WO2010111639A1

WO2010111639A1 - Apparatus and method for applying a biocide to microorganisms during a conditioning, propagation and/or fermentation process

Info

Publication number: WO2010111639A1
Application number: PCT/US2010/028896
Authority: WO
Inventors: Jeffrey Dotson; Allen Ziegler
Original assignee: Resonant Biosciences, Llc
Priority date: 2009-03-26
Filing date: 2010-03-26
Publication date: 2010-09-30

Abstract

In an apparatus and method, biocide is applied in a conditioning, propagation and/or fermentation process. The apparatus comprises a biocide supply tank, a biocide rail wherein the biocide rail is fluidly connected to the biocide supply tank, at least one biocide injection line wherein each of the biocide injection line(s) is connected to the biocide rail, and a conditioning, propagation or fermentation process vessel fluidly connected to each of the biocide injection line(s). The biocide, which circulates within the biocide rail, is applied to the process vessel(s) via the biocide injection line(s). The method comprises supplying biocide in a tank, circulating biocide in a common biocide rail, injecting biocide into at least one of a conditioning, propagation and fermentation process vessel using an individual biocide injection line associated with each of the vessel(s).

Description

APPARATUS AND METHOD FOR APPLYING A BIOCIDE TO MICROORGANISMS DURING A CONDITIONING,

PROPAGATION AND/OR FERMENTATION PROCESS

Cross-Reference to Related Application(s)

[0001] This application relates to and claims priority benefits from U.S. Provisional Patent Application Serial No. 61/163,801 , filed March 26, 2009, entitled "Apparatus and Method for Applying a Biocide to Microorganisms During a Conditioning, Propagation and/or Fermentation Process". The '801 provisional application is hereby incorporated by reference herein in its entirety.

Field of the Invention

[0002] Generally, the technical field involves applying a biocide for use in a conditioning process, a propagation process and/or a fermentation process. Specifically, it involves applying chlorine dioxide to a conditioning, propagation and/or fermentation process using a common distribution system.

Background of the Invention

[0003] Producing microorganisms, such as yeast, fungi and bacteria, are used to produce a number of fermentation products, such as industrial grade ethanol, distilled spirits, beer, wine, pharmaceuticals and nutraceuticals (foodstuff that provides health benefits, such as fortified foods and dietary supplements). [0004] Most of the producing microorganisms used in distilleries and fuel ethanol plants are manufactured through a propagation process. Propagation involves growing a large quantity of producing microorganisms from a small lab culture of that microorganism. During propagation, the producing microorganisms are provided with the oxygen, nitrogen, sugars, proteins, lipids and ions that are desirable for growth through aerobic respiration.

[0005] The producing microorganisms can then undergo conditioning. The objective of both propagation and conditioning is to deliver a large volume of the producing microorganisms to the fermentation tank with high viability, high budding and a low level of infection by undesirable microorganisms. However, conditioning is unlike propagation in that it does not involve growing a large quantity from a small lab culture. During conditioning, conditions are provided to re-hydrate the producing microorganisms, bring them out of hibernation and allow for anaerobic growth and reproduction.

[0006] Following propagation or conditioning, the producing microorganisms enter the fermentation process. The microorganisms are combined in an aqueous solution with fermentable carbohydrates. The producing microorganisms consume the sugars, converting them into aliphatic alcohols, such as ethanol.

[0007] During these three processes the producing microorganisms can become contaminated with bacteria or other undesirable microorganisms. This can occur in one of the many vessels used in propagation, conditioning and/or fermentation. This includes propagation tanks, conditioning tanks, starter tanks, fermentations tanks, piping and heat exchangers between these units.

[0008] Bacterial or microbial contamination reduces the fermentation product yield and can produce unwanted chemical byproducts, which can cause spoilage of entire fermentation batches. As little as a one percent decrease in ethanol yield is highly significant to the fuel ethanol industry. In larger facilities, such a decrease in efficiency will reduce income from 1 million to 3 million dollars per year. Removing these bacteria or other undesirable microorganisms allows the producing microorganisms to thrive, which results in higher efficiency.

