Treatment of organic substrates in watery liquids with plasma generated NOX at a ph range of 4-7, eliminating the emissions of ammonia and methane and pathogenic activity

Abstract

A process, system, and method for treating an alkaline solution in an acidic liquid, where the alkaline solution comprises nitrogen compounds, the acidic liquid comprises NOx compounds and radicals, the process and system is a cyclic process and system, charging feed gas and the alkaline solution into the cyclic process, cycling the acidic liquid and discharging product solution, where the process is an absorption process, absorbing Nitrogen Oxide Gases, NOx, from the gas phase; the method is making use of the process or system and thereby inhibiting biological and chemical formation of ammonia, methane, carbon dioxide, and hydrogen sulfide, the final product being spread to the fields.

Description

Treatment of organic substrates in watery liquids with plasma generated NOx at a pH range of 4-7, eliminating the emissions of ammonia and methane and pathogenic activityTechnical Field

[0001] The present invention relates to treatment of organic substrates in watery liquids by absorbing Nitrogen Oxides, NOx, eliminating the formation and further emissions of ammonia, methane, hydrogen-sulfide, carbon-dioxide as well as reducing pathogens and pathogenic activity. The bio-degradation products from the organic substrate form an alkaline solution containing components like ammonium, ammonium-bi-carbonate solution or slurries with the organic substrates. The invented process is a neutralization or acidification and applies to any mineral or organic substance in a watery solution. The invention comprises an absorption system which is facilitating the oxidation rate from NO to NO2 and further, which is a significant bottleneck in any process for absorption of NOx.Background Art

[0002] In a traditional nitric acid process the absorption process is slowed down because there is no NOx component which can be absorbed into a watery solution without converting part of the NOx back to the relatively inert NO gas. The stoichiometric explanation is shown in the equation below where the reactions in the gas phase is set up in equation I, II and III, and the first round of gas-liquid film absorption reactions is set up in equation IV, VI and VII, and the main reaction in liquid bulk phase is equation VIII.

[0003] The oxidation reactions in gas phase:3NO2(g) + H2O 2HNO3(aq) + NO(g) (VIII)

[0005] The reaction to nitric acid in the watery phase:4NO(g) + 302(g) + 2H2O 4HNO3(aq) (IX)

[0006] The main reaction between alkaline and the acidic components in the watery phase:

[0007] The stoichiometry in the reactions from (I) to (VIII) is clearly illustrating that the NO must re-oxidize and reabsorbed at every stage throughout the absorption process. The theoretical number of stages is easily becoming 70. The liquid flow is effectively recycling HNO2 down or back to the more concentrated stages where reaction (VIII) is producing HNO3 and NO gas. These stages need a high retention time in the gas phase for the NO to be oxidized to NO2 according to reaction in equation (I).

[0008] The reaction in equation I is a three-body reaction which is very sensitive to the concentration of NO gas. At 0,5% NOx in air at atmospheric ambient conditions need retention time of 10 minutes to convert 60% of the NO to the more reactive gasses NO2, N2O4, N2O3 and HNO2.

[0009] In other words, and important for the understanding of the present invention, the formation of nitric acid takes place in two stages:Oxidation : 2NO(g) +Absorption : 3NO2(g) + H2O 2HNO3(aq) + NOf (VIII) i.e. via a relatively slow gas phase reaction (I), which stops at NO2, and a heterogeneous absorption reaction (VIII), in which 1 / 3 of the reacted nitrogen is returned to the initial oxidation state, so that for this part the under technical conditions essentially timedetermining reaction (I) must run again. In reaction (I) the equilibrium is almost completely on the side of NO2, up to approx. 200 °C. The oxidation time of NO / air mixtures at about 30 °C depending on the initial NO content and the degree of conversion is practicable in the sense of the present invention at initial concentrations of more than 6% by volume, see below Figure.This fact corresponds with an important feature of the present invention - the reaction in the gas phase (eq. I), mainly above the common absorption solution, where the gas phase contains (concentrated) NO gas compared to the overall NO concentration through the main process.

[0010] Reactions (X) and (XI) are typical acid-base neutralization reactions. The main component representing the volatile ammonia and CO2 content in the slurry is ammonium-bi-carbonate (ABC) buffering around pH 7,8 - 8,4. The origin of the ABC is first urea and later proteins. The main source of fresh urea (NH2)2=CO is livestock or human urine. The urea will be hydrolyzed by the urease enzyme within a few hours.

[0011] The proteins require days before being biologically converted to ammonium and carbonates. After 3-6 months storage, most of the organic substrates will be biologically degraded, consumed, and finally convert to minerals, gasses and soluble and volatile organic components.

[0012] The natural biological processes combined with inorganic equilibrium convert organic substrates in a watery solution to soluble minerals and emissions of ammonia, methane, carbon dioxide and sulfides.

[0013] The losses of ammonia, methane and carbon dioxide from organic substrates is a function of storage conditions and biological processes decomposing, consuming, and converting the organic substrate to simpler chemical components. In soil chemistry the process is called mineralization, and it is the way organic nutrients are converted to crop available mineral nutrients.

[0014] Prior art has tried to stop this unwanted loss mechanism from taking place before the organic substrate is recycled and applied the field as fertilizer and soil improver. The methods comprise:Composting with a surplus of organically available carbon in order to biologically bind the nutrients until applying the total mass to the field.Storing the substrate cold and contained to minimize the biological process and prevent the volatile gasses from escaping with ambient air. The method of containing the volatile gasses is only a way to delay the evaporation, and the volatile gasses will end up in the air according to the C / N ratio determining the pH and volatility of the ammonia and carbon dioxide. Equation (XII) is showing how the urea in the urine is losing its ammonium as ammonia gas NHs(g). The stable buffering ratio of C / N is the ABC at pH 7,8. The high volatility of the CO2 will always be there as a driving force pulling ammonia along when the surface to air is increased as when spreading.

