HAVING A PARTITIONED VESSEL

FIELD OF INVENTION

The current invention is directed towards a carbonaceous feedstock conversion system having two reaction compartments.

BACKGROUND OF THE INVENTION

As used herein the term "carbonaceous feedstock" is a material that has "fixed carbon feedstock components" and "volatile feedstock components".

As used herein the term "fixed carbon feedstock components" refers to feedstock components present in a carbonaceous feedstock other than volatile feedstock components, contaminants, ash or moisture. Fixed carbon feedstock components are usually solid combustible residue remaining after the removal of moisture and volatile feedstock components from a carbonaceous feedstock.

As used herein the term "volatile feedstock components" refers to components within a carbonaceous feedstock other than fixed carbon feedstock components, contaminants, ash or moisture.

As used herein the term "product gas" refers to volatile reaction products, syngas, or flue gas discharged from a thermochemical reactor undergoing thermochemical processes including hydrous devolatilization, steam reforming, partial oxidation, dry reforming, or combustion.

As used herein the term "syngas" refers to a gaseous mixture containing carbon monoxide (CO), hydrogen (H ₂ ), and other vapors/gases, also including char, if any and usually produced when a carbonaceous material reacts with steam (H ₂ 0), carbon dioxide (C0 ₂ ) and/or oxygen (0 ₂ ). While steam is the reactant in steam reforming, C0 ₂ forms the reactant in dry reforming. Generally, for operation at a specified temperature, the kinetics of steam reforming is faster than that of dry reforming and so steam reforming tends to be favored and more prevalent. As used herein the term "volatile reaction products" refers to vapor or gaseous non-polar organic species that were once present in a solid or liquid state as volatile feedstock components of a carbonaceous feedstock wherein their conversion or vaporization to the vapor or gaseous state was promoted by the process of hydrous devolatilization. Volatile reaction products may contain both, non-condensable species, and condensable species which are desirable for collection and refinement.

As used herein the term "flue gas" refers to a vapor or gaseous mixture containing varying amounts of nitrogen (N ₂ ), carbon dioxide (C0 ₂ ), water (H ₂ 0), and oxygen (0 ₂ ). Flue gas is generated from the thermochemical process of combustion.

As used herein the term a "thermochemical process" refers to a broad classification including various processes that can convert a carbonaceous feedstock into product gas. Among the numerous thermochemical processes or systems that can be considered for the conversion of a carbonaceous material, the present disclosure contemplates: hydrous devolatilization, steam reforming, partial oxidation, dry reforming, and combustion. Thermochemical processes may be either endothermic or exothermic in nature depending upon the specific set of processing conditions employed. Stoichiometry and composition of fluidization medium, type of fluidization medium, fluid bed temperature and pressure, heating rate of the feedstock, residence time, feedstock properties, and catalyst or bed additives all dictate what sub classification of thermochemical processing the system exhibits.

As used herein the term "thermochemical reactor" refers to a fluidization reactor that accepts a carbonaceous feedstock and converts it into one or more product gases.

As used herein the term "hydrous devolatilization" refers to an endothermic thermochemical process wherein volatile feedstock components of a carbonaceous feedstock are converted primarily into volatile reaction products in a steam and hydrogen environment; however some syngas can be generated. Typically this sub classification of a thermochemical process involves the use of steam as a fluidization medium and involves temperatures ranging from 320 °C and 569.99 °C, depending upon the feedstock chemistry. Hydrous devolatilization permits release and thermochemical reaction of volatile feedstock components leaving the fixed carbon feedstock components mostly unreacted as dictated by kinetics.

As used herein the term "steam reforming" refers to a thermochemical process comprising a specific chemical reaction where steam reacts with a carbonaceous feedstock to yield syngas. The main reaction is endothermic wherein the operating temperature range is between 570 and 900 °C, depending upon the feedstock chemistry.

As used herein the term "dry reforming" refers to a thermochemical process comprising a specific chemical reaction where carbon dioxide is used to convert a carbonaceous feedstock into syngas. By limiting the amount of water available, the main reaction is endothermic wherein the operating temperature range is between 600 and 1,000 °C, depending upon the feedstock chemistry.

