PROCESS FOR THE PRODUCTION OF SUGARS FROM BIOMASS DERIVED FROM GUAYULE PLANTS

Abstract

Process for the production of sugars from biomass derived from guayule plants comprising placing an amount of said biomass (G.sub.2) (g) in contact with an amount of water (G.sub.1) (g) and with at least one organic acid, and optionally at least one inorganic acid, obtaining a mixture, said at least one organic acid and said at least one inorganic acid optionally present being used in such amounts that the total moles of said at least one organic acid and said at least one inorganic acid optionally present (m.sub.TOT) contained in said mixture are calculated according to the following equation (1):

m.sub.TOT=m.sub.1+m.sub.2 (1)

wherein m.sub.1 and m.sub.2 are defined according to the following equations (2) and (3), respectively:

m.sub.1=R.sub.1.Math.G.sub.1 (2)

m.sub.2=R.sub.2.Math.G.sub.2 (3)

wherein: R.sub.1 (mmol/g) is the ratio between a first amount of said at least one organic acid (mmol) and a first amount of said at least one inorganic acid (mmol) optionally present and the amount of water G.sub.1 (g) used, R.sub.1 being between 0.06 mmol/g and 0.25 mmol/g, preferably between 0.09 mmol/g and 0.18 mmol/g, said first amount of said at least one organic acid (mmol) and said first amount of said at least one inorganic acid (mmol) optionally present being dependent upon the amount of water G.sub.1 (g); R.sub.2 (mmol/g) is: in the absence of said at least one inorganic acid, the ratio between a second amount of said at least one organic acid (mmol) and the amount of biomass G.sub.2 (g) used; or in the presence of said at least one inorganic acid, the ratio between the sum of said second amount of said at least one organic acid (mmol) and of a second amount of said at least one inorganic acid (mmol) and the amount of biomass G.sub.2 (g) used; or in the presence of said second amount of said at least one inorganic acid (mmol) and in the absence of said second amount of said at least one organic acid (mmol), the ratio between said second amount of said at least one inorganic acid (mmol) and the amount of biomass G.sub.2 (g) used; said second amount of said at least one organic acid (mmol) and said second amount of said at least one inorganic acid (mmol) being dependent upon the amount of biomass G.sub.2 (g);
R.sub.2 being between 0.90 R (mmol/g) and 1.10 R (mmol/g), preferably between 0.95 R (mmol/g) and 1.05 R (mmol/g), R being determined by the following algorithm (4), said algorithm (4) being obtained through the following elementary operations: (i) preparing a volume V (I) of an aqueous solution of said at least one organic acid and of said at least one first amount of said at least one inorganic acid (mmol) optionally present, said aqueous solution having a pH.sub.(1) lower than 7, preferably between 0.7 and 3; (ii) adding an amount of biomass Q (g), dried at 120 C. for 15 hours, to the aqueous solution obtained in (i), said amount of biomass being preferably lower than or equal to 60% by weight, more preferably between 2% by weight and 40% by weight, with respect to the total weight of the mixture obtained; (iii) measuring the pH of the mixture obtained in (ii), said pH being referred to below as pH.sub.(2); (iv) determining R according to the following algorithm (4):

R=(10.sup.pH.sub.(1)10.sup.pH.sub.(2)).Math.1000.Math.V/Q) (4)

wherein pH.sub.(1), pH.sub.(2), V and Q have the same meanings as above, the above elementary operations being carried out at room temperature;
provided that said at least one organic acid is present in an amount such that the R.sub.MINIMUM ratio (mmol/g) defined according to the following equation (5):

R.sub.MINIMUM=m.sub.ORGANIC ACID/G.sub.2 (5)

wherein m.sub.ORGANIC ACID are the mmol of organic acid present and G.sub.2 has the same meaning as above, is higher than or equal to 0.20 mmol/g, preferably higher than or equal to 0.25 mmol/g and, if said at least one inorganic acid is present, said mmol of organic acid (m.sub.ORGANIC ACID) are present in an amount smaller than the sum of the two amounts of acid, that is the sum of the amount of inorganic acid (mmol) and of the amount of organic acid (mmol), said sum corresponding to the total moles M.sub.TOT (mmol) as defined in equation (1) above.

The sugars thus obtained may advantageously be used as sources of carbon in fermentation processes for the production of alcohols (e.g., ethanol, butanol), lipids, diols (e.g., 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol), or in chemical synthesis processes for the production of other intermediates or chemicals. Said alcohols and lipids may in turn advantageously be used in the production of biofuels (e.g., biodiesel or Green Diesel), which may be used as such or in blends with other automotive fuels, while said diols may be used in the production of products such as, for example, bio-butadiene, which may in turn be used in the production of rubbers (e.g., polybutadiene or its copolymers). Said uses are particularly important in the case of a biorefinery.

