MATERIALS

TECHNICAL FIELD

[0001] The present disclosure relates to processes and systems for transporting biomass materials, particularly involving the use of one or more pumps to transport mixtures containing biomass materials.

BACKGROUND

[0002] This section is intended to introduce various aspects of the art, which may be associated with exemplary embodiments of the present invention. This discussion is believed to assist in providing a framework to facilitate a better understanding of particular aspects of the present invention. Accordingly, it should be understood that this section should be read in this light, and not necessarily as admissions of any prior art.

[0003] There has been a recent drive and increased interest in renewable energy sources, including various efforts to convert biomass into fuels (such as ethanol or biogas).

[0004] In general, biomass such as wood and other plant or organic biomass can be processed by two methods: biochemical methods such as fermentation; and thermochemical methods such as gasification or pyrolysis. With either route, one challenge in scaling up operations involve infrastructure and equipment to convey and transport the biomass because the nature of most biomass typically incurs significant handling costs, particularly when compared to existing road, rail, pipeline and river infrastructure for transporting conventional energy products that is already in place. Because transportation constraints act as a limiting factor on the size of a biomass-processing plant, most biomass projects are built well below optimum size. Moreover, once the biomass arrives at a plant, a further major limitation is the handling of the cellulosic biomass materials as feedstocks and their movement within the overall conversion process. Cellulosic biomass materials tend to be relatively higher in solids content, and/or potentially high in viscosity than other feedstocks. Cellulosic biomass materials are typically conveyed through the input and/or pretreatment stages of the bio-refinery by screw conveyor, belt conveyor, drag conveyor, or some equivalent system designed to handle high solids materials. Conveyor systems and/or their equivalents are typically expensive to install, require physical layouts which tend to be less flexible in design or operation, consume significant amounts of energy, and/or are plagued with high maintenance costs, due at least in part to the number of components involved and the damage caused by the particular properties of the cellulosic biomass materials moving through those components.

[0005] One conventional way of addressing some of these issues in previous pumping systems is by diluting the cellulosic biomass material being conveyed to make it suitable for pumping. This dilution, however, introduces a large amount of water that is typically carried throughout the overall conversion process, which reduces product yield thereby increasing operating costs to achieve similar yields, to remove an amount of liquid during the process, and/or treat the liquid as waste water at the end of the process.

[0006] Further, in some situations, the source of the cellulosic biomass material may be some distance from the facilities in which the cellulosic biomass material goes through at least substantially most of the overall conversion process. The greater the distance between the cellulosic biomass feedstock source and such facilities, the more costly and less reliable conveyor systems tend to be relative to pumps in conventional systems. This is particularly an issue where the biomass is an agricultural residue or waste product being sourced from an operation that may be independent of, or located at, some distance from such processing facilities.

[0007] While U.S. Application Publication No. US20100167366 attempts to address these issues by providing a general process for pumping citrus fruit waste as feedstock for a fermentation process, it does not provide an adequate solution to address these issues. Similarly, U.S. Application Publication No. US20080038815 is also insufficient because it does not address debris that are typically found in biomass materials which pose a challenge for subsequent processes. Accordingly, further development in transporting cellulosic biomass materials, particularly in light of the various properties associated with such materials, is desirable.

SUMMARY

[0008] The present disclosure provides for a method of transporting a biomass slurry comprising: (a) providing a conduit network comprising a dilute section, a liquid removal section fluidly connected in series with the dilute section, and a concentrated section fluidly connected in series with the liquid removal section; (b) providing a dilute biomass slurry having a moisture content in a range of at least 95% and an undissolved solids (UDS) amount in a range of 0.1 and up to 5% to the dilute section of the conduit network, wherein the dilute section has a major cross sectional dimension of at least four inches, wherein the dilute biomass slurry comprises biomass particles and a liquid; (c) conveying at least a portion of the dilute biomass slurry along the dilute section of the conduit network for a distance of at least five times the major cross-sectional dimension of the dilute section; (d) conveying the dilute biomass slurry through the liquid removal section to remove liquid from the dilute biomass slurry while the dilute biomass slurry is conveyed along the conduit network, thereby generating a concentrated biomass slurry having an UDS amount of greater than 5%, wherein the concentrated biomass slurry comprises at least a portion of said biomass particles and said liquid; (e) providing the concentrated biomass slurry to the concentrated section of the conduit network; and (f) conveying at least a portion of the biomass particles in the concentrated biomass slurry in plug flow through the concentrated section for a distance of at least five times the major cross-sectional dimension of the concentrated section, wherein the concentrated section has a median cross-sectional dimension that is 10% - 90%, preferably 25% - 50%, smaller than the major cross-sectional dimension of the dilute section; and wherein the ratio of the velocity of biomass particles at a distance from the center of the concentrated section to the velocity of biomass particles at the center of the concentrated section is in a range of 0.90 to 0.99. One way of determining the median cross-sectional includes taking the average of the major and minor cross-sectional dimensions of the concentrated section.

