This application claims benefit of U.S. Provisional Application Ser. No. 61/526,877, entitled, “System and Method for Converting Woody Biomass into Sugar” filed Aug. 24, 2011, the entire disclosure of which is incorporated herein by reference.
The present disclosure is generally related to biomass conversion systems and processes and more particularly is related to a system and process for converting cellulosic biomass materials into a sugar solution.
The extraction of various substances, such as raw liquid extract, from a biomass material is a common and necessary process when making paper or other cellulose-based materials. Wood and other cellulosic biomass naturally contain substances useful for processing into bio-fuel and other products. Cellulosic biomass is one of the largest growing crops on the globe, as measured by mass of the sugar per acre produced, and woody biomass is a sustainable renewable resource that is not designated as a food crop. However, while wood and Cellulosic biomass are regularly processed for making paper or other cellulose-based materials, it has never been efficiently processed into bio-fuel products with commercial success. Particularly, conventional systems are often unable to efficiently remove certain inhibitors from the biomass material, and do so in a cost-effective manner. Furthermore, conventional systems may be unable to monomerize oligimeric sugars contained within the processed cellulosic biomass material and, as a result, unable to produce either a solid or a liquid solution of the sugars.
Thus, an unaddressed need exists in the industry to provide a system and method for converting wood and other cellulosic biomass into sugar.
Embodiments of the present disclosure provide an apparatus and process for converting cellulosic biomass pulp suspension into a sugar solution. Briefly described, one embodiment of such a method, among others, can be broadly summarized by the following steps: combining a quantity of cellulosic biomass pulp suspension with a quantity of acid and a quantity of enzyme; and placing the combined quantity of cellulosic biomass pulp suspension, enzyme, and acid in an enzymatic hydrolysis reactor having a predetermined temperature range and predetermined pH level, thereby producing a quantity of monomeric sugar solution.
The present disclosure can also be viewed as providing an apparatus for converting cellulosic biomass pulp into sugar. Briefly described, one embodiment of such an apparatus, among others, can be implemented as follows: A first mixer is provided for mixing cellulosic biomass pulp and a quantity of acid. A second mixer fed from the first mixer mixes the cellulosic biomass pulp and acid with a quantity of enzyme. An enzymatic hydrolysis reactor receives the mixed cellulosic biomass pulp, acid, and enzyme, wherein the enzymatic hydrolysis reactor has a predetermined temperature range and a predetermined pH level, and wherein the enzymatic hydrolysis reactor outputs a quantity of monomeric sugar solution.
The present disclosure can also be viewed as providing processes for converting cellulose rich biomass pulp into a C6 rich sugar solution. In this regard, one embodiment of such a method, among others, can be broadly summarized by the following steps: combining a quantity of cellulose rich biomass pulp with a quantity of acid and a quantity of enzyme; and placing the combined quantity of cellulose rich biomass pulp, enzyme, and acid in an enzymatic hydrolysis reactor having a predetermined temperature range and predetermined pH level, thereby producing a quantity of monomeric C6 rich sugar solution.
Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims.
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
In order to understand the following disclosures of systems and processes it is necessary to understand the following definitions of materials used in the processes:
A variety of different devices and components to the system I 0 may be used at various stages. Commonly, after the enzymatic hydrolysis reactor 50, the quantity of monomeric sugar solution is transferred to a filter 60 to remove unprocessed pulp and lignin and spent cooking chemicals from the quantity of monomeric sugar solution. The filter may be any type of filtering device or washing device that can separate suspended solids from liquids, such as but not limited to filter press, centrifuge or ultra-filtration system. Any residual solids may be output from the filter 60 via output 62. The filtered quantity of monomeric sugar solution may then be transferred into a water removal device 72, such as an evaporator, via line 76, which may remove a quantity of water via line 73, to concentrate the filtered quantity of monomeric sugar to approximately 100-800 g/l. The concentrated filtered quantity of monomeric sugar may then be processed within a electrodialysis unit 70, connected to the water removal device 72 via line 76 to remove salts, acids, heavy metals, and lignin which are removed from the sugar solution by transferring them to a brine solution which enters the device via line 79 and leaves via line 78, thereby providing a sugar solution. The quantity of sugar solution may then be output via line 80 as a product of the system 10.