As used herein the term "partial oxidation" refers to a thermochemical process wherein substoichiometric oxidation of a carbonaceous feedstock takes place to generate syngas. By limiting the amount of oxygen available, the main reaction is exothermic wherein the operating temperature range is between 500 and 1400 °C, depending upon the feedstock chemistry.

As used herein the term "combustion" refers to a thermochemical process wherein at least the stoichiometric oxidation of a carbonaceous feedstock takes place to generate flue gas.

SUMMARY

In accordance with one aspect of the present invention, the carbonaceous feedstock conversion system includes an integrated two-stage fluid bed thermochemical reaction apparatus having two reaction compartments side by side and physically partitioned from one another in one vessel sharing one or more clusters of horizontal or slanted heat pipes for efficient indirect heat transfer between first and second fluid bed reaction stages and materials therein. One reaction compartment within the reactor accepts a carbonaceous feedstock, comprised of volatile feedstock components and fixed carbon feedstock components, and continuously produces a product gas therefrom, while simultaneously and continuously capturing and transferring the fixed carbon feedstock components to a second compartment within the reactor where they may be continuously thermochemically reacted and converted into either syngas or flue gas.

In another aspect, the present invention is directed towards a continuous, energy-integrated refuse-to-crude oil conversion process and apparatus comprising the continuous hydrous devolatilization of volatile feedstock components and continuous thermochemical conversion of fixed carbon feedstock components.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention and to show how the same may be carried out in practice, reference will now be made to the accompanying drawings, in which:

Figure 1 shows an integrated two-stage thermochemical reactor apparatus in accordance with one embodiment of the present invention;

Figure 2 shows an integrated two-stage thermochemical reactor apparatus in accordance with another embodiment of the present invention;

Figure 3 shows an embodiment of a heat pipe used in the integrated two-stage

thermochemical reactor apparatus;

Figure 4 shows another embodiment of a heat pipe used in the integrated two- stage thermochemical reactor apparatus;

Figure 5 shows an embodiment of a method of heat pipe operation;

Figure 6 shows a list of the combinations of thermochemical reaction regimes that can take place within each partitioned reaction compartment.

DETAILED DESCRIPTION

Figure 1 shows an integrated two-stage fluid bed reactor (50) in accordance with one embodiment of the present invention. It includes a vessel (100) with a first chamber (110), a second chamber (120), and a partition (130) therebetween. The first chamber (110) defines a stage 1 reaction chamber (200). The second chamber (120) defines a stage 2 reaction chamber (300). A plurality of heat pipes (400) extend through the partition (130) between the first chamber (110) and the second chamber (120). Stage 1 reaction chamber (200) and stage 2 reaction chamber (300) are physically separated from one another by the partition (130) and share one or more horizontal or slanted clusters of heat pipes (400) which are used to transfer heat from the second chamber (120) to the first chamber (110). The stage 2 fluid bed (320) within the second chamber (120) generally operates at a higher temperature than the stage 1 fluid bed (220) within the first chamber (110).

As seen in Figure 1, the partition (130) has a first partition passageway (290) for transferring first chamber discharge materials (240) from the stage 1 freeboard zone (295) to a stage 1 primary particulate capture device (350) located within the stage 2 freeboard zone (395). First chamber discharge materials (240) may include product gases, fixed carbon feedstock components, volatile feedstock components, bed media, ash, sorbents, bed material agglomeration prevention additives, catalysts, or combinations thereof. A second partition passageway (390) is configured for transferring second chamber discharge materials (340) from the stage 2 freeboard zone (395) to a stage 2 primary particulate capture device (260) located within the stage 1 freeboard zone (295). Second chamber discharge materials (340) may include product gases, fixed carbon feedstock components, volatile feedstock components, bed media, ash, sorbents, bed material agglomeration prevention additives, catalysts, or combinations thereof.