[0009] Optionally, the dilute biomass slurry further comprises non-biomass particles, said method further comprising: (g) conveying at least a portion of the biomass particles at a velocity in a range of 0.1 m/s to 0.6 m/s to maintain in suspension greater than 50% of the biomass particles in the dilute biomass slurry; and wherein at least a portion of the non biomass particles settles at the bottom of the dilute section. Optionally, the non-biomass material comprises at least one of: dirt, rocks, soil, trash, field debris, sand, biomass fines or particles or other loose organic or inorganic materials with higher densities then the primary biomass particles. Optionally, the dilute biomass slurry comprises 1 - 50 wt% or 1 - 20 wt%, optionally 5 - 20 wt%, including 5 to 15% non-biomass particles. Optionally, the non biomass particles have a mean density at least 20% optionally at least 30%, and up to 400%, greater than the mean density of the dilute biomass slurry. Optionally, at least 25% of the non-biomass particles in the dilute biomass slurry settles at the bottom of the dilute section.

[0010] Optionally, the method further comprises removing at least a portion of the non biomass particles deposited at the bottom of the dilute section. Optionally, the removing of at least a portion of the non-biomass particles comprises providing a means of maintaining the biomass particles in suspended flow, while providing for a separate accumulation zone for the non-biomass particles, such as U-tube, hydro-cyclone, additional dilute aqueous phase or air fluidization based separation, mechanical wet and/or dry based separations based on density and particle sizing.

[0011] Optionally, the biomass particles comprise a grown crop fiber consisting primarily of cellulose, hemicellulose and lignin, and includes, without limitation, grass, switchgrass, straw, corn stover, energy crop, cane or agriculture residuals, general cereal wastes, wood chips. Optionally, the method comprises adding liquid to a biomass feedstock to generate the dilute biomass slurry. Optoinally, at least a portion of the liquid added to the biomass feedstock comprises liquid removed from the dilute biomass slurry. Optionally, the biomass feedstock to which liquid is added comprises an ensiled biomass material produced by storing a biomass material for at least 24 hours. Optionally, the storage produces a leachate and wherein at least a portion of the liquid added to the biomass feedstock comprises said leachate.

[0012] Optionally, the removing of liquid from the dilute biomass slurry comprises applying pressure to the dilute biomass material in the dilute section to displace at least a portion of liquid from the dilute biomass material; and removing at least a portion of the displaced liquid. Optionally, the removing of liquid from the dilute biomass slurry comprises moving the dilute biomass material through a solids concentrator comprising: a first end connected to the dilute section, wherein the first end has a major cross sectional dimension similar to that of the dilute section; a second end connected to the concentrated section having a major cross sectional dimension that is smaller than that of the dilute section; a body disposed between the first and second ends, wherein the diameter of the body gradually changes from the first end to the second end; and one or more perforations disposed along the body to allow a portion of liquid displaced from the dilute biomass slurry to move therethrough.

[0013] Other features of embodiments of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] These drawings illustrate certain aspects of some of the embodiments of the invention and should not be used to limit or define the invention.

[0015] FIG. 1 schematically illustrates one exemplar embodiment to transport a biomass slurry according to aspects described herein.

[0016] FIG. 2 schematically illustrates a second exemplar embodiment to transport a biomass slurry according to aspects described herein.

[0017] FIG. 3 schematically illustrates a third exemplar embodiment to transport a biomass slurry according to aspects described herein.

[0018] FIGS. 4A - 4C are various views of an exemplar solid concentrator that may optionally be used in embodiments according to aspects described herein.

