Additive mixtures for fermentation liquids

Abstract

Additive mixture for fermentation liquids, containing at least the following components: (A) at least one type of activated carbon containing at least one absorbed or adsorbed or absorbed and adsorbed inorganic nitrate, (B) (b1) NADH and / or NADPH nitrate reductase obtained from plants or yeasts or (b2) at least one type of denitrifying bacteria in free form or (b3) at least one type of denitrifying bacteria carried on and / or in at least one type of activated carbon or (b4) at least one type of denitrifying bacteria in free form and supported on and / or in at least one type of activated carbon or (b5) NADH and / or NADPH nitrate reductase obtained from plants or yeasts and at least one type of denitrifying bacteria in free form or (b6) NADH and / or NADPH nitrate reductase derived from plants or yeasts and at least one type of denitrifying bacteria carried on and / or in at least one type of activated carbon or (b7) NADH and / or NADPH nitrate reductase derived from plants or yeasts, at least one type of denitrifying bacteria in free form and at least one type of denitrifying bacteria carried on and / or in at least one type of activated carbon each in a total quantity that is insufficient to replace the nitrate present in (A) according to equation (I) NO3 - +2 H + + 2 e - = NO2 - + H2O (I) to reduce completely to nitrite, and (C) the bacterium Candidatus Brocadia Anammoxidans in free form or supported on and / or in at least one type of activated carbon or in free form and supported on and / or in at least one type of activated carbon, each in a total quantity sufficient to remove the nitrite resulting according to equation (I) and the ammonia present in the fermentation liquid according to equation (II): NH4 + + NO2 - = N2 + H2O (II), to proportionate to nitrogen.

Description

Field of invention

[0001] The present invention relates to an additive mixture based on nitrate charcoal according to parent application DE 10 2019 01 727.7 for fermentation liquids.

[0002] Furthermore, the present invention relates to a method for producing the additive mixture based on the aforementioned nitrate coal.

[0003] Furthermore, the present invention relates to the use of the additive mixture for reducing the ammonia concentration in situ in fermentation liquids and for preventing the formation of foul-smelling, toxic and environmentally harmful emissions. State of the art

[0004] To obtain methane gas, biomass is anaerobically fermented in bioconverters. Within the scope of the present invention, the term "fermentation" refers to the conversion of biological, particularly organic, materials using microorganisms (bacteria, fungi, and / or other cell cultures). Fermentation can also be achieved by adding metabolically active enzymes or other biologically active molecules, such as nutrient substrates for the microorganisms. Fermentation can include both aerobic processes, e.g., acetic acid fermentation, and anaerobic processes, e.g., lactic acid fermentation.

[0005] German patent application DE 102011 / 087635 A1 discloses a process for producing soil-improving substrates by processing digestate obtained from bioconverters. In this process, the digestate or the liquid portion thereof is mixed or brought into contact with at least one magnesium ion source, at least one phosphate ion and / or hydrogen phosphate ion source, and preferably a carbon source. Subsequently, the water is optionally removed completely or partially from the substrates.

[0006] German utility model DE 202014 / 004445 U1 discloses a device for producing biochar and generating heat. The device includes a motorized fuel conveying system for pumping biomass fuel into a burner for carbonizing the conveyed biomass fuel into biochar and combusting the released volatiles to generate heat. The device also includes a biochar conveying system for removing the biochar produced in the burner.

[0007] The American patent application US 2015 / 027179 (A1) describes the use of dried fermentation residues for further processing in a pyrolysis system to produce biochar and synthesis gas.

[0008] The American patent application US 2015 / 175462 describes the use of pancreatin to increase biogas yield. This is achieved through fermentation. Hydrolysis is also to be improved.

[0009] The methods for bioconverters, especially thermo-bioconverters, are described in the American patent application US 2015 / 125921 A1. These destroy environmentally harmful materials, such as antibiotics.

[0010] International patent application WO 2015 / 122688 A1 describes a system and method for the production of biochar. This section details the system. It consists of a preheated tank in which water-containing organic feedstocks are heated, and a reactor where hydrothermal carbonization takes place.

[0011] In their article "Increasing Biogas Yield Through the Addition of Biochar" in Müll und Abfall (Waste and Recycling), 2014, pages 476 to 480, Jan-Markus Rödger, Dipl.-Wi.-Ing., Waldemar Ganagin, M.Eng.-M.Sc., Andreas Krieg, Dipl.-Ing.agr., Christian Roth, B.Sc., and Achim Loewen, Prof. Dr.-Ing., describe the increase in biogas yield through the addition of biochar. The article states that adding large carbon particles to the post-fermenter increased the methane gas yield by 24% within 91 days.

[0012] US patent application 2012 / 0088266 A1 describes a bioreactor in which a community of anaerobic bacteria, including thermophilic bacteria, is immobilized on granules. The granules form a fluidized bed.

[0013] German patent application DE 10 2014 111 287 A1 discloses a process for producing methane in a bioreactor, in which hydrogen is supplied to the bioreactors.

[0014] German patent application DE 10 2015 012 436 A1 describes the use of carbon nanoparticles, carbon microparticles and / or carbon macroparticles to promote the growth of microorganisms and / or to increase metabolism and / or catabolism and / or anabolism and / or to increase the yield of various products and / or to protect the concrete walls in converters.