[0015] Prior patent art is conceptual and has not addressed, nor presented any solution to the practical detailed processing challenges like the oxidation and reabsorption of the NO gas in the absorption process, and thereby also controlling the concentration of HNO2 in the final product.

[0016] Prior scientific art has applied plasma activated air or plasma activated water to treat organic substrates in watery solutions. The applied plasma is typically a Low Temperature and or None-Equilibrium-Plasma giving low concentrations of (re)active species of nitrogen and oxygen. The specific energy consumption is however high and typically back calculated to be 200-2000kWh / kg of nitrate-N or oxygen-O. The low concentrations of reactive species give low absorption efficiencies and low yield of reactive nitrogen in the watery solution. The overall reaction to NOx can be described as triggered by electron excitation and splitting of the oxygen molecule O. Prior scientific art, result in only a small part of the oxygen is reacting with N2 gas to form NOx. In prior scientific art, the main role of reactive oxygen, is to form O3 in the gas and H2O2 in the watery phase.

[0017] Prior patent art is applying commercial acids for the purpose of stopping ammonia losses and methane formation but is only partially succeeding. Commercial nitric acid of 58-70% by wt., or locally produced nitric acid in concentration of 1-30% by wt., is a reactive and dangerous product of pH<l. At this pH, the acid is giving a violent loss-making reaction with the organic material, releasing a mixture of NOx, NH3 together with an ammonium-nitrite / nitrate mist.

[0018] The application of only nitric acid in combination with any other acid to acidify manure, organic waste and bio-residue or AD is not able to stop the formation of N2O from de-nitrification loss mechanism.

[0019] The application of nitric acid solutions in combination with nitrous acid to acidify manure, organic waste and bio-residue / digestate, has over time also proved not effective in stopping the biological activity, disinfecting nor removing smell and content of poisonous gases and potentially carcinogenic gases.Summary of invention

[0020] The present invention relates to: a Process for treating alkaline solutions as described in independent claim 1, a System for treating alkaline solutions as described in independent claim 16, and a Method for treating organic substrates as described in independent claim 24.Further embodiments of the process, system and method according to the present invention are described in the dependent patent claims.

[0021] Generally speaking, the present invention relates to treatment of organic substrates in watery solutions by absorbing Nitrogen Oxide Gases, NOx, stopping the biological formation of and further emissions of ammonia, methane, carbon dioxide and hydrogen sulfide as well as reducing pathogens and pathogenic activity. The absorption of NOx produces a combination of Reactive Oxygen Species (ROS) and the Reactive Nitrogen Species (RON) lowering the pH to between 4 and 6 and reducing the emissions of NH3 and CH4 by 90-99%. The organic substrate(s) may be selected from manure, pretreated manure, urine, livestock slurry, organic waste, pretreated organic waste, biogas residue, and digestate such as anaerobic digestate (AD).

[0022] The present invention is addressing and solving key challenges in using nitrates for acidification and biological stabilization of a variety of concentrations of manure in urine, livestock slurries, organic waste solutions and biogas residue or anaerobic digestate, AD.

[0023] The absorption of NOx gas from plasma into the watery organic substrate solutions takes place in a horizontal stepwise process, where the oxidation of NO to NO2 is accelerated by holding back the NO gas formed by the NO2 and N2O3 gas absorption. The formed NO gas in the absorption reactions is held back in a stagnant gas volume where the concentration of NO is increased compared to the overall NO concentration through the main process.

[0024] The increased NO concentration in air is shifting the equilibrium towards NO2.2NO(g) + 02(g) 2NO2(g) (I)The absorption mechanism is thought to be driven by the formation of N2O3(g).

[0025] The equilibrium is easily shiftable to both sides, and since the N2O3O) is both soluble and reactive in the watery phase, the reactivity of the N2O3 is considered both to be direct as well as a result of the formation of HNO2.N2O3(aq) + H2O 2HNO2(aq) 2H+ + 2NO2’ (V)

[0026] This dual mechanism of bioactive N2O3 and HNO2 is effectively inhibiting and destroying vital biological molecules and its functions as it can move through membranes both in the ionic form and in the molecular neutral form. The nitrous gas radicals and nitrous liquid radicals are all known to react with amino-organic- substrates and subsequently also with the DNA of biology.

[0027] The invention consists of several absorption steps arranged horizontally, and each absorption step consists of an absorption section where the NOx containing gas is brought into contact with the absorption liquid. The contact surface between gas and liquid can be established by any known engineering principle like falling film, packed segment, bubble tray, liquid spray and venturi, as long as the gas is separated from the liquid and the liquid brought down into the common liquid bulk solution. The separated gas from each absorption stage is brought to the next absorption stage where more of the NOx gas (II, V) is absorbed due to the higher pH.

[0028] Each absorption step can be operated co-current or counter current. Retention time of gas and exposed surface of liquid are key points in securing an NOx absorption efficiency of 99%.

[0029] The number of stages in the horizontal absorption system can, at a low cost, be significantly reduced compared to a standard vertical tower. The increased concentration of NO in the stagnant gas volume and the effect of the alkaline organic and mineral component in the absorbent is increasing the effect of the Reactive Oxygen Species (ROS) and the Reactive Nitrogen Species (RON).

[0030] The invented process maintains the radical activity both in the gas and in the watery phase. The process further maintains a redox potential and a pH level sufficient to maintain the direct disinfecting effect from the radicals formed in the plasma, and the long-term inhibition effect from the pH and radical sources molecules as ozone, peroxide, peroxy-nitrite and peroxy-nitrate as well as stopping the main chemical loss mechanism starting from excess nitrites.

[0031] Recent research suggests that ROS / RNS are significant and perhaps even central actors in the actions of antimicrobial and anti-parasite drugs, cancer therapies, wound healing therapies and therapies involving the cardiovascular system.

[0032] The present invention and some embodiments are also described in the claims.Brief description of drawings

[0033] Figure 1 shows a simple embodiment of the system for treatment of organic substrates in watery solutions, absorbing Nitrogen Oxide Gases, and stopping the biological formation of and further emissions.