[0019] FIG. 5 schematically illustrates one exemplar arrangement to provide biomass slurry that may optionally be used in embodiments according to aspects described herein.

[0020] FIG. 6 schematically illustrates another exemplar arrangement to provide biomass slurry that may optionally be used in embodiments according to aspects described herein.

[0021] FIG. 7 schematically illustrates a depiction of a plug flow profile that may be employed in embodiments according to aspects described here.

DETATEED DESCRIPTION

[0022] As used here, biomass or biomass material refers to grown crop fiber consisting primarily of cellulose, hemicellulose and lignin, and includes, without limitation, grass, switchgrass, straw, corn stover, energy crop, cane or agriculture residuals, general cereal wastes, wood chips and the like, that can be converted to ethanol (or other products) according to various known other known technology. The biomass or biomass material may be in any suitable forms, including chopped, harvested, residues remaining after the crop has been harvested (including stalks and stubble (stems), leaves, and seed pod), or mechanically manipulated, such as cubed or pressed, or otherwise densified via mechanical means. As used herein, biomass includes materials that are not free flowing in their native state, such as ligno-cellulosic materials. The invention is intended to be used preferably in connection with the collection and transport of non-free flowing materials (ligno-cellulosic biomass), such as fluidized material or other solids with better flowing properties such as corn kernels or sand, as these non-tree flowing biomass materials are conventionally the most intractable from a materials handling standpoint.

[0023] Such biomass materials are harvested from various fields on which they are grown typically by using commercially available equipment such as various types of harvesters. In commercial crop farming, large harvesting equipment is often used, which leads to various non-biomass material or non-biomass particles such as field debris, including rocks, pebbles, soil, trash, sand, etc., ending up in the collected biomass crop. The non-biomass material poses a challenge in both the transportation of the biomass material to subsequent processing, such as pretreatment, hydrolysis, fermentation, hydrothermal reactions, and/or catalytic reactions, as well as in the subsequent processes themselves, such as inhibiting the reaction, reducing the reaction yields, and/or contribute to generation of unwanted by-product.

[0024] Even if the non-biomass material is not present in the harvested biomass solid material, transportation of such biomass material can be challenging due to its properties. As mentioned above, water or some kind of liquid is often added to the biomass solids to generate a biomass slurry (or a biomass slurry having a high moisture content and undissolved solids) for various reasons, and the biomass slurry needs to be moved or transported between various processing steps in a system, which can be difficult to manage.

[0025] The present disclosure provides for processes and systems to transport biomass slurry or mixture materials where liquid is removed from the biomass slurry while the biomass slurry is being conveyed in the conduit network or system (e.g.,“in-situ water removal”), which saves on operational time and extra equipment because liquid removal is often a desired step prior to biomass processing. In addition, the in-situ water removal from a dilute biomass slurry to generate a concentrated biomass slurry maintains the biomass material in fluid flow in a conduit system, which allows for it to continue to be conveniently transported into the processing system or next processing step as a fluid rather than having the flow interrupted. In particular, instead of having to go from fluid flow into a separate liquid removal apparatus, such as, centrifugal apparatus, extruders, screens or filters, and the solid or more concentrated slurry coming out of such removal apparatus still needs to be transported into the processing system or next processing step which requires additional equipment such as extruder, screw press, or extra energy and equipment to render the material back into fluid flow so to go from the liquid removal apparatus to the next processing step. [0026] Accordingly, one method of transporting a biomass slurry as described herein comprises (i) providing a conduit network comprising a dilute section, a liquid removal section fluidly connected in series with the dilute section, and a concentrated section fluidly connected with the liquid removal section and located downstream of the liquid removal section; (ii) providing a dilute biomass slurry having a moisture content in a range of at least 95% and an undissolved solids (UDS) amount in a range of 0.1 and up to 5% to the dilute section of the conduit network, wherein the dilute section has a major cross sectional dimension of at least four inches, wherein the dilute biomass slurry comprises biomass particles and a liquid; (iii) conveying at least a portion of the dilute biomass slurry along the dilute section of the conduit network for a distance of at least five times the major cross- sectional dimension of the dilute section; (iv) conveying the dilute biomass slurry through the liquid removal section to remove liquid from the dilute biomass slurry while the dilute biomass slurry is conveyed along the conduit network, thereby generating a concentrated biomass slurry having an UDS amount of greater than 5%, wherein the concentrated biomass slurry comprises at least a portion of said biomass particles and said liquid; (v) providing the concentrated biomass slurry to the concentrated section of the conduit network; and (vi) conveying at least a portion, preferably a majority (at least 50%), of the biomass particles in the concentrated biomass slurry in plug flow through the concentrated section for a distance of at least five times the major cross-sectional dimension of the concentrated section, wherein the concentrated section has a median cross-sectional dimension that is from 10% - 90%, optionally 25% to 50%, smaller than the major cross-sectional dimension of the dilute section and the ratio of the velocity of biomass particles at a distance from the center of the concentrated section to the velocity of biomass particles at the center of the concentrated section is in a range of 0.90 to 0.99. It is understood that one of ordinary skill in the art can select or design the appropriate dimensional difference between the concentrated section and the dilute section based on a number of factors, such as the water holding capacity and compressibility of the biomass materials. For instance, if the biomass has a lower water holding property as compared to another crop, a smaller dimensional difference may be adequate to achieve plug flow as compared to a biomass that has a higher water holding property. Similarly, a biomass with higher compressibility may need a smaller dimensional difference to achieve plug flow.