[0015] German patent DE 10 2016 004 026 B4 discloses a bioconverter for the simultaneous production of biogas and a valuable product by fermentation of biomass, which contains at least one carbon-containing suspended body in the fermentation liquid, wherein the suspended body is freely movable in the fermentation liquid or is anchored to the surface of the reactor bottom and - at least one buoyancy aid, - at least one fixed, active carbon mass and - comprising at least one weight, wherein the at least one fixed, active carbon mass and the at least one weight are balanced such that the buoyancy body keeps the suspended body in the fermentation liquid vertically or substantially vertically suspended. Calcium nitrate (E333) may be added to the fixed, active carbon mass as a complexing agent. However, the quantities to be added are not specified.

[0016] European patent EP 2 457 878 ​​B1 claims a method for increasing the production of methane in an anaerobic sludge treatment process, comprising the following steps: a) Feeding sludge into an anaerobic biological sludge or wastewater treatment system, b) Measuring the COD value (Chemical Oxygen Demand value) of the sludge material at a monitoring point of the sludge or wastewater treatment system, c) Calculating the nitrate dose to be added, d) Addition of nitrate as a nitrate salt solution based on the calculations of step c) in an amount corresponding to 1 to 4% of the COD of the organic substances in the inflow to anaerobic degradation, the nitrate dose being calculated using the following equation: q(NO3)[kg / h]=Q(input current)[m3 / h]×COD[kg / m3]×1.55×μ where µ = 0.01 to 0.04.

[0017] A process for producing ammonium-free calcium nitrate melts at 150 to 155 °C is known from American patent US 6,610,267 B1. The melts contain 1.5 wt.% to 5.5 wt.% potassium as potassium nitrate, 13 wt.% to 18 wt.% water, and 70 wt.% to 80 wt.% calcium nitrate. They are used for the production of fertilizer particles.

[0018] US patent 4,141,963 describes a process for the thermal decomposition of metal nitrate melts, such as manganese nitrate melts, below 400 °C. The decomposition of manganese nitrate melts produces manganese dioxide and nitrogen dioxide. However, such a decomposition reaction of calcium nitrate to calcium oxide and with nitrous gases is undesirable.

[0019] It is known that lithium nitrate and potassium nitrate form a eutectic with a melting point of 132 °C.

[0020] The English-language abstract of the publication by Zang, Wen et al., “Pilot preparation technology and properties of new bio-char based nitrogenous fertilizers”, in Nongye Jixie Xuebao (2014), 45(3), 129-133, describes the production of a fertilizer from biochar and ammonium nitrate. Its use in fermenters, bioconverters, or biogas plants is not described.

[0021] The publication by Zisheng Zhao et al., “Ferroferric oxide triggered possible direct interspecies electron transfer between Syntrophomonas and Methanosaeta to enhance waste acrivated sludge anaerobic digestion”, in Biosource Technology, 250, (2018) 79 to 85, shows that hematite increases the methane yield of the fermenter by 68.9% compared to an iron-free fermenter.

[0022] The high nitrogen content poses problems when fermenting protein-rich manure as biomass. Even low concentrations of ammonia in the digester inhibit bacterial growth. At pH 7, ammonia levels are approximately 0.5%, and at pH 8, around 10%. The high nitrogen content is also a disadvantage for the digestate fertilizers produced in biogas plants. If it were possible to halve the nitrogen content, for example, the digestate fertilizer could be applied to half the arable land without the risk of over-fertilization.

[0023] The Finnish company Ductor Oy has developed a process in which ammonia is produced as a valuable product from protein-rich manure in a pre-fermenter using mixed bacterial populations S1 (CBS Accession No. 136063) (see US patents 9,090,914 B2 and US 9,809,795 B2). However, this process is complex in terms of equipment and requires additional infrastructure.

[0024] One possibility for nitrogen reduction could be the anaerobic anammox process of the bacterium Candidatus Brocadia anammoxidans, which was only discovered in the 1980s: NH4 + + NO2 - = N₂ + H₂O. This reaction must be carried out at pH > 7 because, in acidic conditions, carcinogenic nitrosamines can form from the nitrite ions and nitrogen compounds. The Anammox process has been used more and more frequently in wastewater treatment in recent years (see, for example, European patent application EP 3 118 167 A1, "Process and plant for the treatment of ammonium-containing wastewater", or the company brochure from Paques, Netherlands, www.paques.nl, ANAMMOX® "Sustainable nitrogen removal"; downloaded on February 3, 2021).

[0025] Canadian patent application CA 3 085 569 A1 describes Anammox populations supported on isotropic graphite particles with a zeta potential of -35 mV to 0 mV and a mean particle size of 2 µm to 1000 µm. The supported bacteria promote nitrogen removal from wastewater.

[0026] International patent application WO 2015 / 06713A1 discloses a process in which the residue from an anaerobic fermentation reactor is processed as a mash substrate for solid or solid-containing organic biomass for biogas generation. First, the residue undergoes a solid-liquid separation, after which the liquid fraction is fed as a dilute slurry into an insulated reaction vessel. There, it is subjected to anaerobic ammonium oxidation using anammox organisms to reduce the ammonium concentration in a submerged process. The reaction vessel's ecosystem is maintained between 35 and 45 °C. After a certain residence time in the reaction vessel, the nitrogen-depleted substrate is added as process water to the biomass intended for biogas fermentation and, together with this biomass, undergoes the first stage of a biogas process.However, this process requires an additional controlled reaction vessel, which is an additional expense and therefore a disadvantage.

