BEAUCHAMP ANDRE (CA)
| CA2710625A1 | 2011-02-19 | |||
| CA2757608A1 | 2013-05-07 | |||
| US20130075244A1 | 2013-03-28 | |||
| CA2636285A1 | 2007-07-12 |
| CLAIMS: 1 . A torrefaction process for cellulose based material comprising: 1 ) first crystallization of said cellulose based material at about 210°C to about 240°C, for about 10 minutes to about 45 minutes, at a pressure of about 25.4 kPa to about 101 .4 kPa ; 2) lignin breakdown of said cellulose based material at about 170°C to about 200°C, for about 15 minutes to about 35 minutes, at a pressure of about 50.8 kPa to about 101 .4 kPa under an inert atmosphere; 3) second crystallization of said cellulose based material at about 205°C to about 230°C, for about 15 minutes to about 90 minutes, at a pressure of about 50.8 kPa to about 101 .4 kPa, under an inert atmosphere to increase strength of said cellulose based material; and 4) moisture equilibration of said cellulose based material at about 50°C to about 95°C, for about 60 minutes to about 120 minutes, at a pressure of about 10.2 kPa to about 75.2 kPa, prior to returning said cellulose based material to room temperature (about 25°C) and normal atmospheric pressure (about 101 .325 kPa). 2. The torrefaction process of claim 1 , wherein said first crystallization is performed under an ozone, nitrogen or noble gas atmosphere. 3. The torrefaction process of claim 2, wherein said first crystallization is performed under a nitrogen atmosphere. 4. The torrefaction process of claim 1 , wherein said first crystallization is at 230°C. 5. The torrefaction process of any one of claims 1 to 4, wherein said first crystallization is for about 15 minutes. 6. The torrefaction process of any one of claims 1 to 5, wherein said first crystallization is at about 50.7 kPa (0.5 atm). 7. The torrefaction process of any one of claims 1 to 6, wherein said lignin breakdown is at about 180°C. 8. The torrefaction process of any one of claims 1 to 7, wherein said lignin breakdown is for about 20 minutes. 9. The torrefaction process of any one of claims 1 to 8, wherein said lignin breakdown is at about 101 .4 kPa (about 1 atm). 10. The torrefaction process of any one of claims 1 to 9, wherein said lignin breakdown is performed under an inert atmosphere. 1 1 . The torrefaction process of claim 10, wherein said inert atmosphere is a nitrogen atmosphere. 12. The torrefaction process of any one of claims 1 to 10, wherein said lignin breakdown further comprises the presence of 0.05 to 0.1 % ammonia. 13. The torrefaction process of any one of claims 1 to 12, wherein said lignin breakdown is performed under a nitrogen-ammonia atmosphere. 14. The torrefaction process of any one of claims 1 to 13, wherein said second crystallization is at about 210°C to 215°C. 15. The torrefaction process of any one of claims 1 to 14, wherein said second crystallization is for about 30 minutes to 50 minutes. 16. The torrefaction process of any one of claims 1 to 15, wherein said second crystallization is at from about 91 .3 kPa (0.9 atm) to about 101.4 kPa (about 1 atm). 17. The torrefaction process of any one of claims 14 to 16, wherein said second crystallization comprises a slow cooling for about the last 30 minutes of said step, to said moisture equilibration step. 18. The torrefaction process of any one of claims 14 to 17, wherein said second crystallization comprises a slow pressure decrease to about 20.3 kPa (0.2 atm). 19. The torrefaction process of any one of claims 14 to 18, wherein said second crystallization is performed under a nitrogen atmosphere. 20. The torrefaction process of any one of claims 1 to 16, wherein said moisture equilibration step is at about 95°C. 21 . The torrefaction process of any one of claims 1 to 20, wherein said moisture equilibration step is for about 60 minutes. 22. The torrefaction process of any one of claims 1 to 21 , wherein said moisture equilibration step is at about 50.7 kPa (about 0.5 atm). 23. The torrefaction process of any one of claims 1 to 21 , wherein said moisture equilibration step is at about 81 .1 kPa (0.8 atm) to about 101 .4 kPa (1 atm). 24. The torrefaction process of any one of claim 1 to 23, wherein said moisture equilibration step is performed in an atmosphere having about 50% humidity. 25. The torrefaction process of any one of claims 1 to 21 , further comprising a gas and acid extraction step, prior to first crystallization. 26. The torrefaction process of claim 25, wherein said gas and acid extraction step is at about 120°C. 27. The torrefaction process of any one of claims 25 - 26, wherein said gas an acid extraction step is for about 90 minutes to about 120 minutes. 28. The torrefaction process of any one of claims 25 - 27, wherein said gas and acid extraction step is at about 101 .4 kPa (about 1 atm). 29. The torrefaction process of any one of claim 1 to 28, further comprising a hemicellulose conversion step, after second crystallization. 30. The torrefaction process of claim 29, wherein said hemicellulose conversion step is at about 195°C. 31 . The torrefaction process of claim 29, wherein said hemicellulose conversion step is for about 15 minutes. 32. The torrefaction process of claim 29, wherein said hemicellulose conversion step is at about 101 .4 kPa (about 1 atm). 33. The torrefaction process of any one of claims 1 to 32, wherein hemicellulose conversion step is performed under a nitrogen-ammonia atmosphere. 34. The torrefaction process of any one of claims 1 to 33, further comprising a slow cooling initiation step after said second crystallization, at about 210°C for about 1 minute, at about 91 .3 kPa (0.9 atm). 35. The torrefaction process of any one of claims 29 to 34, further comprising a torrefaction step, after said hemicellulose conversion step. 36. The torrefaction process of claim 35, wherein said torrefaction step is at about 120°C. 37. The torrefaction process of any one of claims 35 to 36, wherein said torrefaction step is for about 45 minutes. 38. The torrefaction process of any one of claims 35 to 37, wherein torrefaction step is at about 101 .4 kPa (about 1 atm). 39. The torrefaction process of any one of claims 35 to 38, further comprising a compacting step, after said torrefaction step. 40. The torrefaction process of claim 39, wherein said compacting step is at about 180°C. 41 . The torrefaction process of any one of claims 39 to 40, wherein said compacting step is for about 15 minutes. 42. The torrefaction process of any one of claims 39 to 41 , wherein said compacting step is at about 91 .3 kPa (0.9 atm). |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of US provisional patent application 62/069,921 , filed on October 29, 2014, the specification of which is hereby incorporated by reference.
