Modified sulfuric acid and uses thereof

Abstract

An aqueous composition comprising sulfuric acid, a compound comprising an amine moiety, a compound comprising a sulfonic acid moiety, and a peroxide, the composition being capable of delignifying biomass.

Description

[Technical field]

[0001] TECHNICAL FIELD TO WHICH THEINVENTION BELONGS The present invention relates in broad terms to methods and compositions useful for decomposing organic matter, such as biomass, by oxidation, such as delignification of the biomass, and more specifically to methods and compositions for doing so under more optimal conditions than those under which the Kraft process is currently carried out. [Background technology]

[0002] 2. Background of the Invention The largest energy consumer in paper production is the production of pulp. Wood and other plants from which pulp is made contain three main components: cellulose fibers, lignin, and hemicellulose, as well as water. The primary objective of pulping is to separate the fibers and lignin. Lignin is a three-dimensional polymer that acts as a kind of mortar that holds all the fibers together in the plant. Lignin is undesirable in pulp and does not add anything to the final product. Wood pulping involves breaking down the bulk structure of fibrous raw materials, such as chips, stems, and other plant parts, into their constituent fibers. Cellulose fibers are the most important component in the papermaking process. Hemicellulose is a shorter branched carbohydrate polymer made up of various sugar monomers randomly arranged in an amorphous polymeric structure. The presence of hemicellulose in the finished pulp is not as important for the stiffness of the paper as cellulose. This is also true for biomass conversion. The challenges are similar; the desired results are different. In biomass conversion, further degradation to monovalent carbohydrates is the desired outcome, but in pulp and paper processes this is usually stopped soon after lignin dissolution.

[0003] There are two main approaches to the preparation of wood pulp or woody biomass: mechanical and chemical processing. Mechanical processing or pulping generally aims to physically tear the wood chips, thus splitting the cellulose fibers and separating them from each other. The disadvantages of this method are that the cellulose fibers are cut or damaged, resulting in shorter fibers, and that lignin is mixed or left in the cellulose fibers, resulting in impurities in the final product. The process is also energy-intensive and capital-intensive, since it requires high pressure, caustic chemicals, and heat. There are several approaches and processes for chemical pulping. These generally focus on breaking down the lignin and hemicellulose into water-soluble molecules. These broken down components are separated from the cellulose fibers by washing, without damaging the cellulose fibers. This chemical process is energy-intensive, since it requires a large amount of heat, and also often requires stirring and mechanical intervention, which increases the inefficiency and cost of the process.

[0004] Pulping or processing methods exist that combine the chemical aspects of pulping with the mechanical aspects of pulping to various degrees. Examples include thermomechanical pulping (also commonly referred to as TMP), chemi-thermo-mechanical pulping (CTMP), etc. By selecting the advantages offered by each common pulping method, the process is performed to reduce the amount of energy required for the mechanical aspects of the pulping process. This can also have a direct impact on the degradation of strength or tensile strength of fibers subjected to these combined pulping approaches. In general, these approaches shorten the chemical treatment (compared to traditional dedicated chemical pulping) and usually follow it with a mechanical treatment to separate the fibers.

[0005] The most common method of producing pulp for papermaking is the Kraft process. In the Kraft process, wood chips are converted into wood pulp, which is almost pure cellulose fiber. - The Kraft process begins by impregnating and treating the wood chips with chemical solutions. This is done by soaking the wood chips and preheating them with steam. This process expands the wood chips, expelling the air inside the chips and replacing the air with liquid. At this time, black liquor is generated as a by-product of the Kraft process. Black liquor contains moisture, lignin residues, hemicellulose, and inorganic chemicals. White liquor is a strong alkaline solution that contains sodium hydroxide and sodium sulfide. After soaking the wood chips in various chemical solutions, they are cooked. To delignify the wood chips, they are boiled at temperatures up to 176°C for several hours. At this temperature, the lignin breaks down and water-soluble fragments are produced. After cooking, the remaining cellulose fibers are collected and washed.