[0027] Chinese patent application CN 000108862841 A discloses an anaerobic-anoxic-aerobic (A2O) process for wastewater treatment. In this process, nitrogen is released in the anaerobic tank by anammoxic bacteria such as Candidatus Brocadia anammoxidans. An anoxic tank following the anaerobic tank is equipped with a cathode that is connected to a third aerobic tank via an anode in a closed loop. While the anode is made of nickel, copper, or titanium, the cathode consists of activated carbon fibers. A biofilm of denitrifying bacteria is immobilized on this carbon. This system does not, however, constitute an additive.

[0028] The abstract with Accession Number: 2014:1843258-Document Number (CA Abstract Number): 162:189556, Source: Nongye Jixie Xuebao (2014), 45 (3), 129-133 describes three types of nitrogen-containing fertilizers based on biochar. The fertilizers are produced from biochar and ammonium nitrate using a mixing process, an adsorption process, or a reactive process. Object of the present invention

[0029] The present invention was therefore based on the objective of reducing the nitrogen content, and in particular the ammonia content, of fermentation liquids in situ in biogas plants, fermenters, municipal and industrial wastewater treatment plants, sewers and wastewater systems, as well as in bioreactors for the basic production of, for example, acetic acid, propionic acid, butyric acid, esters, and ketones, while requiring little or no additional equipment. The reduction of the nitrogen content should also make it possible to apply the resulting fermentation substrate fertilizer to a smaller area of ​​arable land without the risk of over-fertilization.

[0030] Furthermore, the operation of biogas plants, fermenters, municipal and industrial wastewater treatment plants, sewers and sewage canals, as well as bioreactors for basic production, should from the outset reduce or completely prevent the formation of foul-smelling, toxic, and environmentally harmful emissions.

[0031] The advantages achieved through the technical teaching of the parent application, such as an ideal habitat on the activated carbon for a variety of bacteria and archaea, especially for methane-producing archaea that live and multiply in symbiosis therein, a faster and more pronounced colonization of methane-producing bacteria, improved gas quality through the reduction of hydrogen content, suppression of sulfate-reducing bacteria in the acetogenic phase and strengthening of denitrifying bacteria, should be fully retained.

[0032] Activated carbon, especially biochar, should continue to function as a carrier for highly concentrated aqueous nitrate solutions, allowing the highly concentrated aqueous nitrate solutions to be provided in a solid, safely transportable and precisely dosable form, thus eliminating the need for on-site production and dosing of nitrate solutions, while simultaneously providing activated carbon, especially biochar, as a habitat for bacteria and archaea. Inventive solution

[0033] Accordingly, the additive mixture for the fermentation liquid for biogas production was found according to independent claim 1. Advantageous embodiments of the additive mixture are the subject of dependent claims 2 to 16.

[0034] Furthermore, the use of the additive mixture according to independent claim 17 was found, wherein an advantageous embodiment of this use is the subject of dependent claim 18. Advantages of the invention

[0035] In view of the prior art, it was surprising and unforeseeable for the person skilled in the art that the problem underlying the present invention could be solved using the additive mixture according to the invention and its use according to the invention.

[0036] Thus, with the additive mixture according to the invention and its use according to the invention, the nitrogen content, in particular the ammonia content, of the fermentation liquids could be reduced in situ in biogas plants, fermenters, municipal and industrial wastewater treatment plants, in sewers and wastewater channels, as well as in bioreactors for the basic production itself, with little or no additional equipment being required. The reduction of the nitrogen content also made it possible to apply the resulting fermentation substrate fertilizer to a smaller arable area without the risk of over-fertilization.

[0037] Furthermore, the operation of biogas plants and fermenters has made it possible to reduce or completely prevent the formation of foul-smelling, toxic, and environmentally harmful emissions from the outset.

[0038] The advantages achieved through the technical teaching of the parent application, such as an ideal habitat on the activated carbon for a variety of bacteria and archaea, especially for methane-producing archaea that live and multiply in symbiosis therein, a faster and more pronounced colonization of methane-producing bacteria, improved gas quality through the reduction of hydrogen content, suppression of sulfate-reducing bacteria in the acetogenic phase and strengthening of denitrifying bacteria, were fully retained.

[0039] Activated carbons, especially biochar, continued to function as carriers for highly concentrated aqueous nitrate solutions, making it possible to provide these solutions in a solid, safely transportable, and precisely dosable form. This eliminated the need for on-site production and dosing of nitrate solutions, while simultaneously providing activated carbon, especially biochar, as a habitat for bacteria and archaea. Detailed description of the invention

[0040] The basis of the first essential component A is nitrate coal.

[0041] The basis of the nitrate charcoal is at least one type of activated carbon, preferably at least one type of solid, porous, pyrogenic biochar with a high capillary density, which ensures particularly effective material flows and substrate supply. Preferably, the at least one type of biochar has an internal surface area (BET) of at least 300 m². 2 / g, preferably 500 m 2 / g and in particular a maximum of 700 m 2 / g, which promotes bacterial growth. Its pH is particularly preferably between 8 and 8.7, which is especially advantageous for the growth of methane-producing archaea. In particular, the H / C ratio is <0.7, preferably <0.6, and especially <0.5, in accordance with the European Biochar Certificate guidelines.

[0042] Preferably, the at least one activated carbon, in particular the at least one solid, porous, pyrogenic biochar, still allows the plant structure of the starting materials to be recognized. Examples of suitable starting materials for pyrolysis, which is preferably carried out above 300 °C and preferably above 500 °C, are kiri trees, bamboo, shrubs, beech, oak, and ash, as well as C4 plants exhibiting a crown-like structure, in particular grasses, maize, sugar cane, millet, giant miscanthus, and amaranth. Beech wood is particularly well-suited as a starting material.