Claims

1. A process for the production of sugars from biomass derived from guayule plants comprising placing an amount of said biomass (G.sub.2) (g) in contact with an amount of water (G.sub.1) (g) and with at least one organic acid, and optionally at least one inorganic acid, obtaining a mixture, said at least one organic acid and said at least one inorganic acid optionally present being used in such amounts that the total moles of said at least one organic acid and said at least one inorganic acid optionally present (m.sub.TOT) contained in said mixture are calculated according to the following equation (1):
m.sub.TOT=m.sub.1+m.sub.2 (1) wherein m.sub.1 and m.sub.2 are defined according to the following equations (2) and (3), respectively:
m.sub.1=R.sub.1.Math.G.sub.1 (2)
m.sub.2=R.sub.2.Math.G.sub.2 (3) wherein: R.sub.1 (mmol/g) is the ratio between a first amount of said at least one organic acid (mmol) and a first amount of said at least one inorganic acid (mmol) optionally present and the amount of water G.sub.1 (g) used, R.sub.1 being between 0.06 mmol/g and 0.25 mmol/g, said first amount of said at least one organic acid (mmol) and said first amount of said at least one inorganic acid (mmol) optionally present being dependent upon the amount of water G.sub.1 (g); R.sub.2 (mmol/g) is: in the absence of said at least one inorganic acid, the ratio between a second amount of said at least one organic acid (mmol) and the amount of biomass G.sub.2 (g) used; or in the presence of said at least one inorganic acid, the ratio between the sum of said second amount of said at least one organic acid (mmol) and of a second amount of said at least one inorganic acid (mmol) and the amount of biomass G.sub.2 (g) used; or in the presence of said second amount of said at least one inorganic acid (mmol) and in the absence of said second amount of said at least one organic acid (mmol), the ratio between said second amount of said at least one inorganic acid (mmol) and the amount of biomass G.sub.2 (g) used; said second amount of said at least one organic acid (mmol) and said second amount of said at least one inorganic acid (mmol) being dependent upon the amount of biomass G.sub.2 (g); R.sub.2 being between 0.90 R (mmol/g) and 1.10 R (mmol/g), R being determined by means of the following algorithm (4), said algorithm (4) being obtained through the following elementary operations: (i) preparing a volume V (I) of an aqueous solution of said at least one organic acid and said at least a first amount of said at least one inorganic acid (mmol) optionally present, said aqueous solution having a pH.sub.(1) lower than 7; (ii) adding an amount of biomass Q (g), dried at 120 C. for 15 h, to the aqueous solution obtained in (i), said amount of biomass being lower than or equal to 60% by weight, with respect to the total weight of the mixture obtained; (iii) measuring the pH of the mixture obtained in (ii), said pH being referred to below as pH.sub.(2); (iv) determining R according to the following algorithm (4):
R=(10.sup.pH.sub.(1)10.sup.pH.sub.(2)).Math.1000.Math.V/Q) (4) wherein pH.sub.(1), pH.sub.(2), V and Q have the same meanings as above, the above elementary operations being carried out at room temperature; provided that said at least one organic acid is present in an amount such that the R.sub.MINIMUM ratio (mmol/g) defined according to the following equation (5):
R.sub.MINIMUM=m.sub.ORGANIC mACID/G.sub.2 (5) wherein m.sub.ORGANIC mACID is the mmol of organic acid present and (G.sub.2) has the same meaning as above, is higher than or equal to 0.20 mmol/g, and, if said at least one inorganic acid is present, said mmol of organic acid (m.sub.ORGANIC ACID) are present in an amount smaller than the sum of the two amounts of acid, that is the sum of the amount of inorganic acid (mmol) and of the amount of organic acid (mmol), said sum corresponding to the total m.sub.TOT (mmol) moles as defined in equation (1) above.

2. The process for the production of sugars from biomass derived from guayule plants according to claim 1, wherein said biomass derived from guayule plants is the bagasse derived from the extraction processes to which said guayule plants are subjected.

3. The process for the production of sugars from biomass derived from guayule plants according to claim 1, wherein said biomass is subjected to a preliminary grinding process before being placed in contact with water and with said at least one organic acid and optionally at least one inorganic acid.

4. The process for the production of sugars from biomass derived from guayule plants according to claim 1, wherein said at least one organic acid is selected from alkylsulfonic acids having general formula (I):
RSO.sub.3H (I) wherein R represents a linear or branched C.sub.1-C.sub.6.

5. The process for the production of sugars from biomass derived from guayule plants according to claim 1, wherein said at least one inorganic acid is selected from strong inorganic acids including hydrochloric acid (HCl), nitric acid (HNO.sub.3), sulfuric acid (H.sub.2SO.sub.4), or mixtures thereof.

6. The process for the production of sugars from biomass derived from guayule plants according to claims 1, wherein said process comprises: (a) placing an amount of said biomass (G.sub.2) (g) in contact with an amount of water (G.sub.1) (g) and with at least one organic acid and optionally at least one inorganic acid, in a reactor, obtaining a first reaction mixture; (b) heating the reactor to the desired temperature, preferably between 100 C. and 180 C., more preferably between 130 C. and 150 C., in a time of between 20 minutes and 2 hours, preferably between 40 minutes and 1 hour, obtaining a second reaction mixture comprising a first solid phase and a first aqueous phase; (c) optionally, holding said second reaction mixture comprising a first solid phase and a first aqueous phase at said desired temperature for a time of between 30 seconds and 1 hour, preferably between 5 minutes and 20 minutes; (d) recovering said second reaction mixture from said reactor.

7. The process for the production of sugars from biomass derived from guayule plants according to claim 6, wherein: said biomass is present in said first reaction mixture in in amounts of between 1% by weight and 60% by weight, preferably between 5% by weight and 45% by weight, even more preferably between 10% by weight and 30% by weight, with respect to the total weight of said first reaction mixture; and/or said reactor said reactor is selected from slurry reactors with continuous biomass feed (CSTRContinuous Stirred-Tank Reactor); and/or said first solid phase comprises lignin and cellulose and said first aqueous phase comprises at least one sugar having 5 carbon atoms (C5) and, optionally, at least one sugar having 6 carbon atoms (C6) and said at least one organic acid and optionally said at least one inorganic acid.

8. The process for the production of sugars from biomass derived from guayule plants according to claim 1, wherein said guayule plants are of the species Parthenium argentatum.

9. The process for the production of sugars from biomass derived from guayule plants according to claim 1, wherein R.sub.1 is between 0.09 mmol/g and 0.18 mmol/g.

10. The process for the production of sugars from biomass derived from guayule plants according to claim 1, wherein the pH.sub.(1) is between 0.7 and 3.

11. The process for the production of sugars from biomass derived from guayule plants according to claim 1, wherein R.sub.2 is between 0.95 R (mmol/g) and 1.05 R (mmol/g).

12. The process for the production of sugars from biomass derived from guayule plants according to claim 1, wherein said amount of biomass is between 2% by weight and 40% by weight.

13. The process for the production of sugars from biomass derived from guayule plants according to claim 1, wherein (G.sub.2) is higher than or equal to 0.25 mmol/g.

14. The process for the production of sugars from biomass derived from guayule plants according to claim 3, wherein said biomass is ground to obtain particles having a diameter of between 0.5 mm and 4 mm.

15. The process for the production of sugars from biomass derived from guayule plants according to claim 3, wherein said biomass is ground to obtain particles having a diameter of lower than 2 mm.

16. The process for the production of sugars from biomass derived from guayule plants according to claim 3, wherein said biomass is ground to obtain particles having a diameter of between 0.1 mm and 10 mm.

17. The process for the production of sugars from biomass derived from guayule plants according to claim 4, wherein R represents a linear or branched C.sub.1-C.sub.3, alkyl group.

18. The process for the production of sugars from biomass derived from guayule plants according to claim 4, wherein R represents methanesulfonic acid (CH.sub.3SO.sub.3H).

19. The process for the production of sugars from biomass derived from guayule plants according to claim 5, wherein the strong inorganic acid is sulfuric acid (H.sub.2SO.sub.4).

