DE102018000939A1 - Process for controlling ammonia, laughing gas outgassing / control of eutrophication and thereby reducing nitrate pollution of groundwater - Google Patents

Abstract

Process for reducing or eliminating the ammonia, ammonium and nitrous oxide outgassing by treatment of manure and organic residues such as fermentation residues from biogas plants in storage tanks and lagoons by using CO-containing waste gases preferably from biogas plants or CHP plants or other available clean recyclableCO -Sources (gas-fired power plants) thereby conversion of the "aqueous" environment (manure / fermentation residues)) located ammonia to ammonia carbonate. With this processing step, one obtains already a slight to strong consistency change of slurry / digestate suspension further processing / treatment of the liquid to pasty manure / digestate carbonate mass (suspension) with finely divided / dusty mineral / metallic oxides, as they are advantageously associated in filter ashes of coal-fired power plants incurred as waste and for recovery gem. KRWG (Kreislaufwirtschaftsgesetz) are pending in large quantities. Additionally, by adding metallic / mineral dusty ashes, further egg leaching of the slurry / digestate hydrate mass can be achieved and granules produced during the process in a specific compulsory mixer. The product can be stored under roof, can be traded as bagged or bulk goods. The granules can be dosed in accordance with the Fertilizer Ordinance and thus counteract eutrophication.

Description

Recent climate studies find that the climate impacts of ammonia (NH ³ ) ammonium (NH ⁴ ) and nitrous oxide (N ₂ O) are quite the same, if not higher, of climate pollution compared to CO ₂ .

The main culprit is agriculture with excessive animal husbandry and its fermentation / biogas plants. Due to the extensive climate-damaging emissions humans and animals are equally damaged.

• • In der Schweinehaltung entsteht der Großteil der Emissionen direkt im Stall, in der Rinderhaltung bei der Lagerung von Wirtschaftsdünger und seiner Ausbringung. Ammoniak breitet sich in der Atmosphäre aus. Es kann dort mit anderen Bestandteilen der Atmosphäre reagieren und lagert sich anschließend wieder in Ökosystemen ab. Ammoniak selbst und das nach Umwandlung entstehende Ammonium schädigen Land- und Wasserökosysteme erheblich durch Versauerung und Eutrophierung (Nährstoffanreicherung). Bodenversauerung und Nährstoffüberversorgung natürlicher und naturnaher Ökosysteme (wie zum Beispiel Moore, Magerstandorte, Gewässer) können zu Veränderung der Artenvielfalt führen. Ammoniak und Ammonium sind außerdem wesentliche Vorläufersubstanzen für die Bildung von gesundheitsschädlichem Feinstaub. Eine geeignete Minderung der Emissionen aus dem Stall sind Abluftreinigungsanlagen. Deren HN³-beladende Wasch-Wässer gehen zur Entsorgung in die Gülle.

"Emissions of agriculture, UBA 06.06.2014" (excerpt)

• • In pig farming, most of the emissions are generated directly in the barn, in cattle keeping in the storage of manure and its application. Ammonia spreads in the atmosphere. It can react there with other constituents of the atmosphere and then settles back into ecosystems. Ammonia itself and the resulting ammonium after conversion damage land and water ecosystems considerably by acidification and eutrophication (nutrient enrichment). Soil acidification and nutrient overfeeding of natural and semi-natural ecosystems (such as moors, low-lying sites, bodies of water) can lead to changes in biodiversity. Ammonia and ammonium are also important precursors for the formation of harmful particulate matter. A suitable reduction of emissions from the barn are exhaust air purification plants. Their HN ³ -loading wash waters go into the manure for disposal.

Manure, (urea carrier (containing ammonia) with 90 to 95% water content) is the most important source of NH ³ emissions when used as manure. Urea is hydrologically converted to ammonium (NH ⁴ ) in the soil by the enzyme urease. At the same time, the pH in the soil is increased, which in turn promotes NH ³ formation and release. In the case of farmyard manure, rapid incorporation of urea into the soil, in a period of 1 to 4 hours (legally required) after application of manure, is particularly important in order to reduce NH ³ losses (NH ³ outgassing).

The application of urease inhibitors may delay the reaction of the urea and thus the infiltration into the soil before the reaction.

The conversion of urea to ammonium (NH ⁴ ) takes place within a few days. At this point, urease brakes (inhibitors) can intervene and keep the nitrogen longer in the urea phase. The pH increases less quickly, ammonia losses are reduced. Nitrification inhibitors act on the ammonium phase and slow down the conversion to nitrite and nitrate for several weeks, which reduces nitrate leaching and nitrous oxide (N ₂ O) losses (evaporation / climate damaging). Use of inhibitors is a financially complicated treatment method of the soil. Their use is ultimately a costly effort with minimal impact, because the outgassing can not be extensively or completely prevented.