[0006] U.S. Patent No. 5,080,756 teaches an improved kraft pulping process, characterized in that a spent concentrated sulfuric acid composition containing organic matter is added to a kraft recovery system to provide a mixture enriched in its total sulfur content which is subjected to dehydration, pyrolysis and reduction in a recovery furnace. The organic matter of the sulfuric acid composition is particularly useful as a source of thermal energy that can easily maintain high heat levels to promote the oxidation and reduction reactions that occur in the furnace, resulting in the formation of sulfides which are used to prepare a cooking liquor suitable for pulping.

[0007] Caro's acid, also known as peroxymonosulfuric acid (H2SO5), is one of the strongest oxidizing agents known. Several reactions are known for the preparation of Caro's acid, but one of the simplest involves the reaction of sulfuric acid (H2SO4) with hydrogen peroxide (H2O2). Once prepared in this manner, Caro's acid can be further reacted to produce potassium monopersulfate (PMPS), a valuable bleaching and oxidizing agent. Caro's acid has several known useful applications, most notably in wood delignification.

[0008] Biofuel production is also a potential application of the Kraft process. A current drawback of biofuel production is the need to use food-grade plant parts (such as seeds) to convert carbohydrates into fuel in a reasonably efficient process. Carbohydrates can also be obtained from cellulosic fibers by using non-food-grade biomass in the Kraft process, but the Kraft process is energy-intensive for delignification, making it a less commercially viable option. To build a plant-based chemical resource cycle, there is a great need for energy-efficient processes that can utilize plant-based feedstocks that do not compete with human food production.

[0009] The kraft pulping process is the most widely used chemical pulping process in the world, but it is very energy demanding and also has drawbacks, such as, for example, unpleasant odors emanating from the pulping plant surroundings and general exhaust gases that are currently strongly regulated in many pulp and paper manufacturing jurisdictions. In view of current environmental and economic issues, climate change, and the introduction of emission fees, it is highly desirable to optimize current pulping processes in order to provide at least linear quality fiber without currently causing substantial harm to the environment during its production. Thus, there remains a need for compositions that are capable of delignifying wood material at lower temperatures and pressures than those currently used, and without the need for additional capital investments. Summary of the Invention

[0010] Summary of the Invention According to one aspect of the present invention, there is provided an aqueous acidic composition comprising: Sulfuric acid; Compounds containing an amine moiety; Compounds containing a sulfonic acid moiety; and Peroxides, 1. An aqueous acidic composition comprising:

[0011] According to one aspect of the present invention, there is provided an aqueous acidic composition comprising: Sulfuric acid; Compounds containing an amine moiety; Compounds containing a sulfonic acid moiety; and Peroxides, An aqueous acidic composition comprising: wherein the sulfuric acid, the compound containing an amine moiety, and the compound containing a sulfonic acid moiety are present in a molar ratio of 1:1:1 or greater.

[0012] Preferably, sulfuric acid, the compound comprising an amine moiety, and the compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 28:1:1 to 2:1:1. More preferably, sulfuric acid, the compound comprising an amine moiety, and the compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 24:1:1 to 3:1:1. Preferably, sulfuric acid, the compound comprising an amine moiety, and the compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 20:1:1 to 4:1:1. More preferably, the sulfuric acid, the compound comprising an amine moiety, and the compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 16:1:1 to 5:1:1. According to a preferred embodiment of the present invention, sulfuric acid, the compound comprising an amine moiety, and the compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 12:1:1 to 6:1:1.

[0013] According to a preferred embodiment of the invention, the compound comprising an amine moiety and the compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 2:1 to 1:2.

[0014] According to another preferred embodiment of the invention, said compound comprising an amine moiety and said compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 3:1 to 1:3.

[0015] According to a preferred embodiment of the invention, the compound comprising an amine moiety and the compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 4:1 to 1:4.

