WO2010056457A2

WO2010056457A2 - Deep shaft reactor with reactant concentration differentials

Info

Publication number: WO2010056457A2
Application number: PCT/US2009/060797
Authority: WO
Inventors: Jens Wiik Jensen; Eric Dickman
Original assignee: Uni-Control, Llc
Priority date: 2008-11-12
Filing date: 2009-10-15
Publication date: 2010-05-20
Also published as: WO2010056457A3

Abstract

Herein disclosed is a reactor system comprising a shaft reactor, having a vertical depth to the shaft bottom that is at least twice the shaft width; a reactor volume, the reactor volume including a gas volume positioned vertically above a liquid volume, and sharing a gas-liquid interface, the liquid volume comprising a reactant suspension; a divider configured to separate the liquid volume into a first volume and a second volume, wherein the first volume and second volume comprise conduits within the reactor; a reactant enrichment & saturation system, the reactant enrichment saturation system fluidly coupled to the shaft reactor, configured for removing biomass and water from the shaft reactor, injecting enriching reactants into the return water, and re-introducing enriched saturated reactant into the shaft reactor; and a pump & venturi configured for re-injecting return water to the reactant enrichment system.

Description

DEEP SHAFT REACTOR WITH REACTANT CONCENTRATION

DIFFERENTIALS

BACKGROUND

Field of the Invention

[0001] This invention relates generally to the reactor design. More specifically this invention relates to shaft reactor with reactant concentration differentials and gas supply system. Background of the Invention

[0002] Deep shaft reactors represent a potential new method of operating bioreactors, chemical reactors, and treatment facilities. Deep shaft reactors are improvements over many commercially applied technologies, as they do not take up large tracts of land with expansive above ground infrastructure. Examples for implementing deep shaft reactors include water- gas shift, biodiesel production, sludge digestion/treatment, as well as various commercially important fermentations, such as ethanol.

[0003] Deep shaft reactors may be beneficial for carbon monoxide water-gas shift reactions as a means to produce hydrogen fuels. The introduction of gaseous reactants drives a riser column and provides motive force for the circulation within the reactor. Further, removal of products at or near the ground level reduces complications, and infrastructure requirements. In certain cases, a reactor for the water-gas shift reaction may be suitable for fermentation reactions, such as to product ethanol, butanol, or other commercially important products. [0004] Additionally, the growth of certain carbon fixing algae, bacteria, and other microorganisms might be beneficially enhanced in a deep shaft reactor. Certain alterations to ensure the continued activation of carbon-fixing pathways may be included such as grow lamps. The addition of carbon dioxide gas into the reactor may drive a riser column and provide circulation for the mixture. Removal of algae from the surface of the reactor allows them to be transported efficiently for biodiesel harvesting, or other applications. [0005] Wastewater treatment routinely relies on the biofiltering, and/or bioremediation of certain compounds from a waste effluent. Introduction of oxidative gases, inert gases, and air to drive the reaction process, would also drive the riser column of a shaft reactor. As the suspended solids settle they may drive a downcomer column in the shaft reactor thereby increasing circulation. Clean water may be easily separated or removed at ground level, and the remaining waste reintroduced into the reactor.

[0006] However, a method of designing and operating a reactor in this configuration has not been described. Furthermore, the means to introduce appropriate reactants, including gaseous reactants, has not been described. Consequently, there is a need in the industry for a shaft reactor design, and reactant introduction system for a deep shaft reactor for a variety of processes.

