, horse manure, chicken manure, pig manure, and food waste, and combinations thereof.

6. The method of claim 1, wherein the acid component further comprises an additional acid selected from hydrochloric acid, sulfuric acid, acetic acid, hydrobromic acid, hydrofluoric acid, and combinations thereof.

7. The method of claim 1, wherein the oxidizing agent component comprises a metal oxide selected from iron (II) oxide, iron (III) oxide, iron (II, III) oxide, titanium oxide, titanium dioxide, zirconium (II) oxide, zirconium (IV) oxide, zinc (II) oxide, copper (II) oxide, nickel (II) oxide, manganese (II) oxide, manganese (IV) oxide, cobalt oxide, molybdenum (VI) oxide, silicon dioxide, and combinations thereof.

8. The method of claim 1, wherein the oxidizing agent component comprises a metal chloride selected from iron chlorides, aluminum chlorides, nickel chlorides, manganese chlorides, zinc chlorides, copper chlorides, cobalt chlorides, titanium chlorides, and combinations thereof.

9. The method of claim 1, wherein the oxidizing agent component comprises a metal nitrate, metal nitrite, or metal sulfate selected from iron (III) nitrate, iron (II) nitrate, zinc nitrate, silver nitrate, manganese (II) nitrate, iron (II) acetate, aluminum nitrate, nickel nitrate, molybdenum nitrate, potassium nitrate, potassium nitrite, manganese nitrite, iron (II) sulfate, manganese (II) sulfate, copper (II) sulfate, nickel (II) sulfate, aluminum sulfate, and combinations thereof.

10. The method of claim 1, wherein the oxidizing agent component comprises a nitrite salt selected from potassium nitrite, calcium nitrite, magnesium nitrite, and combinations thereof.11 . The method of claim 1 , wherein the amount of the acid component is from about 10 mmol to about 300 mmol per gram of biomass.

12. The method of claim 1, wherein the amount of the oxidizing agent is from 0.05 mmol to about 60 mmol per gram of biomass.

13. The method of claim 1 , wherein the mixture of acid and oxidizing agent is at a temperature from about 40 °C. to about 100 °C., for a period of time from about 0.5 hours to about 72 hours.

14. The method of claim 1, wherein the fibers subject to mechanical treatments selected from sonication, homogenization, cryocrushing, grinding, steam explosion, and combination thereof, wherein the method occurs for a period from about 1 min to around 360 min.

15. The method of claim 1, wherein the oxidized cellulose fibers have a mean fiber length from about 10 nm to about 10000 nm.

16. The method of claim 1, wherein the oxidized cellulose fibers have a mean nominal diameter from 2 nm to about 200 nm.

17. The method of claim 1, wherein the weight percentage (wt%) of the gellable substrate is from about 0.5% by weight to about 10% by weight.

18. The method of claim 1, wherein the gellable substrate has a lignin and hemicellulose content from about 2% by weight to about 20% by weight.

19. The method of claim 1, wherein the base components or their salts selected from sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, magnesiumhydroxide, zinc hydroxide, and combinations thereof, are utilized to neutralize the produced NOP effluent.

20. The method of claim 1, wherein cellulose-based biogels are produced via crosslinking with the cations in the neutralized NOP effluent selected from calcium, magnesium, iron (II), iron (III), zinc, manganese, nickel, aluminum, sodium, potassium, and combinations thereof.

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