[0027] Not intending to be bound by theory, the plug flow in the concentrated section achieved as a result of pushing or squeezing the water out of the biomass creates a lubricating layer surrounding the plug flow (adjacent to the wall of the respective section, i.e., the lubricating layer is between the wall of the section and the biomass portion in plug flow) that contains more water. Having this lubricating layer allows for improved flowability of concentrated biomass slurry having an UDS amount of greater than 5%.

[0028] FIG. 1 schematically illustrates one exemplar embodiment of the method and system to transport a biomass slurry according to aspects described herein. As shown, system 100 comprises conduit network 102 comprising dilute section 104, a first liquid removal section 106, a first concentrated section 108, a second liquid removal section 110, and a second concentrated section 112. Dilute section 104 has a major cross-sectional dimension (such as a diameter) of at least 4 inches. Dilute biomass slurry has (a) a moisture content in a range of at least 95% and (b) an undissolved solids (UDS) amount in a range of 0.1 and up to 5%, and the dilute biomass slurry comprises biomass particles and a liquid. While the biomass slurries (including dilute and concentrated) are not depicted, the direction of flow of the slurries are indicated by arrows in FIG. 1. The biomass slurries may be provided to and conveyed through conduit network 102 using conventional or known in the art pumping equipment such as a progressive cavity pump. It is understood by one of ordinary skill that suitable pumping equipment can include, for instance, positive displacement pumps, such as piston pumps, progressive cavity, rotary lobe, and/or gear pumps. “Conduit” or“section” as used herein includes, without limitation, pipes, or like structures used to transport a fluid, including a slurry material via a pumping equipment. The dilute biomass slurry is conveyed along dilute section 104 for a distance of at least five times (5x) the major cross-sectional dimension of dilute section 104. That is, dilute section 104 has a length that is at least five times (5x) its major cross-section dimension. For instance, if dilute section 104 were a pipe or has a generally cylindrical shape, its length may be at least five times (5x) its diameter.