The first and second chamber discharge materials (240, 340) will depend on the exact nature of the thermochemical process conducted in each chamber. For example, in operational embodiment (1001) of Fig. 6, the first chamber (110) is operated in a hydrous devolatilization mode and the second chamber (120) is operated in a partial oxidation steam reforming mode. In such case, the first chamber discharge materials sent to the second chamber (120) will include volatile reaction products, bed media, ash, fixed carbon feedstock components, and volatile feedstock components while the second chamber discharge materials returned to the first chamber (110) will include syngas and bed media but only trace amounts of fixed carbon feedstock components and volatile feedstock components. Thus, in operational embodiment (1001) of Fig. 1, the first chamber discharge materials are substantially carbon-laden while the second chamber discharge materials are substantially carbon-depleted.

In an alternative embodiment, as seen in Figure 2, an alternate first passageway (291) through the exterior wall of the vessel (100) is used for transferring first chamber discharge materials (240) from the stage 1 freeboard zone (295) to a stage 1 primary particulate capture device (350) located external to the vessel (100). An accompanying alternate second passageway (391) through the exterior wall of the vessel (100) may be used for transferring second chamber discharge materials (340) from the stage 2 freeboard zone (395) to a stage 2 primary particulate capture device (260) located external to the vessel (100).

As seen in Figure 1 and Figure 2, the first chamber (110) includes a: feedstock inlet port (210) for receiving carbonaceous feedstock (150); a stage 1 freeboard zone fluid inlet port (212) for introducing a stage 1 freeboard zone fluid (213) including, but not limited to, an oxidant, such as carbon dioxide, oxygen, air, and steam or a mixture thereof; a stage 1 fluid bed (220) with stage 1 fluid bed material (225); a stage 1 fluidization medium inlet port (231) located near the bottom of the stage 1 reaction chamber (200) for introducing a stage 1 fluidization medium (232); a stage 1 fluidization medium distributor (230) which substantially evenly distributes the stage 1 fluidization medium (232) over the cross sectional area of the stage 1 reaction chamber (200); a stage 1 secondary material inlet port (284) for introducing a stage 1 secondary material (282) comprised of a sorbent, bed material agglomeration prevention additive, or catalyst; and a stage 1 freeboard zone (295) located above the stage 1 fluid bed level (201). The stage 1 fluidization medium (232) may be one or more from the group consisting of steam, carbon dioxide, air, oxygen, hydrogen, syngas, and product gas, and mixtures thereof.

The first chamber (110) further includes a stage 2 primary particulate capture device (260), such as a cyclone, which includes an inlet (270a), a particulate discharge (270b), and a product gas discharge (270c). Stage 2 primary particulate capture device (260) may be located internally to the vessel (100) as in Figure 1, or, externally to the vessel (100) with connections as shown in Figure 2.

The stage 2 primary particulate capture device (260) accepts second chamber discharge materials (340) from stage 2 freeboard zone (395), separates first particulates (900a) therefrom, and said separated first particulates exit stage 2 primary particulate capture device (260) through a particulate discharge (270b) and are transferred to the stage 1 fluid bed (220). First particulates (900a) are most likely to be carbon-depleted fhiidized bed material and may include fixed carbon feedstock components, ash, sorbent, catalyst, agglomeration prevention additives, or mixtures thereof.

The stage 2 secondary particulate capture device (600) includes: an inlet (610a); a particulate discharge (610b); and, a product gas discharge (610c). First product gas (900b) is discharged from stage 2 primary particulate capture device (260) through a product gas discharge (270c) and enters stage 2 secondary particulate capture device (600) through inlet (610a). Fourth particulates (1300a) including fixed carbon feedstock components are separated within stage 2 secondary particulate capture device (600) and are discharged through a particulate discharge (610b) either for return to the second chamber (120) or for ash storage and collection. A fourth product gas (1300b) is discharged from the stage 2 secondary particulate capture device (600) through a product gas discharge (610c).

The optional stage 2 tertiary particulate capture device (700) includes: an inlet (710a); a particulate discharge (710b) ; and, a product gas discharge (710c) . The fourth product gas ( 1300b) discharged from stage 2 secondary particulate capture device (600) through the product gas discharge (610c) enters the stage 2 tertiary particulate capture device (700) through inlet (710a). Fifth particulates (1400a), including ash, are separated within the stage 2 tertiary particulate capture device (700) and are discharged through a particulate discharge (710b). A fifth product gas (1400b) is discharged from the stage 2 tertiary particulate capture device (700) through a product gas discharge (710c). Devices 260, 600 and 700 handle progressively finer and lighter solids with device 700 discharging mostly ash laden solids. Depending on the feedstock and the application, either two cyclones in series (260 and 600) arrangement or three cyclones in series (260, 600 and 700) arrangement may be used.