[0034] Figure 2 shows a preferred embodiment of the system with two middle absorption towers.

[0035] Figure 3 is the embodiment as in figure 1 and shows the pH value (range) in the different parts of, and partially some chemical compounds within the process and the system.

[0036] Figure 4 shows the method for treatment of organic substrates which uses the described process or system.

[0037] Figure 5 is the embodiment of the system as in figure 1 and shows substances of the system.

[0038] Figure 6 is the embodiment of the system as in figure 2 and shows substances of the system.

[0039] Reference ListTechnical feature two digits bold xx, substances three digits xxx01 feed, of 001001 feed gas or feed air, containing the NOx gas02 mixer03 first absorption tower04 middle absorption tower04.1 1st middle absorption tower04.2 2ndmiddle absorption tower04.3 ... etc.05 last absorption tower06 absorption solution tank07 baffle plate08 discharge of 008008 off gas, cleaned09 compartment of 009009 acidic absorption solution10 compartment of 010010 product absorption solution11 feed, flow of Oil on alkaline solution12 discharge, flow of 012012 product acidic solution13 feed, flow of 013013 stored product solution, from product solution tank 2914 discharge, flow of 014014 product solution, to product solution tank 2915 feed, of 015015 oxidation gas (like air, O2, O3, ...)16 circulation pump17 circulation pump18 suction flow to circulation pump 16018 processed acidic absorption solution19 feed, flow of 019019 acidic absorption liquid20 suction flow to circulation pump 1721 feed, flow of 021021 product absorption liquid22 feed, flow of 022022 gas-solution-liquid23 discharge / feed, flow of 023023 off gasses from absorption tower 0324 discharge / feed, flow of 024024 off gasses from absorption tower 0424.1 discharge / feed, flow of 024.1024.1 off gasses from absorption tower 04.124.2 discharge / feed, flow of 024.2024.2 off gasses from absorption tower 04.225 discharge / feed, flow of 025025 absorption solution, leaving at the bottom of absorption tower 0326 feed, of 026026 head space gas, entering at the bottom of absorption tower 0327 feed, flow of 027027 acidic absorption liquid 019, to mixer 0228 plasma generator29 product solution tank30 cow inside the barn-house 3131 house032 urine033 feces34 slurry cellar034 slurry; containing urine, feces, and product acidic solution 012035 gasses being released from the slurry36 ventilation036 ventilation air, extracted from the headspace of the slurry cellar 34 037 gas being released from product solution tank 29 038 slurry being spread to the fieldDetailed description of the invention

[0040] In the context of the invention, NOx is understood as NO, NO2, N2O3, N2O4, HNO2 and NO(x+l) er NO2, N2O3, N2O4, HNO2, and NO is understood as NO. In the context of the invention, it is also understood that mentioned pH values and ranges can deviate with up to 0,5 from the mentioned values and ranges.Description of the Process

[0041] The present invention relates to a process and system for treatment of organic substrates in watery solutions by absorbing Nitrogen Oxide Gases, NOx.

[0042] For a better understanding of the process, reference is made to figure 1, 2, 5 and 6 and the reference numbers of the solutions, liquids, and gases.

[0043] It is disclosed a process of treating alkaline solutions, where the alkaline solution is again pre-treated manure or organic waste. In some embodiments the alkaline solution is pre-treated, partially pre-treated or untreated manure, urine, feces, organic waste, and the like, or a mineral solution. In some embodiments the alkaline solution is technical.

[0044] The main pre-treatment of manure or organic waste is filtering, to receive an alkaline solution Oil mainly consisting of one phase. In some embodiments the pretreated alkaline solution is watery dispersion of different phases, including solids, liquids, and / or gasses.

[0045] In an embodiment, the pre-treated manure or organic waste, the alkaline solution (pH 7-8,5) Oil, is added to processed acidic absorption solution (pH 4,5-5) 018, resulting in an acidic absorption liquid 019 (pH 5-7) and / or 027 (pH 5-7).

[0046] The overall process of the present invention is absorbing NOx. In a preferred embodiment, the NOx is produced from air and the NOx / air mixture 001 is used in the process, providing the main reactants NOx and O2. In a preferred embodiment the NOx / air mixture is produced in a plasma generator, such as an electric arc, microwave, or any other type of plasma generator.

[0047] The process of treating the alkaline solution Oil comprises forcing the oxidation of NO to NO2. The oxidation is forced by an increasing NO concentration, an increasing pH and, in some embodiment, by adding of further oxidation gas, like air, O2, O3, or other oxidation agents, to the process.

[0048] The process comprises absorbing of the NOx and oxidation of NO to NO2 within a pH from 4 to 6, preferred from 4,5 to 5,5, at ambient temperature and pressure.

[0049] In the beginning of the process, the alkaline solution Oil is feed to the processed acidic absorption solution 018 forming an acidic absorption liquid 019 and 027, with pH 5-7. The acidic absorption liquid 027 is mixed with the NOx / air mixture 001 forming a gas-solution-liquid (pH 4-4,5) 022, and the absorption process starts with absorbing NOx, more precisely, absorbing NO2, in turn starting the release of NO from the solution.3NO2(g) + H2O 2HNO3(aq) + NO(g) (V)In the reaction equations the (different) solutions are often simplifying presented as H2O.

[0050] During the mixing with NOx / air, the pH in 027 decreases from 4,5-5 to 4-4,5, due to the neutralization of the alkali by the formed nitric acid.

[0051] In a first stage of the absorption process, the gas-solution-liquid 022 is added to further acidic absorption liquid 019 and mechanically treated, the liquid is absorbing NO2, N2O4, N2O3, HNO2 and releasing NO gas. The gasses are partially from the gas-solution- liquid 022 and partially from the gas phase 026 (the concentrated NOx oxidized to NO2) over and from the common absorption solution 009-010. The gas and liquid phases are separated into a gas-phase 023 containing air and NOx, and a liquid phase, the absorption solution 025.

[0052] After the first stage, the liquid phases, the absorption solutions, have an increased nitrate and nitrite content, and are released into the common absorption solution 009-010.

[0053] During the first stage, the pH of 022 decreases within the range of 4-4,5 due to further absorption of NO(x+l) which is forming nitric acid.

[0054] At the end of the first stage and in a preferred embodiment, the gas-phase 023, the off-gas, contains <2 Vol% NOx and <1 Vol% NO and is released to the next stage.

[0055] Due to said increasing nitric acid concentration, towards the end of the first stage, when the liquid is released into the common absorption solution, more NO is released from the common absorption solution, according to eq. (V), to the gas-phase 026 above the common absorption solution.3NO2(g) + H2O 2HNO3(aq) + NOf (V)

[0056] The gas phase above the common absorption solution therefore contains (concentrated) NOx gas compared to the overall NOx concentration through the main process. The higher NOx concentration is driving the oxidation of NO to NO(x+l). In an embodiment a flow of air or oxygen 015 can be added to the gas phase 026 above the common absorption solution 009-010 accelerating the formation of NO2, eq. (I)

[0057] The gas phase 026 above the common absorption solution is receiving most of its NO from the first stage and having a maximum retention time before re-entering the gas phase in the first stage, meeting the liquid phase.

[0058] The absorption mechanism is thought to be driven by the formation of N2O3(g) and HNO2.NO(g) + NO2(g) N2O3(g) (II)

[0059] In a second stage of the absorption process, the off gas 023 from the first stage and acidic absorption liquid 019 is mechanically treated, the solution is absorbing NO2, N2O4, N2O3, HNO2 and some of the NO gas.

[0060] The off gas 023 from the first stage, meeting acidic absorption liquid 019 in the second stage, has a lower NOx amount as the gas from the gas-solution-liquid 022 meeting the acidic absorption liquid 019 in the first stage, and accordingly, a lower potential to neutralize the alkaline in the second stage. Accordingly, the pH in the second stage (4,5-5) is higher as the pH in the first stage (4-4,5).

[0061] During the mechanical treatment of the second stage, the components are separated into a gas-phase 024 (off gas) containing air, NOx, and a liquid phase, the absorption solution.

[0062] After the second stage, the liquid phase, the absorption solution, has an increased nitrate and nitrite content, and is released into the common absorption solution 009-010.

[0063] At the end of the second stage and in a preferred embodiment, the gas-phase amount, the off gas 024, is reduced and released to the next stage.

[0064] In a third stage of the absorption process, the off gas 024 from the second stage is added to product absorption liquid 021 (pH 5-6), optionally also to acidic absorption liquid 019 and mechanically treated. The liquid is absorbing NO(x+l) and most of the residue NO gas, due to the increased pH. The percentage of the acidic absorption liquid 019 and the product absorption liquid 021 is determined to adjust the pH of the liquid to 4,5-6 before the treatment with the off gas 024.

[0065] The off gas 024 from the second stage, meeting absorption liquid 019 and product absorption liquid 021 in the third stage, has a lower NOx amount as the off gas from the first stage meeting the acidic absorption liquid 019 in the second stage, and accordingly, a lower potential to neutralize the acidic absorption liquid or product absorption liquid in the third stage. Accordingly, the pH in the third stage (pH 5,5-6) is higher as the pH in the second stage (pH 4,5-5).

[0066] During the mechanical treatment, the components are separated into a clean gas-phase 008 (off gas) ideally without NOx, and NO, and a liquid phase, the absorption solution.

[0067] After the third stage the absorption solution, has an increased nitrate and nitrite content, and is released into the common absorption solution.

[0068] At the end of the third stage and in a preferred embodiment, the gas-phase amount, the off gas 008, is reduced and released, in a preferred embodiment to the air.

[0069] In an embodiment, the released off gas 008 after the third stage is treated / cleaned in a further process. In an embodiment, the released off gas after the third stage is released back to the gas phase above the common absorption solution.

[0070] Generally speaking, in a preferred embodiment, (100%) NOx entering the mixer 02 and / or the first tower 03, 80% of the NOx are absorbed and 20% NOx are leaving the first tower 03 with / in the off gas 023, entering the second tower 04. From the (20%) of the NOx entering the second tower 04, 80% of the NOx are absorbed and 20% NOx are leaving the second tower 04 with / in the off gas 024, entering the last tower 05. From the(5%) of the NOx entering the third tower 05, 80% of the NOx are absorbed and 20% NOx are leaving the third tower 05 with / in the off gas 008. The off gas 008 leaving the system contains <1% of the NOx entering the system. The efficiency of the NOx absorption in the system and / or the absorption towers is adjusted by retention time and contact area.

[0071] The process in summary: The absorption of NOx gas into the alkaline solutions takes place in a multistage process. The main NOx containing feed gas flows through the system passing each absorption stage and contacting the acidic absorption liquid 019, which is absorbing the NO2 N2O4, N2O3 and HNO2 and some of the NO gas. Some NO gas is absorbed because of the pH effect. The gas is meeting an increasing pH profile through the absorption stages. The oxidation of NO to NO2 is accelerated by concentrating the formed NO gas above the common absorption solution, where the concentration of NO is increased compared to the overall NO concentration through the stages. The increased NO concentration in air is accelerating the oxidation to NO2, Eq. I.2NO(g) + 02(g) 2NO2(g) (I)The absorption mechanism is thought to be driven by the formation of N2O3(g).NO(g) + NO2(g) N2O3(g) (II)The N2O3(g) is both soluble and reactive in the watery phase. The reactivity of the N2O3 is considered both to be direct as well as a result of the formation of HNO2.Off gas from each absorption stage is brought to the next absorption stage where more of the partially oxidized NOx gas is absorbed due to the higher pH. Retention time of 60- 120s of gas and exposed surface of liquid are key points in securing an NOx absorption efficiency of 99%.Description of the System

[0072] The present invention relates to a process and system for treatment of organic substrates in watery solutions by absorbing Nitrogen Oxide Gases, NOx. Figure 1 shows an embodiment of the system according to the invention.