BACKGROUND
[0002] Torrefaction is a mild form of pyrolysis extracting volatile components, liquids, waxes, tar and dust. Several of these compounds are armful for the environment and need to be destroyed or recycled according to specific processes. In this invention, it is disclosed how to control the waste compounds generation and safely turned them in recyclable energy for a manufacturing process.
[0003] Torrefaction is also known as a process of making wood more durable in exterior use. Simply burning a wood surface in open fire will make it more durable. The key of the present invention is to improve the torrefaction process to improve wood quality and durability.
[0004] Torrefaction consists of heating wood at a very high temperature, typically from 190°C to 240°C, in a torrefaction kiln under a controlled atmosphere and with low oxygen. The time and temperature depends on the type of wood being torrefied and the desired classification and color objective. Torrefaction requires 3 steps: drying, heat-treatment and conditioning-cooling. A pre-drying process using conventional kiln driers is required to initially lower the moisture level to between 6% and 10% specific humidity, which is a standard convention, relating to a ratio of the water vapor content of the mixture to the total air content on a mass basis. The torrefaction kiln then lowers the moisture level further to 0%. In the final step the wood is placed in a chamber where the temperature is gradually lowered through a controlled injection of steam. The moisture level of the product is increased to between 3% and 6%, in order to give the wood a natural flexibility. Conditioning helps stabilize the wood and promotes better quality manufacturing.
[0005] Actual methods are difficult to control and the torrefied wood characteristics may vary and lack consistency, generating unwanted waste and costs. In this invention, it is proposed a novel process increasing the reliability and quality of production.
[0006] In torrefaction, various gases are evolved, such as carbon monoxide, carbon dioxide, various organic compounds, water, and possibly other non-organic compounds. One aspect of this invention is to burn the carbon monoxide and organic vapors and use the heat evolved to provide some of the heat for drying and torrefying. The inert atmosphere may consist substantially of steam and/or other inert gas such as nitrogen. Torrefaction of the cellulosic products, and more specifically the removal of bound water and volatiles in the feedstock, are conducted in a closed, inert, system which may allow capture of volatile materials.
SUMMARY
[0007] According to an embodiment, there is provided a torrefaction process for cellulose based material comprising:
1 ) first crystallization of the cellulose based material at about 210°C to about 240°C, for about 10 minutes to about 45 minutes, at a pressure of about 25.4 kPa to about 101 .4 kPa ;
2) lignin breakdown of the cellulose based material at about 170°C to about 200°C, for about 15 minutes to about 35 minutes, at a pressure of about 50.8 kPa to about 101 .4 kPa under an inert atmosphere, optionally in the presence of 0.05 to 0.1 % ammonia; 3) second crystallization of the cellulose based material at about 205°C to about 230°C, for about 15 minutes to about 90 minutes, at a pressure of about 50.8 kPa to about 101 .4 kPa, under an inert atmosphere to increase strength of the cellulose based material; and
4) moisture equilibration of the cellulose based material at about 50°C to about 95°C, for about 60 minutes to about 120 minutes, at a pressure of about 10.2 kPa to about 75.2 kPa, prior to returning the cellulose based material to room temperature (about 25°C) and normal atmospheric pressure (about 101 .325 kPa).
[0008] The first crystallization may be performed under an ozone, nitrogen or noble gas atmosphere.
[0009] The first crystallization may be performed under a nitrogen atmosphere.
[0010] The first crystallization may be at 230°C.
[0011] The first crystallization may be for about 15 minutes.
[0012] The first crystallization may be at about 50.7 kPa (0.5 atm).
[0013] The lignin breakdown may be at about 180°C.
[0014] The lignin breakdown may be for about 20 minutes.
[0015] The lignin breakdown may be at about 101.4 kPa (about 1 atm)
[0016] The lignin breakdown may be performed under an atmosphere.
[0017] The inert atmosphere may be a nitrogen atmosphere.
[0018] The lignin breakdown may further comprise the presence of 0.05 to 0.1 % ammonia. [0019] The lignin breakdown may be performed under a nitrogen-ammonia atmosphere.
[0020] The second crystallization may be at about 210°C to 215°C.
[0021] The second crystallization may be for about 30 minutes to 50 minutes.
[0022] The second crystallization may be at from about 91.3 kPa (0.9 atm) to about 101 .4 kPa (about 1 atm).
[0023] The second crystallization may further comprise a slow cooling for about the last 30 minutes of the step, to the moisture equilibration step.
[0024] The second crystallization comprises a slow pressure decrease to about 20.3 kPa (0.2 atm).
[0025] The second crystallization may be performed under a nitrogen atmosphere.
[0026] The moisture equilibration step may be at about 95°C.
[0027] The moisture equilibration step may be for about 60 minutes.
[0028] The moisture equilibration step may be at about 50.7 kPa (about 0.5 atm).
[0029] The moisture equilibration step may be at about 81 .1 kPa (0.8 atm) to about 101 .4 kPa (1 atm).
[0030] The moisture equilibration step may be performed in an atmosphere having about 50% humidity.
[0031] The torrefaction process may further comprise a gas and acid extraction step, prior to first crystallization.
[0032] The gas and acid extraction step may be at about 120°C. [0033] The gas an acid extraction step may be for about 90 minutes to about 120 minutes.
[0034] The gas and acid extraction step may be at about 101 .4 kPa (about 1 atm).
[0035] The torrefaction process may further comprise a hemicellulose conversion step, after second crystallization.
[0036] The hemicellulose conversion step may be at about 195°C.
[0037] The hemicellulose conversion step may be for about 15 minutes.
[0038] The hemicellulose conversion step may be at about 101.4 kPa (about 1 atm).
[0039] The hemicellulose conversion step may be performed under a nitrogen-ammonia atmosphere.
[0040] The torrefaction process may further comprise a slow cooling initiation step after the second crystallization, at about 210°C for about 1 minute, at about 91.3 kPa (0.9 atm).
[0041] The torrefaction process may further comprise a torrefaction step, after the hemicellulose conversion step.
[0042] The torrefaction step may be at about 120°C.
[0043] The torrefaction step may be for about 45 minutes.
[0044] The torrefaction step may be at about 101 .4 kPa (about 1 atm).
[0045] The torrefaction process may further comprise a compacting step, after the torrefaction step.
[0046] The compacting step may be at about 180°C. [0047] The compacting step may be for about 15 minutes. The compacting step may be at about 91.3 kPa (0.9 atm). [0048] The following terms are defined below.
[0049] The term "cellulose based material" is intended to mean mainly wood, which may be softwood (such as conifers) or hardwood (such as oak, maple, and the likes).