Reaction process (simplified, for information):

$$\begin{array}{c}\text{ammonia}-\text{ammonium}-\text{nitrite}-\text{nitrate}\\ \text{Liquid manure application / urea}-/\mathbf{ammonia}\left({\mathbf{NH}}^3\right)-\text{entry into the ground}+\text{Enzyme urease}=\\ \text{ammonium}\left({\mathbf{NH}}^4\right)+\text{bacteria}\left(\text{Nitrosomonas}\right)=\mathbf{nitrite}\left(\mathbf{N}{\mathbf{O}}_2\right)\text{+}\\ \text{bacteria}\left(\text{Nitrobacter}\right)\text{Reaction to}\mathbf{NITRATE}\left(\mathbf{N}{\mathbf{O}}_3\right),\end{array}$$

A more effective reduction or suppression of the exhalations of manure and digestate, with an ecologically important result according to the invention provides the inerting measure of liquid manure and / or digestate in the first phase by use / utilization / leaching of the liquid manure digestate mass with nitrogen (N) or carbon dioxide (CO ₂ ) and in the second treatment phase, the mixing of the organic mass with finely divided to dusty mineral / metallic oxides for inerting, sterilization and consistency change.

In particular, the gasification with CO ₂ leads to ammonium carbonate in ammonia in an aqueous environment. NH3 (ammonia) in H2O environment arises NH4 + OH with the addition of CO ₂ produced (NH4) 2CO3 + H ₂ O ammonium carbonate a crystalline compound. By treatment with CO _{2 of} the organic substance, the outgassing of ammonia vapors massively restricted or brought to a complete halt.

The second treatment phase of the organic / mineral mixture describes a process for the ammonia-contaminated organic and germ-contaminated wastes / residues in particular manure from livestock and poultry and fermentation residues from biogas plants, generally present in liquid form, without specific heat in a free-flowing germ-free state of aggregation. The blending gem. Invention should be possible only with metallic and / or mineral oxide molecules of finely divided ashes and / or ground slags (iron and steel industry), grain size preferably 70 to 90 microns done.

Due to the small grain size, the mixture has a large surface area with good to excellent reactivity. In the course of the mixing process in a compulsory mixer with manure / fermentation residues together with finely divided oxidic mineral and metallic components of ashes and or ground slags, new chemical compounds are formed, which are the molecules of ammonia (NH ³ ), ammonium carbonate as well as nitrous oxide (N ₂ O) according to the invention binds chemically, without external heat input and immobilized or prevents the climate-damaging volatility / outgassing reaction of ammonia and nitrous oxide, but without losing the nutrient contents for the plant. Reaction formula (example): a) CaO + 2 HNO ³ = Ca (HNO ₃ ) + H ₂ O // calcium nitrate b) MgO + 2HNO ³ = Mg (HNO ₃ ) + 2H ₂ O // magnesium nitrate c) 2NH ³ + H ₂ O + CO ₂ = (NH ₄ ) ₂ CO ₃ // ammonium carbonate

The produced and matured agglomerate is a free-flowing mineral fertilizer (solidified liquid manure) and can be stored well in this state of aggregation, transported and metered for fertilization brought to discharge. When handled correctly, the legal fertilizer requirements can be easily achieved and excessive fertilization (eutrophication) can be avoided. Another but significant advantage of the process is located in a central as well as decentralized manure / Gärreste- collection point with attached processing. Manure / fermentation residues are continuously agglomerated and stored under roof. If necessary for manure for a field order, the fertilizer ex warehouse can be made available to the farmers. The availability of such a treatment facility with the necessary environmentally sound manure / digestate storage capacities would be particularly cost-effective for the farmers and would make a good measurable environmental contribution, in which there would be no large capacity storage facilities in the yard. covered lagoons, storage tanks for a manure / digestate stockpiling, which temporarily store a manure amount of up to 9 months produced on the farm in an environment-friendly manner and acc. Law is to install.

The oxidic constituents of the filter ashes are suitable as soil adjuvants according to their analytical nature. These ashes are according to KrWG waste and gem. To use the law. Currently, they are disposed of in suitable landfills (for example, charred opencast mines) mainly due to lack of utilization forms. When implementing the method presented here, large quantities of such ashes or even ground slags from steelmaking could be used as fertilizer.