BRIEF SUMMARY

[0007] Herein disclosed is a reactor system comprising a shaft reactor, having a vertical depth to the shaft bottom that is at least twice the shaft width; a reactor volume, the reactor volume including a gas volume positioned vertically above a liquid volume, and sharing a gas-liquid interface, the liquid volume comprising a reactant suspension; a divider configured to separate the liquid volume into a first volume and a second volume, wherein the first volume and second volume comprise conduits within the reactor; a reactant enrichment & saturation system, the reactant enrichment saturation system fluidly coupled to the shaft reactor, configured for removing biomass and water from the shaft reactor, injecting enriching reactants into the return water, and re-introducing enriched saturated reactant into the shaft reactor; and a pump & venturi configured for re-injecting return water to the reactant enrichment system. [0008] In some embodiments, the divider extends vertically from below the gas-liquid interface to above the shaft bottom, configured for directing a circulation within the liquid volume. In some embodiments, the first volume is at least 51% and the second volume at least 49% or less to force a slow flow fast flow environment. In some embodiments, the first flow volume is greater than the second flow volume. In some embodiments, the first flow volume comprises a downcomer. In some embodiments, the first flow volume comprises a slow flow zone. In some embodiments, the first flow volume comprises a reactant-depleted zone. In some embodiments, the second flow volume comprises a riser. In some embodiments, the riser comprises a gas-lift riser. In some embodiments, the second flow volume comprises a fast flow zone. In some embodiments, the second flow volume comprises a reactant-enriched zone. In some embodiments, the gas-liquid interface comprises an operational fill level. [0009] In some embodiments, the gas volume comprises a reactor head. In some embodiments, the reactor head comprises a degassed chamber, including at least one means to remove product gas from the reactor head for processing. In some embodiments, the product gas is a hydrogen (H₂) containing gas. In some embodiments, the reactant enrichment system comprises a reactor outlet, disposed below the gas-liquid interface. In some embodiments, the reactor outlet is disposed adjacent to the first volume. In some embodiments, the reactor outlet is in fluid communication with an enrichment vessel after separation of biomass using centrifuges. [0010] In some embodiments, the enrichment vessel is in fluid communication with a reactant source. In some embodiments, the reactant source comprises a carbon monoxide (CO) containing gas. In some embodiments, the reactor enrichment system further comprises an injecting means disposed below the gas-liquid interface, and above the reactor outlet. In some embodiments, the injecting means comprises at least one nozzle disposed within second volume, and in fluid communication with second volume. In some embodiments, the injecting means is configured to provide gas-lift means to the second volume. In some embodiments, the injecting means comprises multiple nozzle injection system in the second volume. In some embodiments, the multiple nozzle injections system comprises the capability of variating injection volume, concentration, pressure, temperature.

[0011] Also described herein is an CO gas saturation system for maximum water-gas saturation, comprising a shaft reactor, having a vertical depth to the shaft bottom that is at least twice the shaft width; a reactor volume, the reactor volume including a gas volume positioned vertically above a liquid volume, and sharing a gas-liquid interface, the liquid volume comprising a reactant suspension; a divider configured to separate the liquid volume into a first volume and a second volume, wherein the first volume and second volume comprise conduits within the reactor; a reactant enrichment & saturation system, the reactant enrichment saturation system fluidly coupled to the shaft reactor, configured for removing biomass and water from the shaft reactor, injecting enriching reactants into the return water, and reintroducing enriched saturated reactant into the shaft reactor; and a pump & venturi configured for re-injecting return water to the reactant enrichment system.

[0012] The foregoing has outlined rather broadly the features and technical advantages of the invention in order that the detailed description of the invention that follows may be better understood. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, and by referring to the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

[0013] For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:

[0014] FIGURE 1 illustrates an embodiment of a shaft reactor.

[0015] FIGURE 2A illustrates an embodiment of an enrichment system fluidly coupled to shaft reactor in vertical cross-section; [0016] FIGURE 2B illustrates an embodiment of an enrichment system fluidly coupled to shaft reactor in horizontal cross-section.