[0050] The term "specific humidity" is intended to mean the ratio of the water vapor content of the mixture to the total air content on a mass basis, presented in %.
[0051] The term "percentage" when referring to percentage atmosphere is intended to mean the relative percentage of the component relative to the total atmosphere.
[0052] Features and advantages of the subject matter hereof will become more apparent in light of the following detailed description of selected embodiments, as illustrated in the accompanying figures. As will be realized, the subject matter disclosed and claimed is capable of modifications in various respects, all without departing from the scope of the claims. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not as restrictive and the full scope of the subject matter is set forth in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
[0054] Fig. 1 illustrates a torrefaction process diagram according to the prior art.
[0055] Fig. 2 illustrates a torrefaction process diagram according to the present invention. Red line represents the average, the top horizontal line represents 180°C, the full line represents the cellulose based material (wood) temperature and the other (varying) line represents the temperature of the apparatus. The heating phase is from about 0 to 180°C, the torrefaction phase starts at about 180°C to the maximum temperature reached, and the cooling phase is from max temperature to stop of the process.
[0056] Fig. 3 illustrates a process and flow diagram according to an embodiment of the present invention. Specific humidity, shown as value % is a ratio of the water vapor content of the mixture to the total air content on a mass basis.
[0057] Fig. 4 illustrates in (A) and (B) processes flow diagram according to an embodiment of the present invention. (A) illustrates the basic process of the present invention while (B) presents optional steps that may be introduce in the process of the present invention.
DETAILED DESCRIPTION
[0058] In embodiments there are disclosed processes for the torrefaction of cellulose based materials. The process of the present invention is a complex mixture of endothermic and exothermic reactions from which is achieved the right torrefaction degree needed for obtaining torrefied cellulose based material (wood) as construction material and not dry combustible. Known torrefaction processes are combined with acid (mainly acetic and formic acid) releases from the cellulose break down (degradation), leading to more fragile less mechanically suitable material. The present invention overcome these problems, as the hydrolysis of the wood polysaccharides is optimized by controlling the pH (acidic to neutral) of the environment, and associate it to the most adequate torrefaction process window (temperature, atmosphere, pH, time and pressure) to obtain the most efficient remaining mass percentage of the treated timber with the desired properties (water resistance, adequate grindability, minimized brittleness, highest mechanical strength (for handling/cutting), coating and protecting receptivity and slower biodegradation). [0059] Now referring to Fig. 4A, according to a first embodiment, there is provided a torrefaction process 100 to speed and improve torrefaction conditions of different wood species, including softwoods as well as hardwoods, which improves the final cellulose based material product for construction purposes. The process 100 of the present invention involves different sequences of treatments that improve the final product for later construction application. The process of the present invention regularizes the final product using temperature variations over time between 120°C to 240°C, and involves different atmosphere conditions, minimizing free radicals while increasing hardness. The process of the present invention involves a combination of events, starting with dry heat control under ozone, nitrogen or rare gas (such as argon) atmosphere, followed by vacuum dryness, and temperature humidity down sequences. The temperature control and atmosphere is essential to control of the torrefaction level, in order to generate construction material and not combustion material. A major advantage of the process of the present invention is to be able to control the cellulose breakdown to maintain mechanical strength of wood adequate to construction applications, as well as controlling the resulting color of the final product.
[0060] According to an embodiment of the torrefaction process 100, the cellulose based material may be subjected to a first crystallization 10 of the cellulose based material at about 210°C to about 240°C, or from about 210°C to about 235°C, or from about 210°C to about 230°C, or from about 210°C to about 225°C, or from about 210°C to about 220°C, or from about 210°C to about 215°C, or about 215°C to about 240°C, or from about 215°C to about 235°C, or from about 215°C to about 230°C, or from about 215°C to about 225°C, or from about 215°C to about 220°C, or about 220°C to about 240°C, or from about 220°C to about 235°C, or from about 220°C to about 230°C, or from about 220°C to about 225°C, or about 225°C to about 240°C, or from about 225°C to about 235°C, or from about 225°C to about 230°C, or about 230°C to about 240°C, or from about 230°C to about 235°C, or, about 235°C to about 240°C, preferably at 230°C. The first crystallization may be for about 10 minutes to about 45 minutes, or from about 10 minutes to about 40 minutes, or from about 10 minutes to about 35 minutes, or from about 10 minutes to about 30 minutes, or from about 10 minutes to about 25 minutes, or from about 10 minutes to about 20 minutes, or from about 10 minutes to about 15 minutes, or from 15 minutes to about 45 minutes, or from about 15 minutes to about 40 minutes, or from about 15 minutes to about 35 minutes, or from about 15 minutes to about 30 minutes, or from about 15 minutes to about 25 minutes, or from about 15 minutes to about 20 minutes, or from 20 minutes to about 45 minutes, or from about 20 minutes to about 40 minutes, or from about 20 minutes to about 35 minutes, or from about 20 minutes to about 30 minutes, or from about 20 minutes to about 25 minutes, or from 25 minutes to about 45 minutes, or from about 25 minutes to about 40 minutes, or from about 25 minutes to about 35 minutes, or from about 25 minutes to about 30 minutes, or from 30 minutes to about 45 minutes, or from about 30 minutes to about 40 minutes, or from about 30 minutes to about 35 minutes, from 35 minutes to about 45 minutes, or from about 35 minutes to about 40 minutes, or from 40 minutes to about 45 minutes, preferably at 15 minutes.