[0009] Biocides can be applied to producing microorganisms during propagation, conditioning and/or fermentation. Chlorine dioxide (ClO₂) is an effective and powerful biocide, disinfectant and oxidizer. Applicants have shown ClO₂ to be effective at treating microorganisms during propagation, conditioning and/or fermentation in United States Patent Application Serial Number 11/626172, filed on January 23, 2007, entitled "Apparatus and Method for Treatment of Microorganisms during Propagation, Conditioning and Fermentation" which is incorporated herein in its entirety. [0010] Previously, biocides have been applied to propagation, conditioning and/or fermentation systems using a chemical storage tank connected to a pump for each individual injection point. The pumps could then be controlled individually with their own piping to each desired treatment point. In another previous method, solenoid valve headers were used. Solenoid valve headers allow for multiple streams from a single pump. In yet another previous method, manual flow controlling valves have been used.

Summary of the Invention

[0011] The present apparatus and method allows for flexibility of adding treatment locations without having to redesign each system or add additional pumps or controls to the equipment. The present apparatus and method can employ a common pipe header, flow controlling valves and logic controller to maintain precise flow and pressure in the propagation, conditioning and/or fermentation system.

[0012] One embodiment of the present apparatus for applying a biocide to at least one of a conditioning process, a propagation process and a fermentation process, the apparatus comprises (a) a biocide supply tank; (b) a biocide rail wherein the biocide rail is fluidly connected to the biocide supply tank; (c) at least one biocide injection line wherein each of the at least one biocide injection lines is connected to the biocide rail; and (d) at least one of a conditioning process vessel, a propagation process vessel and a fermentation process vessel fluidly connected to each of the at least one biocide injection line wherein the biocide flows within the biocide rail and is applied to the at least one process vessel via the one at least biocide injection line.

[0013] The apparatus can further comprise a flowmeter on each of the at least one biocide injection line. The apparatus can further comprise a motorized flow control valve on each of the at least one biocide injection line past the flowmeter. The apparatus can further comprise a centrifugal pump on each of the at least one biocide injection line past the motorized flow control valve. The apparatus can further comprise a flow control valve on each of the at least one biocide injection line before the flowmeter. The apparatus can further comprise a second flow control valve on each of the at least one biocide injection line after the motorized flow control valve. The apparatus can further comprise a back pressure valve on each of the at least one biocide injection line after the second flow control valve.

[0014] The apparatus of can further comprise a rail supply pump on the biocide rail. The apparatus can further comprise a rail inlet pulsation dampener fluidly connected to the biocide rail. The apparatus can further comprise a rail outlet pulsation dampener fluidly connected to the biocide rail. The apparatus can further comprise a rail flow verification flowmeter on the biocide rail. The apparatus can further comprise a pressure sensor on the biocide rail. The apparatus can further comprise a motorized ball valve on the biocide rail.

[0015] The biocide supply tank can be a chlorine dioxide solution generator.

[0016] The apparatus of claim can further comprise a common pipe header that maintains a constant pressure in the biocide rail. The apparatus can further comprise a flow controlling valves for further maintaining the constant pressure in the biocide rail. The apparatus can further comprise a logic controller for further maintaining the constant pressure in the biocide rail.

[0017] The current method of applying a biocide to at least one of a conditioning process, a propagation process and a fermentation process, the method comprises (a) supplying the biocide in a tank; (b) circulating the biocide in a common biocide rail; and (c) injecting the biocide into at least one of a conditioning, process vessel, a propagation process vessel and a fermentation process vessel using an individual biocide injection line associated with each of the at least one process vessel. These steps can be performed sequentially.

Brief Description of the Drawings

[0018] FIG. 1 illustrates an embodiment of the present apparatus for applying a biocide for use in a conditioning, propagation and/or fermentation process.

[0019] FIG. 2 illustrates a blow up view of an embodiment of the biocide injection line of the present apparatus for applying a biocide for use in a conditioning, propagation and/or fermentation process.