Description

EXAMPLE 1 (comparative)

[0132] 885 g of water and 10.7 g (111.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) were placed in a 2 l Brignole autoclave in the open air (R.sub.1=0.13 mmol/g). Subsequently, 135 g of bagasse (1) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added (R.sub.2=0.00 mmol/g; R.sub.MINIMUM=0.82 mmol/g).

[0133] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0134] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0135] The composition of the starting biomass, determined as described above, was as follows: 42.3% by weight of cellulose, 18.2% by weight of hemicellulose, 24.1% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids, mineral salts, resin and residual rubber.

[0136] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 1): [0137] yield: 80.3% (with respect to the total amount of hemicellulose present in the starting biomass); [0138] C6 degradation: 0.0%; [0139] C5 degradation: 0.7%; [0140] C5 content: 79.4%.

EXAMPLE 2 (comparative)

[0141] 885 g of water and 10.7 g (109.1 mmol) of sulfuric acid (H2SO4) (first amount of inorganic acid) were placed in a 2 l Brignole autoclave in the open air (R1=0.12 mmol/g). Subsequently, 135 g of bagasse (1) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added (R2=0.00 mmol/g; R.sub.MINIMUM=0.00 mmol/g).

[0142] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0143] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0144] The composition of the starting biomass, determined as described above, was as follows: 42.3% by weight of cellulose, 18.2% by weight of hemicellulose, 24.1% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids, mineral salts, resin and residual rubber.

[0145] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 1): [0146] yield: 69.1% (with respect to the total amount of hemicellulose present in the starting biomass); [0147] C6 degradation: 1.7%; [0148] C5 degradation: 3.2%; [0149] C5 content: 72.6%.

EXAMPLE 3 (invention)

[0150] 885 g of water and 10.7 g (111.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) were placed in a 2 l Brignole autoclave in the open air (R.sub.1=0.13 mmol/g). Subsequently, 135 g of bagasse (1) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) were added. Finally, 7.1 g (73.9 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (second amount of organic acid) determined according to equation (1) and following equations (R.sub.2=0.55 mmol/g; R.sub.MINIMUM=1.37 mmol/g) was added: in total m.sub.TOT=185.2 mmol were added.

[0151] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0152] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0153] The composition of the starting biomass, determined as described above, was as follows: 42.3% by weight of cellulose, 18.2% by weight of hemicellulose, 24.1% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids, mineral salts, resin and residual rubber.

[0154] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 1): [0155] yield: 95.0% (with respect to the total amount of hemicellulose present in the starting biomass); [0156] C6 degradation: 0.0%; [0157] C5 degradation: 4.6%; [0158] C5 content: 80.5%.

EXAMPLE 4 (comparative)

[0159] 885 g of water and 10.7 g (111.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) were placed in a 2 l Brignole autoclave in the open air (R.sub.1=0.13 mmol/g). Subsequently, 135 g of bagasse (2) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added (R.sub.2=0.00 mmol/g; R.sub.MINIMUM=0.82 mmol/g).

[0160] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0161] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0162] The composition of the starting biomass, determined as described above, was as follows: 47.0% by weight of cellulose, 20.2% by weight of hemicellulose, 26.8% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids and mineral salts.

[0163] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 2): [0164] yield: 79.9% (with respect to the total amount of hemicellulose present in the starting biomass); [0165] C6 degradation: 0.0%; [0166] C5 degradation: 0.6%; [0167] C5 content: 80.4%.

EXAMPLE 5 (comparative)

[0168] 885 g of water and 10.7 g (109.1 mmol) of sulfuric acid (H.sub.2SO.sub.4) (first amount of inorganic acid) were placed in a 2 l Brignole autoclave in the open air (R.sub.1=0.12 mmol/g). Subsequently, 135 g of bagasse (2) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added (R.sub.2=0.00 mmol/g; R.sub.MINIMUM=0.00 mmol/g).

[0169] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0170] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0171] The composition of the starting biomass, determined as described above, was as follows: 47.0% by weight of cellulose, 20.2% by weight of hemicellulose, 26.8% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids and mineral salts.

[0172] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 2): [0173] yield: 68.4% (with respect to the total amount of hemicellulose present in the starting biomass); [0174] C6 degradation: 2.4%; [0175] C5 degradation: 3.6%; [0176] C5 content: 70.1%.

EXAMPLE 6 (invention)

[0177] 885 g of water and 10.7 g (111.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) were placed in a 2 l Brignole autoclave in the open air (R.sub.1=0.13 mmol/g). Subsequently, 135 g of bagasse (2) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, 7.1 g (73.9 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (second amount of organic acid) determined according to equation (1) and following equations (R.sub.2=0.55 mmol/g; R.sub.MINIMUM=1.37 mmol/g) was added: in total m.sub.TOT=185.2 mmol was added.

[0178] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0179] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0180] The composition of the starting biomass, determined as described above, was as follows: 47.0% by weight of cellulose, 20.2% by weight of hemicellulose, 26.8% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids and mineral salts.

[0181] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 2): [0182] yield: 95.2% (with respect to the total amount of hemicellulose present in the starting biomass); [0183] C6 degradation: 0.0%; [0184] C5 degradation: 4.4%; [0185] C5 content: 80.7%.

EXAMPLE 7 (invention)

[0186] 885 g of water and 10.7 g (111.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) were placed in a 2 l Brignole autoclave in the open air (R.sub.1=0.13 mmol/g). Subsequently, 135 g of bagasse (1) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, 7.1 g (72.4 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid) determined according to equation (1) and following equations (R.sub.2=0.54 mmol/g; R.sub.MINIMUM=0.82 mmol/g) was added: in total m.sub.TOT=183.7 mmol was added.

[0187] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0188] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0189] The composition of the starting biomass, determined as described above, was as follows: 42.3% by weight of cellulose, 18.2% by weight of hemicellulose, 24.1% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids, mineral salts, resin and residual rubber.

[0190] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 1 and Table 3): [0191] yield: 95.1% (with respect to the total amount of hemicellulose present in the starting biomass); [0192] C6 degradation: 0.0%; [0193] C5 degradation: 4.5%; [0194] C5 content: 80.1%.

EXAMPLE 8 (invention)

[0195] 885 g of water and 10.7 g (111.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) were placed in a 2 l Brignole autoclave in the open air (R.sub.1=0.13 mmol/g). Subsequently, 135 g of bagasse (2) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, 7.1 g (72.4 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid) determined according to equation (1) and following equations (R.sub.2=0.54 mmol/g; R.sub.MINIMUM=0.82 mmol/g) was added: in total m.sub.TOT=183.7 mmol was added.