[0029] Liquid is removed from the dilute biomass slurry while the dilute biomass slurry is conveyed or transported in or along conduit network 102 through first liquid removal section 104 to produce a concentrated biomass slurry (not shown), which is provided to concentrated section 106. The concentrated biomass slurry has an UDS amount of greater than 5%, where the concentrated biomass slurry comprises at least a portion of biomass particles and liquid in the dilute biomass slurry from dilute section 104. As shown in FIG. 1, liquid removal section 106 is fluidly connected in series with dilute section 104 with a first end of liquid removal section 106 connected to dilute conduit 104 to receive dilute biomass slurry and a second end connected to concentrated section 108 to provide the concentrated biomass slurry thereto. Referring to FIG. 1, concentrated section 108 has a cross-sectional dimension that is smaller than the cross-sectional dimension of the dilute section 104. Preferably, the cross-sectional dimension of concentrated section 108 is from 10% - 90%, optionally 25% to 50%, smaller than the cross-sectional dimension of the dilute section 104. Optionally as shown in FIG. 1, the dilute end of liquid removal section 106 that is fluidly connected in series to dilute section 104 has a similar (or substantially the same) cross-sectional dimension as that of dilute section 104, and the concentrated end that is fluid connected in series to concentrated section 108 has a similar (or substantially the same) cross-sectional dimension as that of concentrated section 108. Such similar (or substantially the same) cross-sectional dimensions allow for the various sections or portions to be easily coupled or connected to one another in manners known to one of ordinary skill. The body of liquid removal section 106 comprises a plurality of openings to allow liquid to leave the biomass slurry traveling through liquid removal section 106 and eventually leave liquid removal section 106 while the majority of the biomass particles are retained in the biomass slurry as it travels to the concentrated end and is provided to section 108 as a concentrated biomass slurry having less liquid than the dilute biomass slurry in section 104, such as a concentrated biomass slurry has an UDS amount of greater than 5%, including greater than 6%, greater than 7%, greater than 8%, greater than 9%, greater than 10%, or greater than 15%. The change in cross-sectional dimension of the dilute end of the liquid removal section 106 and its concentrated end helps to squeeze out more water from the biomass slurry travelling therethrough than if the cross-sectional dimension remains the same from one end to another. It is understood that one of ordinary skill in the art may design or determine a length and difference in cross-sectional dimension of the ends of liquid removal section 106 to achieve the desired level of liquid removal from the biomass slurry to achieve the desired moisture and solid contents in the concentrated biomass slurry.

[0030] The desired level of liquid removal may also be achieved using more than one liquid removal sections. For example, as shown in FIG. 1, optional additional liquid removal section 110 may be provided to further extract liquid from the concentrated biomass slurry coming from concentrated section 108 to provide a further concentrated biomass slurry in concentrated section 112, which has a lower moisture content than the concentrated biomass slurry in section 108. It is understood that more than one or two (e.g., three, four, five, etc.) liquid removal sections may be utilized to achieve the desired liquid removal amount. [0031] The concentrated biomass slurry is conveyed along concentrated section 108 or 112 (or additional concentrated sections as applicable) for a distance of at least five times the major cross-sectional dimension of the applicable concentrated section and where at least a portion of the biomass particles (and not necessarily the liquid) in the concentrated biomass slurry has a flow profile that can be characterized as plug flow (or“in plug flow”). Referring to FIG. 7, the plug flow profile can be characterized as the ratio of v _x :v ₀ is in a range of 0.90 to 0.99, where v _x is the velocity of the biomass particles at a distance from the center of concentrated conduit 108 and v ₀ is the velocity of the biomass particles at the center of concentrated section 108 or 112 (or additional concentrated sections as applicable), respectively.

[0032] FIGS. 2 and 3 depict systems 200 and 300 respectively showing additional exemplary embodiments of the systems and methods to transport a biomass slurry as described herein. When like elements are used in one or more figures, identical reference numbers will be used in each figure. The detailed description of the element that is provided herein, usually but not necessarily at the first occurrence, is applicable to that element in all instances, whether or not such applicability is explicitly noted. Some features of the systems and methods described herein may be omitted in certain depicted configurations in the interest of clarity. Referring to FIG. 2, conduit network 202 of system 200 has similar features as those of system 100, except system 200 has liquid removal section 206, which comprises two portions, first portion 216 and second portion 218, and transition section 214. As can be seen in FIG. 2, first portion 216 of liquid removal section 206 can be similar to liquid removal section 106, so applicable descriptions of section 106 also apply here, such as portion 216 having a dilute inlet to receive the dilute slurry biomass from dilute section 104 and a concentrated end with a major cross-sectional dimension that is smaller than that of the dilute end. However, instead of the concentrated end of portion 216 fluidly connected in series to a concentrated section such as sections 106 and 108, it is fluidly connected in series to portion 218 via an inlet end that has a major cross-sectional diameter that is similar (or substantially the same) as that of the outlet end of portion 218 and the concentrated end of portion 216. The outlet end of portion 218 is fluidly connected in series with the inlet end of transition section 214, which has a major cross-sectional diameter that is similar (or substantially the same) as that of the outlet end of portion 218. The major cross-sectional dimension of the body of portion 218 disposed between its inlet and outlet ends remains relatively constant. Similar to section 106 and portion 216, the body of portion 218 comprises openings to allow for liquid in the biomass slurry to exit as the biomass slurry travels through section 206 toward transition section 214.