DETAILED DESCRIPTION

[0017] Figure 1 shows an embodiment of reactor system 10 configured for reactant saturation in a reactor system 10. Reactor system 10 circulates a reactant suspension, or Mixed Liquor Suspended Solids (MLSS), through an apparatus that comprises vessel 12, reactant saturation system 30, reactant source 34, and removal system 90. Vessel 12 has reactor volume 20 and head 50. Vessel 12 is configured for fluid flow or circulation 18 about division 16. Head 50 includes a vent system 52 for removing gases. In embodiments, MLSS comprises any mixture of compounds suitable for reacting in a liquid phase. Alternatively, the reactant suspension may comprise a plurality of gases homogenously or in-homogenously dispersed in the suspension.

[0018] Vessel 12 is a cylinder having a top 12a and bottom 12b. In certain embodiments, the vessel 12 has a long axis L_a oriented vertically between the top 12a and the bottom 12b. Long axis L_a is between about 10 m and about 600 m. Long axis L_a is selected, or built, to configure reactor system 10 for optimal MLSS circulation time. Short axis S_a is oriented horizontally between vessel walls 12c; alternatively perpendicular to long axis L_a. Short axis S_a is selected, or built, to configure reactor system 10 for optimal MLSS circulation volume. Short axis S_a is the inner diameter of the vessel in cylindrical embodiments. Vessel 12 may have alternative shapes such as without limitation, rectangular, or polygonal.

[0019] In embodiments, vessel 50 is a shaft reactor. A shaft reactor is any reactor that has a long axis L_a that is at least twice the dimension of the short axis S_a. In certain instances, vessel 50 is disposed below ground, for instance in a shaft, borehole, or other vertically oriented compartment in the earth. Alternatively, vessel 12 is at least partially above ground. In preferred embodiments, vessel 12 is a deep shaft reactor, wherein long axis L_a is greater than about 50m.

[0020] Vessel 12 is constructed of any material suitable for resisting corrosion. Further, vessel 12 is constructed of a thermally conductive material for transferring heat to surroundings, such as the ground. In certain embodiments, vessel 12 is constructed of aluminum, or stainless steel. Vessel 12 comprises a reactor suitable for conducting a biological reaction aerobic as well as anaerobic. Vessel 12 comprises any suitable vessel for carrying out a fermentation reaction. In embodiments, vessel 12 is an open-ended pressurized vessel, reactor, container or the like configured to contain a bio-mediated reaction. Alternatively, vessel 12 is configured to hold a reaction mixture comprising wastewater for digestion, methane fermentation, or bio-filtering. In certain embodiments, vessel 12 comprises any suitable for containing MLSS suspension of reactants, products, solids, liquids, and gases without limitation. Alternatively, vessel 12 is configured to contain any bioreaction, for example the enzymatic digestion of biomass to produce liquor. The reactor can be used for the production of ethanol, butanol, methane gas, acetone, biodiesel, and hydrogen. Further, the reactor may be used for water-gas shift, biodiesel production, sludge digestion/treatment, and the like, without limitation. Vessel 12 may have any shape or size suitable for enhancing the reaction kinetics within reactant suspension, for example frustro-conical. Further, vessel 12 and all internal structures are coated, treated, or polished to prevent the formation of bacterial, microorganism plaques, carbon deposits, slag, or other deposits as known to one skilled in the art.

[0021] Vessel 12 has reactor volume 20. Reactor volume 20 extends from vessel bottom 12b to reactor volume surface 22. Reactor volume surface 22 comprises a fluid/gas interface within vessel 12. Reactor volume 20 is between about 50 % and about 99% of the total volume of vessel 12. Total volume of vessel may be calculated by π L_a (S_a/2)². Reactor volume 20 is a fluid volume configured to include circulation 18, and division 16. Alternatively, reactor volume 20 is an internal compartment of vessel 12.