As seen in Figures 1 and 2, the stage 2 reaction chamber (300) includes a stage 2 fluid bed (320) with stage 2 fluid bed material (325). A stage 2 fluidization medium inlet port (331) is located near the bottom of the stage 2 reaction chamber (300) for introducing a stage 2 fluidization medium (332). A stage 2 fluidization medium distributor (330) substantially evenly distributes the stage 2 fluidization medium (332) over the cross sectional area of the stage 2 reaction chamber (300). The stage 2 fhiidization medium (332) may be one or more from the group consisting of steam, carbon dioxide, air, oxygen, hydrogen, syngas, and product gas. A stage 2 secondary material inlet port (384) is configured to introduce a stage 2 secondary material (382) comprised of one or more of sorbent, bed material agglomeration prevention additive, catalyst, tail-gas, syngas, tars, a hydrocarbon liquid, oil and solvent. A stage 2 freeboard zone (395) is located above the stage 2 fluid bed level (301) and is configured to accept a stage 2 freeboard zone fluid (313) comprised of one or more of oxygen, air, steam, and carbon dioxide introduced through a stage 2 freeboard zone fluid inlet port (312). A stage 2 fluid bed fluid injection port (310) is configured to introduce a stage 2 fluid bed zone fluid (311) comprised of one or more of steam, carbon dioxide, or nitrogen as necessary and/or particulates (1300a) comprised primarily of fixed carbon feedstock components.

The second chamber (120) further includes: a stage 1 primary particulate capture device (350), such as a cyclone; and a stage 1 secondary particulate capture device (370), such as a cyclone. Each said particulate capture device, i.e., (350) and/or (370), may be located external to the vessel (100) as depicted in Figure 2, or located within the stage 2 freeboard zone (395) and thus internal to the vessel (100) as depicted in Figure 1.

The stage 1 primary particulate capture device (350) includes: an inlet (360a); a particulate discharge (360b); and, a product gas discharge (360c). First chamber discharge materials (240) comprised of product gas, bed material, fixed carbon feedstock components, volatile feedstock components, and/or ash are discharged from stage 1 freeboard zone (295) and transferred through first partition passageway (290) to inlet (360a). Second particulates (1100a) including at least one of fixed carbon feedstock components, volatile feedstock components, bed material, and/or ash are separated within the stage 1 primary particulate capture device (350) and discharged through particulate discharge (360b) and transferred to the stage 2 fluid bed (320).

The stage 1 secondary particulate capture device (370) includes: an inlet (380a); a particulate discharge (380b); and, a product gas discharge (380c). Second product gas (1100b) is discharged from the stage 1 primary particulate capture device (350) through a product gas discharge (360c) and enters stage 1 secondary particulate capture device (370) through inlet (380a).

Third particulates (1200a) including bed media, fixed carbon feedstock components, volatile feedstock components, and/or ash are separated within stage 1 secondary particulate capture device (370) and are transferred to stage 2 fluid bed (320) through particulate discharge (380b). A third product gas (1200b) is discharged from stage 1 secondary particulate capture device (370) through product gas discharge (380c). Devices 350 and 370 provide two stages of solids separation to discharge a product gas substantially lower in particulates. This arrangement facilitates the transfer of carbon-laden solids from the first chamber (110) to the second chamber (120), reacting fixed carbon feedstock components in the second chamber (120) at a higher temperature and returning the carbon-depleted solids to the first chamber (110).

Figure 3 shows a detailed view of one embodiment of a heat pipe of the sort that may be employed in the present invention. The construction and design of a suitable heat pipe is described generally at http://www.thermacore.com/thermal-basics/heat-pipe-technolog y.aspx, retrieved January 15, 2013, and available from Thermacore of Lancaster, Pennsylvania, USA. Each heat pipe (400) includes an evaporation portion (410), an adiabatic portion (420), a condensation portion (430), a wick internal structure (440), a heat carrier fluid (450), a heat transfer surface (470), and a vapor space (475). In one embodiment, the heat carrier fluid comprises sodium, potassium, lithium, cesium, or a mixture thereof. In another embodiment, the wick internal structure (440) may be comprised of a porous capillary type structure, metal gauze, capillary grooves, a system of arteries, a combination thereof, or the like. In another embodiment, the entire heat transfer surface (470) of the heat pipe (400) is contiguous with an intermetallic hydrogen diffusion impermeable coating (460), or barrier layer, prepared from metals selected from copper, chromium, zirconium, yttrium, partially stabilized zirconium, platinum, iridium, lanthanum, rhodium, and compounds, mixtures, alloys, and intermetallic compounds thereof.

Figure 4 shows a detailed view of another embodiment of a heat pipe of the sort that may be employed in the present invention. It includes features present in Figure 3, however, the entire heat pipe (400) is placed within a sealed thermowell (500) which may be purged or pressurized with a gas (510) that is transferred through a gas injection port (505). Hydrogen diffusion into the heat pipe (400) may be mediated by making a gas (510) available to the space (515) in between the heat pipe's heat transfer surface (470) and the thermowell (500). Preferred gases for this application may be nitrogen, carbon dioxide, helium, argon, steam or the like.

The evaporation portion (410) is configured to accept a heat input (485) which vaporizes the heat carrier fluid (450). The adiabatic portion (420) is configured to enable the vaporized heat carrier fluid (450) to travel to the condensation portion (430) through the vapor space (475). The condensation portion (430) is configured to release a heat output (495) which in turn permits condensation of the vaporized heat carrier fluid (450). The wick internal structure (440) is configured to return the condensed heat carrier fluid (450) from the condensation portion (430) to the evaporation portion (410).

The evaporation portion (410) of each of the heat pipes (400) is situated in the second chamber (120). The condensation portion (430) of each heat pipe (400) is situated in the first chamber (110). As best seen in Figure 1 and Figure 2, the heat pipe (400) configuration preferably extends at a downward angle (e.g., 5 to 30 degrees with respect to the horizontal) from the first chamber (110) to the second chamber (120). This non-limiting embodiment is preferred since gravity flow assists the return of the condensed heat carrier fluid (450) from the condensation portion (430) to the evaporation portion (410).

Figure 5 presents a flow chart depicting one embodiment of the operation of the stage 1 reaction chamber (200), stage 2 reaction chamber (300), and the heat pipes (400) in the vessel (100). The stage 1 reaction chamber (200) receives carbonaceous feedstock (150) and converts at least a portion of that carbonaceous feedstock (150) into first chamber discharge materials (240) in an endo thermic process. The stage 1 reaction chamber (200) may operate in one or more reaction regimes/modes such as hydrous devolatilization, steam reforming, dry reforming and partial oxidation utilizing primarily endothermic reactions with supplementary exothermic reactions as necessary. The stage 2 reaction chamber (300) receives the first chamber discharge materials (240) from the stage 1 reaction chamber (200) via the first partition passageway (290).

The stage 2 reaction chamber (300) may operate in one or more reaction modes such as steam reforming, dry reforming, partial or full oxidation (i.e. combustion) utilizing primarily exothermic reactions with supplementary endothermic reactions . The heat produced from the reaction in the stage 2 reaction chamber (300) enters the heat pipe (400) at its evaporation portion (410) (Step 1412). Heat released from the reaction causes the heat carrier fluid (450) within the evaporation portion (410) of the heat pipe (400) to evaporate (vaporize) (Step 1422). The vaporized heat carrier fluid (450) creates a pressure gradient which forces the heat carrier fluid (450) toward the condensation portion (430). The vaporized heat carrier fluid (450) travels through the vapor space (475) of the adiabatic portion (420) to the condensation portion (430) (Step 1432). The pressure drop in the heat pipe (400) is low, therefore little temperature change and thus minimal energy loss is associated with the adiabatic portion (420). The vaporized heat carrier fluid (450) condenses in the condensation portion (430) and releases its latent heat of vaporization into the stage 1 reaction chamber (200) (Step 1442). This provides the heat necessary for the endothermic reactions to occur in the stage 1 reaction chamber (200) (Step 1452). The condensed heat carrier fluid (450) is drawn into the pores of the wick internal structure (440) to return to the evaporation portion (410) (Step 1462). The wick internal structure (440) uses capillary pressure to return the heat carrier fluid (450) to the evaporation portion (410) (Step 1472). The wick internal structure (440) also acts as an extended surface to allow higher heat fluxes in the heat pipe (400). The endothermic and/or exothermic reactions in the stage 1 reaction chamber (200) and the stage 2 reaction chamber (300) continually occur, with heat continually transferring from the stage 2 reaction chamber (300) to the stage 1 reaction chamber (200) via the heat pipes (400).

Figure 6 presents a number of embodiments capable of being implemented using the system disclosed herein. Each row of the table in Figure 6 presents combinations of thermochemical reaction regimes that can take place within each side by side chamber. It is understood that the corresponding elements and features necessary to realize each combination would be needed in a system.

The disclosed process can be configured by the formulator to meet the desired need. The disclosed process provides several unmet advantages to convert varying types of carbonaceous feedstocks into valuable end products. Although the present invention has been described with reference to certain embodiments, it should be understood that various alterations and modifications could be made without departing from the spirit or scope of the invention as hereinafter claimed.

TABLE OF REFERENCE NUMERALS

integrated two-stage fluid bed reactor (50)

vessel (100)

first chamber (110)

second chamber (120)

partition (130)

carbonaceous feedstock (150)

stage 1 reaction chamber (200)

stage 1 fluid bed level (201)

feedstock inlet port (210)

stage 1 freeboard zone fluid inlet port (212)

stage 1 freeboard zone fluid (213)

stage 1 fluid bed (220)

stage 1 fluid bed material (225)

stage 1 fluidization medium distributor (230)

stage 1 fluidization medium inlet port (231)

stage 1 fluidization medium (232)

first chamber discharge materials (240)

stage 2 primary particulate capture device (260)

inlet (270a)

particulate discharge (270b)

product gas discharge (270c)

stage 1 secondary material (282)

stage 1 secondary material inlet port (284)

first partition passageway (290)

alternate first passageway (291)

stage 1 freeboard zone (295)

stage 2 reaction chamber (300)

stage 2 fluid bed level (301)

stage 2 fluid bed fluid injection port (310)

stage 2 fluid bed zone fluid (311)

stage 2 freeboard zone fluid inlet port (312)

stage 2 freeboard zone fluid (313)

stage 2 fluid bed (320)

stage 2 fluid bed material (325)

stage 2 fluidization medium distributor (330)

stage 2 fluidization medium inlet port (331)

stage 2 fluidization medium (332)

second chamber discharge materials (340)

stage 1 primary particulate capture device (350) inlet (360a)

particulate discharge (360b)

product gas discharge (360c)

stage 1 secondary particulate capture device (370) inlet (380a)

particulate discharge (380b)

product gas discharge (380c)

stage 2 secondary material (382)

stage 2 secondary material inlet port (384) second partition passageway (390)

alternate second passageway (391)

particulates return passageway (392)

particulates return passageway (393)

stage 2 freeboard zone (395)

heat pipes (400)

evaporation portion (410)

adiabatic portion (420)

condensation portion (430)

wick internal structure (440)

heat earner fluid (450)

hydrogen diffusion impermeable coating (460) heat transfer surface (470)

vapor space (475)

heat input (485)

heat output (495)

thermowell (500)

gas injection port (505)

gas (510)

space (515)

stage 2 secondary particulate capture device (600) inlet (610a)

particulate discharge (610b)

product gas discharge (610c)

stage 2 tertiary particulate capture device (700) inlet (710a)

particulate discharge (710b)

product gas discharge (710c)

first particulates (900a)

first product gas (900b)

second particulates (1100a)

second product gas (1100b)

third particulates (1200a)

third product gas (1200b)

fourth particulates (1300a)

fourth product gas (1300b)

fifth particulates (1400a) fifth product gas (1400b)

Step 1412

Step 1422

Step 1432

Step 1442

Step 1452

Step 1462

Step 1472