[0061] The first crystallization 10 may be performed at pressures of about 25.4 kPa to about 101 .4 kPa, or from about 25.4 kPa to about 91.3 kPa, or from about 25.4 kPa to about 81 .1 kPa, or from about 25.4 kPa to about 76.1 kPa, or from about 25.4 kPa to about 71 kPa, or from about 25.4 kPa to about 60.8 kPa, or from about 25.4 kPa to about 50.7 kPa, or from about 25.4 kPa to about 40.6 kPa, or from about 25.4 kPa to about 33.8 kPa, or from about 33.8 kPa to about 101.4 kPa, or from about 33.8 kPa to about 91.3 kPa, or from about 33.8 kPa to about 81 .1 kPa, or from about 33.8 kPa to about 76.1 kPa, or from about 33.8 kPa to about 71 kPa, or from about 33.8 kPa to about 60.8 kPa, or from about 33.8 kPa to about 50.7 kPa, or from about 33.8 kPa to about 40.6 kPa, or from about 40.6 kPa to about 101 .4 kPa, or from about 40.6 kPa to about 91 .3 kPa, or from about 40.6 kPa to about 81 .1 kPa, or from about 40.6 kPa to about 76.1 kPa, or from about 40.6 kPa to about 71 kPa, or from about 40.6 kPa to about 60.8 kPa, or from about 40.6 kPa to about 50.7 kPa, or from about 50.7 kPa to about 101 .4 kPa, or from about 50.7 kPa to about 91 .3 kPa, or from about 50.7 kPa to about 81 .1 kPa, or from about 50.7 kPa to about 76.1 kPa, or from about 50.7 kPa to about 71 kPa, or from about 50.7 kPa to about 60.8 kPa, or from about 60.8 kPa to about 101 .4 kPa, or from about 60.8 kPa to about 91 .3 kPa, or from about 60.8 kPa to about 81 .1 kPa, or from about 60.8 kPa to about 76.1 kPa, or from about 60.8 kPa to about 71 kPa, or from about 71 kPa to about 101.4 kPa, or from about 71 kPa to about 91 .3 kPa, or from about 71 kPa to about 81 .1 kPa, or from about 71 kPa to about 76.1 kPa, or from about 76.1 kPa to about 101.4 kPa, or from about 76.1 kPa to about 91 .3 kPa, or from about 76.1 kPa to about 81 .1 kPa, or from about 81 .1 kPa to about 101 .4 kPa, or from about 81 .1 kPa to about 91 .3 kPa, or from about 91.3 kPa to about 101 .4 kPa, preferably at 50.7 kPa (0.5 atm).
[0062] In embodiments, the first crystallization is performed under ozone, nitrogen or rare (noble) gas (such as helium, neon, argon, krypton, or xenon) atmosphere, preferably nitrogen.
[0063] This step may be followed by a lignin breakdown step 20, at about 170°C to about 200°C, or from about 170°C to about 195°C, or from about 170°C to about 190°C, or from about 170°C to about 185°C, or from about 170°C to about 180°C, or from about 170°C to about 175°C, or from about 175°C to about 200°C, or from about 175°C to about 195°C, or from about 175°C to about 190°C, or from about 175°C to about 185°C, or from about 175°C to about 180°C, or from about 180°C to about 200°C, or from about 180°C to about 195°C, or from about 180°C to about 190°C, or from about 180°C to about 185°C, or from about 185°C to about 200°C, or from about 185°C to about 195°C, or from about 185°C to about 190°C, or from about 190°C to about 200°C, or from about 190°C to about 195°C, or from about 195°C to about 200°C, preferably 180°C. The lignin breakdown step may be for about 15 minutes to about 35 minutes, or from about 15 minutes to about 30 minutes, or from about 15 minutes to about 25 minutes, or from about 15 minutes to about 20 minutes, or from about 20 minutes to about 35 minutes, or from about 20 minutes to about 30 minutes, or from about 20 minutes to about 25 minutes, or from about 25 minutes to about 35 minutes, or from about 25 minutes to about 30 minutes, or from about 30 minutes to about 35 minutes, preferably 20 minutes.
[0064] This second step (lignin breakdown 20) may be performed at a pressure of about 50.7 kPa to about 101 .4 kPa, or about 50.7 kPa to about 91 .3 kPa, or about 50.7 kPa to about 81 .1 kPa, or about 50.7 kPa to about 76.1 kPa, or about 50.7 kPa to about 71 kPa, or about 50.7 kPa to about 60.8 kPa, or from about 60.8 kPa to about 101.4 kPa, or about 60.8 kPa to about 91 .3 kPa, or about 60.8 kPa to about 81 .1 kPa, or about 60.8 kPa to about 76.1 kPa, or about 60.8 kPa to about 71 kPa, or from about 71 kPa to about 101 .4 kPa, or about 71 kPa to about 91 .3 kPa, or about 71 kPa to about 81 .1 kPa, or about 71 kPa to about 76.1 kPa, or from about 76.1 kPa to about 101 .4 kPa, or about 76.1 kPa to about 91 .3 kPa, or about 76.1 kPa to about 81 .1 kPa, or from about 81 .1 kPa to about 101 .4 kPa, or about 81 .1 kPa to about 91.3 kPa, or from about 91.3 kPa to about 101.4 kPa, preferably 101 .4 kPa (1 atm).
[0065] This second step (lignin breakdown 20) may be performed under an inert atmosphere (e.g. a nitrogen atmosphere or rare (noble) gas (such as helium, neon, argon, krypton, or xenon) atmosphere, and preferably nitrogen), optionally in the presence of 0.05 to 0.1 % ammonia.
[0066] The cellulose based material may then be subjected to a second crystallization 30 of the cellulose based material at about 205°C to about 230°C, or from about 205°C to about 225°C, or from about 205°C to about 220°C, or from about 205°C to about 215°C, or from about 205°C to about 210°C, or from about 210°C to about 230°C, or from about 210°C to about 225°C, or from about 210°C to about 220°C, or from about 210°C to about 215°C, or from about 215°C to about 230°C, or from about 215°C to about 225°C, or from about 215°C to about 220°C, or from about 220°C to about 230°C, or from about 220°C to about 225°C, or from about 225°C to about 230°C, preferably at . 210°C to about 215°C, and most preferably 215°C.