[0016] According to a preferred embodiment of the invention, the compound comprising an amine moiety and the compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 5:1 to 1:5.

[0017] Also preferably, the compound containing an amine moiety has a molecular weight of less than 300 g / mol. Also preferably, the compound containing an amine moiety has a molecular weight of less than 150 g / mol. More preferably, the compound containing an amine moiety is a primary amine. Even more preferably, the compound containing an amine moiety is an alkanolamine. Even more preferably, the compound containing an amine moiety is a tertiary amine.

[0018] According to a preferred embodiment of the present invention, the alkanolamine is selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, and combinations thereof. Preferably, the alkanolamine is triethanolamine.

[0019] According to a preferred embodiment of the present invention, the compound containing a sulfonic acid moiety is selected from the group consisting of alkylsulfonic acids, where the alkyl group ranges from C1 to C6 and is linear or branched; and combinations thereof. Preferably, the compound containing a sulfonic acid moiety is selected from the group consisting of methanesulfonic acid; ethanesulfonic acid; propanesulfonic acid; 2-propanesulfonic acid; isobutylsulfonic acid; t-butylsulfonic acid; butanesulfonic acid; iso-pentylsulfonic acid; t-pentylsulfonic acid; pentanesulfonic acid; t-butylhexanesulfonic acid; and combinations thereof. More preferably, the compound containing a sulfonic acid moiety is methanesulfonic acid.

[0020] According to one aspect of the present invention, there is provided an aqueous composition comprising: Sulfuric acid; Compounds containing an amine moiety; Compounds containing a sulfonic acid moiety; and Peroxides, 1. An aqueous composition for use in delignification of biomass, such as wood, comprising: wherein the sulfuric acid, the compound containing an amine moiety, and the compound containing a sulfonic acid moiety are present in a molar ratio ranging from 2:1:1 to 30:1:1.

[0021] According to one aspect of the present invention, there is provided an aqueous composition comprising: 1. An aqueous composition for use in the decomposition of cellulose from biomass (i.e., plant sources), said composition comprising: sulfuric acid, from 20 to 70 wt. % relative to the total weight of the composition; Compounds containing an amine moiety; Compounds containing a sulfonic acid moiety; and Peroxide; Including, wherein the sulfuric acid, the compound comprising an amine moiety, and the compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 2:1:1 to 30:1:1.

[0022] Preferably, the peroxide is hydrogen peroxide.

[0023] According to one aspect of the present invention, there is provided a method comprising: 1. A method for delignification of biomass / plant material comprising the steps of: - providing said plant material comprising cellulose fibers and lignin; - said plant material in need, 20-70 wt.% of sulfuric acid based on the total weight of the composition; Compounds containing an amine moiety; and a compound comprising a sulfonic acid moiety; for a time sufficient to remove substantially all of the lignin present on the plant material; The method comprising: Preferably, the composition further comprises a peroxide.

[0024] Preferably, the compound containing a sulfonic acid moiety is selected from the group consisting of alkylsulfonic acids, where the alkyl group is in the range of C1-C6, linear or branched; and combinations thereof. Preferably, the compound containing a sulfonic acid moiety is selected from the group consisting of methanesulfonic acid; ethanesulfonic acid; propanesulfonic acid; 2-propanesulfonic acid; isobutylsulfonic acid; t-butylsulfonic acid; butanesulfonic acid; iso-pentylsulfonic acid; t-pentylsulfonic acid; pentanesulfonic acid; t-butylhexanesulfonic acid; and combinations thereof. More preferably, the compound containing a sulfonic acid moiety is methanesulfonic acid.

[0025] Preferably, the compound comprising an amine moiety has a molecular weight of less than 300 g / mol. More preferably, the compound comprising an amine moiety has a molecular weight of less than 150 g / mol. According to a preferred embodiment of the present invention, the composition has a pH of less than 1, and according to another preferred embodiment of the present invention, the composition has a pH of less than 0.5.