As an example, the metallic, mineral oxide material composition of a German lignite ash is presented as a suitable medium for the treatment of manure as well as other organically contaminated waste in aqueous to firm consistency. The ashes have u.a. a relatively high lime and magnesium oxide (CaO / MgO) content. When mixed with manure, with a water content of 90 to 95%, for example, it comes to a chemical exothermic reaction - s. o. Reaction formula - which can reach 70 ° C and more, is germicidal and has a sterilizing effect. Due to the strongly basic environment, a further disinfecting effect is added. MRSA germs as well as Legionella bacteria and avian influenza virus can be rendered harmless by this treatment route, if necessary, with additions of Weichbranntkalk (caustic soda 90% CaO) in their effect.

Filter ash analysis (coarse) Brown coal power plant Rheinisches Revier:

component % By weight reacts in connection with manure to "fertilizer": SiO ₂ 7 Fe ₂ O ₃ 15 Iron (III) nitrate Fe (NO ₃ ) ₃ Al ₂ O ₃ 5 Alumiumnitrat Al (NO ₃ ) ₃ CaO 35 calcium nitrate Ca (NO ₃ ) ₂ MgO 16 magnesium nitrate Mg (NO ₃ ) ₂ Na ₂ O 5 K ₂ O 1 potassium nitrate KNO ₃ SO ₃ 16 MnO 0.5 manganese nitrate Mn (NO ₃ ) ₂ Ash granulation is 70 μm to 90 μm.

In intensive mixing of the oxide molecules of the ash with liquid manure to a moist but not flowable mass occurs at different intervals because of different reactivity of the oxide molecules to chemical reactions the reaction of CaO + slurry is most obvious, highly reactive and short term after contact of the substances (water , Manure) the connection reaction (hydration) begins with release of heat and water. After about 20 minutes, the reaction stops. The reaction of magnesium oxide with manure starts cautiously and lasts longer compared to calcium oxide (CaO), as well as the other oxides. (see reaction formula) The hydration of manure / fermentation residues inhibits the evaporation reactions (properties) and volatilization of ammonia / ammonium.

The product produced in a compulsory mixer is available as an agglomerate / pellet and can be stored dry in such consistency under roof, traded as bag and heap and dosed as such on agricultural soils. If the farmer sticks permanently to the Fertilizer Ordinance, he can control and ultimately reduce eutrophication. Such action would significantly reduce the nitrate / nitrite pollution of groundwater, thus counteracting creeping poisoning of the population.

It is important, however, that the nutrient contents of the agglomerates produced are preserved and available to the plants.

Furthermore, the recovered product can be "exported" as bulk or bagged goods in nutrient-poor regions.

Claims (7)

The invention relates to a method for reducing or eliminating the ammonia, ammonium and nitrous oxide outgassing by treatment of liquid manure and digestate in storage tanks and / or lagoons by using CO ₂ or CO ₂ -containing exhaust gases, preferably from biogas plants or CHP plants. Installations or coal-fired power plants thereby conversion of the ammonia in "aqueous" environment (manure / fermentation residues) to ammonium carbonate. Parallel or even slightly delayed further treatment / thickening in a forced mixer of liquid to mushy manure / digestate carbonate mass means finely divided / dusty mineral / metallic oxides, as they are advantageously associated in filter ashes of coal-fired power plants incurred as waste and for recovery acc. KRWG (Circular Economy Act) are pending in large quantities and are looking for a comprehensive and ecologically meaningful recovery. With the thickening and the accompanying chemical reactions of the various substances / components with each other, a strongly basic environment (germicidal) is created, a further inertization is achieved, thereby preventing outgassing, especially of the dangerous greenhouse gases (ammonia vapors). The nutrient content of the fertilizer mass produced is retained for the plant world. When using the ashes in the presented process according to 1) according to the invention large amounts of waste ash according to KRWG can be used ecologically meaningful. Use of CO ₂ exhaust gases for drying / carbonation from cogeneration plants (combined heat and power plants / biogas plants) or gas engines, which are used to drive, for example, rotary treatment plants. Mineral binding / conditioning of liquid manure, fermentation residues, organic liquid to pulpy pasty substances and production of storable agglomerates. To Claim 4 ) characterized in that agglomerates can be shipped / exported as low-odor fertilizer as sack or bulk goods in nutrient-poor areas. This relieves strained agricultural regions and reduces / suppresses eutrophication. Method according to Claims 1 ), 2) and 3), characterized in that the mixture is sterile and by application as a fertilizer no health hazard by germ / bacterial spread (MRSA, Legionella) takes place. The fertilizer pellets produced can be gem. Fertilizer Ordinance targeted and legally compliant. Thereby reducing the eutrophication and nitrate pollution of groundwater. Strong measure against creeping poisoning of the population by contaminated groundwater and drinking water with nitrate.