[0067] The second crystallization 30 may be for about 15 minutes to about 90 minutes, or from about 15 minutes to about 85 minutes, or from about 15 minutes to about 80 minutes, or from about 15 minutes to about 75 minutes, or from about 15 minutes to about 70 minutes, or from about 15 minutes to about 65 minutes, or from about 15 minutes to about 60 minutes, or from about 15 minutes to about 55 minutes, or from about 15 minutes to about 50 minutes, or from about 15 minutes to about 45 minutes, or from about 15 minutes to about 40 minutes, or from about 15 minutes to about 35 minutes, or from about 15 minutes to about 30 minutes, or from about 15 minutes to about 25 minutes, or from about 15 minutes to about 20 minutes, or from about 20 minutes to about 90 minutes, or from about 20 minutes to about 85 minutes, or from about 20 minutes to about 80 minutes, or from about 20 minutes to about 75 minutes, or from about 20 minutes to about 70 minutes, or from about 20 minutes to about 65 minutes, or from about 20 minutes to about 60 minutes, or from about 20 minutes to about 55 minutes, or from about 20 minutes to about 50 minutes, or from about 20 minutes to about 45 minutes, or from about 20 minutes to about 40 minutes, or from about 20 minutes to about 35 minutes, or from about 20 minutes to about 30 minutes, or from about 20 minutes to about 25 minutes, or from about 25 minutes to about 90 minutes, or from about 25 minutes to about 85 minutes, or from about 25 minutes to about 80 minutes, or from about 25 minutes to about 75 minutes, or from about 25 minutes to about 70 minutes, or from about 25 minutes to about 65 minutes, or from about 25 minutes to about 60 minutes, or from about 25 minutes to about 55 minutes, or from about 25 minutes to about 50 minutes, or from about 25 minutes to about 45 minutes, or from about 25 minutes to about 40 minutes, or from about 25 minutes to about 35 minutes, or from about 25 minutes to about 30 minutes, or from about 30 minutes to about 90 minutes, or from about 30 minutes to about 85 minutes, or from about 30 minutes to about 80 minutes, or from about 30 minutes to about 75 minutes, or from about 30 minutes to about 70 minutes, or from about 30 minutes to about 65 minutes, or from about 30 minutes to about 60 minutes, or from about 30 minutes to about 55 minutes, or from about 30 minutes to about 50 minutes, or from about 30 minutes to about 45 minutes, or from about 30 minutes to about 40 minutes, or from about 30 minutes to about 35 minutes, or from about 35 minutes to about 90 minutes, or from about 35 minutes to about 85 minutes, or from about 35 minutes to about 80 minutes, or from about 35 minutes to about 75 minutes, or from about 35 minutes to about 70 minutes, or from about 35 minutes to about 65 minutes, or from about 35 minutes to about 60 minutes, or from about 35 minutes to about 55 minutes, or from about 35 minutes to about 50 minutes, or from about 35 minutes to about 45 minutes, or from about 35 minutes to about 40 minutes, or from about 40 minutes to about 90 minutes, or from about 40 minutes to about 85 minutes, or from about 40 minutes to about 80 minutes, or from about 40 minutes to about 75 minutes, or from about 40 minutes to about 70 minutes, or from about 40 minutes to about 65 minutes, or from about 40 minutes to about 60 minutes, or from about 40 minutes to about 55 minutes, or from about 40 minutes to about 50 minutes, or from about 40 minutes to about 45 minutes, or from about 45 minutes to about 90 minutes, or from about 45 minutes to about 85 minutes, or from about 45 minutes to about 80 minutes, or from about 45 minutes to about 75 minutes, or from about 45 minutes to about 70 minutes, or from about 45 minutes to about 65 minutes, or from about 45 minutes to about 60 minutes, or from about 45 minutes to about 55 minutes, or from about 45 minutes to about 50 minutes, or from about 50 minutes to about 90 minutes, or from about 50 minutes to about 85 minutes, or from about 50 minutes to about 80 minutes, or from about 50 minutes to about 75 minutes, or from about 50 minutes to about 70 minutes, or from about 50 minutes to about 65 minutes, or from about 50 minutes to about 60 minutes, or from about 50 minutes to about 55 minutes, or from about 55 minutes to about 90 minutes, or from about 55 minutes to about 85 minutes, or from about 55 minutes to about 80 minutes, or from about 55 minutes to about 75 minutes, or from about 55 minutes to about 70 minutes, or from about 55 minutes to about 65 minutes, or from about 55 minutes to about 60 minutes, or from about 60 minutes to about 90 minutes, or from about 60 minutes to about 85 minutes, or from about 60 minutes to about 80 minutes, or from about 60 minutes to about 75 minutes, or from about 60 minutes to about 70 minutes, or from about 60 minutes to about 65 minutes, or from about 65 minutes to about 90 minutes, or from about 65 minutes to about 85 minutes, or from about 65 minutes to about 80 minutes, or from about 65 minutes to about 75 minutes, or from about 65 minutes to about 70 minutes, or from about 70 minutes to about 90 minutes, or from about 70 minutes to about 85 minutes, or from about 70 minutes to about 80 minutes, or from about 70 minutes to about 75 minutes, or from about 75 minutes to about 90 minutes, or from about 75 minutes to about 85 minutes, or from about 75 minutes to about 80 minutes, or from about 80 minutes to about 90 minutes, or from about 80 minutes to about 85 minutes, or from about 85 minutes to about 90 minutes, preferably for about 30 minutes to 50 minutes, and most preferably 30 minutes.
[0068] This step 30 is performed at a pressure of about 50.7 kPa to about 101.4 kPa, or about 50.7 kPa to about 91 .3 kPa, or about 50.7 kPa to about 81 .1 kPa, or about 50.7 kPa to about 76.1 kPa, or about 50.7 kPa to about 71 kPa, or about 50.7 kPa to about 60.8 kPa, or from about 60.8 kPa to about 101 .4 kPa, or about 60.8 kPa to about 91 .3 kPa, or about 60.8 kPa to about 81 .1 kPa, or about 60.8 kPa to about 76.1 kPa, or about 60.8 kPa to about 71 kPa, or from about 71 kPa to about 101 .4 kPa, or about 71 kPa to about 91 .3 kPa, or about 71 kPa to about 81 .1 kPa, or about 71 kPa to about 76.1 kPa, or from about 76.1 kPa to about 101 .4 kPa, or about 76.1 kPa to about 91.3 kPa, or about 76.1 kPa to about 81 .1 kPa, or from about 81 .1 kPa to about 101 .4 kPa, or about 81 .1 kPa to about 91 .3 kPa, or from about 91 .3 kPa to about 101 .4 kPa, preferably about 20.3 kPa (0.2 atm), to increase strength of the cellulose based material. The step 30 may be performed under an inert atmosphere (e.g. nitrogen or rare (noble) gas (such as helium, neon, argon, krypton, or xenon) atmosphere), preferably a nitrogen atmosphere, to increase strength of the cellulose based material.
[0069] The cellulose based material is then subjected to moisture equilibration step 40, at about 50°C to about 95°C, or about 50°C to about 90°C, or about 50°C to about 85°C, or about 50°C to about 80°C, or about 50°C to about 75°C, or about 50°C to about 70°C, or about 50°C to about 65°C, or about 50°C to about 60°C, or about 50°C to about 55°C, or from about 55°C to about 95°C, or about 55°C to about 90°C, or about 55°C to about 85°C, or about 55°C to about 80°C, or about 55°C to about 75°C, or about 55°C to about 70°C, or about 55°C to about 65°C, or about 55°C to about 60°C, or about 55°C to about 55°C, or from about 60°C to about 95°C, or about 60°C to about 90°C, or about 60°C to about 85°C, or about 60°C to about 80°C, or about 60°C to about 75°C, or about 60°C to about 70°C, or about 60°C to about 65°C, or from about 65°C to about 95°C, or about 65°C to about 90°C, or about 65°C to about 85°C, or about 65°C to about 80°C, or about 65°C to about 75°C, or about 65°C to about 70°C, or from about 70°C to about 95°C, or about 70°C to about 90°C, or about 70°C to about 85°C, or about 70°C to about 80°C, or about 70°C to about 75°C, or from about 75°C to about 95°C, or about 75°C to about 90°C, or about 75°C to about 85°C, or about 75°C to about 80°C, or from about 80°C to about 95°C, or about 80°C to about 90°C, or about 80°C to about 85°C, or from about 85°C to about 95°C, or about 85°C to about 90°C, or from about 90°C to about 95°C, preferably 95°C, prior to returning the cellulose based material to room temperature (about 25°C) and normal atmospheric pressure (about 101.325 kPa).