[0196] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0197] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0198] The composition of the starting biomass, determined as described above, was as follows: 47.0% by weight of cellulose, 20.2% by weight of hemicellulose, 26.8% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids and mineral salts.

[0199] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 2 and Table 4): [0200] yield: 95.4% (with respect to the total amount of hemicellulose present in the starting biomass); [0201] C6 degradation: 0.0%; [0202] C5 degradation: 4.5%; [0203] C5 content: 80.3%.

EXAMPLE 9 (comparative)

[0204] 885 g of water and 10.7 g (111.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) were placed in a 2 l Brignole autoclave in the open air (R.sub.1=0.13 mmol/g). Subsequently, 135 g of bagasse (1) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, 3.0 g (30.6 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid), lower than that determined according to equation (1) and following equations (R.sub.2=0.23 mmol/g; R.sub.MINIMUM=0.82 mmol/g) was added: in total m.sub.TOT=141.9 mmol was added.

[0205] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0206] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0207] The composition of the starting biomass, determined as described above, was as follows: 42.3% by weight of cellulose, 18.2% by weight of hemicellulose, 24.1% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids, mineral salts, resin and residual rubber.

[0208] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 3): [0209] yield: 87.8% (with respect to the total amount of hemicellulose present in the starting biomass); [0210] C6 degradation: 0.0%; [0211] C5 degradation: 3.9%; [0212] C5 content: 80.1%.

EXAMPLE 10 (comparative)

[0213] 885 g of water and 10.7 g (111.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) were placed in a 2 l Brignole autoclave in the open air (R.sub.1=0.13 mmol/g). Subsequently, 135 g of bagasse (1) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, 11.0 g (112.2 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid), more than that determined according to equation (1) and following equations (R.sub.2=0.82 mmol/g; R.sub.MINIMUM=0.82 mmol/g) was added: in total m.sub.TOT=223.5 mmol was added.

[0214] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0215] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0216] The composition of the starting biomass, determined as described above, was as follows: 42.3% by weight of cellulose, 18.2% by weight of hemicellulose, 24.1% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids, mineral salts, resin and residual rubber.

[0217] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 3): [0218] yield: 86.1% (with respect to the total amount of hemicellulose present in the starting biomass); [0219] C6 degradation: 0.0%; [0220] C5 degradation: 7.2%; [0221] C5 content: 74.3%.

EXAMPLE 11 (comparative)

[0222] 885 g of water and 10.7 g (111.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) were placed in a 2 l Brignole autoclave in the open air (R.sub.1=0.13 mmol/g). Subsequently, 135 g of bagasse (2) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) were added. Finally, 3.0 g (30.6 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid), lower than that determined according to equation (1) and following equations (R.sub.2=0.23 mmol/g; R.sub.MINIMUM=0.82 mmol/g) was added: in total m.sub.TOT=141.9 mmol was added.

[0223] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0224] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0225] The composition of the starting biomass, determined as described above, was as follows: 47.0% by weight of cellulose, 20.2% by weight of hemicellulose, 26.8% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids and mineral salts.

[0226] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 4): [0227] yield: 84.7% (with respect to the total amount of hemicellulose present in the starting biomass); [0228] C6 degradation: 0.0%; [0229] C5 degradation: 3.2%; [0230] C5 content: 80.5%.

EXAMPLE 12 (comparative)

[0231] 885 g of water and 10.7 g (111.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) were placed in a 2 l Brignole autoclave in the open air (R.sub.1=0.13 mmol/g). Subsequently, 135 g of bagasse (2) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, 11.0 g (112.2 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid), more than that determined according to equation (1) and following equations (R.sub.2=0.82 mmol/g; R.sub.MINIMUM=0.82 mmol/g) was added: in total m.sub.TOT=223.5 mmol was added.

[0232] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0233] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0234] The composition of the starting biomass, determined as described above, was as follows: 47.0% by weight of cellulose, 20.2% by weight of hemicellulose, 26.8% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids and mineral salts.

[0235] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 4): [0236] yield: 86.3% (with respect to the total amount of hemicellulose present in the starting biomass); [0237] C6 degradation: 4.3%; [0238] C5 degradation: 7.4%; [0239] C5 content: 71.3%.

EXAMPLE 13 (invention)

[0240] 885 g of water, 5.3 g (55.14 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) and 5.5 g (56.2 mmol) of sulfuric acid (H.sub.2SO.sub.4) (first amount of inorganic acid) (R.sub.1=0.13 mmol/g) were placed in a 2 l Brignole autoclave in the open air. Subsequently, 135 g of bagasse (1) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, an additional 7.0 g (71.4 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid), determined according to equation (1) and following equations (R.sub.2=0.53 mmol/g; R.sub.MINIMUM=0.41 mmol/g) was added: in total m.sub.TOT=182.7 mmol was added.

[0241] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0242] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0243] The composition of the starting biomass, determined as described above, was as follows: 42.3% by weight of cellulose, 18.2% by weight of hemicellulose, 24.1% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids, mineral salts, resin and residual rubber.

[0244] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 5): [0245] yield: 96.0% (with respect to the total amount of hemicellulose present in the starting biomass); [0246] C6 degradation: 0.0%; [0247] C5 degradation: 4.6%; [0248] C5 content: 81.2%.

EXAMPLE 14 (invention)

[0249] 885 g of water, 3.3 g (34.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) and 7.6 g (77.5 mmol) of sulfuric acid (H.sub.2SO.sub.4) (first amount of inorganic acid) (R.sub.1=0.13 mmol/g) were placed in a 2 l Brignole autoclave in the open air. Subsequently, 135 g of bagasse (1) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, an additional 7.0 g (71.4 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid) determined according to equation (1) and following equations (R.sub.2=0.53 mmol/g; R.sub.MINIMUM=0.25 mmol/g) was added: in total m.sub.TOT=183.2 mmol was added.

[0250] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0251] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0252] The composition of the starting biomass, determined as described above, was as follows: 42.3% by weight of cellulose, 18.2% by weight of hemicellulose, 24.1% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids, mineral salts, resin and residual rubber.

[0253] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 5): [0254] yield: 95.4% (with respect to the total amount of hemicellulose present in the starting biomass); [0255] C6 degradation: 0.0%; [0256] C5 degradation: 4.2%; [0257] C5 content: 79.8%.