[0026] The inventors have discovered that delignification of biomass, such as wood material / wood pulp (e.g., but not limited to, wood chips), can occur at temperatures significantly lower than those used during conventional kraft pulping processes. Indeed, experiments conducted at room temperature with a preferred composition according to the present invention have shown to degrade lignin present in wood chips to liberate cellulose fibers. According to a preferred embodiment of the method according to the present invention, wood samples were dissolved at 30° C. upon exposure to a composition according to a preferred embodiment of the present invention. According to a preferred embodiment of the present invention, the energy input costs involved in current pulp delignification can be substantially reduced by applying a method comprising a preferred composition of the present invention. [Brief description of the drawings]

[0027] Brief description of the drawings The present invention may be more fully understood from consideration of the following description of various embodiments of the invention in conjunction with the accompanying drawings, in which: FIG. [Figure 1] FIG. 1 is a photograph of the dissolution of wood chips in a composition according to the invention with an elapsed time of 1 minute; and [Diagram 2] FIG. 2 is a photograph of the dissolution of wood chips in a composition according to the invention over a period of 24 hours. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Detailed Description of the Invention Experiments carried out with aqueous acidic compositions according to preferred embodiments of the present invention have shown that wood chips can be delignified under controlled reaction conditions to eliminate or at least minimize the degradation of cellulose, whereby degradation is understood to mean the blackening or charring of cellulose (conversion to carbon black), which is emblematic of uncontrolled acid attack on cellulose and its staining.

[0029] Preferably, the compound containing the amine moiety and the compound containing the sulfonic acid moiety are present in a 1:1 ratio. There appears to be a coordination of the compounds that, when combined in the presence of sulfuric acid, act as a modified sulfuric acid. In that respect, it is believed that the presence of the sulfonic acid group along with the amine group forms part of this modified acid. The strength of the modified acid is defined by the number of moles of sulfuric acid relative to the number of moles of the compound containing the amine moiety and the compound containing the sulfonic acid moiety. Thus, a composition having a molar ratio of sulfuric acid:compound containing the amine moiety:compound containing the sulfonic acid moiety of 6:1:1 will be much less reactive than a composition containing the same components in a molar ratio of 28:1:1. It has also been noted that the ratio between the compound containing the amine moiety and the compound containing the sulfonic acid moiety can be varied without a significant effect on the reactivity of the overall composition, i.e., when placed in the presence of sulfuric acid, from 0.5:1 to 2:1.

[0030] When wood delignification is carried out using compositions according to preferred embodiments of the invention, the process can be carried out at temperatures significantly lower than those used in conventional kraft pulping processes. The advantages are considerable, some of which are listed here: Whereas kraft pulping processes require temperatures around 176-180°C to carry out the delignification step, preferred embodiments of the process according to the invention are capable of delignifying wood at much lower temperatures, even as low as 20°C. According to preferred embodiments of the invention, wood delignification can be carried out at temperatures as low as 0°C. According to preferred embodiments of the invention, wood delignification can be carried out at temperatures as low as 10°C. According to preferred embodiments of the invention, wood delignification can be carried out at temperatures as low as 30°C. According to another preferred embodiment of the invention, wood delignification can be carried out at temperatures as low as 40°C. According to yet another preferred embodiment of the invention, wood delignification can be carried out at temperatures as low as 50°C. According to yet another preferred embodiment of the invention, wood delignification can be carried out at temperatures as low as 60°C. Other advantages include reduced energy input; lower emissions and lower capital expenditures; reduced maintenance; reduced shutdown / turnaround costs; and also HSE advantages compared to conventional kraft pulped compositions.

[0031] In each one of the above preferred embodiments, the temperature at which the process is carried out is substantially lower than current energy intensive kraft processes.

[0032] Additionally, the Kraft process uses high pressure to perform wood delignification, which is initially capital intensive, hazardous, expensive to maintain, and has high associated turnaround costs. In accordance with preferred embodiments of the present invention, wood delignification can be performed at atmospheric pressure. This, in turn, avoids the need for highly specialized and expensive industrial equipment such as pressure vessels / digestors. It also allows for the implementation of delignification units in many parts of the world where the implementation of Kraft plants was previously not feasible for a variety of reasons.