[0073] 01 is the feed for the feed gas 001 or feed air, containing NOx gas. Preferably, the NOx is produced from air in a plasma reactor and the feed gas is NOx / air mixture. The feed gas is fed into a mixer 02. In a preferred embodiment the NOx / air mixture is produced in a plasma generator, such as an electric arc, microwave, or any other type of plasma generator.

[0074] 02 is the mixer where the feed gas meets the acidic absorption liquid 027 forming a gas-solution-liquid 022. In an embodiment the mixer is an absorption tower.

[0075] 03 is the first absorption tower where the gas-solution-liquid 022 from the mixer 02 being separated. The gas-solution liquid is meeting more acidic absorption liquid 019 before the gas 023 is leaving the absorption tower at the top via discharge flow 23. The liquid is falling down into the common absorption solution 009-010 of the absorption solution tank 06. The NOx gas 026 from the absorption solution tank is entering the first absorption tower 03 at the gas feed 26 in the bottom and following the total gas flow, released at discharge 23. Absorption tower 03 is not submerged in the liquid surface 009-010 of absorption solution tank 06. In an embodiment gas feed 26 is an open bottom.

[0076] 04 is the middle absorption tower which is receiving off gasses 023 from the first absorption tower 03 via feed 23, entering the middle absorption tower above the liquid level, in a preferred embodiment at the lower end of the absorption tower. The gasses 023 are brought in contact with the acidic absorption liquid 019 entering the middle absorption tower, preferred at the top. The remaining gas flow 024 is leaving at the top of absorption tower 04 via discharge 24. Absorption tower 04 is submerged into the liquid surface of the absorption solution tank to prevent an inflow of gas 026 from the headspace of the common absorption solution tank 06.

[0077] The middle absorption tower 04 of the present system corresponds to the second stage of the above-described process. In an embodiment the second stage comprises more than one middle absorption tower, in a preferred embodiment the second stage comprises at least two middle absorption towers 04.1 and 04.2, see figure 2, where the off gas 024.1, discharged from the aforegoing middle absorption tower 24.1, is feed to the subsequent middle absorption tower 24.2. In a more preferred embodiment, the second stage comprises up to 5 middle absorption towers.

[0078] 05 is the last absorption tower and it is receiving the off gasses 024 from absorption tower 04 via feed 24 entering the middle absorption tower above the liquid level. The gasses 024 are flowing countercurrent to the product absorption liquid 021, entering the absorption tower 05 at the top via feed 21, and the leaving off gas 008 is clean from NOx, released via discharge 08. Absorption tower 05 is submerged in the liquid surface of the common absorption solution to prevent an inflow of gas 026 from the headspace of the common absorption solution tank 06.

[0079] In an embodiment, in absorption tower 05, the gasses 024 are flowing countercurrent to the product absorption liquid 021 and the acidic absorption liquid 019. The percentage of the acidic absorption liquid 019 and the product absorption liquid 021 is determined to adjust the pH of the liquid before the treatment with the off gas 024.

[0080] 06 is the common absorption solution tank containing the common absorption solution 009-010. In a preferred embodiment, the common absorption solution 009-010 has a pH gradient and comprises an acidic absorption solution 009 at the one end with a pH of 4 - 4,5, and a product absorption solution 010 at the other end with a pH of 5 - 5,5.

[0081] In an embodiment, several baffle plates 07 are arranged in the common absorption solution tank 06, preferred between the absorption towers. The baffle plates 07 are separating the acidic absorption solution 009, the product absorption solution 010, and the intermediates, by repressing mixing.

[0082] The gas headspace 026 above the liquid level of the absorption solution tank 06 contains the released and oxidized NOx 026 which is re-entering the absorption towers through feed 26.

[0083] 08 is the discharge of the off gas 008. In an embodiment the discharge is led to feed 15.

[0084] 09 is the compartment of the acidic absorption solution 009.

[0085] 10 is the compartment of the product absorption solution 010.

[0086] 11 is the feed of the alkaline solution Oil, the raw material, entering the circulation flow of the acidic absorption solution loop 18, 19, (25). Feed flow 11 is controlling the pH of the acidic absorption solution 019 before entering the mixer 02 and / or the absorption towers. The alkaline solution is fed, via feed 11, to the acidic absorption liquid 019 when the pH is below a given set-point in the acidic solution 009. In an embodiment, other substances being fed to the acidic absorption solution loop as well.

[0087] 12 is the discharge of the acidic absorption solution product grade - the product acidic solution 012. The acidic absorption solution 009 product grade is discharged via 12 when the pH is in accordance with a given set-point. Discharge 12 is also controlling the level of the absorption solution 009-010 in the absorption solution tank 06. In an embodiment the acidic absorption solution 009 product grade is discharged in an acidic absorption solution tank or to the stables for the direct treatment of alkaline organic materials.

[0088] 13 is the feed of stored product solution 013 from the product solution tank 29, entering the circulation flow of the product absorption solution loop 20, 21. Feed flow 13 is controlling the pH of the product absorption liquid 021 before entering the last absorption tower(s). The stored product solution is fed, via feed 13, to the product absorption liquid 021 when the pH is below a given set-point in the product absorption solution 010. In an embodiment, other substances being fed to the acidic absorptionsolution loop as well. In an embodiment, alkaline solution Oil is fed to the product absorption liquid 021.

[0089] In the product solution tank 29, the pH (5,5-6) of the product solution 014, slightly increases over time to around 6, due to post reactions.