[0022] In certain instances, division 16 is a virtual division, wherein the reactor volume 20 is a unified volume. In this embodiment, division 16 is an axis of circulation in which the reactant suspension circulates through reactor volume 20. Division 16 may comprise a shear in division zone 17 such that fluid flowing downward and fluid flowing upward interact. In preferred embodiments, division 16 is a baffle, wall, or other component of vessel 12 to direct or control fluid flow. Division 16 may be oriented in any direction with respect to long axis L_a of the vessel 12. In preferred embodiments, division 16 is oriented vertically, or parallel to long axis L_a. Division 16 extends a partial distance through reactor volume 20 a parallel to long axis L_a. Division 16 extends parallel to short axis S_a, in alternative instances. [0023] In embodiments, division 16 divides the reactor volume 20 into at least two compartments: a first compartment 20a, and a second compartment 20b. In certain embodiments, division 16 is vertical contact with vessel walls 12c. Compartments 20a, 20b created by division 16 are about equal in volume. Alternatively, as illustrated in Figures 2 A, and 2B, division 16 creates a first compartment 20a with a volume that is greater than about the volume of the second compartment 20b. First compartment 20a has a volume of at least about

51% of reactor volume 20. Second compartment 20b has a volume of maximum about 49%. In certain instances, a configuration with unequal compartment volumes is a configuration for altering the velocity of circulation 18 between the first compartment 20a and the second compartment 20b.

[0024] In certain embodiments, first compartment 20a is a downcomer compartment. Further, the downcomer, or first compartment 20a, is configured for slow suspension flow or circulation 18a. Direction of circulation 18a is generally directed towards the bottom 12b of vessel. First compartment 20a is a reactant depleted flow region within vessel 12. The reactant-depleted region will act as a starvation mode of the biomass, which thereafter in the riser will be supersaturated with CO gas thus reacting with increased reaction capability to reduce toxic CO2 effects and to increase the water-shift reaction capacity. Due to the larger volume of the downcomer 20a compared to volume of the second compartment 20b the liquid flow of downcomer 20a is slower. Due to the injection of saturated reactant in the second compartment 20b, the liquid flow will starts its circular motion around the separation wall 16. Further, second compartment 20b is a riser compartment. In embodiments, the riser or second compartment 20b is configured for fast suspension flow, or circulation 18b. In further embodiments, second compartment 20b is configured a gas lift compartment. In embodiments, second compartment 20b comprises a gas-enriched flow in reactor. Direction of circulation 18b is generally directed towards reactor volume surface 22 and top 12a of vessel. Second compartment 20b is a reactant enriched flow region within vessel 12. In certain embodiments, second compartment 20b is fluidly coupled to a reactant inlet.

[0025] Referring again to Figure 1, in embodiments, division 16 includes gaps, openings, or the like, without limitation. Top gap or spillover 16a located proximal to the surface 22 of reactor volume 20. Spillover 16a is configured to allow circulation 18 to continue over or around division 16 between compartments 20a, 20b. Further, division 16 includes lower gap or flow-through 16b, that is configured such that circulation 18 continues under, or around division 16 between compartments 20a, 20b. In certain instances, spillover 16a and flow- through 16b are constructed to increase turbulence and mixing of reactants in reactor volume 20. In certain instances, division 16 includes baffles, fins, or other turbulence inducing structures configured to agitate the flow in division zone 17. Furthermore, these structures may be disposed on vessel walls 12c. Without wishing to be limited by theory, turbulence may increase reaction between reactants. Division 16 is constructed such that circulation 18 may continue in any direction such that reactant suspension in vessel 12 are circulated from top to bottom to top of reaction volume 20 about division 16 and between first compartment 20a, and second compartment 20b. [0026] Referring now to Figure 2A, a vertical cross-section of vessel 12 for reactor system 10. Vessel 12 is coupled to saturation and mixing system 30 via outlet system 32 and injector system 36. Outlet system 32 withdraws MLSS from vessel 12 to mixing system 30. Saturation and mixing system 30 comprises mixing vessel 38 coupled to reactant source 34 by reactant stream 40. Injector system 36 reintroduces the enriched reactant MLSS suspension from mixing system 30 to vessel 12 for further processing in the riser 20b. Mixing system 30 exposes reactant suspension to reactant source 34. Mixing system 30 is configured to enhance, or enrich reactant suspension in mixing vessel 38 for re-introduction to vessel 12 as supersaturated MLSS mixture. Mixing system 30 is configured for saturating the reactant suspension to accelerate the reaction rate.