[0070] The moisture equilibration step 40 may be for about 60 minutes to about 120 minutes, or from about 60 minutes to about 1 15 minutes, or from about 60 minutes to about 1 10 minutes, or from about 60 minutes to about 105 minutes, or from about 60 minutes to about 100 minutes, or from about 60 minutes to about 95 minutes, or from about 60 minutes to about 90 minutes, or from about 60 minutes to about 85 minutes, or from about 60 minutes to about 80 minutes, or from about 60 minutes to about 75 minutes, or from about 60 minutes to about 70 minutes, or from about 60 minutes to about 65 minutes, or from about 65 minutes to about 120 minutes, or from about 65 minutes to about 1 15 minutes, or from about 65 minutes to about 1 10 minutes, or from about 65 minutes to about 105 minutes, or from about 65 minutes to about 100 minutes, or from about 65 minutes to about 95 minutes, or from about 65 minutes to about 90 minutes, or from about 65 minutes to about 85 minutes, or from about 65 minutes to about 80 minutes, or from about 65 minutes to about 75 minutes, or from about 65 minutes to about 70 minutes, or from about 70 minutes to about 120 minutes, or from about 70 minutes to about 1 15 minutes, or from about 70 minutes to about 1 10 minutes, or from about 70 minutes to about 105 minutes, or from about 70 minutes to about 100 minutes, or from about 70 minutes to about 95 minutes, or from about 70 minutes to about 90 minutes, or from about 70 minutes to about 85 minutes, or from about 70 minutes to about 80 minutes, or from about 70 minutes to about 75 minutes, or from about 75 minutes to about 120 minutes, or from about 75 minutes to about 1 15 minutes, or from about 75 minutes to about 1 10 minutes, or from about 75 minutes to about 105 minutes, or from about 75 minutes to about 100 minutes, or from about 75 minutes to about 95 minutes, or from about 75 minutes to about 90 minutes, or from about 75 minutes to about 85 minutes, or from about 75 minutes to about 80 minutes, or from about 80 minutes to about 120 minutes, or from about 80 minutes to about 1 15 minutes, or from about 80 minutes to about 1 10 minutes, or from about 80 minutes to about 105 minutes, or from about 80 minutes to about 100 minutes, or from about 80 minutes to about 95 minutes, or from about 80 minutes to about 90 minutes, or from about 80 minutes to about 85 minutes, or from about 85 minutes to about 120 minutes, or from about 85 minutes to about 1 15 minutes, or from about 85 minutes to about 1 10 minutes, or from about 85 minutes to about 105 minutes, or from about 85 minutes to about 100 minutes, or from about 85 minutes to about 95 minutes, or from about 85 minutes to about 90 minutes, or from about 90 minutes to about 120 minutes, or from about 90 minutes to about 1 15 minutes, or from about 90 minutes to about 1 10 minutes, or from about 90 minutes to about 105 minutes, or from about 90 minutes to about 100 minutes, or from about 90 minutes to about 95 minutes, or from about 95 minutes to about 120 minutes, or from about 95 minutes to about 1 15 minutes, or from about 95 minutes to about 1 10 minutes, or from about 95 minutes to about 105 minutes, or from about 95 minutes to about 100 minutes, or from about 100 minutes to about 120 minutes, or from about 100 minutes to about 1 15 minutes, or from about 100 minutes to about 1 10 minutes, or from about 100 minutes to about 105 minutes, or from about 105 minutes to about 120 minutes, or from about 105 minutes to about 1 15 minutes, or from about 105 minutes to about 1 10 minutes, or from about 1 10 m inutes to about 120 m inutes, or from about 1 10 m inutes to about 1 15 minutes, or from about 1 15 minutes to about 120 minutes, preferably 60 minutes, prior to returning the cellulose based material to room temperature (about 25°C) and normal atmospheric pressure (about 101 .325 kPa).
[0071] The moisture equilibration step 40 may be performed at a pressure of about 10.2 kPa to about 75.2 kPa, or from about 10.2 kPa to about 71 kPa, or from about 10.2 kPa to about 60.8 kPa, or from about 10.2 kPa to about 50.7 kPa, or from about 10.2 kPa to about 40.6 kPa, or from about 10.2 kPa to about 33.8 kPa, or from about 10.2 kPa to about 25.4 kPa, or from about 10.2 kPa to about 20.3 kPa, or from about 20.3 kPa to about 75.2 kPa, or from about 20.3 kPa to about 71 kPa, or from about 20.3 kPa to about 60.8 kPa, or from about 20.3 kPa to about 50.7 kPa, or from about 20.3 kPa to about 40.6 kPa, or from about 20.3 kPa to about 33.8 kPa, or from about 20.3 kPa to about 25.4 kPa, or from about 25.4 kPa to about 75.2 kPa, or from about 25.4 kPa to about 71 kPa, or from about 25.4 kPa to about 60.8 kPa, or from about 25.4 kPa to about 50.7 kPa, or from about 25.4 kPa to about 40.6 kPa, or from about 25.4 kPa to about 33.8 kPa, or from about 33.8 kPa to about 75.2 kPa, or from about 33.8 kPa to about 71 kPa, or from about 33.8 kPa to about 60.8 kPa, or from about 33.8 kPa to about 50.7 kPa, or from about 33.8 kPa to about 40.6 kPa, or from about 40.6 kPa to about 75.2 kPa, or from about 40.6 kPa to about 71 kPa, or from about 40.6 kPa to about 60.8 kPa, or from about 40.6 kPa to about 50.7 kPa, or from about 50.7 kPa to about 75.2 kPa, or from about 50.7 kPa to about 71 kPa, or from about 50.7 kPa to about 60.8 kPa, or from about 60.8 kPa to about 75.2 kPa, or from about 60.8 kPa to about 71 kPa, or from about 71 kPa to about 75.2 kPa, preferably 50.7 kPa (0.5 atm), prior to returning the cellulose based material to room temperature (about 25°C) and normal atmospheric pressure (about 101.325 kPa). According to an embodiment, the atmosphere equilibration step 40 is performed under an atmosphere having about 40%, 50%, 60%, humidity, or from about 40% to about 60%, or from about 40% to about 55%, or from about 40% to about 50%, or from about 40% to about 45%, or from about 45% to about 60%, or from about 45% to about 55%, or from about 45% to about 50%, %, or from about 50% to about 60%, or from about 50% to about 55%, or from about 55% to about 60% and preferably 50% humidity.