[0090] 14 is the discharge of the product solution 010 product grade - the product solution 014. The product solution 010 product grade is discharged via 14 when the pH is in accordance with a given set-point, to the product solution tank 29. Discharge 14 is also controlling the level of the absorption solution in the absorption solution tank. In an embodiment the product solution 014 product grade is discharged in a product solution product grade tank or to the fields.

[0091] 15 is the feed of the oxidation gas 015 to the head space and the head space gas 026 of the common absorption solution tank 06. In an embodiment the head space is fed with off gas 008, containing residue NOx and air.

[0092] 16 is the circulation pump for the acidic absorption solution 009, 018 giving the circulation flow of the acidic absorption solution loop 18, 19, (25,) 27, being separated into flow 19 and flow 27. The provided circulation flow, feed flow 11 and discharge 12 out balance each other in average.

[0093] 17 is the circulation pump for the product absorption solution 010, 020 giving the circulation flow of the product absorption solution loop 20, 21. The provided circulation flow, feed flow 13 and discharge 14 out balance each other in average.

[0094] 18 is the suction flow to circulation pump 16 for the acidic absorption solution009, 018.

[0095] 19 is the feed flow of acidic absorption liquid 019 to the first absorption tower(s) 03, the middle absorption towers 04, and optionally the first of the last absorption towers 05.

[0096] 20 is the suction flow to circulation pump 17 for the product absorption solution010, 020.

[0097] 21 is the feed flow of product absorption liquid 021 to the last absorption tower(s) 05, and optionally the last of the middle absorption towers 04.

[0098] 22 is discharge, from mixer 02, and feed, to first absorption tower 03, of the gas-solution-liquid 022. In an embodiment the feed 02, the gas-solution liquid 022 respectively, is entering the first absorption tower 03 from the top and following the liquid flow of the acidic absorption liquid 019.

[0099] 23 is discharge, from first absorption tower 03, and feed, to middle absorption tower 04, of the off gas 023. In an embodiment, the discharge 23 is at the top of thefirst absorption tower. In a further embodiment, the feed 23 is entering the middle absorption tower above the liquid phase or higher up.

[0100] 24 is discharge, from middle absorption tower 04, and feed, to last absorption tower 05, of the off gas 024. In an embodiment, the discharge 24 is at the top of the first absorption tower. In a further embodiment, the feed 24 is entering the last absorption tower above the liquid phase or higher up.

[0101] 25 is discharge, from the absorption tower(s) to the common absorption solution tank 06.

[0102] 26 is feed of the head space gas 026 from the common absorption solution tank 06, entering the first absorption tower 03 in the open bottom and following the total gas flow, going out via discharge 23.

[0103] l is feed of acidic absorption liquid 019 to the mixer 02.

[0104] The contact surface between gas (001, 008, 026, 023, 024) and liquid (002, 019, 021) can be established by any known engineering principle like falling film, packed segment, bubble tray, liquid spray or venturi, as long as the gas is separated from the liquid and leaving at the gas discharge (08, 23, 24) and the liquid is brought down into the common absorption solution 009-010 of the common absorption solution tank 06.

[0105] The reaction in the common absorption solution 009-010 of the common absorption solution tank 06 is releasing NO into the gas phase 026 (head space) above the liquid phase. The gas phase 026 is made up released NO gas, the other vapor pressures from the common absorption solution 009-010, and the optionally oxidation gas 015.Description of the Method

[0106] The present invention relates to a process and system for treatment of organic substrates in watery solutions by absorbing Nitrogen Oxide Gases, NOx, and a method making use of the process and system.

[0107] Figure 4 schematically shows how the described process and system is used in the method of treating organic substrates, like urine and feces, from the origin to the end use, like fertilizers.

[0108] 30 is the cow inside the barn-house 31 who delivers the organic substrate, like urine 032 and feces 033, forming the slurry 034. As a matter of course, the cow and the slurry are just an example of the source of the organic substrate.

[0109] 34 is the slurry cellar. The slurry 034 in the slurry cellar is a mixture of urine 032, feces 033, and product acidic solution 012 from the above-described process according to the invention.

[0110] The product acidic solution 012 in the slurry is essential for the method according to the invention. Without product acidic solution 012, the urea in the slurry is hydrolyzed to ammonium-bi-carbonate, for example within 24 hours.The ammonia is released from the slurry as a result of the hydrolyzation. Per mole urea, one mole ammonia is released. In the product acidic solution 012, the urea enzymes have been inhibited by the plasma treatment and the fermentation of the organic material is inhibited. In addition, the ammonia is "bound by the acid" and the ammonia release is also inhibited. Therefore, the gases 035, respectively 036, released from the slurry, respectively the house, containing zero to very little ammonia and methane.

[0111] Solid structures like straw and sand are filtered off in order to facilitate flow of the slurry 034, thereby forming the alkaline solution Oil, entering the system via feed 11.

[0112] The organic substrate Oil according to the invention is at least a fluid, in the preferred embodiments a liquid - a watery solution and / or dispersion.

[0113] The treated organic substrate Oil is fee to the system at a point of good mixing and at a rate where the system pH is kept in the range of 4-7. Treating the organic solution by absorbing NOx gasses from air plasma to acidify and stabilize the organic solution at a product pH of 4,5-5 depending on more specific requirements.

[0114] Discharging the product solution 014 via discharge 14 from the system to a long-term storage, the product solution tank 29. Also recycling the product solution 013 from the long-term storage 29 to re-acidify and stabilize the process according to the invention. Long term storage means 30-200 days

[0115] 001 is the plasma-air coming from the plasma reactor 28, being air or gas containing 1-12% NOx.

[0116] In the stored product solution 013, the urea enzymes have been inhibited by the plasma treatment and the fermentation of the organic material is inhibited. 037 is the gas being released from product solution tank 29, containing verry little to zero ammonia and methane.

[0117] The method, using the process and system according to the invention, is stopping the biological formation and further emissions of ammonia, methane, carbondioxide and sulfides as well as reducing pathogens and pathogenic activity. The amountof released gasses 035, 036, 037, namely ammonia and methane, is reduced by 90- 99%. At the same time the nitrogen content of the slurry 038 being spread to the field is increased to 200-300%, compared to the nitrogen content of untreated and stored organic substrate.