[0033] Some of the advantages of the process according to the preferred embodiment of the present invention over the conventional kraft process are substantial, as the heat / energy requirements for the latter are not only a major source of pollution, but are a large part of the reason why the resulting pulp product is so expensive and has high initial capital requirements. Energy savings in implementing the process according to the preferred embodiment of the present invention will be reflected in lower priced pulp and environmental benefits that will have both immediate and long-term multi-generational benefits for all.

[0034] Further cost savings in the full or partial implementation of a process according to a preferred embodiment of the present invention can be found in the absence or minimization of restrictive regulations on the operation of the high temperature and high pressure pulp digester.

[0035] Experiment 1 A preferred embodiment of the composition according to the present invention was tested to determine its ability to delignify wood chips.

[0036] Experiments were completed using approximately 0.2 g of wood and approximately 20 g of solution. The mixture was stirred at 200 rpm at a temperature of 30°C.

[0037] Figures 1 and 2 show the dissolution of two wood chips in the presence of a composition according to a preferred embodiment of the present invention, which contains sulfuric acid, monoethanolamine, and methanesulfonic acid in a ratio of 6:1:1. It is noteworthy that the solution is clear even after 1 minute (see Figure 1). A sulfuric acid composition would have already shown signs of discoloration, indicating that the cellulose had been broken down into carbon black. In fact, the solution remained clear throughout the 24-hour experiment (see Figure 2). After 24 hours, the solution has dissolved all the lignin contained in the wood chips, leaving the packets of crystalline cellulose intact (or substantially intact). This is evidence of a mild oxidizing composition that targets the lignin and leaves the cellulose.

[0038] The above experiments clearly demonstrate that preferred compositions according to the present invention are valuable not only in providing adequate dissolving acid to delignify plant material, but also in controlling the ultimate decomposition of cellulosic material into carbon black residues, potentially resulting in higher yields for operators while reducing emissions and risks to employees, contractors and the public.

[0039] Additional delignification experiments Sulfuric acid, methanesulfonic acid (MSA), triethanolamine (TEOA) and hydrogen peroxide were mixed with increasing concentrations of MSA and TEOA and reacted with biomass (wood chips) overnight at room temperature to evaluate the effect of varying the molar ratio on the extent of reaction. Control studies were also performed on mixtures where kraft lignin or cellulose was added instead of biomass. Commercially available lignin (Sigma-Aldrich; Lignin, kraft; Prod# 471003) was used as a control in the study. Commercially available cellulose (Sigma-Aldrich; Cellulose, fibers (medium); Prod# C6288) was also used as a control in the study.

[0040] The solid phase of each blend was filtered after 20 hours reaction time, washed with water and then dried to constant weight in an oven at 45 °C. An effective blend should dissolve all the lignin and leave the cellulose as intact as possible. The experimental results are reported in Table 1 below.

[0041] [Table 1]

[0042] A 28:1:1:28 ratio blend of sulfuric acid (used at 96% concentration), MSA, TEOA, and hydrogen peroxide (as a 30% solution) resulted in 43% mass recovery from wood and cellulose. This shows that the acid / peroxide mixture is too aggressive and depolymerizes much of the cellulose. No lignin is recovered, which is the desired result. If the concentration of the MSA / TEOA retarder mixture is increased to one-tenth the concentration of the acid and peroxide, all of the lignin is still depolymerized enough to go into solution. However, the cellulose is not attacked as much. With this formulation, 89% of the cellulose could be recovered. Increasing the retarder concentration to half the acid / peroxide concentration slows down the digestion of the biomass and is less favorable. 55% of the wood and 92% of the cellulose could be recovered, but 22% of the lignin was not put into solution.