Detailed Description of Preferred Embodiment(s)

[0020] In the present apparatus and method, a biocide is applied to a conditioning process, a propagation process and/or a fermentation process. Specifically, in the present apparatus and method, chlorine dioxide is applied to a conditioning, propagation and/or fermentation process using a common distribution system.

[0021] Previously the application of biocides to propagation, conditioning and fermentation systems involved the use of a chemical storage tank connected to a pump for each individual injection point. The pumps would then be controlled individually with their own piping to each desired treatment location. This method allowed for controlling each pump to output a controlled amount of solution. This process would incur design changes, in order to add pumps and/or treatment locations. Design changes are undesirable because they increase time and money spent adding the new pumps and/or treatment location. [0022] Solenoid valve headers were also used to reduce the number of pumps. The solenoid valve headers allow for multiple streams from a single pump. When treatment locations are added, precise solution application was not provided. This is because the pump output was not adjusted accordingly to make up for pressure losses caused by adding new treatment points. Precise solution application is desirable in applying biocide to propagation, conditioning and fermentation systems because adding too little biocide may be ineffective while adding too much biocide can kill or stress the desirable producing microorganisms, such as yeast used to produce ethanol.

[0023] Manual flow controlling valves were also used in the past. These also do not adjust the pump output accordingly when changes are made or when the process conditions change. This makes precise solution application difficult, which is undesirable as discussed above.

[0024] The current method and apparatus uses a common distribution from a single pump. The single pump pumps biocide through a common biocide rail. The common biocide rail is connected to individual biocide injection line, which attach to the various treatment vessels. This allows for flexibility of adding treatment locations without having to redesign each system or add additional pumps or controls to the equipment. The current method and apparatus uses a common pipe header that maintains a constant pressure. This common pipe header can utilize flow controlling valves and a logic controller to maintain precise flow to various points.

[0025] The current method and apparatus controls pressure in the rail by adjusting a valve dependent upon process conditions to maintain the desired pressure. The current method and apparatus also controls the flow of solution to each treatment point by monitoring a flow feedback signal and adjusting a flow control valve to maintain a desired flow.

[0026] The current method and apparatus have been able to provide an actual dose of biocide to each injection point, whether singular or multiple points were being treated, to within 3% of the desired dose.

[0027] The current method and apparatus decreases the components and footprint of the overall conditioning, propagation and/or fermentation system while allowing for flexible biocide treatment. The current method and apparatus allows for multiple points of treatment without incurring engineering changes or adding additional pumps. This reduces the cost of the overall conditioning, propagation and/or fermentation system for each additional treatment point. This also reduces the electrical power consumption of the system for each treatment point. [0028] FIG. 1 illustrates an embodiment of the present apparatus for applying a biocide for use in a conditioning, propagation and/or fermentation process 100. The apparatus comprises a biocide supply tank 102; a biocide rail 104 wherein the biocide rail 104 is fluidly connected to the biocide supply tank 102; at least one biocide injection line 106 wherein each of the at least one biocide injection line(s) 106 is connected to the biocide rail 104; and a conditioning, propagation and/or fermentation process vessel 108 fluidly connected to each of the biocide injection line(s) wherein the biocide flows within the biocide rail 104 and is applied to the process vessel(s) 108 via the biocide injection line(s) 106.

[0029] The current apparatus comprises a biocide supply tank 102. The biocide supply tank supplies the biocide rail 104 with a biocide. In one embodiment the biocide supply tank 102 is a chlorine dioxide solution generator. Since ClO₂ gas can decompose explosively, it is typically produced on-site. There are a number of methods of producing ClO₂ gas having a known purity, which are known to persons familiar with the technology involved here. One or more of these methods can be used. The ClO₂ gas is then dissolved in a solvent in order to create a ClO₂ solution. ClO₂ gas is readily soluble in water.