Claims

AMENDED CLAIMS received by the International Bureau on 13 November 2024 (13.11 .2024)1. A process for treating an alkaline solution (Oil) in an acidic liquid (009, 010, 018, 019, 021, 022, 025, 027); where the alkaline solution (Oil) comprises nitrogen compounds; where the process is a cyclic process, mainly charging feed gas (001) and the alkaline solution (Oil) into the cyclic process, cycling the acidic liquid (009, 010, 018, 019, 021, 022, 025, 027) within the process, and mainly discharging product solution (012, 014) out of the process; where the process is an absorption process, absorbing Nitrogen Oxide Gases, NOx from the gas phase (001, 008, 015, 023, 024, 026) of the process; the process comprises the following steps: a) charging the alkaline solution (Oil) to processed acidic absorption solution (018), resulting in acidic absorption liquid (019, 027); the alkaline solution (Oil) has a pH of 7-8,5, the processed acidic absorption solution (018) has a pH of 4,5-5, the acidic absorption liquid (019) has a pH of 4,5-5, the acidic absorption liquid (027) has a pH of 4,5-5; b) charging feed gas (001) to the acidic absorption liquid (027), partially absorbing the feed gas and forming a gas-solution-liquid (022); the feed gas is a NOx / air mixture, the gas-solution-liquid has a pH of 4-4,5; c) in a first stage of the process, adding and mechanically treating the gassolution-liquid (022) to acidic absorption liquid (019), thereby absorbing NOx and HNOx from the gas-solution-liquid (022) and the gas phase (026) above the acidic absorption solution (009), separating the gas and liquid phases, into the gas phase (023) released from the first stage, and into the liquid phase (025) released to the acidic absorption solution (009); the liquid phase (025) has a pH of 4-4,5 and acidic absorption solution (009) has a pH of 4,5- 5, the pH in the first stage is 4-4,5; d) adding the gas phase (026) released from the acidic absorption solution (009) to the first stage; the NOx concentration in the gas phase (026) above the acidic absorption solution (009) is concentrated compared to the NOx concentration through the main process; e) in a second stage of the process, adding and mechanically treating the off gas (023) from the first stage to acidic absorption liquid (019), therebyAMENDED SHEET (ARTICLE 19)absorbing NOx, and HNOx from the off gas (023) and the gas phase released from the absorption solution (009, 010), separating the gas and liquid phases, into the gas phase (024) released from the second stage, and into the liquid phase released into the absorption solution (009, 010); the pH in the second stage is 4,5-5; f) in a third stage of the process, adding and mechanically treating the off gas (024) from the second stage to product absorption liquid (021), thereby absorbing NOx, and HNOx from the off gas (024) and the gas phase released from the absorption solution (009, 010), separating the gas and liquid phases, into the gas phase (008) released from the third stage, and into the liquid phase released into the absorption solution (009, 010); the pH in the third stage is 5-6.

2. The process according to the previous claim, where the alkaline solution (Oil) comprises nitrogen compounds like urea, proteins, and ammonia.

3. The process according to any of the previous claims, where the acidic liquid (009, 010, 018, 019, 021, 022, 025, 027) comprises water, NOx compounds and radicals, oxoacids of nitrogen, acidifying and oxidizing gas components, ammonium salts, nitrites and nitrates.

4. The process according to any of the previous claims, further comprising the steps of:- charging stored product solution (013) to the product absorption liquid (021); the stored product solution (013) has a pH of ca. 5-6.

5. The process according to any of the previous claims, where the alkaline solution and / or the acidic liquid is a watery dispersion.

6. The process according to any of the previous claims, where the alkaline solution is an organic substrate.

7. The process according to any of the previous claims, where the NOx comes from air plasma like an oxygen enriched air plasma.

8. The process according to any of the previous claims, where biological activity and degradation of the organic substrates forming ammonia, methane, sulfides, and carbon dioxide, is inhibited.

9. The process according to any of the previous claims, where the organic substrate is a pretreated manure or organic waste, where the pretreatment comprises filtering, receiving an alkaline solution mainly consisting of one phase.AMENDED SHEET (ARTICLE 19)10. The process according to any of the previous claims, where, relative to the product absorption liquid (021), 0-100% acidic absorption liquid (019) is added to the gas phase (024), where the percentage of the acidic absorption liquid (019) and the product absorption liquid (021) is determined to adjust the pH of the liquid to 4,5-6 before the treatment with the off gas (024); the product absorption liquid (021) has a pH of 5-6.

11. The process according to any of the previous claims, where the feed gas (001) is produced in a plasma generator, such as an electric arc, microwave, or any other type of plasma generator.

12. The process according to any of the previous claims, where the gas phase (008) is released off the system, and / or back to the gas phase above the absorption liquid (009, 010).

13. The process according to any of the previous claims, where the stages applying a horizontal absorption process, where released NOx gas can achieve a higher NOx concentration and retention time to be oxidized to NO2 gas.

14. The process according to any of the previous claims, where an oxidation potential is maintained by electrolytically producing O and O2 at a cathodic reaction.

15. The process according to any of the previous claims, where step- b) is charging feed gas (001) to the acidic absorption liquid (019), partially absorbing the feed gas and forming a gas-solution-liquid; and step- c) is, in a first stage of the process, mechanically treating the gas-solution- liquid, thereby absorbing NOx and HNOx from the gas-solution-liquid and the gas phase (026) above the acidic absorption solution (009), separating the gas and liquid phases, into the gas phase (023) released from the first stage, and into the liquid phase (025) released to the acidic absorption solution (009); the liquid phase (025) and acidic absorption solution (009) have a pH of 4-4,5, the pH in the first stage is 4-4,5.