[0043] For the production of the nitrate charcoal, preferably at least one activated charcoal, in particular at least one plant charcoal, is used, which preferably has a medium particle size d 50from 2 cm to 20 cm. For use in the essential components, the at least one activated carbon, in particular the at least one vegetable carbon, is finely ground, preferably to medium particle sizes d. 50 from 0.5 mm to 2 mm.

[0044] In a preferred embodiment, the at least one activated carbon, in particular the at least one vegetable carbon, is dried before adsorption.

[0045] In a further preferred embodiment, the at least one activated carbon, in particular the at least one vegetable carbon, is treated in a vacuum mixer with the nitrate solution or the melt.

[0046] In yet another preferred embodiment, the at least one activated carbon, in particular the at least one vegetable carbon, is dried after adsorption at atmospheric pressure or under vacuum at temperatures of preferably 30 °C to 200 °C.

[0047] Preferably, the nitrate charcoal is produced by bringing at least one, in particular one, aqueous solution containing at least one inorganic nitrate into contact with the at least one activated charcoal, in particular the at least one biochar, whereby the at least one aqueous nitrate solution is adsorbed and / or absorbed by the at least one activated charcoal, in particular the at least one biochar. The process can be carried out in a simple manner by pouring at least one, in particular one, aqueous solution of at least one inorganic nitrate over the at least one activated charcoal, in particular the at least one biochar, and mixing the resulting mixture in a mixing unit until a dry, free-flowing powder is obtained, which can be packaged and stored and transported until its use according to the invention without clumping or forming clumps.

[0048] Preferably, the at least one, in particular an aqueous solution of at least one inorganic nitrate contains the at least one nitrate in an amount of, in each case based on the total amount of the aqueous solution, 20 wt.% to 80 wt.%, particularly preferably 30 wt.% to 70 wt.% and in particular 30 wt.% to 60 wt.%.

[0049] In a further embodiment of the process, the at least one activated carbon, in particular the at least one biochar, is brought into contact with a melt of at least one inorganic nitrate, such that the at least one activated carbon, in particular the at least one biochar, adsorbs and / or absorbs the at least one molten or liquid inorganic nitrate. In a preferred embodiment, the waste heat from the pyrolysis process for producing the activated carbon, in particular the biochar, is used for melting the at least one inorganic nitrate. In yet another preferred embodiment, the activated carbon, in particular the biochar, is doped with the at least one molten or liquid inorganic nitrate under vacuum.After the complete absorption of at least one molten or liquid inorganic nitrate, the resulting nitrate coal is dried, for which the waste heat from the pyrolysis process can also be used.

[0050] Subsequently, in both embodiments of the method, the process steps can be repeated at least once, preferably at least twice and in particular as often as necessary until the maximum loading of the nitrate coal is reached.

[0051] When melting or liquefying the at least one inorganic nitrate, care must be taken to ensure that the temperature is not set so high that the at least one inorganic nitrate decomposes into the metal oxide and nitrous gases. Therefore, the process is preferably carried out at temperatures below 500 °C, more preferably below 400 °C, and particularly below 300 °C.

[0052] Preferably, the at least one inorganic nitrate is selected from the group consisting of the nitrates of ammonium, lithium, sodium, potassium, magnesium, calcium, strontium, barium, aluminum, gallium, indium, scandium, yttrium, lanthanum, cerium, the lanthanides, chromium, iron, cobalt, nickel, copper, silver, and zinc. The nitrates of sodium, potassium, magnesium, calcium, iron, copper, and / or zinc are particularly preferred.

[0053] In particular, calcium and / or iron nitrates, as well as zinc and magnesium nitrates, are used in the form of their aqueous solutions or their melts. For the melts, they are preferably used in the form of their tetrahydrates, hexahydrates, and / or nonanitrates. If necessary, they are used in mixtures with alkali nitrates, with which they can form low-melting eutectic mixtures.

[0054] Examples of suitable inorganic nitrates for melting are zinc nitrate hexahydrate (alpha form) with a melting point of 25 °C, zinc nitrate hexahydrate (beta form) with a melting point of 36 °C, zinc nitrate tetrahydrate with a melting point of 45 °C, magnesium nitrate mixed with lithium nitrate with a melting point of 72 °C, magnesium nitrate hexahydrate with a melting point of 89 °C, calcium nitrate tetrahydrate mixed with lithium, sodium and / or potassium nitrate at 155 °C, the eutectic lithium nitrate / potassium nitrate with a melting point of 132 °C, calcium nitrate tetrahydrate with a melting point of 45 °C and iron(III) nitrate nonahydrate with a melting point of 47 °C.

[0055] In a further alternative embodiment of the process, the nitrate carbon according to the invention is produced by the oxidation of activated carbon, in particular biochar, loaded with ammonium salts, using nitrifying bacteria in the presence of oxygen. In a preferred embodiment, this is carried out in a bioreactor or fermenter using nitrifying bacteria and the active addition of oxygen. The ammonium salts can be mineral ammonium salts, manure, and / or ammonium sources from industrial or agricultural processes.

[0056] The process steps described above can be repeated at least once, preferably at least twice. Preferably, they are repeated until 70% to 98% of the maximum absorption capacity of the activated carbon, in particular the biochar, for at least one solid inorganic nitrate is reached.

[0057] The resulting powdered nitrate charcoal according to the invention can also be processed into pellets and / or granules. For this purpose, a biodegradable adhesive such as starches, prolamins such as zein (maize), gliadin (wheat), secalin (rye), avenin (oats), hordein (barley), oryzin (rice), and kafirin (millet), or Epotal® Eco from BASF SE can be added to the powdered nitrate charcoal according to the invention.

[0058] Furthermore, the additive mixture according to the invention may contain at least one further component E, selected from the group consisting of trace elements, ultratrace elements, microelements, ultramicroelements, micronutrients, hydroxides, filter residues, activated effective microorganisms, humic substances, 5-(hydroxymethyl)furfural, bacteria, enzymes, coenzymes, nutrients, essential nutrients, carbohydrates, fats, proteins, minerals, vitamins and adhesives, in particular the aforementioned adhesives.

[0059] This at least one additional component may be adsorbed and / or absorbed onto and / or into the nitrate charcoal, exist as a separate component and / or be carried on and / or in activated charcoal, in particular biochar.

[0060] Preferably, the trace elements, ultratrace elements, microelements and ultramicroelements are selected from the group consisting of lithium, rubidium, cesium, strontium, barium, chromium, cobalt, iron, fluorine, bromine, iodine, copper, manganese, molybdenum, tungsten, mercury, selenium, boron, aluminium, thallium, lead, silicon, zinc, arsenic, antimony, nickel, rubidium, tin and vanadium, and the bacteria from the group of archaea.

[0061] The second essential component B of the additive mixture according to the invention is NADH and / or NADPH nitrate reductase, which can be easily obtained from plants and yeasts, as described, for example, in German patent application DE 40 04 900 1. Alternatively or additionally, at least one type of denitrifying bacteria is used in free form and / or carried on and / or at least one type of activated carbon, in particular a type of vegetable carbon.

[0062] The total amount of denitrifying bacteria and / or nitrate reductases is chosen so that it is not sufficient to convert all the nitrate present in the nitrate charcoal according to equation (1): NO3 + 2 H + + 2 e - = NO2 + H2O (I), to reduce to nitrite, which is why an effective amount of nitrate charcoal is always present in the additive mixture according to the invention.

[0063] The third essential component C of the additive mixture according to the invention is the bacterium Candidatus Brocadia Anammoxidans or its population in free form and / or on and / or in at least one type of activated carbon, in particular at least one type of vegetable carbon.

[0064] The total amount of Candidatus Brocadia Anammoxidans is chosen to be sufficient to remove all the nitrite resulting from equation (I) and all the ammonia present in the fermentation liquid according to equation (II): NH4 + + NO2 - = N2 + H2O (II), to comproportionate or synproportionate to nitrogen.

[0065] An advantageous embodiment of the additive mixture according to the invention contains at least one inorganic mixed-valence compound of iron [Fe(II, III)] and / or one inorganic compound of trivalent iron [Fe(III)] as component D. Preferably, the at least one compound of trivalent iron (D) is iron(III) hydroxide, iron(III) oxide, and / or iron(III) nitrate, and the at least one mixed-valence compound of iron is hematite. Hematite is particularly preferred. The iron(III) hydroxide, the iron(III) oxide, and / or the hematite can be present as finely divided solid(s) and / or adsorbed and / or absorbed on and / or in at least one type of activated carbon, in particular vegetable carbon.

[0066] The additive mixture according to the invention is preferably produced using the method described below.

[0067] In this process, at least one first essential component A is extracted. a1 by adsorption and / or absorption of at least a 20 wt.% to 80 wt.% aqueous solution of at least one inorganic nitrate or a2 by adsorption and / or absorption of a melt of at least one inorganic nitrate selected from the group consisting of zinc nitrate hexahydrate (alpha form), zinc nitrate hexahydrate (beta form), zinc nitrate tetrahydrate, magnesium nitrate in a mixture with lithium nitrate, magnesium nitrate hexahydrate, calcium nitrate tetrahydrate in a mixture with lithium, sodium and / or potassium nitrate, the eutectic ‘lithium nitrate / potassium nitrate’, calcium nitrate tetrahydrate and iron(III) nitrate nonahydrate, at temperatures <500 °C on and / or in at least one type of activated carbon at atmospheric pressure or under vacuum or a3 by the oxidation of at least one type of activated carbon loaded with ammonium salts, with nitrifying bacteria in the presence of oxygen manufactured.

[0068] Furthermore, the process involves at least one second essential component B. b1 by isolating NADH and / or NADPH nitrate reductase in free form from plants or yeasts and / or b2 by isolating at least one type of denitrifying bacteria in free form and / or by b3 by the adsorption and / or absorption of NADH and / or NADPH nitrate reductase and / or of at least one type of denitrifying bacteria on and / or in at least one type of activated carbon manufactured.

[0069] Furthermore, the process requires at least one third essential component C. c1 by isolating the bacterium Candidatus Brocadia Anammoxidans in free form and / or c2 through its adsorption and / or adsorption on and / or in at least one type of activated carbon manufactured.

[0070] It is advantageous if the at least one type of activated carbon, in particular the at least one type of vegetable carbon, is dried before adsorption and / or absorption of at least the components A, B and C or A, B, C and D or A, B, C and E or A, B, C, D and E.

[0071] It is also advantageous if at least components A, B and C or A, B, C and D or A, B, C and E or A, B, C, D and E are mixed together before and / or during the use of the additive in a biogas plant or fermenter.

[0072] Furthermore, it is advantageous if at least one of the components D and / or E is added before the use of the additive mixture according to the invention and / or added during the use of the additive according to the invention.

[0073] Preferably, the thermal energy for the process is supplied by the waste heat of at least one pyrolysis plant for the production of at least one type of activated carbon, in particular at least one type of solid, porous, pyrogenic plant carbon with high capillary density.

[0074] The additive mixture according to the invention is used in particular to reduce the ammonia concentration in situ in the fermentation liquids of biogas plants, fermenters, municipal and industrial wastewater treatment plants, in sewers and wastewater systems, as well as in bioreactors for basic production, and to prevent the formation of foul-smelling, toxic, and environmentally harmful emissions. This use according to the invention significantly increases the yield of methane gas from biogas plants. A further advantage is that the additive mixture according to the invention can be added to the wastewater before or at its discharge into a sewer system, thereby reducing, if not completely eliminating, the known foul odors in the systems. According to the invention, these advantages are based on the comproportionation or synproportionation of nitrite and ammonium ions to nitrogen in the fermentation liquids. Examples and comparative experiments: Production examples 1 to 5 and comparative experiment V1: The production of nitrate coal A at atmospheric pressure and under vacuum

[0075] Biochar derived from beech wood was stripped of the carbon particles smaller than 4 mm and dried twice on an infrared drying scale until a moisture content of 1.28 wt% was reached. Fifteen parts by weight (Examples 1 to 4) and 60 parts by weight (Example 5) of the dried biochar, consisting of carbon particles measuring 4 to 20 mm and with a residual moisture content of 1.28 wt%, were completely coated with a 45 wt% calcium nitrate solution.

[0076] In examples 1 and 3, the nitrate solutions were allowed to react for 5 minutes at atmospheric pressure. The carbon pieces were then separated from the nitrate solutions using sieves with a mesh size of <1.0 mm. The carbon pieces were then lightly patted dry on cellulose, after which the resulting total weight of the doped carbon pieces was determined. The measured values ​​are shown in Table 1. Table 1: Adsorption of calcium nitrate solution on biochar at atmospheric pressure Example No. Coal (g) Nitrate solution (g) Weight gain (g / %) Adsorbate content, based on coal + adsorbate (%) 1 15 26,5 11,5 / 43,4 30,26 3 15 24,3 9,3 / 38,3 27,6

[0077] In examples 1 and 4, the dried biochar was completely immersed in calcium nitrate solution. The samples were treated for 30 seconds at a pressure of 0.2 bar while being gently agitated. The pressure was then increased back to atmospheric pressure for 1 minute. In example 6, the samples were agitated under vacuum. For comparison purposes, nitrate-free tap water was used in the comparative experiment V2. The post-treatment of the doped biochar pieces was carried out as described above. The measured values ​​are shown in Table 2. Table 2: Adsorption of calcium nitrate solution and water onto biochar at a pressure of 0.2 bar Example No. Money Ca(NO3)2 solution weight gain Adsorbate content, based on coal + adsorbate (g) (g) (g / %) (%) 2 15 39,4 24,4 / 61,9 38,2 4 15 41,3 24,3 / 63,7 38,9 5 60 187,8 127,8 / 68 40,5 V1 60 138,9 a) 78,9 / 56,8 a) 36,2 a) a) Tap water

[0078] The comparison of the values ​​in Table 1 with the values ​​in Table 2 showed that the adsorption of calcium nitrate solution on dried biochar could be significantly increased by vacuum treatment.

[0079] The biochar samples from Examples 1 to 5, treated with calcium nitrate solutions, were dried to a residual moisture content of 5 wt%, based on biochar + adsorbate. The samples were then treated again with calcium nitrate solutions as described above and subsequently dried. These process steps can be repeated several times until the maximum absorption capacity of the biochar for calcium nitrate is reached. Production example 6: The production of nitrate coal A in a nitrate melt

[0080] Biochar was produced from beech wood in a pyrolysis plant. The biochar was crushed and sieved to obtain granules with a medium particle size of d. 50A melt of 2 mm was produced from calcium nitrate tetrahydrate, iron(III) nitrate nonahydrate, and magnesium nitrate hexahydrate in a weight ratio of 16:3:1 at 80 °C and mixed with the biochar in a vacuum mixer until the melt was completely absorbed. The resulting nitrate carbon A was then dried under vacuum at 120 °C. After cooling to 80 °C, it was mixed with the melt again and dried. This process was repeated until no more melt was absorbed by the nitrate carbon. The nitrate carbon A was then separated from the melt by washing out the unadsorbed nitrates with a small amount of water. The necessary thermal energy for this process was supplied by the waste heat from the pyrolysis plant. This was a particular advantage of the process. Production example 7: The production of powdered nitrate coal A

[0081] The nitrate coals A produced according to production examples 1 to 6 were slightly moistened and ground in powder mills to a medium grain size d. 50 ground to 1 mm. Production example 8: The production of the essential component B

[0082] Anaerobic denitrifying bacteria isolated from putrefactive sludge were propagated in the usual and known manner and irrigated on and / or in biochar derived from beech wood of a medium grain size d 50 The material was adsorbed and / or absorbed by 1 mm, resulting in the essential component B. The denitrifying activity of essential component B was determined using standard and known microbiological methods. Production example 9: The production of the essential component C

[0083] Candidatus Brocadia Anammoxidans was propagated in the usual and known manner and grown on and / or in beechwood biochar of a medium grain size. 50The nitrite was adsorbed and / or absorbed from a 1 mm surface area, resulting in the essential component C. The activity regarding the synproportionation of nitrite and ammonium to nitrogen was also determined using standard and well-known microbiological methods. Examples 1 to 6: The production of the additive mixtures 1 to 6 according to the invention

[0084] The powdered nitrate coals A of production examples 1 to 6, produced according to production example 7, were each mixed in powder mixers with the essential component B produced according to production example 8, the essential component C produced according to production example 9, hematite powder (component D) and powdered humic acids doped with elements and ultratrace elements (component E), resulting in the powdered additive mixtures 1 to 6 according to the invention.