[0030] ClO₂ gas can be produced using electrochemical cells and a sodium chlorite or sodium chlorate solution. An equipment based sodium chlorate/hydrogen peroxide method also exists. Alternatively, non-equipment based binary, multiple precursor dry or liquid precursor technologies can be used. Examples of non- equipment based methods of ClO₂ generation include dry mix chlorine dioxide packets that include both a chlorite precursor packet and an acid activator packet. Other such processes include, but are not limited to, acidification of sodium chlorite, oxidation of chlorite by chlorine, oxidation of chlorite by persulfate, use of acetic anhydride on chlorite, use of sodium hypochlorite and sodium chlorite, use of dry chlorine/chlorite, reduction of chlorates by acidification in the presence of oxalic acid, reduction of chlorates by sulfur dioxide, and the ERCO R-2^®, R-3^®, R-5^®, R-8^®, R- 10^® and R- 11^® processes, from which ClO₂ is generated from NaClθ₃ in the presence of NaCl and H₂Sθ₄ (R-2 and R-3 processes), from NaClO₃ in the presence of HCl (R-5 process), from NaClO₃ in the presence of H₂SO₄ and CH₃OH (R-8 and R-IO processes), and from NaClO₃ in the presence OfH₂O₂ and H₂SO₄ (R-11 process).

[0031] Here, three methods will illustrate some possibilities. In the first method, chlorine reacts with water to form hypochlorous acid and hydrochloric acid. These acids then react with sodium chlorite to form chlorine dioxide, water and sodium chloride. In a second method, sodium hypochlorite is combined with hydrochloric or other acid to form hypochlorous acid. Sodium chlorite is then added to this reaction mixture to produce chlorine dioxide. The third method combines sodium chlorite and sufficient hydrochloric acid.

[0032]

[0033] The biocide supply tank 102 is fluidly connected to a biocide rail 104. The biocide circulates within the biocide rail 104. In one embodiment the biocide rail 104 is a dead headed rail. The biocide rail 104 supplies the chlorine dioxide to the application points. The biocide rail 104 maintains a constant pressure and as this pressure is reduced due to delivery of chemical to the application point the rail supply pump actuates until a pressure equilibrium is obtained.

[0034] In various embodiments of the current apparatus other equipment can be located on the biocide rail 104. For example in certain embodiments a rail supply pump, a rail inlet pulsation dampener, a rail outlet pulsation dampener, a rail flow verification flowmeter, a pressure sensor, and/or a motorized ball valve can be fluidly connected or located on the biocide rail 104.

[0035] The biocide rail 104 is fluidly connected to at least one biocide injection line. The biocide flows from the biocide rail 104 to the biocide injection line(s) 106. In various embodiments of the current apparatus other equipment can be located on the biocide injection lines 106. For example in certain embodiments a flowmeter 110 can be located on each of the biocide injection line(s). A motorized flow control valve 1 14 can be located on each of the biocide injection line(s) 106 past the flowmeter 110. A centrifugal pump 116 can be located on each of the biocide injection line(s) 106 past the motorized flow control valve 114. A flow control valve 118 can be located on each of the biocide injection line(s) 106 before the flowmeter 110. A second flow control valve 120 can be located on each of the biocide injection line(s) 106 after the motorized flow control valve 1 14. A back pressure 122 valve can be located on each of the biocide injection line(s) 106 after the second flow control valve 120.

[0036] Each biocide injection line 106 is fluidly connected to a conditioning, propagation and/or fermentation process vessel 108. The biocide is applied to the process vessels 108 via the biocide injection lines 106. Biocide can be added at various points in the propagation, conditioning and/or fermentation processes to kill unwanted microorganisms and promote growth and survival of the desirable microorganisms. Biocide can be added as an aqueous solution or a gas. The biocide can be added during propagation, conditioning and/or fermentation. For example, the biocide can be added to cook vessels, fermentation tanks, propagation tanks, conditioning tanks, starter tanks, mash headers, mash heat exchangers, carbon dioxide scrubbers, cook water, thin stillage, whole stillage or during liquefaction. The biocide solution can also be added to the interstage heat exchange system or heat exchangers.

[0037] The biocide rail 104 and biocide injection lines 106 can also be used to accommodate supplying other products to the propagation, conditioning and/or fermentation process. These other product include, but are not limited to, enzymes, yeast & yeast nutrients, antimicrobials (such as antibiotics), and other processing aids (such as de-foamers, hydrogen peroxide, or other food contact or food additive products). An additive tank 124containing the other products can be attached to the biocide rail 104. The other products can then flow through the biocide rail and biocide injection lines into the conditioning process vessel, the propagation process vessel and/or the fermentation process vessel.

[0038] In an embodiment of the present method, a biocide is applied in a conditioning, propagation and/or fermentation process. The method includes the steps of supplying biocide in a tank 102, circulating biocide in a common biocide rail 104, and injecting biocide into at least one a conditioning process vessel, a propagation process vessel and/or a fermentation process vessel 108 using an individual biocide injection line 106 associated with each of the vessel(s).

[0039] While particular elements, embodiments and applications of the present invention have been shown and described, it will be understood, of course, that the invention is not limited thereto since modifications can be made by those skilled in the art without departing from the scope of the present disclosure, particularly in light of the foregoing teachings.

Claims

What is claimed is:

1. An apparatus for applying a biocide to at least one of a conditioning process, a propagation process and a fermentation process, the apparatus comprising:

(a) a biocide supply tank;

(b) a biocide rail wherein said biocide rail is fluidly connected to said biocide supply tank;

(c) at least one biocide injection line wherein each of said at least one biocide injection lines is connected to said biocide rail; and

(d) at least one of a conditioning process vessel, a propagation process vessel and a fermentation process vessel fluidly connected to each of said at least one biocide injection line; wherein said biocide flows within said biocide rail and is applied to said at least one process vessel via said one at least biocide injection line.

2. The apparatus of claim 1 further comprising a flowmeter on each of said at least one biocide injection line.

3 The apparatus of claim 2 further comprising a motorized flow control valve on each of said at least one biocide injection line past said flowmeter.

4 The apparatus of claim 3 further comprising a centrifugal pump on each of said at least one biocide injection line past said motorized flow control valve.

5. The apparatus of claim 4 further comprising a flow control valve on each of said at least one biocide injection line before said flowmeter.

6. The apparatus of claim 5 further comprising a second flow control valve on each of said at least one biocide injection line after said motorized flow control valve.

7. The apparatus of claim 6 further comprising a back pressure valve on each of said at least one biocide injection line after said second flow control valve.

8. The apparatus of claim 1 further comprising a rail supply pump on said biocide rail.

9. The apparatus of claim 8 further comprising a rail inlet pulsation dampener fluidly connected to said biocide rail.

10. The apparatus of claim 9 further comprising a rail outlet pulsation dampener fluidly connected to said biocide rail.

11. The apparatus of claim 10 further comprising a rail flow verification flowmeter on said biocide rail.

12. The apparatus of claim 1 1 further comprising a pressure sensor on said biocide rail.

13. The apparatus of claim 12 further comprising a motorized ball valve on said biocide rail.

14. The apparatus of claim 1 wherein said biocide supply tank is a chlorine dioxide solution generator.

15. The apparatus of claim 1 further comprising a common pipe header.

16. The apparatus of claim 15 wherein the common pipe header maintains a constant pressure in the biocide rail.

17. The apparatus of claim 16 wherein a flow controlling valves further maintains the constant pressure in the biocide rail.

18. The apparatus of claim 16 wherein a logic controller further maintains the constant pressure in the biocide rail.

19. A method of applying a biocide to at least one of a conditioning process, a propagation process and a fermentation process, the method comprising:

(a) supplying said biocide in a tank;

(b) circulating said biocide in a common biocide rail; and (c) injecting said biocide into at least one of a conditioning, process vessel, a propagation process vessel and a fermentation process vessel using an individual biocide injection line associated with each of said at least one process vessel.

20. The method of claim 19 wherein the steps are performed sequentially.