[0033] As can be seen, transition section 214 is fluidly connected in series with concentrated section 208, which is downstream of and in fluid communication with liquid removal section 206. Concentrated section 208 is similar to that of section 108 so the descriptions for section 108 are applicable to section 208 and need not be repeated. The outlet end of transition section 214 has a major cross-sectional dimension that is larger than that of its inlet end, which allows for a plug flow profile as described above in a section with a major cross-sectional dimension that is larger than the concentrated end of portion 216 or concentrated end of section 106. That is, transition section 214 allows for use of a liquid removal section with inlet and outlet ends with different major cross-sectional dimensions (such as section 106) for more efficient liquid extraction without the need to use subsequently smaller and smaller conduits. While FIG. 2 shows concentrated section 208 with a similar (or substantially the same) major cross-sectional dimension as that of dilute section 104, it is understood that one of ordinary skill can select any suitable or desirable major cross-section dimension for the concentrated section. Moreover, it is understood that more than one or two (e.g., three, four, five, etc.) liquid removal sections 206 may be utilized to achieve the desired liquid removal amount and/or a final concentrated section with the desired or suitable major cross-sectional dimension prior to the final concentrated biomass slurry entering a processing system.

[0034] System 300 in FIG. 3 is yet another exemplary embodiment of the biomass transport systems and methods described herein. Conduit network 302 of system 300 has similar features as those of system 100 in that it comprises liquid removal section 106 and concentrated section 108 and those of system 200 in that it comprises transition section 114 and concentrated section 208. As illustrated by system 300, a conduit network of various arrangements and numbers of sections and portions (e.g., 106, 108, 206, 208, and 214) may be designed to achieve the desired liquid removal and volumetric flow associated with a conduit section of a certain major cross-sectional dimension while achieving in-situ liquid removal and a plug flow profile for biomass particles in the concentrated biomass slurry being conveyed through a concentrated conduit section.

[0035] Referring to FIGS. 1 - 3, the liquid removed from the dilute biomass slurry in various liquid removal sections (e.g., 106, 110, 206, and/or additional liquid removal sections if employed), is optionally collected (arrows 118) for various applications, one of which is optionally to add to a biomass material to generate the dilute biomass slurry. System 100 can optionally further include funnel 120 coupled to and situated below various liquid removal sections to facilitate such liquid collection. It is understood that funnel 120 may be any form of a cone with a polygon base and a vertex at a point that is noncoplanar to the base. Examples of cone shapes include a pyramid or any other cones with a regular polygon as a base, and a circular cone is one with a circle as a base. Preferably, the size and shape of the base of funnel 120 are configured to allow for coupling with a particular liquid removal section to receive liquid removed from the biomass slurry conveyed through that liquid removal section.

[0036] As noted above, the liquid removal section may have any number of suitable openings that allow liquid to leave the biomass slurry while a majority (at least 50%) of the biomass particles are retained. Optionally, the liquid removal section can comprise a solid concentrator as depicted in FIGS. 4 A - 4C, which show various views of an exemplary solids concentrator with reference numeral 406. In general, solids concentrator 406 comprises a first end 403 that optionally has a major cross sectional dimension similar to that of a dilute section (such as section 104) to allow it to be connected to such dilute section; a second end 405 that has a major cross sectional dimension that is smaller than that of the dilute section and optionally similar to that of a concentrated section (such as section 108) to allow it to be connected to such concentrated section. As shown, solids concentrator 106 further comprises a body 407 disposed between the first end 403 and the second end 405. The major cross sectional dimension of the body 407 gradually decreases from the first end 403 to the second end. Body 407 comprises one or more perforations 409 disposed along it, which allows for at least a portion of liquid from the biomass slurry moving therethrough to separate from the biomass slurry and flow through one or more perforations 409 (at least due to gravity and/or the transition from a larger available volume near the first end 403 toward a smaller available volume near second end 405) and hence be removed from such biomass slurry. Such liquid separated from the biomass slurry may be routed and/or collected via means known to one of ordinary skill in the art such as additional conduits, sections, and/or components such funnel 120. The spacing between the perforations utilized in one or more liquid removal sections (such as perforations 409 of concentrator 406) are preferably smaller than the mean size of the biomass particles in the biomass slurry conveyed therethrough to retain the biomass particles in biomass slurry rather than exiting with the liquid through perforations 409. [0037] If the system employs more than one liquid removal sections, all the liquid removal sections can employ similarly sized perforations or various sizes as needed or desired. As shown, one option to arrange perforations 408 is to space them longitudinally around the perimeter (e.g., circumference) of body 407. It is understood other options may be used, including circular openings, varying diameter circular openings as a function of axial distance, or combinations of slots and circular openings, or other type of geometric openings to permit movement of water while retaining the biomass particles. Optionally, as shown in FIG. 4B, solids concentrator 406 may be in a housing 411 that is configured to facilitate further coupling with other components, such as funnel 120 and/or other sections, such as sections 104 and 108. Further, as shown in FIG. 2C, solids concentrator 106 may optionally further comprise component 413, which may be provided as support to facilitate mechanical connection between various components for structural integrity.