16. A system for treating an alkaline solution (Oil) in an acidic liquid (009, 010, 018, 019, 021, 022, 025, 027); the system comprises: a feed (01) for the feed gas (001); a mixer (02) mixing the feed gas (001) and the acidic absorption liquid (027) forming a gas-solution-liquid (022);AMENDED SHEET (ARTICLE 19)a first absorption tower (03), treating and separating the gas-solution-liquid (022), acidic absorption liquid (019), and head space gas (026) entering the first absorption tower via a gas feed (26) in the bottom and following the total gas flow, the gas (023) is leaving the absorption tower (03) at the top via discharge flow (23), the liquid is falling down, into a absorption solution tank (06); absorption tower (03) is not submerged in the liquid surface (009, 010) of a absorption solution tank (06); a middle absorption tower (04) receiving off gasses (023) via feed (23), entering the middle absorption tower (04) above the liquid level (009, 010), the gasses (023) are brought in contact, flowing counter current to the acidic absorption liquid (019) entering the middle absorption tower (04), preferred at the top, the remaining gas flow (024) is leaving at the top of absorption tower (04) via discharge (24), absorption tower (04) is submerged into the liquid surface (009, 010) of the absorption solution tank (06) to prevent inflow of head space gas (026) of the absorption solution tank (06); a last absorption tower (05) receiving off gasses (024) via feed (24), entering the last absorption tower (05) above the liquid level (009, 010), the gasses (024) are brought in contact, flowing counter current to the product absorption liquid (021) entering the absorption tower (05), preferred at the top, the off gas (008), preferred clean from NOx, is released via discharge (08), absorption tower (05) is submerged into the liquid surface (009, 010) of the absorption solution tank (06) to prevent inflow of head space gas (026) absorption solution tank (06), an absorption solution tank (06) containing the absorption solution (009, 010); a feed (11), feeding the alkaline solution (Oil) to the process, and controlling the pH of the acidic absorption solution (019) before entering the mixer (02) and / or the absorption towers; a discharge (12), discharging the acidic absorption solution (012) from the process, also controlling the level of the absorption solution (009, 010) in the absorption solution tank (06); a feed (13), feeding the product solution (013) to the process, and controlling the pH of the product absorption liquid (021) before entering the last absorption tower;AMENDED SHEET (ARTICLE 19)a discharge (14), discharging the product solution (010) from the process, also controlling the level of the absorption solution (009, 010) in the absorption solution tank (06); a feed flow (19), cycling and feeding acidic absorption liquid (019) through the system and to the first absorption tower (03), the middle absorption tower (04), and optionally to the last absorption tower (05); a feed flow (21), cycling and feeding product absorption liquid (021) through the system and to the last absorption tower (05), and optionally to the middle absorption tower (04).

17. The system according to the previous claim, where the mixer (02) is an absorption tower.

18. The system according to any of the previous claims, where the gas feed (26) is an open bottom.

19. The system according to any of the previous claims, where the system comprises more than one first absorption tower, and / or more than one middle absorption tower and / or more than one last absorption tower.

20. The system according to any of the previous claims, further comprising several baffle plates (07) arranged in the absorption solution tank (06), preferred between the absorption towers, separating the acidic absorption solution (009), the product absorption solution (010), and the intermediates, by repressing mixing.

21. The system according to any of the previous claims, where the discharge (08) is led to a feed (15), feeding the off gas (008) to the head space of the absorption solution tank (06).

22. The system according to any of the previous claims, where the mixer is functionally included in the first absorption tower (03); mixing the feed gas (001) and the acidic absorption liquid (019) forming a gassolution-liquid, treating and separating the gas-solution-liquid, and head space gas (026) entering the first absorption tower via a gas feed (26) in the bottom and following the total gas flow, the gas (023) is leaving the absorption tower (03) at the top via discharge flow (23), the liquid is falling down, into a absorption solution tank (06); absorption tower (03) is not submerged in the liquid surface (009, 010) of a absorption solution tank (06).

23. The system according to any of the previous claims, where the system comprises a house (31) containing a slurry (34) of organic substrate (32, 33) and productAMENDED SHEET (ARTICLE 19)acidic solution (012); and a product solution tank (29) containing stored product solution (013).

24. A method for treating organic substrate, the method comprising: adding product acidic solution (012) from the process of any of claims 1-15 or system of any of claims 16-23 to organic substrate (032, 033) to form a slurry (034), thereby minimizing or inhibiting biological and chemical formation of i.a. ammonia, methane, carbon dioxide, and hydrogen sulfide; feeding the resulting slurry (034) as alkaline solution (Oil) to the process of any of claims 1-15 or system of any of claims 16-23; treating the alkaline solution (Oil) in the process of any of claims 1-15 or system of any of claims 16-23; discharging product solution (014) from the process of any of claims 1-15 or system of any of claims 16-23 to a product solution tank (29); adding stored product solution (013) from the product solution tank (29) to the process of any of claims 1-15 or system of any of claims 16-23.

25. The method according to the previous claim, where the organic substrate treated by the method is preferably a fresh (0-3 hours) organic substrate.

26. The method according to any of the previous claims, where the organic substrate is manure, livestock slurries, organic waste solutions and biogas residue or anaerobic digestate.

27. The method according to any of the previous claims, where solid structures like straw and sand are filtered off in order to facilitate flow of the slurry (034), thereby forming the alkaline solution (Oil) entering the system via feed (11).

28. The method according to any of the previous claims, where the product solution storage of product solution (014) in the product solution tank (29) resulting in the stored product solution (013, 038), is a long-term storage.

29. The method according to any of the previous claims, where the slurry (038) being spread to the fields.

30. The method according to any of the previous claims, where the amount of released gasses (035, 036, 037), namely ammonia and methane, is reduced by 90-99%, and the nitrogen content of the slurry (038) being spread to the field is increased to 200-300%, compared to the nitrogen content of the untreated and stored organic substrate.AMENDED SHEET (ARTICLE 19)

Images