EXAMPLE 15 (comparative)

[0258] 885 g of water, 2.1 g (21.8 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) and 8.7 g (88.7 mmol) of sulfuric acid (H.sub.2SO.sub.4) (first amount of inorganic acid) (R.sub.1=0.13 mmol/g) were placed in a 2 l Brignole autoclave in the open air. Subsequently, 135 g of bagasse (1) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, an additional 7.0 g (71.4 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid), determined according to equation (1) and following equations (R.sub.2=0.53 mmol/g; R.sub.MINIMUM=0.16 mmol/g) was added: in total m.sub.TOT=181.9 mmol was added.

[0259] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0260] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0261] The composition of the starting biomass, determined as described above, was as follows: 42.3% by weight of cellulose, 18.2% by weight of hemicellulose, 24.1% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids, mineral salts, resin and residual rubber.

[0262] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 5): [0263] yield: 81.4% (with respect to the total amount of hemicellulose present in the starting biomass); [0264] C6 degradation: 0.0%; [0265] C5 degradation: 1.1%; [0266] C5 content: 79.2%.

EXAMPLE 16 (invention)

[0267] 885 g of water, 5.3 g (55.14 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) and 5.5 g (56.2 mmol) of sulfuric acid (H.sub.2SO.sub.4) (first amount of inorganic acid) (R.sub.1=0.13 mmol/g) were placed in a 2 l Brignole autoclave in the open air. Subsequently, 135 g of bagasse (2) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, an additional 7.0 g (71.4 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid), determined according to equation (1) and following equations (R.sub.2=0.53 mmol/g; R.sub.MINIMUM=0.41 mmol/g) was added: in total m.sub.TOT=182.7 mmol were added.

[0268] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0269] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0270] The composition of the starting biomass, determined as described above, was as follows: 47.0% by weight of cellulose, 20.2% by weight of hemicellulose, 26.8% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids and mineral salts.

[0271] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 6): [0272] yield: 95.2% (with respect to the total amount of hemicellulose present in the starting biomass); [0273] C6 degradation: 0.0%; [0274] C5 degradation: 4.3%; [0275] C5 content: 80.7%.

EXAMPLE 17 (invention)

[0276] 885 g of water, 3.3 g (34.3 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) and 7.6 g (77.5 mmol) of sulfuric acid (H.sub.2SO.sub.4) (first amount of inorganic acid) (R.sub.1=0.13 mmol/g) were placed in a 2 l Brignole autoclave in the open air. Subsequently, 135 g of bagasse (2) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, an additional 7.0 g (71.4 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid), determined according to equation (1) and following equations (R.sub.2=0.53 mmol/g; R.sub.MINIMUM=0.25 mmol/g) was added: in total m.sub.TOT=183.2 mmol was added.

[0277] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0278] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0279] The composition of the starting biomass, determined as described above, was as follows: 47.0% by weight of cellulose, 20.2% by weight of hemicellulose, 26.8% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids and mineral salts.

[0280] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 6): [0281] yield: 95.0% (with respect to the total amount of hemicellulose present in the starting biomass); [0282] C6 degradation: 0.0%; [0283] C5 degradation: 4.6%; [0284] C5 content: 81.2%.

EXAMPLE 18 (comparative)

[0285] 885 g of water, 2.1 g (21.8 mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) (first amount of organic acid) and 8.7 g (88.7 mmol) of sulfuric acid (H.sub.2SO.sub.4) (first amount of inorganic acid) (R.sub.1=0.13 mmol/g), were placed in a 2 l Brignole autoclave in the open air. Subsequently, 135 g of bagasse (1) derived from previously ground guayule plants (Parthenium argentatum) (seived to below 2 mm) was added. Finally, an additional 7.0 g (71.4 mmol) of sulfuric acid (H.sub.2SO.sub.4) (second amount of inorganic acid), determined according to equation (1) and following equations (R.sub.2=0.53 mmol/g; R.sub.MINIMUM=0.16 mmol/g) was added: in total m.sub.TOT=181.9 mmol was added.

[0286] The first reaction mixture thus obtained was kept vigorously stirred (600 rpm) until it reached a temperature of 140 C. within 45 minutes, resulting in a second reaction mixture comprising a first solid phase containing lignin and cellulose and a first aqueous phase containing the sugars deriving from hemicellulose.

[0287] After allowing the autoclave to cool to room temperature, said phases were separated by filtration.

[0288] The composition of the starting biomass, determined as described above, was as follows: 47.0% by weight of cellulose, 20.2% by weight of hemicellulose, 26.8% by weight of lignin, with respect to the total weight of the starting biomass. The remaining part was made up of organic acids, protein and non-protein nitrogen substances, lipids and mineral salts.

[0289] The first aqueous phase was analysed as described above, obtaining the following results (shown in Table 6): [0290] yield: 79.4% (with respect to the total amount of hemicellulose present in the starting biomass); [0291] C6 degradation: 0.0%; [0292] C5 degradation: 1.5%; [0293] C5 content: 78.8%.

TABLE-US-00001 TABLE 1 Results obtained from the acid hydrolysis of bagasse (1) m.sub.1 m.sub.2 R.sub.1 R.sub.2 R.sub.MINIMUM Yield C6 degradation C5 degradation C5 content Example (mmol) (mmol) (mmol/g) (mmol/g) (mmol/g) (%) (%) (%) (%) 1 (comp.) CH.sub.3SO.sub.3H.sup.(*.sup.) 0.13 0.00 0.82 80.3 0.0 0.7 79.4 (111.3) 2 (comp.) H.sub.2SO.sub.4.sup.(*.sup.) 0.12 0.00 0.00 69.1 1.7 3.2 72.6 (109.1) 3 (inv.) CH.sub.3SO.sub.3H.sup.(*.sup.) CH.sub.3SO.sub.3H.sup.(**.sup.) 0.13 0.55 1.37 95.0 0.0 4.6 80.5 (111.3) (73.9) 7 (inv.) CH.sub.3SO.sub.3H.sup.(*.sup.) H.sub.2SO.sub.4.sup.(**.sup.) 0.13 0.54 0.82 95.1 0.0 4.5 80.1 (111.3) (72.4) .sup.(*.sup.)moles of acid, with respect to the amount of water (G.sub.1), determined according to equation (1) shown above; .sup.(**.sup.)moles of acid, with respect to the amount of biomass (G.sub.2), determined according to equation (1) shown above.

TABLE-US-00002 TABLE 2 Results obtained from the acid hydrolysis of bagasse (2) m.sub.1 m.sub.2 R.sub.1 R.sub.2 R.sub.MINIMUM Yield C6 degradation C5 degradation C5 content Example (mmol) (mmol) (mmol/g) (mmol/g) (mmol/g) (%) (%) (%) (%) 4 (comp.) CH.sub.3SO.sub.3H.sup.(*.sup.) 0.13 0.00 0.82 79.9 0.0 0.6 80.4 (111.3) 5 (comp.) H.sub.2SO.sub.4.sup.(*.sup.) 0.12 0.00 0.00 68.4 2.4 3.6 70.1 (109.1) 6 (inv.) CH.sub.3SO.sub.3H.sup.(*.sup.) CH.sub.3SO.sub.3H.sup.(**.sup.) 0.13 0.55 1.37 95.2 0.0 4.4 80.7 (111.3) (73.9) 8 (inv.) CH.sub.3SO.sub.3H.sup.(*.sup.) H.sub.2SO.sub.4.sup.(**.sup.) 0.13 0.54 0.82 95.4 0.0 4.5 80.3 (111.3) (72.4) .sup.(*.sup.)moles of acid, with respect to the amount of water (G.sub.1), determined according to equation (1) shown above; .sup.(**.sup.)moles of acid, with respect to the amount of biomass (G.sub.2), determined according to equation (1) shown above.

TABLE-US-00003 TABLE 3 Results obtained from the acid hydrolysis of bagasse (1) with varying amounts of H.sub.2SO.sub.4 m.sub.1 m.sub.2 R.sub.1 R.sub.2 R.sub.MINIMUM Yield C6 degradation C5 degradation C5 content Example (mmol) (mmol) (mmol/g) (mmol/g) (mmol/g) (%) (%) (%) (%) 7 (inv.) CH.sub.3SO.sub.3H.sup.(*.sup.) H.sub.2SO.sub.4.sup.(**.sup.) 0.13 0.54 0.82 95.1 0.0 4.5 80.1 (111.3) (72.4) 9 (comp.) CH.sub.3SO.sub.3H.sup.(*.sup.) H.sub.2SO.sub.4.sup.(**.sup.) 0.13 0.23 0.82 87.8 0.0 3.9 80.1 (111.3) (shortfall) (30.6) 10 (comp.) CH.sub.3SO.sub.3H.sup.(*.sup.) H.sub.2SO.sub.4.sup.(**.sup.) 0.13 0.82 0.82 86.1 1.1 7.2 74.3 (111.3) (excess) (112.2) .sup.(*.sup.)moles of acid, with respect to the amount of water (G.sub.1), determined according to equation (1) shown above; .sup.(**.sup.)moles of acid, with respect to the amount of biomass (G.sub.2), determined according to equation (1) shown above.

TABLE-US-00004 TABLE 4 Results obtained from the acid hydrolysis of bagasse (2) with varying amounts of H.sub.2SO.sub.4 m.sub.1 m.sub.2 R.sub.1 R.sub.2 R.sub.MINIMUM Yield C6 degradation C5 degradation C5 content Example (mmol) (mmol) (mmol/g) (mmol/g) (mmol/g) (%) (%) (%) (%) 8 (inv.) CH.sub.3SO.sub.3H.sup.(*.sup.) H.sub.2SO.sub.4.sup.(**.sup.) 0.13 0.54 0.82 95.4 0.0 4.5 80.3 (111.3) (72.4) 11 (comp.) CH.sub.3SO.sub.3H.sup.(*.sup.) H.sub.2SO.sub.4.sup.(**.sup.) 0.13 0.23 0.82 84.7 0.0 3.2 80.5 (111.3) (shortfall) (30.6) 12 (comp.) CH.sub.3SO.sub.3H.sup.(*.sup.) H.sub.2SO.sub.4.sup.(**.sup.) 0.13 0.82 0.82 86.3 4.3 7.4 71.3 (111.3) (excess) (112.2) .sup.(*.sup.)moles of acid, with respect to the amount of water (G.sub.1), determined according to equation (1) shown above; .sup.(**.sup.)moles of acid, with respect to the amount of biomass (G.sub.2), determined according to equation (1) shown above.

TABLE-US-00005 TABLE 5 Results obtained from the acid hydrolysis of bagasse (1) for different R.sub.MINIMUM ratios (mmol/g).sup.(*.sup.) R.sub.1 R.sub.2 R.sub.MINIMUM Yield C6 degradation C5 degradation C5 content Example (mmol/g) (mmol/g) (mmol/g) (%) (%) (%) (%) 13 (inv.) 0.13 0.53 0.41 96.0 0.0 4.6 81.2 14 (inv.) 0.13 0.53 0.25 95.4 0.0 4.2 79.8 15 (comp.) 0.13 0.53 0.16 81.4 0.0 1.1 79.2 .sup.(*.sup.)R.sub.MINIMUM (mmol/g) defines the ratio between the moles of organic acid (CH.sub.3SO.sub.3H) (mmol) and biomass (G.sub.2) used; in order to obtain the total moles of acid m.sub.TOT, according to equation (1) shown above, the inorganic acid H.sub.2SO.sub.4 was used.

TABLE-US-00006 TABLE 6 Results obtained from the acid hydrolysis of bagasse (2) for different R.sub.MINIMUM ratios(mmol/g).sup.(*.sup.) R.sub.1 R.sub.2 R.sub.MINIMUM Yield C6 degradation C5 degradation C5 content Example (mmol/g) (mmol/g) (mmol/g) (%) (%) (%) (%) 16 (inv.) 0.13 0.53 0.41 95.2 0.0 4.3 80.7 17 (inv.) 0.13 0.53 0.25 95.0 0.0 4.6 81.2 18 (comp.) 0.13 0.53 0.16 79.4 0.0 1.5 78.8 .sup.(*.sup.)R.sub.MINIMUM (mmol/g) defines the ratio between the moles of organic acid (CH.sub.3SO.sub.3H) (mmol) and biomass (G.sub.2) used; in order to obtain the total moles of acid m.sub.TOT, according to equation (1) shown above, the inorganic acid H.sub.2SO.sub.4 was used.

[0294] The data shown in Table 1 [bagasse (1)] show that: [0295] Example 1 (comparative), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water (G.sub.1) used, without further addition of the amount m.sub.2 (mmol) of organic or inorganic acid determined according to equation (1) and following equations, has a low yield of sugars [Yield (%)] (80.3%); furthermore, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.00 mmol/g and R.sub.MINIMUM=0.82 mmol/g, it is clear that the value of R.sub.2 is not in accordance with the present invention; [0296] Example 2 (comparative), wherein an amount m.sub.1 (mmol) of sulfuric acid (H.sub.2SO.sub.4) was used with respect to the amount of water (G.sub.1) used, without further addition of the amount m.sub.2 (mmol) of organic or inorganic acid determined according to equation (1) and the following equations, has a low yield of sugars [Yield (%)] (69.1%), lower than that in Example 1 (comparative); furthermore, with respect to Example 1 (comparative), hydroxymethylfurfural (HMF) is observed to form in not insignificant amounts (degradation ratio equal to 1.7%), together with a marked increase in degradation to furfural (F) (degradation ratio equal to 3.2%); furthermore, from the examination of the parameters R.sub.1=0.12 mmol/g, R.sub.2=0.00 mmol/g and R.sub.MINIMUM=0.00 mmol/g, it is clear that the values of R.sub.2 and R.sub.MINIMUM are not in accordance with the present invention; [0297] Example 3 (invention), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water (G.sub.1) used and an amount m.sub.2 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of biomass (G.sub.2) used, determined according to equation (1) and the following equations, has a high yield of sugars [Yield (%)] (95.0%); also no formation of hydroxymethylfurfural (HMF) is observed (degradation ratio equal to 0.0%); furthermore, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.55 mmol/g and R.sub.MINIMUM=1.37 mmol/g, it is clear that the values of R.sub.1, R.sub.2 and R.sub.MINIMUM are in accordance with the present invention; [0298] Example 7 (invention), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water (G.sub.1) used and an amount m.sub.2 (mmol) of sulfuric acid (H.sub.2SO.sub.4) was used with respect to the amount of biomass (G.sub.2) used, determined according to equation (1) and the following equations, has a high yield of sugars [Yield (%)] (95.1%) comparable with that in Example 3 (invention); finally, a degradation to furfural (F) (degradation ratio equal to 4.5%) is observed comparable to that obtained in Example 3 (invention) confirming, therefore, that the use of sulfuric acid (H.sub.2SO.sub.4) does not adversely affect either the sugar yield or degradation to furfural; furthermore, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.54 mmol/g and R.sub.MINIMUM=0.82 mmol/g, it is clear that the values of R.sub.1, R.sub.2 and R.sub.MINIMUM, are in accordance with the present invention.

[0299] The data shown in Table 2 ((bagasse (2)) show that: [0300] Example 4 (comparative), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water G.sub.1 used, without further addition of the amount m.sub.2 (mmol) of organic or inorganic acid determined according to equation (1) and the following equations, has a low yield of sugars [Yield (%)] (79.9%); furthermore, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.00 mmol/g and R.sub.MINIMUM=0.82 mmol/g, it is clear that the value of R.sub.2 is not in accordance with the present invention; [0301] Example 5 (comparative), wherein an amount m.sub.1 (mmol) of sulfuric acid (H.sub.2SO.sub.4) was used with respect to the amount of water (G.sub.1) used, without further addition of the amount m.sub.2 (mmol) of organic or inorganic acid determined according to equation (1) and the following equations, has a low yield of sugars [Yield (%)] (68.4%) and lower than that in Example 5 (comparative); furthermore, with respect to Example 5 (comparative), hydroxymethylfurfural (HMF) is observed to form in non-negligible amounts (degradation ratio equal to 2.4%), together with a marked increase in furfural (F) degradation (degradation ratio equal to 3.6%); furthermore, from the examination of the parameters R.sub.1=0.12 mmol/g, R.sub.2=0.00 mmol/g and R.sub.MINIMUM=0.00 mmol/g, it is clear that the values of R.sub.2 and R.sub.MINIMUM are not in accordance with the present invention; [0302] Example 6 (invention), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water (G.sub.1) used and an amount m.sub.2 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of biomass (G.sub.2) used, determined according to equation (1) and the following equations, has a high yield of sugars [Yield (%)] (95.2%); furthermore, no formation of hydroxymethylfurfural (HMF) is observed (degradation ratio equal to 0.0%); furthermore, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.55 mmol/g and R.sub.MINIMUM=1.37 mmol/g, it is clear that the values of R.sub.1, R.sub.2 and R.sub.MINIMUM, are in accordance with the present invention; [0303] Example 8 (invention), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water (G.sub.1) used and an amount m.sub.2 (mmol) of sulfuric acid (H.sub.2SO.sub.4) was used with respect to the amount of biomass (G.sub.2) used, determined according to equation (1) and the following equations, has a high yield of sugars [Yield (%)] (95.4%) comparable with that in Example 6 (invention); finally, there is degradation to furfural (F) (degradation ratio equal to 4.5%) comparable to that in Example 6 (invention) confirming, therefore, that the use of sulfuric acid (H.sub.2SO.sub.4) does not adversely affect either the sugar yield or degradation to furfural; furthermore, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.54 mmol/g and R.sub.MINIMUM=0.82 mmol/g, it is clear that the values of R.sub.1, R.sub.2 and R.sub.MINIMUM, are in accordance with the present invention.

[0304] The data shown in Table 3 [bagasse (1)] show that: [0305] Example 7 (invention), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water G.sub.1 used and an amount m.sub.2 (mmol) of sulfuric acid (H.sub.2SO.sub.4) was used with respect to the amount of biomass (G.sub.2) used, determined according to equation (1) and the following equations, has a high yield of sugars [Yield (%)] (95.1%); furthermore, no formation of hydroxymethylfurfural (HMF) is observed (degradation ratio equal to 0.0%); furthermore, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.54 mmol/g and R.sub.MINIMUM=0.82 mmol/g, it is clear that the values of R.sub.1, R.sub.2 and R.sub.MINIMUM, are in accordance with the present invention; [0306] Example 9 (comparative), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water (G.sub.1) used and an amount m.sub.2 (mmol) of sulfuric acid (H.sub.2SO.sub.4) was used with respect to the amount of biomass (G.sub.2) used, lower than that determined according to equation (1) and the following equations, has a lower yield of sugars [Yield (%)] (87.8%) than that in Example 7 (invention); furthermore, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.23 mmol/g and R.sub.MINIMUM=0.82 mmol/g, it is clear that the value of R.sub.2 is not in accordance with the present invention; [0307] Example 10 (comparative), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water (G.sub.1) used and an amount m.sub.2 (mmol) of sulfuric acid (H.sub.2SO.sub.4) was used with respect to the amount of biomass (G.sub.2) used, higher than that determined according to equation (1) and the following equations, has a lower yield of sugars [Yield (%)] (86.1%) than that in Example 7 (invention); there is also a marked increase in degradation to furfural (F) (degradation ratio equal to 7.2%); furthermore, examination of parameters R.sub.1=0.13 mmol/g, R.sub.2=0.82 mmol/g and R.sub.MINIMUM=0.82 mmol/g, it is clear that the value of R.sub.2 is not in accordance with the present invention.

[0308] The data shown in Table 4 [bagasse (2)] shows that: [0309] Example 8 (invention), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water (G.sub.1) used and an amount m.sub.2 (mmol) of sulfuric acid (H.sub.2SO.sub.4) was used with respect to the amount of biomass (G.sub.2) used, determined according to equation (1) and the following equations, has a high yield of sugars [Yield (%)] (95.4%); furthermore, no formation of hydroxymethylfurfural (HMF) is observed (degradation ratio equal to 0.0%); furthermore, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.54 mmol/g and R.sub.MINIMUM=0.82 mmol/g, shows that the values of R.sub.1, R.sub.2 and R.sub.MINIMUM, are in accordance with the present invention; [0310] Example 11 (comparative), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water (G.sub.1) used and an amount m.sub.2 (mmol) of sulfuric acid (H.sub.2SO.sub.4) was used with respect to the amount of biomass (G.sub.2) used, lower than that determined according to equation (1) and the following equations, has a lower yield of sugars [Yield (%)] 84.7%) than that in Example 8 (invention); furthermore, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.23 mmol/g and R.sub.MINIMUM=0.82 mmol/g, shows that the value of R.sub.2 is not in accordance with the present invention; [0311] Example 12 (comparative), wherein an amount m.sub.1 (mmol) of methanesulfonic acid (CH.sub.3SO.sub.3H) was used with respect to the amount of water (G.sub.1) used and an amount m.sub.2 (mmol) of sulfuric acid (H.sub.2SO.sub.4) was used with respect to the amount of biomass G.sub.2 used, higher than that determined according to equation (1) and the following equations, has a lower yield of sugars (Yield (%) 86.3%) than that in Example 8 (invention); there is also a marked increase in degradation to furfural (F) (degradation ratio between 7.4%); furthermore, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.82 mmol/g and R.sub.MINIMUM=0.82 mmol/g, shows that the value of R.sub.2 is not in accordance with the present invention;

[0312] The data shown in Table 5 [bagasse (1)] show that: [0313] Example 13 (invention), wherein methanesulfonic acid (CH.sub.3SO.sub.3H) and sulfuric acid (H.sub.2SO.sub.4) were used has a high yield of sugars [Yield (%)] (95.1%) and degradation to furfural (F) (degradation ratio equal to 4.6%) comparable to that obtained in Examples 3, 6, 7 and 8 (invention) confirming, therefore, that the use of sulfuric acid (H.sub.2SO.sub.4) does not adversely affect either sugar yield or degradation to furfural; in particular, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.53 mmol/g and R.sub.MINIMUM=0.41 mmol/g shows that the values of R.sub.1, R.sub.2 and R.sub.MINIMUM, are in accordance with the present invention; [0314] Example 14 (invention), wherein methanesulfonic acid (CH.sub.3SO.sub.3H) and sulfuric acid (H.sub.2SO.sub.4) were used has a high yield of sugars [Yield (%)] (95.4%) and degradation to furfural (F) (degradation ratio equal to 4.2%) comparable to that obtained in Examples 3, 6, 7 and 8 (invention) confirming, therefore, that the use of sulfuric acid (H.sub.2SO.sub.4) does not adversely affect either sugar yield or degradation to furfural; in particular, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.53 mmol/g and R.sub.MINIMUM=0.25 mmol/g, shows that the values of R.sub.1, R.sub.2 and R.sub.MINIMUM, are in accordance with the present invention; [0315] Example 15 (comparative), wherein methanesulfonic acid (CH.sub.3SO.sub.3H) and sulfuric acid (H.sub.2SO.sub.4) were used has a low yield of sugars [Yield (%)] (81.4%); in particular, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.53 mmol/g and R.sub.MINIMUM=0.16 mmol/g, shows that the value of R.sub.MINIMUM is not in accordance with the present invention (i.e. insufficient amount of organic acid is present).

[0316] The data shown in Table 6 [bagasse (2)] show that: [0317] Example 16 (invention), wherein methanesulfonic acid (CH.sub.3SO.sub.3H) and sulfuric acid (H.sub.2SO.sub.4) were used has a high yield of sugars [Yield (%)] (95.2%) and degradation to furfural (F) (degradation ratio equal to 4.3%) comparable to that obtained in Examples 3, 6, 7 and 8 (invention) confirming, therefore, that the use of sulfuric acid (H.sub.2SO.sub.4) does not adversely affect either sugar yield, or degradation to furfural; in particular, from the examination of the parameters R.sub.1=0.13 mmol/g, R.sub.2=0.53 mmol/g and R.sub.MINIMUM=0.41 mmol/g, shows that the values of R.sub.1, R.sub.2 and R.sub.MINIMUM, are in accordance with the present invention; [0318] Example 17 (invention), wherein methanesulfonic acid (CH.sub.3SO.sub.3H) and sulfuric acid (H.sub.2SO.sub.4) were used has a high yield of sugars (Yield (%) 95.0%) and degradation to furfural (F) (degradation ratio between 4.6%) comparable to that obtained in Examples 3, 6, 7 and 8 (invention) confirming, therefore, that the use of sulfuric acid (H.sub.2SO.sub.4) does not adversely affect either sugar yield, or degradation to furfural; in particular, from the examination of parameters R.sub.1=0.13 mmol/g, R.sub.2=0.53 mmol/g and R.sub.MINIMUM=0.25 mmol/g shows that the values of R.sub.1, R.sub.2 and R.sub.MINIMUM, are in accordance with the present invention; [0319] Example 18 (comparative), wherein methanesulfonic acid (CH.sub.3SO.sub.3H) and sulfuric acid (H.sub.2SO.sub.4) were used has a low yield of sugars [Yield (%)] (79.4%); in particular, from the examination the of parameters R.sub.1=0.13 mmol/g, R.sub.2=0.53 mmol/g and R.sub.MINIMUM=0.16 mmol/g, shows that the value of R.sub.MINIMUM is not in accordance with the present invention (i.e. insufficient amount of organic acid is present).

[0320] It should also be noted that using bagasse (1) or bagasse (2) gives comparable results, supporting the fact that the process for obtaining bagasse is irrelevant for the purposes of the present invention.