As is shown in
It is noted that the term ‘line’ herein may refer to any type of conduit, pipe, or substance transportation device. It is further noted that the arrangement of the components of the system 100 may be altered and adjusted as needed. This may include, for example, combining various substances within mixing devices or directly within conduits, transferring unconverted or unused materials back into the system 100 for additional use, and/or inserting additional components to further refine the substances processed within the system 100.
The process within the chemical pulp-cooking device may include any type of biomass pulping process, including kraft, sulfite, soda and near neutral sulfite. For example, in the kraft process, the woody biomass is treated with a mixture of sodium hydroxide, sodium carbonate, and sodium sulfide, known as ‘white liquor’ to break the bonds that link the lignin to the cellulose. Any of the various chemical processes used may have specific parameters and requirements, any of which may be incorporated into the system 100 without reservation. It should also be noted that mechanical or thermal mechanical pulping processes may be used.
The quantity of cellulosic biomass pulp suspension may be characterized as a material that is approximately 60%-98% cellulose. Other quantities of the cellulose within the quantity of cellulosic biomass may also be within the scope of the present disclosure. The remainder of the quantity of cellulosic biomass pulp, i.e., 2%-40%, may be primarily a hemi-cellulose material. As is described further herein, the quantity of cellulose material may be processed into glucose or other C6 sugars, whereas any portion of the quantity of hemi-cellulose material may be processed into xylose or other C5 sugars.
Filter 130 may filter the quantity of cellulosic biomass pulp to produce a suspension of cellulosic biomass pulp and a solution of spent cooking liquor which contains a quantity of the lignin which enters the process with the biomass and is known as black liquor. A portion of the cellulosic biomass suspension may be transferred to the next processing step through line 136. The black liquor or other spent cooking liquor may be disposed of or processed accordingly, such as via disposal line 132. The quantity of cellulosic biomass pulp suspension is transferred by line 136 to a pulp washer 141 which intakes water via line 145 and outputs dilute spent cooking liquor via line 142. The cellulosic biomass pulp suspension enters mixer 143 via line 137 where acid is added via line 140; the output continues through line 138 to mixer 146 where enzyme is added by line 144. The cellulosic biomass pulp, acid and enzyme suspension then passes to the enzyme hydrolysis reactor 150 through line 139. The enzymatic hydrolysis reactor may be any vessel or structure that allows for digestion, processing, or a catalytic transformation of the cellulose, hemicellulose suspension and the acid and enzyme to produce the quantity of monomeric sugar solution. The enzymatic hydrolysis reactor 150 may have a predetermined temperature range and predetermined pH level to produce the quantity of monomeric sugar solution. For example, the enzymatic hydrolysis reactor 150 may have a temperature range of 35° C. to 70° C. and a pH level between 3.0 and 7.5, although other ranges are considered within the scope of the present disclosure. Additionally, the feed to the enzymatic hydrolysis reactor 150 may have a total solids concentration of 5 to 25 weight percent. The cellulosic biomass pulp, acid and enzyme suspension may stay within the enzymatic hydrolysis reactor 150 for any amount of time, preferably 12 to 100 hours. During this time, the enzyme transforms the solid materials to a quantity of monomeric sugar solution. The quantity of monomeric sugar solution may include both C5 and C6 sugars. When the transformation has reached a satisfactory point, the quantity of monomeric sugar solution is output via line 152 to the second filter 160, which filters the quantity of monomeric sugar solution to remove unconverted pulp, lignin and other residual solid matter. The second filter 160 may be any type of filter, such as but not limited to, a filter press, centrifuge or ultra-filtration unit, which is capable of substantially separating the solid matter from the monomeric sugar solution. The filtered residual solid matter may be removed via line 162. The filtered quantity of monomeric sugar solution may then be transferred into a water removal device 172 via line 164, which may remove a quantity of water via line 173, to concentrate the filtered quantity of monomeric sugar to approximately 100-800 g/l. The concentrated filtered quantity of monomeric sugar may then be processed within a electrodialysis unit 170, connected to the water removal device 172 via line 176 to remove salts, acids, heavy metals, and lignin which are removed from the sugar solution by transferring them to a brine solution which enters the device via line 177 and leaves via line 178, thereby providing a sugar solution. The quantity of sugar solution may then be output via line 180 as a product of the system 100.