[0085] The respective ratios of the nitrate coal A and the essential component B were chosen such that B was present in a deficit with respect to the available nitrates, so that only a portion of the available nitrates were reduced to nitrite.

[0086] The respective ratios of essential component B to essential component C were chosen such that the total resulting nitrite combined with any ammonia to form nitrogen. Examples 7 to 12 and comparative experiment V2: The influence of nitrate coal on the methane yield of fermenters

[0087] Seven identical fermenters, 1 to 7, with a common central substrate supply of protein-rich slurry, were subjected to a nine-month comparison. Fermenters 1 to 6 were operated in the presence of one of the additive mixtures according to the invention from Examples 1 to 6 (Examples 7 to 12). Fermenter 7 was operated without an additive mixture according to the invention (comparative test V2).

[0088] In Examples 7 to 12, fermenters 1 to 6 were initially fed with high doses of the respective additives 1 to 6 for 10 days to ensure absorption of all necessary trace elements and methane-producing archaea onto the essential components A, B, and C, and to stabilize the respective process biology. Subsequently, a daily ration of 22 kg of each of the additive mixtures 1 to 6 according to the invention was added to the fermentation liquid. After the absorption phase, an average increase in methane yield of 10% to 14% was observed from fermenters 1 to 6 (Examples 7 to 12) compared to the methane yield of the comparative experiment V2.

[0089] The ammonium content of the fermentation liquid from the fermenter in the comparative experiment V2 reached a level of 6.5% to 7% after the absorption phase, based on the volume of the fermentation liquid, which led to a significant reduction in methane yield. Odor nuisance was also observed in the vicinity of this fermenter.

[0090] In contrast, the ammonium content of the fermentation liquids from fermenters 1 to 6 of examples 7 to 12 was between 2% and 3%, based on the volume of the fermentation liquid. Furthermore, no unpleasant odors were detected in the vicinity of the fermenters. The digestate fertilizers obtained from examples 1 to 6, with a significantly lower nitrogen content, exhibited only a comparatively faint odor and could be applied without risk of over-fertilization to an area of ​​land only half the size of the area required to apply the digestate fertilizer obtained in comparison experiment V2.

Claims

[1] Mixture of additives for fermentation liquids, containing at least the following components: (A) at least one type of activated carbon containing at least one absorbed or adsorbed or absorbed and adsorbed inorganic nitrate, (B) (b1) NADH and / or NADPH nitrate reductase obtained from plants or yeasts or (b2) at least one type of denitrifying bacteria in free form or (b3) at least one type of denitrifying bacteria carried on and / or in at least one type of activated carbon or (b4) at least one type of denitrifying bacteria in free form and supported on and / or in at least one type of activated carbon or (b5) NADH and / or NADPH nitrate reductase obtained from plants or yeasts and at least one type of denitrifying bacteria in free form or (b6) NADH and / or NADPH nitrate reductase derived from plants or yeasts and at least one type of denitrifying bacteria carried on and / or in at least one type of activated carbon or (b7) NADH and / or NADPH nitrate reductase derived from plants or yeasts, at least one type of denitrifying bacteria in free form and at least one type of denitrifying bacteria carried on and / or in at least one type of activated carbon each in a total quantity that is insufficient to replace the nitrate present in (A) according to equation (I) NO3 - +2 H + + 2 e - = NO2 - + H2O (I) to reduce completely to nitrite, and (C) the bacterium Candidatus Brocadia Anammoxidans in free form or supported on and / or in at least one type of activated carbon or in free form and supported on and / or in at least one type of activated carbon, each in a total quantity sufficient to remove the nitrite resulting according to equation (I) and the ammonia present in the fermentation liquid according to equation (II): NH4 + + NO2 - = N2 + H2O (II), to proportionate to nitrogen. [2] Additive mixture according to claim 1, characterized by , that at least one type of activated carbon is at least one type of solid, porous, pyrogenic biochar of high capillary density. [3] Additive mixture according to claim 2, characterized by , that at least one type of solid, porous, pyrogenic biochar of high capillary density has an internal surface area according to BET of at least 300 m² 2 / g, has a pH value of 8 to 8.7 and an H / C ratio according to the guideline of the European Biochar Certificate <0.