[0038] Referring to FIG. 5, there is provided system 500 showing additional exemplary embodiments of the systems and methods to transport a biomass slurry as described herein. As shown, system 500 comprises conduit network 102 as described above. As noted above, the biomass material to which liquid is added to produce a dilute biomass slurry oftentimes further contains non-biomass material such as field debris that pose as a challenge to the transport of the dilute biomass slurry into subsequent processing steps, such as pretreatment and subsequent hydrolysis and/or fermentation or other processing, including conversion to biogas or drop-in fuels (e.g. gasoline, diesel, jet fuel, etc.). In addition to allowing for flow transportation of a dilute biomass slurry with in-situ liquid removal, the systems and methods described herein can also optionally allow for in-situ removal of at least a portion of non biomass material.

[0039] As described above, at least a portion, preferably a majority (at least 50%), of the biomass particles in the concentrated biomass slurry is conveyed at a certain velocity through the dilute section and then in plug flow through a concentrated section, meaning such portion of biomass particles has substantially similar (within 90 - 99% range) velocity as it moves through the concentrated section. Particles that have significantly different properties, such as denser and/or larger size, tend to be non-biomass particles, which have a slower velocity and hence get separated from the flow of the majority of the dilute biomass slurry and/or such plug flow of the concentrated biomass slurry and drop to the bottom of a concentrated section due to gravity, allowing them to be collected over time as they accumulate. [0040] It is understood that one of ordinary skill in the art can select or design the appropriate spacing or size of the perforations depending on various factors, such as the type(s) of non-biomass particles in the biomass slurry, the mean size of such non-biomass particles, the mean size of the biomass particles, the flow rate of the biomass slurry, etc. The spacing is preferably selected to retain the majority of the biomass material in the biomass slurry while allowing for the majority of the non-biomass material and the selected amount of water to be removed from the biomass slurry as it flows through the respective conduit (i.e., in situ removal).

[0041] Accordingly, the methods described herein where the dilute biomass slurry comprises non-biomass particles can further comprise conveying at least a portion of the biomass particles at a velocity in a range of 0.1 m/s to 0.6 m/s to maintain in suspension greater than 50%, including greater than 55%, greater than 60%, greater than 65%, greater than 70%, greater than 75%, or greater than 80% of the biomass particles in the dilute biomass slurry; and wherein at least a portion of the non-biomass particles is not conveyed to the next section with said portion of biomass particles and remains in the dilute section. The separation of the portion of non-biomass particles from the biomass slurry which is conveyed to the next section (e.g., liquid removal section) can result in an accumulation of non-biomass particles that remain in the dilute section, particularly at the bottom of the dilute section, as additional dilute biomass slurry comprising non-biomass particles is continuously conveyed through the dilute section and additional non-biomass particles are separated out. In subsequent sections, such as the liquid removal section and subsequent concentrated sections, the biomass slurry traveling through those sections would have less non-biomass particles, which results in less non-biomass particles that would inhibit, contaminate, and/or pose material handling challenges in subsequent processes (e.g., pretreatment, hydrolysis, fermentation, and/or certain conversion reactions).