[0027] Mixing vessel 38 may comprise a reactor, a vessel, a tank, deep shaft or the like for holding a plurality of reactants, and reactant phases. Mixing vessel comprises inlet 38a and outlet 38b. In certain embodiments, inlet 38a and outlet 38b are valves to alter, restrict, or stop the flow of a liquid or gas therethrough. Further, mixing vessel 38 is a holding tank or storage vessel, for maintaining the suspension in contact with reactant stream 40. Alternatively, mixing vessel 38 enriches the suspension by agitating, or stirring the suspension. Mixing vessel 38 may be configured to maintain a flow path or enriching circulation 118. Mixing and gas saturation vessel 38 may include internal structures designed to direct, or improve enriching circulation 118, such as, but not limited to conduits, baffles, sluices, settlers, and filters. [0028] Reactant source 34 comprises a source of raw material or compounds for participation, acceleration, catalysis of, or interaction with the reactant suspension, without limitation. In embodiments, reactant source 34 comprises a gas source. Alternatively, reactant source 34 comprises any gaseous or liquid reactant suitable for a bioreaction, a fermentation reaction, a catalysis reaction, or a synthesis reaction. In certain instances reactant source 34 may comprise catalytic particles, such as nanoparticles. Reactant source 34 is fluidly coupled to mixing vessel 38 by reactant stream 40. In one embodiment, reactant stream 40 feeds directly into mixing vessel 38 and enriching circulation 118 contained therein. Reactant stream 40 comprises a control means to adjust the reactant concentration in mixing vessel 38. In certain instances, reactant stream 40 is adjusted to modulate at least one gaseous component's concentration in mixing vessel 38. Exemplary adjustments reactant stream 40 is configured to include, without limitation, reactant flowrate, reactant pressure, and/or reactant concentrations. In embodiments, reactant stream 40 is configured to adjust and monitor reactant-containing gases. [0029] In further embodiments, Vessel connected to the centrifuge 90 to receive return water filtrate, Outlet system 92 comprises any conduit suitable for withdrawing the return water filtrate from centrifuge 90 from vessel 12, to mixing vessel 38, via a centrifuge to separate biomass, without limitation. In certain instances, a plurality of suitable conduits may be used to maximize the volume of MLSS suspension withdrawn from vessel 12 to meet the reactant volume requirements to feed gas reactants and to separate solid materials. In embodiments, outlet system 32 withdraws MLSS suspension adjacent to head 20a of vessel 12 via unit 90. In addition, outlet system 32 is configured to withdraw MLSS suspension adjacent to flow- through 16a (fϊgl). The outlet system 32 is disposed in first compartment 20b near the head under the surface 22, adjacent to flow-through 16a, and adjacent to head 16a (fϊgl). Alternatively, outlet system 32 is disposed in second compartment 20b, adjacent to flow- through 16b, and adjacent to vessel bottom 12b.

[0030] Outlet system 32 withdraws MLSS suspension from riser 20b to mixing vessel 38. In embodiments, outlet system 32 includes a venturi pump 144. Venturi pump 144 is configured to pump suspension from vessel 12 into mixing vessel 38 prior to centrifuge separation of MLSS. Additionally, venturi pump 144 is configured to pump, or inject, reactant feedstream 40 from reactant source 34 into MLSS suspension in reactor 12. The use of a venturi eliminates the use of compressing the reactant to ensure sufficient pressure during injection at certain depths of the reactor 12. In further instances, venturi pump 144 comprises a venturi driven liquid/gas injection system. Venturi pump 144 is further configured for pumping pressurized or non-CO gas into MLSS suspension via a vacuum generated in the venturi. [0031] In certain instances, venturi pump 144 lyses, kills, ruptures, or otherwise reduces the microorganism population in MLSS suspension prior to introduction into mixing vessel 38. In certain instances, this is beneficial to the overall operation of the reactor system 10 as the ruptured cells increase the abundance of certain biomaterials as the MLSS suspension is enriched in mixing vessel 38.

[0032] Alternatively, reactor system 10 comprises removal system 90 disposed near the vessel top 12a. Removal system 90 may be used as an alternative to outlet system 32. As previously described, use of a venturi pump to remove MLSS may cause physical stress to the reactant mixture. Removal system 90 comprises outlet stream 91, recycle stream 92, and product stream 93. Removal system may further comprise a centrifuge, filter, or other device capable of separating product stream 93 from outlet stream 91 without additional stress on the MLSS solution. In certain instances, stress may include shear, high pressures, or cavitation that causes death to microorganisms, attrition to catalysts, break-down of products, or other physical stresses known to one skilled in the art of the particular process the reactor is configured for. After separation of MLSS in removal system 90, remaining reactants are returned to the mixing system 30 via recycle stream 92. Recycle stream 92 is returned to mixing vessel 38 for re- enrichment and introduction into reactor 12. Alternatively, recycle stream 92 is used as makeup liquid for liquid removed by product stream 93.

[0033] Product stream 93 is configured to remove the desirable product of the reaction without limitation. Product stream 93 may comprise filters, distillation, or other processes as understood by one skilled in the art to produce useable fuels, alcohols, liquids and the like without limitation. Alternatively, product stream 93 may feed a generator, boiler, refinery, or other facility to produce power.

[0034] As illustrated in Figures 2A and 2B, injector system 36 introduces enriched-reactant suspension from mixing system 30 to second compartment 20b. Preferably, injector system 36 is constructed to have a plurality of injectors 137. In embodiments, injectors 137 comprise any suitable device for injecting a suspension, emulsion, solution, foam, or gas-liquid mixture stream without limitation. Alternatively, injectors 137 and injector system 136 are configured to pass small particles, such as solid catalyst particles without clogging or fouling. Injectors 137 are disposed on vessel wall 12c; alternatively mounted in vessel wall 12c. Further, injectors 137 may comprise nozzles, configured for spraying a plurality of enriched reactant streams 139 into vessel 12. Enriched streams 139 are gasified, or gas enriched reactant suspension streams. Further, enriched streams 139 provide gas-lift to compartment 20b. In certain embodiments, enriched streams inject an inert gas into reactant suspension in order to provide gas lift.

[0035] In some embodiments illustrated in Figures 2A and 2B, injector system 36 in is fluid communication with a cleaning stream 170. Injector system 36 includes at least one injector 137 in fluid communication with mixing vessel 38 and cleaning stream 170. Additionally, injectors 137 are configured for clean-in-place (CIP) processes. In certain embodiments, additional injectors 137a having cleaning streams 139a are disposed in the first compartment 20a for CIP processes. In an exemplary embodiment, injectors 137 are Alfa-Laval (Toftejorg) Nozzles or other rotary-type nozzle spray-injectors. Outlet valve 38b prevents contamination of mixing vessel 38. In certain embodiments, injector system 36 is controlled by outlet valve 38b. Outlet valve 38b is configured to seal mixing vessel from injector system 36. For example, pressurization of injector system 36 by injector 137 resistance with activates outlet valve 38b to close. Outlet valve 38b is configured to modulate pressure in injector system 36. In some embodiments, the injection of cleaning solution 170 is done in line 32 to clean additionally the CO saturation vessel.

[0036] While the preferred embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of the invention. The embodiments described and the examples provided herein are exemplary only, and are not intended to be limiting. Many variations and modifications of the invention disclosed herein are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited by the description set out above, but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims.