7. [4] Additive mixture according to claim 2 or 3, characterized by , that at least one type of solid, porous, pyrogenic biochar of high capillary density can be produced from beech wood. [5] Additive mixture according to any one of claims 1 to 4, characterized by , that it (D) contains at least one inorganic mixed-valence compound of iron [Fe(II, III)] and / or one inorganic compound of trivalent iron [Fe(III)]. [6] Additive mixture according to claim 5, characterized by , that the at least one compound of trivalent iron (D) is iron(III) hydroxide, iron(III) oxide and / or iron(III) nitrate and the at least one mixed-valence compound of iron is hematite. [7] Additive mixture according to any one of claims 1 to 6, characterized in that the iron(III) hydroxide (D), the iron(III) oxide (D) and / or the hematite (D) is present as a finely divided solid and / or adsorbed and / or absorbed on and / or in at least one type of activated carbon. [8] additive mixture according to any one of claims 1 to 7, characterized by, that the at least one inorganic nitrate is present in and / or on the component (A) in the form of an adsorbed and / or absorbed dried aqueous solution of alkali nitrates, alkaline earth nitrates, zinc nitrate and / or iron(III) nitrate in the form of adsorbed and / or absorbed solid calcium nitrate and / or in the form of an adsorbed and / or absorbed cooled melt of at least one inorganic nitrate selected from the group consisting of zinc nitrate hexahydrate (alpha form), zinc nitrate hexahydrate (beta form), zinc nitrate tetrahydrate, magnesium nitrate in a mixture with lithium nitrate, magnesium nitrate hexahydrate, calcium nitrate tetrahydrate in a mixture with lithium, sodium and / or potassium nitrate, and the eutectic ‘lithium nitrate / potassium nitrate’, calcium nitrate tetrahydrate, iron(III) nitrate nonahydrate’. [9] Additive mixture according to claim 8, characterized by, that the melt is selected from the group consisting of zinc nitrate hexahydrate (alpha form) with a melting point of 25 °C, zinc nitrate hexahydrate (beta form) with a melting point of 36 °C, zinc nitrate tetrahydrate with a melting point of 45 °C, magnesium nitrate mixed with lithium nitrate with a melting point of 72 °C, lithium nitrate trihydrate with a melting point of 30 °C, magnesium nitrate hexahydrate with a melting point of 89 °C, calcium nitrate tetrahydrate mixed with lithium, sodium and / or potassium nitrate with a melting point of 155 °C, the eutectic lithium nitrate / potassium nitrate with a melting point of 132 °C, calcium nitrate tetrahydrate with a melting point of 45 °C and iron(III) nitrate nonahydrate with a melting point of 47 °C. [10] Additive mixture according to any one of claims 1 to 9, characterized by , that the at least one component (A) (a1) by adsorption and / or absorption of at least a 20 wt.% to 80 wt.% aqueous solution of at least one inorganic nitrate or (a2) by adsorption and / or absorption of a melt of at least one inorganic nitrate selected from the group consisting of zinc nitrate hexahydrate (alpha form), zinc nitrate hexahydrate (beta form), zinc nitrate tetrahydrate, magnesium nitrate mixed with lithium nitrate, magnesium nitrate hexahydrate, calcium nitrate tetrahydrate mixed with lithium, sodium and / or potassium nitrate, the eutectic ‘lithium nitrate / potassium nitrate’, calcium nitrate tetrahydrate and iron(III) nitrate nonahydrate, at temperatures <500 °C on and / or in at least one type of activated carbon at atmospheric pressure or under vacuum or (a3) can be produced by the oxidation of at least one type of activated carbon loaded with ammonium salts using nitrifying bacteria in the presence of oxygen. [11] Additive mixture according to any one of claims 1 to 10, characterized by , that the at least one component (B) is by (i) the isolation of NADH and / or NADPH nitrate reductase in free form from plants or yeasts and / or (ii) the isolation of at least one species of denitrifying bacteria in free form and / or by (iii) the adsorption and / or absorption of NADH and / or NADPH nitrate reductase and / or of at least one type of denitrifying bacteria on and / or in at least one type of activated carbon can be manufactured. [12] Additive mixture according to any one of claims 1 to 11, characterized by , that the at least one component (C) is by (c1) the isolation of the bacterium Candidatus Brocadia Anammoxidans in free form and / or by (c2) its adsorption and / or adsorption on and / or in at least one type of activated carbon is producible. [13] Additive mixture according to any one of claims 1 to 12, characterized by , that it can be produced by mixing at least the components (A), (B) and (C). [14] Additive mixture according to any one of claims 1 to 13, characterized by , that it is in the form of dispersions, pastes, suspended solids, free-flowing powders, pellets and / or granules. [15] Additive mixture according to any one of claims 1 to 12, characterized by , that it (E) contains at least one further component selected from the group consisting of trace elements, ultratrace elements, micro elements, ultramicro elements, micronutrients, hydroxides, filter residues, activated effective microorganisms, enzymes, coenzymes, humic substances, 5-(hydroxymethyl)furfural, bacterial nutrients, essential nutrients, carbohydrates, fats, proteins, minerals, vitamins and adhesives. [16] Additive mixture according to claim 15, characterized by, that the trace elements, ultratrace elements, microelements and ultramicroelements (E) are selected from the group consisting of lithium, rubidium, cesium, strontium, barium, chromium, cobalt, iron, fluorine, bromine, iodine, copper, manganese, molybdenum, tungsten, mercury, selenium, boron, aluminium, thallium, lead, silicon, zinc, arsenic, antimony, nickel, rubidium, tin and vanadium, and the bacteria are selected from the group of archaea. [17] Use of the additive mixture according to any one of claims 1 to 16 for reducing the ammonia concentration in situ in the fermentation liquids of biogas plants, fermenters, municipal and industrial wastewater treatment plants, in sewers and sewage canals, and in bioreactors for basic production and for preventing the formation of foul-smelling, toxic and environmentally harmful emissions. [18] Use according to claim 17, characterized by, that the reduction of nitrogen concentration in situ and the prevention of the formation of foul-smelling, toxic, environmentally harmful emissions is achieved through the comproportionation of nitrite ions and ammonium ions to nitrogen in the fermentation liquids.