[0042] The non-biomass material or particles can comprise at least one of: dirt, rocks, soil, trash, field debris, sand, biomass fines or particles or other loose organic or inorganic materials with higher densities then the primary biomass particles. The dilute biomass slurry can comprise 1 - 50 wt% or 1 - 20 wt% non-biomass particles, optionally 5 - 20 wt%, including 5 to 15%. The non-biomass particles can have a mean density at least 20%, optionally at least 30%, and up to 400% (such as small rocks or sand), greater than the mean density of the dilute biomass slurry. Optionally, at least 25%, such as at least 30%, of the non-biomass particles in any given portion of the dilute biomass slurry in the dilute section settles to the bottom of either the respective dilute section or the concentrated section and is not conveyed to the next section with said portion of biomass particles and remains in the dilute section. The methods can optionally comprise continuously convey the dilute biomass slurry through the dilute section and subsequently to the next section: the liquid removal section to continuously remove liquid in-situ and allow non-biomass particles to be separated from the flow of the rest of the dilute biomass slurry and accumulate in the dilute section. The accumulated non-biomass particles may be removed from the system using methods known to one of ordinary skill such as U-tube, hydro-cyclone, additional dilute aqueous phase or air fluidization based separation, mechanical wet and/or dry based separations based on density and particle sizing.

[0043] Referring to FIG. 5, which shows a simplified depiction of conduit network 102 where certain portion 501 non-biomass particles may be removed from dilute section 104 and other certain portions 503 and 505 of non-biomass particles are removed in subsequent concentrated section(s) 108 and 112, as optionally employed. Generally speaking, portion 501 of non-biomass particles may have a mean distribution of size and/or density that is greater than those of the non-biomass particles in portion 503, and optionaly portion 505. Similar non-biomass particle removal equipment and/or methods may be employed in conjunction with concentrated sections 108 and 112. Accordingly, the separation and accumulation of non-biomass particles described for dilute biomass slurry in the dilute section above are equally applicable to the concentrated biomass slurry in subsequent concentrated section(s) as well and need not be repeated. That is, the phrase“concentrated biomass slurry” or“concentrated section” may be substituted for the phrase“dilute biomass slurry” or“dilute section” in paragraphs [0035] - [0037], respectively and as applicable, the context of which would be understood by one of ordinary skills in the art.

[0044] As mentioned above, the biomass material in the biomass slurry may be a crop that is harvested. In particular, the biomass particles can comprise grown crop fiber consisting primarily of cellulose, hemicellulose and lignin, and includes, without limitation, grass, switchgrass, straw, corn stover, energy crop, cane or agriculture residuals, general cereal wastes, wood chips and the like, that can be converted to ethanol (or other products) according to various known other known technology. The biomass or biomass material may be in any suitable forms, including chopped, harvested, residues remaining after the crop has been harvested (including stalks and stubble (stems), leaves, and seed pod), or mechanically manipulated, such as cubed or pressed. [0045] Optionally, at least a portion of the liquid added to the biomass feedstock to prepare the dilute biomass slurry comprises liquid collected from the liquid removal section of conduit network 102. For instance, referring to FIG. 1, at least a portion of liquid in line 118 may be routed to one central line 122 for collection and further optional processing, such as waste water treatment and/or routed to liquid collection point 524 in FIG. 5 which may be added to the biomass feedstock provided from one or more biomass collection sites 526 to prepare a dilute biomass slurry having a moisture content of at least 95% and an undissolved solids (UDS) amount in a range of 0.1 and up to 5%. The biomass feedstock from one or more biomass collection sites 526 likely already has a certain moisture content but it is lower than 95% and requires additional liquid to achieve the at least 95% moisture content.

[0046] Optionally, the biomass feedstock to which liquid is added to prepare a dilute biomass slurry (such as the biomass feedstock in one or more biomass collection sites 526) comprises an ensiled biomass material produced by storing a biomass material for at least 24 hours. Such storage optionally produces a leachate and wherein at least a portion of the liquid added to the biomass feedstock comprises said leachate. Referring to FIG. 6, it is understood that the biomass collection sites may have various configurations (such as those depicted for sites 626) that optimizes the space available.

[0047] While embodiments of the invention are subject to modifications and alternative forms, specific embodiments thereof are shown by way of examples herein described in detail. It should be understood, that the detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. The present invention will be illustrated by the following illustrative embodiment, which is provided for illustration only and is not to be construed as limiting the claimed invention in any way.