Claims

CLAIMSWe Claim:

1. A reactor system comprising: a shaft reactor, having a vertical depth to the shaft bottom that is at least twice the shaft width; a reactor volume, the reactor volume including a gas volume positioned vertically above a liquid volume, and sharing a gas-liquid interface, the liquid volume comprising a reactant suspension; a divider configured to separate the liquid volume into a first volume and a second volume, wherein the first volume and second volume comprise conduits within the reactor; a reactant enrichment & saturation system, the reactant enrichment saturation system fluidly coupled to the shaft reactor, configured for removing biomass and water from the shaft reactor, injecting enriching reactants into the return water, and re-introducing enriched saturated reactant into the shaft reactor; and a pump & venturi configured for re-injecting return water to the reactant enrichment system.

2. The system of claim 1 wherein the divider extends vertically from below the gas-liquid interface to above the shaft bottom, configured for directing a circulation within the liquid volume.

3. The system of claim 1 wherein the first volume is at least 51% and the second volume at least 49% or less to force a slow flow fast flow environment.

4. The system of claim 1 wherein the first flow volume is greater than the second flow volume.

5. The system of claim 1 , wherein the first flow volume comprises a downcomer.

6. The system of claim 1 wherein the first flow volume comprises a slow flow zone.

7. The system of claim 1 wherein the first flow volume comprises a reactant-depleted zone.

8. The system of claim 1 wherein the second flow volume comprises a riser.

9. The system of claim 8 wherein the riser comprises a gas-lift riser.

10. The system of claim 1 wherein the second flow volume comprises a fast flow zone.

11. The system of claim 1 wherein the second flow volume comprises a reactant-enriched zone.

12. The system of claim 1 wherein the gas-liquid interface comprises an operational fill level.

13. The system of claim 1 wherein the gas volume comprises a reactor head.

14. The system of claim 14 wherein the reactor head comprises a degassed chamber, including at least one means to remove product gas from the reactor head for processing.

15. The system of claim 14 wherein the product gas is a hydrogen (H₂) containing gas.

16. The system of claim 1 wherein the reactant enrichment system comprises a reactor outlet, disposed below the gas-liquid interface.

17. The system of claim 16 wherein the reactor outlet is disposed adjacent to the first volume.

18. The system of claim 16 wherein the reactor outlet is in fluid communication with an enrichment vessel after separation of biomass using centrifuges.

19. The system of claim 18 wherein the enrichment vessel is in fluid communication with a reactant source.

20. The system of claim 19 wherein the reactant source comprises a carbon monoxide (CO) containing gas.

21. The system of claim 16 wherein the reactor enrichment system further comprises an injecting means disposed below the gas-liquid interface, and above the reactor outlet.

22. The system of claim 21 wherein the injecting means comprises at least one nozzle disposed within second volume, and in fluid communication with second volume.

23. The system of claim 22 wherein injecting means is configured to provide gas-lift means to second volume.

24. The system of claim 21 wherein the injecting means comprises multiple nozzle injection system in the second volume,

25. The system of claim 24 wherein the multiple nozzle injections system comprises the capability of variating injection volume, concentration, pressure, temperature.

26. An CO gas saturation system for maximum water-gas saturation, comprising a shaft reactor, having a vertical depth to the shaft bottom that is at least twice the shaft width; a reactor volume, the reactor volume including a gas volume positioned vertically above a liquid volume, and sharing a gas-liquid interface, the liquid volume comprising a reactant suspension; a divider configured to separate the liquid volume into a first volume and a second volume, wherein the first volume and second volume comprise conduits within the reactor; a reactant enrichment & saturation system, the reactant enrichment saturation system fluidly coupled to the shaft reactor, configured for removing biomass and water from the shaft reactor, injecting enriching reactants into the return water, and re-introducing enriched saturated reactant into the shaft reactor; and a pump & venturi configured for re-injecting return water to the reactant enrichment system.