It is noted that the water removal device 172 may be used optionally or used at any position within the system 100.
A variety of different devices and components to the system 200 may be used at various stages. Commonly, after the enzymatic hydrolysis reactor 250, the quantity of C6 rich monomeric sugar solution is transferred to a filter 260 to remove unprocessed pulp and lignin, from the quantity of C6 rich monomeric sugar solution. The filter may be any type of filtering device that can separate suspended solids from liquids, such as but not limited to filter press, centrifuge or ultra-filtration system. Any residual solids may be output from the filter 260 via output 262. The filtered quantity of C6 rich monomeric sugar solution may then be transferred into a water removal device 272 via line 264, which may remove a quantity of water via line 273, to concentrate the filtered quantity of C6 rich monomeric sugar solution to approximately 100-800 g/l total sugar concentration. The concentrated filtered quantity of C6 rich monomeric sugar may then be processed within an electrodialysis unit 270, connected to the evaporator 272 via line 276 to remove salts, acids, heavy metals, and lignin which are removed from the sugar solution by transferring them to a brine solution which enters the device via line 277 and leaves via line 278. The C6 rich monomeric sugar solution leaves the electrodialysis unit 270 via line 278 and may enter an adsorption unit 274 via line 279 where further amounts of lignin, acids, salts and coloring matter may be removed. The adsorbents in this unit may be any of a variety of activated char and/or a variety of ion exchange resins depending on the specific applications to which the C6 rich monomeric sugar will be used. The C6 rich monomeric sugar solution is outputted as product via line 280.
As is shown in
The process within the chemical pulp-cooking device may include any type of biomass pulping process, including kraft, sulfite, soda, or near neutral sulfite. For example, in the kraft process, the woody biomass is treated with a mixture of sodium hydroxide, sodium carbonate, and sodium sulfide, known as ‘white liquor’ to break the bonds that link the lignin to the cellulose. Any of the various chemical processes used may have specific parameters and requirements, any of which may be incorporated into the system 300 without reservation. It should also be noted that mechanical or thermal mechanical pulping processes may be used.
The quantity of cellulose rich biomass pulp may be characterized as a material that is approximately 70%-98% cellulose. Other quantities of the cellulose within the quantity of cellulose rich biomass may also be within the scope of the present disclosure. The remainder of the quantity of cellulose rich biomass pulp, i.e., 2%-30%, may be primarily a hemi-cellulose material. As is described further herein the quantity of cellulose material may be processed into glucose or other C6 sugars, whereas any portion of the quantity of hemi-cellulose material may be processed into xylose or other C5 sugars.
Filter 330 may filter the quantity of cellulose rich biomass pulp suspension to remove a quantity of cellulose rich biomass pulp suspension and a solution of spent cooking liquor, which is known as black liquor, and contains a quantity of the lignin which entered the process with the biomass. A portion of the cellulose rich biomass pulp suspension may be transferred to the next processing step through line 336. The black liquor or other spent cooking liquor may be disposed of or processed accordingly, such as via disposal line 332. The quantity of cellulose rich biomass pulp suspension is transferred by line 336 to a pulp washer 341 which intakes water via line 345 and outputs dilute spent cooking liquor via line 342. The cellulose rich biomass pulp suspension enters mixer 343 via line 337 where acid is added via line 340; the output continues through line 338 to mixer 346 where enzyme is added by line 344. The cellulose rich biomass, acid and enzyme suspension then passes to the enzyme hydrolysis reactor 350 through line 339. The enzymatic hydrolysis reactor may be any vessel or structure that allows for digestion, processing, or a catalytic transformation of the cellulose rich biomass and the acid and enzyme suspension to produce the quantity of C6 rich monomeric sugar solution. The enzymatic hydrolysis reactor 350 may have a predetermined temperature range and predetermined pH level to produce the quantity of monomeric sugar solution. For example, the enzymatic hydrolysis reactor 350 may have a temperature range of 35° C. to 70° C. and a pH level between 3.0 and 7.5, although other ranges are considered within the scope of the present disclosure. Additionally, the feed to the enzymatic hydrolysis reactor 350 may have a total solids concentration of 5 to 25 weight percent. The cellulose rich biomass pulp, acid, and enzyme suspension, may stay within the enzymatic hydrolysis reactor 350 for any amount of time, preferably 12 to 100 hours. During this time, the enzyme transforms the solid materials to a quantity of C6 rich monomeric sugar solution. The quantity of C6 rich monomeric sugar solution may include both C5 and C6 sugars. When the transformation has reached a satisfactory point, the quantity of C6 rich monomeric sugar solution is output via line 352 to the second filter 360, which filters the quantity of C6 rich monomeric sugar solution to remove residual solid matter. The second filter 360 may be any type of filter, such as but not limited to, a filter press, centrifuge or ultra-filtration unit, which is capable of substantially separating the solid matter from the C6 rich monomeric sugar solution. The filtered residual solid matter may be removed via line 362. The filtered quantity of C6 rich monomeric sugar solution may then be transferred into a water removal device 372 via line 364, which may remove a quantity of water via line 373, to concentrate the filtered quantity of C6 rich monomeric sugar to approximately 100-800 g/l. The concentrated filtered quantity of C6 rich monomeric sugar solution may then be processed within an electrodialysis unit 370, connected to the evaporator 372 via line 376 to remove salts, acids, heavy metals, and lignin which are removed from the sugar solution by transferring them to a brine solution which enters the device via line 377 and leaves via line 378. The C6 rich monomeric sugar solution leaves the electrodialysis unit 370 via line 379 and may enter an adsorption unit 374 where further amounts of lignin, acids, salts and coloring matter may be removed. The adsorbents in this unit may be any of a variety of activated char and/or a variety of ion exchange resins depending on the specific applications to which the C6 rich monomeric sugar will be used. The C6 rich monomeric sugar solution is outputted as product via line 380 as a product of the system 300. It is noted that the water removal device 372 may be used optionally or used at any position within the system 300.
As is shown by block 402, a quantity of cellulosic biomass pulp suspension is mixed with a quantity of acid and a quantity of enzyme. The combined quantity of cellulosic biomass pulp suspension, quantity of acid and quantity of enzyme, with the concentration of total solids in the suspension in the range of 5% to 25%, are transferred to an enzymatic hydrolysis reactor where it is subjected to temperature between 35 to 70 degrees C. and ph levels between 3.0 to 7.5 for 12 to 100 hours; thereby producing a quantity of monomeric sugar solution (block 404). The quantity of monomeric sugar solution is filtered, thereby removing residual solid matter and producing a monomeric sugar solution (block 406). The filtered quantity of monomeric sugar solution is concentrated to a sugar concentration of 100 to 800 g/L of total sugar (block 408). The filtered and concentrated monomeric sugar solution is treated in an electrodialysis unit to remove salts, acids, lignin and heavy metals, thereby producing a monomeric sugar solution (block 410). Any additional steps or variations not explicitly discussed may also be included with the method, all of which are considered within the scope of the present disclosure.
It should be emphasized that the above-described embodiments of the present disclosure, particularly, any “preferred” embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described embodiments of the disclosure without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present disclosure and protected by the following claims.
This invention was made in part with Government support under Contract No. DE-EE 0003364 awarded by U S Department of Energy. The Government may have certain rights in the invention.
Number | Date | Country | |
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61526877 | Aug 2011 | US |