[0043] H 2 SO 4 :TEOA:MSA:H 2 O 2 were blended in a molar ratio of 10:1:1:10 in a batch process. To scale up the composition and process described above, a batch process was carried out. For the preparation of the batch process, 3,409 g of sulfuric acid (93%) was placed in a large glass reactor (10 L) and 444 g of methanesulfonic acid (70%) and 482 g of triethanolamine were added. The mixture was stirred at 100 RPM. Next, 3,665 g of hydrogen peroxide solution (29%) was slowly (over 1-1.5 hours) added to the modified acid. The reactor was cooled to dissipate the heat generated so that the temperature of the blend did not exceed 40°C. After the addition of hydrogen peroxide, the reactor system was left to equilibrate to ambient temperature (30 minutes). The molar blend ratio (order of addition) was 10:1:1:10. 400 g of unsized wood chips (sawdust) were slowly added to the reactor. The temperature rise was monitored. When the reactor temperature reached 55°C, the reactor was cooled to a temperature of 26°C. After this, cooling was no longer necessary. After 20 hours of reaction, the reaction mixture was transferred to a filter system equipped with a 20 μm Teflon filter sheet. The filtrate was discarded and the remaining filter cake was washed with 12 L of water until the effluent had a pH value of about 6. The filter cake was oven-dried (45° C.) overnight. The cellulose yield compared to the added biomass was 43.2%.

[0044] The resulting cellulose had a hydrocarbon content of 94.4%, close to the Sigma-Aldrich cellulose Lot# WXBC9745V-95.7% standard used for comparison. The moisture content was 1.70%, close to the Sigma-Aldrich cellulose Lot# WXBC9745V-3% standard used for comparison. It also had a Kappa# = 0, indicating that no lignin remained in the sample. X-ray diffraction revealed an apparent crystallinity of 58.2%, consistent with previous testing, and 62.9% for Aldrich commercial cellulose. Scanning electron microscopy showed a very high fiber content.

[0045] A method for obtaining glucose from wood pulp would be an important advance over current processes where such conversion is chemically and energy intensive, costly, emissions heavy, and hazardous while not resulting in high efficiency, especially in large scale operations. It would be desirable to employ a composition that allows some operator control to delignify wood and preserve cellulose rather than decompose it into carbon black, resulting in higher efficiency and yields, improved safety, and reduced overall costs.

[0046] According to a preferred embodiment of the method of the present invention, the separation of lignin is effectively performed and the resulting cellulose fibers can be further processed to obtain glucose monomers. Glucose chemistry has numerous applications as a starting block for the preparation of widely used chemicals including, but not limited to, diacetonides, dithioacetals, glucosides, glucals and hydroxyglucals.

[0047] According to another preferred embodiment of the present invention, the composition can be used for decomposition of organic matter by oxidation, such as those used in water treatment, water purification and / or desalination. An example of this is the removal (i.e., destruction) of algae on filtration membranes. Filtration membranes are expensive, so it is desirable to use them as long as possible. However, it is difficult to remove organic matter attached to the membrane, and a new approach is needed to remove it efficiently without damaging the membrane. Mineral acids are too strong, so they can remove organic matter, but they will damage the filtration membrane. The preferred composition of the present invention improves this problem because it is less aggressive than mineral acids, resulting in a much gentler approach to remove organic pollutants, thus sparing the membrane.