[0072] Now referring to Fig. 4B, the process of the present invention may comprise sereval optional steps that may be performed in order to further improve the properties of the cellulose based material.
[0073] According to an embodiment, the process may include prior to the first crystallization 10, an optional gas and acid extraction step 12. This step may be performed for about 90 minutes to about 120 minutes, or from about 90 minutes to about 1 15 minutes, or from about 90 minutes to about 1 10 minutes, or from about 90 minutes to about 105 minutes, or from about 90 minutes to about 100 minutes, or from about 90 minutes to about 95 minutes, or from about 95 minutes to about 120 minutes, or from about 95 minutes to about 1 15 minutes, or from about 95 minutes to about 1 10 minutes, or from about 95 minutes to about 105 minutes, or from about 95 minutes to about 100 minutes, or from about 100 minutes to about 120 minutes, or from about 100 minutes to about 1 15 minutes, or from about 100 minutes to about 1 10 minutes, or from about 100 minutes to about 105 minutes, or from about 105 minutes to about 120 minutes, or from about 105 minutes to about 1 15 minutes, or from about 105 minutes to about 1 10 minutes, or from about 1 10 minutes to about 120 minutes, or from about 1 10 minutes to about 1 15 minutes, or from about 1 15 minutes to about 120 minutes.
[0074] The step 12 may be performed at about 120°C to about 140 °C, or from about 120°C to about 135°C, or from about 120°C to about 130°C, or from about 120°C to about 125°C, or from about 125°C to about 140 °C, or from about 125°C to about 135°C, or from about 125°C to about 130°C, or from about 130°C to about 140 °C, or from about 130°C to about 135°C, or from about 135°C to about 140 °C.
[0075] The step 12 may be performed at about 70 kPa to about 1 10 kPa, or from about 70 kPa to about 105 kPa, or from about 70 kPa to about 100 kPa, or from about 70 kPa to about 95 kPa, or from about 70 kPa to about 90 kPa, or from about 70 kPa to about 85 kPa, or from about 70 kPa to about 80 kPa, or from about 70 kPa to about 75 kPa, or from about 75 kPa to about 1 10 kPa, or from about 75 kPa to about 105 kPa, or from about 75 kPa to about 100 kPa, or from about 75 kPa to about 95 kPa, or from about 75 kPa to about 90 kPa, or from about 75 kPa to about 85 kPa, or from about 75 kPa to about 80 kPa, or from about 80 kPa to about 1 10 kPa, or from about 80 kPa to about 105 kPa, or from about 80 kPa to about 100 kPa, or from about 80 kPa to about 95 kPa, or from about 80 kPa to about 90 kPa, or from about 80 kPa to about 85 kPa, or from about 85 kPa to about 1 10 kPa, or from about 85 kPa to about 105 kPa, or from about 85 kPa to about 100 kPa, or from about 85 kPa to about 95 kPa, or from about 85 kPa to about 90 kPa, or from about 90 kPa to about 1 10 kPa, or from about 90 kPa to about 105 kPa, or from about 90 kPa to about 100 kPa, or from about 90 kPa to about 95 kPa, or from about 95 kPa to about 1 10 kPa, or from about 95 kPa to about 105 kPa, or from about 95 kPa to about 100 kPa, or from about 100 kPa to about 1 10 kPa, or from about 100 kPa to about 105 kPa, or from about 105 kPa to about 100 kPa, or from about 71 kPa to about 101 .4 kPa, or about 71 kPa to about 91 .3 kPa, or about 71 kPa to about 81 .1 kPa, or about 71 kPa to about 76.1 kPa, or from about 76.1 kPa to about 101 .4 kPa, or about 76.1 kPa to about 91 .3 kPa, or about 76.1 kPa to about 81 .1 kPa, or from about 81 .1 kPa to about 101 .4 kPa, or about 81.1 kPa to about 91 .3 kPa, or from about 91 .3 kPa to about 101 .4 kPa.
[0076] According to another embodiment, the process may comprise an optional hemicellulose conversion step 32, which may be performed at about 145°C to about 195°C, or from about 145°C to about 190°C, or from about 145°C to about 185°C, or from about 145°C to about 180°C, or from about 145°C to about 175°C, or from about 145°C to about 170°C, or from about 145°C to about
165°C, or from about 145°C to about 160°C, or from about 145°C to about
155°C, or from about 145°C to about 150°C, or from about 150°C to about
195°C, or from about 150°C to about 190°C, or from about 150°C to about
185°C, or from about 150°C to about 180°C, or from about 150°C to about
175°C, or from about 150°C to about 170°C, or from about 150°C to about
165°C, or from about 150°C to about 160°C, or from about 150°C to about
155°C, or from about 155°C to about 195°C, or from about 155°C to about
190°C, or from about 155°C to about 185°C, or from about 155°C to about
180°C, or from about 155°C to about 175°C, or from about 155°C to about
170°C, or from about 155°C to about 165°C, or from about 155°C to about
160°C, or from about 160°C to about 195°C, or from about 160°C to about
190°C, or from about 160°C to about 185°C, or from about 160°C to about
180°C, or from about 160°C to about 175°C, or from about 160°C to about
170°C, or from about 160°C to about 165°C, or from about 165°C to about
195°C, or from about 165°C to about 190°C, or from about 165°C to about 185°C, or from about 165°C to about 180°C, or from about 165°C to about 175°C, or from about 165°C to about 170°C, or from about 170°C to about 195°C, or from about 170°C to about 190°C, or from about 170°C to about 185°C, or from about 170°C to about 180°C, or from about 170°C to about 175°C, or from about 175°C to about 195°C, or from about 175°C to about 190°C, or from about 175°C to about 185°C, or from about 175°C to about 180°C, or from about 180°C to about 195°C, or from about 180°C to about 190°C, or from about 180°C to about 185°C, or from about 185°C to about 195°C, or from about 185°C to about 190°C, or from about 190°C to about 195°C, and preferably 195°C.