[0048] Although the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be understood by those skilled in the relevant art, once familiar with this disclosure, that various changes in form and detail may be made therein without departing from the true scope of the invention as set forth in the appended claims. In relation to the present invention, the following is further disclosed: [1] Sulfuric acid; Compounds containing an amine moiety; Compounds containing a sulfonic acid moiety; and Peroxides, 1. An aqueous acidic composition comprising: [2] Sulfuric acid; Compounds containing an amine moiety; Compounds containing a sulfonic acid moiety; and Peroxides, An aqueous acidic composition comprising: wherein the sulfuric acid, the compound containing an amine moiety, and the compound containing a sulfonic acid moiety are present in a molar ratio of 1:1:1 or greater. [3] The composition according to [1] or [2], wherein sulfuric acid, the compound comprising an amine moiety, and the compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 28:1:1 to 2:1:1. [4] The composition according to any one of [1] to [3], wherein the compound containing an amine moiety has a molecular weight of less than 300 g / mol. [5] The composition according to any one of [1] to [4], wherein the compound containing an amine moiety is a primary amine. [6] The composition according to any one of [1] to [4], wherein the compound containing an amine moiety is an alkanolamine. [7] The composition according to any one of [1] to [4], wherein the compound containing an amine moiety is a tertiary amine. [8] The composition of [6], wherein the alkanolamine is selected from the group consisting of monoethanolamine; diethanolamine; triethanolamine; and combinations thereof. [9] The composition according to any one of [1] to [8], wherein the alkanolamine is triethanolamine.

[10] The composition according to any one of [1] to [9], wherein the compound containing a sulfonic acid moiety is selected from the group consisting of alkylsulfonic acids and combinations thereof.

[11] The composition according to

[10] , wherein the alkyl sulfonic acid is selected from the group consisting of alkyl sulfonic acids, wherein the alkyl group is in the range of C1 to C6 and is linear or branched; and combinations thereof.

[12] The composition of claim

[11] , wherein the alkyl sulfonic acid is selected from the group consisting of methanesulfonic acid; ethanesulfonic acid; propanesulfonic acid; 2-propanesulfonic acid; isobutylsulfonic acid; t-butylsulfonic acid; butanesulfonic acid; isopentylsulfonic acid; t-pentylsulfonic acid; pentanesulfonic acid; t-butylhexanesulfonic acid; and combinations thereof.

[13] The composition according to any one of [1] to

[12] , wherein the compound containing a sulfonic acid moiety is methanesulfonic acid.

[14] Sulfuric acid; Compounds containing an amine moiety; Compounds containing a sulfonic acid moiety; and Peroxides, 1. An aqueous composition for use in wood delignification comprising: wherein the sulfuric acid, the compound containing an amine moiety, and the compound containing a sulfonic acid moiety are present in a molar ratio ranging from 2:1:1 to 28:1:1.

[15] 1. An aqueous composition for use in the treatment and depolymerization of cellulose from plant sources, said composition comprising: sulfuric acid, from 20 to 70 wt. % relative to the total weight of the composition; Compounds containing an amine moiety; Compounds containing a sulfonic acid moiety; and Peroxide; Including, wherein the sulfuric acid, the compound comprising an amine moiety, and the compound comprising a sulfonic acid moiety are present in a molar ratio ranging from 2:1:1 to 28:1:1.

[16] The composition according to any one of [1] to

[15] , wherein the peroxide is hydrogen peroxide.

[17] 1. A method for delignification of plant material comprising the steps of: - providing said plant material comprising cellulose fibers and lignin; - said plant material in need, 20-70 wt.% of sulfuric acid based on the total weight of the composition; Compounds containing an amine moiety; and a compound comprising a sulfonic acid moiety; for a time sufficient to remove substantially all of the lignin present on the plant material; The method comprising:

[18] 18. The method of claim 17, wherein the compound containing a sulfonic acid moiety is selected from the group consisting of methanesulfonic acid; ethanesulfonic acid; propanesulfonic acid; butanesulfonic acid; pentanesulfonic acid; hexanesulfonic acid; and combinations thereof.

[19] The method of any one of

[17] to

[18] , wherein the compound comprising an amine moiety has a molecular weight of less than 300 g / mol.

[20] The method according to any one of

[17] to

[19] , wherein the composition further comprises a peroxide.

[21] Sulfuric acid; Compounds containing an amine moiety; Compounds containing a sulfonic acid moiety; and Peroxides, An aqueous acidic composition comprising: wherein the compound containing an amine moiety and the compound containing a sulfonic acid moiety are present in a molar ratio ranging from 2:1 to 1:2.

Claims

1. Sulfuric acid; A compound containing an amine moiety selected from the group consisting of alkanolamines; Compounds containing a sulfonic acid moiety selected from the group consisting of alkylsulfonic acids, where the alkyl group ranges from C1 to C6 and is linear or branched; and Peroxides, An aqueous acidic composition comprising: wherein the sulfuric acid and the compound containing an amine moiety are present in a molar ratio of 1:1 or greater.

2. 2. The composition of claim 1, wherein the sulfuric acid and the compound containing an amine moiety are present in a molar ratio ranging from 28:1 to 2:

1.

3. 3. The composition of claim 1 or 2, wherein the compound containing an amine moiety has a molecular weight of less than 300 g / mol.

4. The composition of any one of claims 1 to 3, wherein the compound containing an amine moiety is a primary amine.

5. The composition of any one of claims 1 to 3, wherein the compound containing an amine moiety is a tertiary amine.

6. The composition of any one of claims 1 to 3, wherein the alkanolamine is selected from the group consisting of monoethanolamine; diethanolamine; triethanolamine; and combinations thereof.

7. The composition according to any one of claims 1 to 3, wherein the alkanolamine is triethanolamine.

8. 8. The composition of any one of claims 1 to 7, wherein the alkyl sulfonic acid is selected from the group consisting of methanesulfonic acid; ethanesulfonic acid; propanesulfonic acid; 2-propanesulfonic acid; isobutylsulfonic acid; t-butylsulfonic acid; butanesulfonic acid; isopentylsulfonic acid; t-pentylsulfonic acid; pentanesulfonic acid; t-butylhexanesulfonic acid; and combinations thereof.

9. The composition of any one of claims 1 to 8, wherein the compound containing a sulfonic acid moiety is methanesulfonic acid.

10. The composition according to any one of claims 1 to 9, wherein the peroxide is hydrogen peroxide.

11. Use of an aqueous composition in wood delignification, said composition comprising: Sulfuric acid; A compound containing an amine moiety selected from the group consisting of alkanolamines; Compounds containing a sulfonic acid moiety selected from the group consisting of alkylsulfonic acids, where the alkyl group ranges from C1 to C6 and is linear or branched; and Peroxides, Including, wherein the sulfuric acid and the compound containing an amine moiety are present in a molar ratio ranging from 2:1 to 28:

1.

12. 1. Use of an aqueous composition in the treatment and depolymerization of cellulose from plant sources, said composition comprising: 20 to 70 wt % of sulfuric acid, based on the total weight of the composition; A compound containing an amine moiety selected from the group consisting of alkanolamines; Compounds containing a sulfonic acid moiety selected from the group consisting of alkylsulfonic acids, where the alkyl group ranges from C1 to C6 and is linear or branched; and Peroxides, Including, wherein the sulfuric acid and the compound containing an amine moiety are present in a molar ratio ranging from 2:1 to 28:

1.

13. 1. A method for delignification of plant material comprising the steps of: - providing said plant material comprising cellulose fibres and lignin; - said plant material in need, 20-70 wt. % of sulfuric acid, based on the total weight of the composition; A compound containing an amine moiety selected from the group consisting of alkanolamines; and Compounds containing a sulfonic acid moiety selected from the group consisting of alkylsulfonic acids, where the alkyl group ranges from C1 to C6 and is linear or branched; and peroxide for a time sufficient to remove substantially all of the lignin present on the plant material; The method comprising:

14. 14. The method of claim 13, wherein the compound containing a sulfonic acid moiety is selected from the group consisting of methanesulfonic acid; ethanesulfonic acid; propanesulfonic acid; butanesulfonic acid; pentanesulfonic acid; hexanesulfonic acid; and combinations thereof.

15. 15. The method of claim 13 or 14, wherein the compound comprising an amine moiety has a molecular weight of less than 300 g / mol.

16. 16. The method of any one of claims 13 to 15, wherein the composition further comprises a peroxide.

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