[0077] The optional hemicellulose conversion step 32 may be performed for about 10 minutes to about 25 minutes, or from about 10 minutes to about 20 minutes, or from about 10 minutes to about 15 minutes, or from about 15 minutes to about 25 minutes, or from about 15 minutes to about 20 minutes, or from about 20 minutes to about 25 minutes, preferably 15 minutes.
[0078] The optional hemicellulose conversion step 32 may be performed at 70 kPa to about 1 10 kPa, or from about 70 kPa to about 105 kPa, or from about 70 kPa to about 100 kPa, or from about 70 kPa to about 95 kPa, or from about 70 kPa to about 90 kPa, or from about 70 kPa to about 85 kPa, or from about 70 kPa to about 80 kPa, or from about 70 kPa to about 75 kPa, or from about 75 kPa to about 1 10 kPa, or from about 75 kPa to about 105 kPa, or from about 75 kPa to about 100 kPa, or from about 75 kPa to about 95 kPa, or from about 75 kPa to about 90 kPa, or from about 75 kPa to about 85 kPa, or from about 75 kPa to about 80 kPa, or from about 80 kPa to about 1 10 kPa, or from about 80 kPa to about 105 kPa, or from about 80 kPa to about 100 kPa, or from about 80 kPa to about 95 kPa, or from about 80 kPa to about 90 kPa, or from about 80 kPa to about 85 kPa, or from about 85 kPa to about 1 10 kPa, or from about 85 kPa to about 105 kPa, or from about 85 kPa to about 100 kPa, or from about 85 kPa to about 95 kPa, or from about 85 kPa to about 90 kPa, or from about 90 kPa to about 1 10 kPa, or from about 90 kPa to about 105 kPa, or from about 90 kPa to about 100 kPa, or from about 90 kPa to about 95 kPa, or from about 95 kPa to about 1 10 kPa, or from about 95 kPa to about 105 kPa, or from about 95 kPa to about 100 kPa, or from about 100 kPa to about 1 10 kPa, or from about 100 kPa to about 105 kPa, or from about 105 kPa to about 100 kPa, or from about 71 kPa to about 101 .4 kPa, or about 71 kPa to about 91 .3 kPa, or about 71 kPa to about 81 .1 kPa, or about 71 kPa to about 76.1 kPa, or from about 76.1 kPa to about 101.4 kPa, or about 76.1 kPa to about 91 .3 kPa, or about 76.1 kPa to about 81 .1 kPa, or from about 81 .1 kPa to about 101 .4 kPa, or about 81.1 kPa to about 91 .3 kPa, or from about 91 .3 kPa to about 101 .4 kPa, preferably at 101 .4 kPa. The hemicellulose conversion step 32 may be performed under a nitrogen-ammonia atmosphere, for example a nitrogen atmosphere comprising about 0.05 to 0.1 % ammonia (relative concentration with respect to the total atmosphere).
[0079] According to another embodiment, the process of the present invention may comprise a slow cooling initiation step 34, after the crystallization 30, at about 210°C for about 1 minute, at about 91.3 kPa (0.9 atm).
[0080] According to yet another embodiment, the process of the present invention may replace the slow cooling initiation step with a further torrefaction step 34, which is performed at about 1 10°C to about 130°C, or about 1 10°C to about 125°C, or about 1 10°C to about 120°C, or about 1 10°C to about 1 15°C, or about 1 15°C to about 130°C, or about 1 15°C to about 125°C, or about 1 15°C to about 120°C, or about 120°C to about 130°C, or about 120°C to about 125°C, or about 125°C to about 130°C, preferably 120°C. The torrefaction step 34 may be for about for about 30 minutes to about 50 minutes, or from about 30 minutes to about 45 minute, or from about 30 minutes to about 40 minute, or from about 30 minutes to about 35 minute or from about for about 35 minutes to about 50 minutes, or from about 35 minutes to about 45 minute, or from about 35 minutes to about 40 minute, or from about for about 40 minutes to about 50 minutes, or from about 40 minutes to about 45 minute, or from about for about 45 minutes to about 50 minutes, preferably 45 minutes, at about 91 .3 to about 1 10 kPa, or from about 91 .3 to about 101 .4 kPa, preferably 101 .4 kPa.
[0081] Furthermore, according to yet another embodiment, the torrefaction step 34 may be followed by optional compacting step 36, performed at about 175°C to about 190°C, or from about 175°C to about 185°C, or from about 175°C to about 180°C, or from about 180°C to about 190°C, or from about 180°C to about 185°C, or from about 185°C to about 190°C, preferably 180°C, for about 10 minutes to about 20 minutes, or about 10 minutes to about 15 minutes, or about 15 minutes to about 20 minutes, preferably 15 minutes, at about 81 .1 kPa, to about 101 .4 kPa, or about 81.1 kPa to about 91 .3 kPa, or about 91 .3 kPa (0.9 atm) to about 101 .4 kPa (1 atm).
[0082] The present invention will be more readily understood by referring to the following examples which are given to illustrate the invention rather than to limit its scope.
EXAMPLE 1
EXAMPLARY PROCESS #1
[0083] According to an embodiment, the process of the present invention is a temperature and time cycling to control the decomposition of natural organic polymers in the various layers of cellulose based material which imparts desired characteristics of construction materials or elements, such as moisture level, stability, durability, strength, toughness, weather resistance, paintability and glueability.
[0084] According to an embodiment of the invention, the torrefaction apparatus is cycled according to specific temperatures and times, and alternate the injection of gas or of a vacuum. For instance the following table describe the step by step process realized in a single apparatus providing optimized construction material:
Table 1 - Example process #1
EXAMPLE 2
EXAMPLARY PROCESS #2
[0085] According to another embodiment, the process of the present invention may involve the following cycles in a torrefaction apparatus:
Table 2 - Example process #2 EXAMPLE 3 EXAMPLARY PROCESS #3
[0086] According to another embodiment, the minimal essential steps of the process of the present invention treat the cellulose based material and appropriately modify the composition and structure of the material are:
Table 3 - Example process #3
[0087] The other steps suggested in this invention will refine the needed characteristics of the wood according to intended use.
EXAMPLE 4
Process cycle under controlled atmosphere
[0088] Figure 3 describe a flow diagram of the process specifying changes in controlled atmosphere inside the kiln. Using inert gas and/or injection of ammonia (to neutralize acids) we drastically improved the wood durability.
[0089] While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made without departing from this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure.