Browsing by Subject "Ammonia"

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Emission von Ammoniak (NH₃) und Lachgas (N₂O) von landwirtschaftlich genutzten Böden in Abhängigkeit von produktionstechnischen Maßnahmen
(2003) Leick, Barbara Cornelia Elisabeth; Engels, Christof
The goal of this research was to quantify event-based NH₃ and N₂O emissions in various farming systems and to propose emission-avoidance strategies. Emission measurements were made on pasture land (Allgaeu, Hohenheim) and on cultivated fields (Hohenheim, Biberach). These measurements were made after applying organic and mineral fertilizers, after incorporating crop residues, and after freeze / thaw cycles; furthermore, experiments were conducted using container plants of different species (leguminous, and non-leguminous) and different fertilizers. NH3 emissions data was gathered under field conditions using the wind tunnel method and the IHF method (Integrated Horizontal Flux). In the container experiments, data was gathered by taking photo-acoustic measurements. N₂O emissions data was compiled using closed chambers (Hohenheim measuring chambers) and using an open-chamber system in which an exchange occurred between the air in the chambers and the ambient air. N₂O levels were determined using a gas chromatograph or by photo-acoustic measurements. The NH₃ emissions after applying liquid manure to pasture land varied between 11 and 40% of the total nitrogen applied. Emission levels of less than 20% occurred when it rained shortly after spreading liquid manure causing it to be washed into the soil. The application technique (splash plate, surface banding and liquid manure injection) had no apparent influence on NH₃ emissions under these conditions. The N₂O emissions after liquid manure fertilization on pasture land in Hohenheim were 0.16% of the total NH4+-N. In comparison, the emissions in the Allgäu were between 1.7 and 2.3% of the total NH4+-N applied. Liquid manure injection led to higher emissions as did application using a splash plate. In the Allgäu, the N₂O emissions after mineral-nitrogen fertilization were markedly lower (0.3 to 0.8% of applied N) than after liquid manure application. In Hohenheim, the nitrogen form had no distinct influence on the emissions (<0.16% of applied N). Definitive differences between the two locations were observed during the experiments. These differences were based on N₂O losses due to the respective soil and weather conditions (precipitation, temperature). The higher emissions after applying liquid manure compared to those after applying mineral nitrogen fertilizer are explainable in that aside from the nitrogen compounds found in liquid manure, carbon compounds which promote the microbial formation of N₂O were also entering the soil. The NH3 emissions after liquid manure fertilization on cultivated fields using a splash plate varied between 25 and 35% of the applied NH4+-N. By using a slurry cultivator which combines application with immediate incorporation, the NH3 emissions can be clearly reduced to 6% of the applied NH4+-N. Application with a drag hose, in comparison to using a splash plate, did not always result in an emission reduction; however, in taller plants, a readable emission reduction was measured. The N₂O emissions after liquid manure application on cultivated fields varied between 0.1 and 2.2% of the applied NH4+-N whereby the emissions after guided application with the drag hose were always higher than after using a splash plate. Mineral fertilizer had lower N2O emissions (<0.13% of applied N), especially when ammonium fertilizer was brought out in combination with a nitrification inhibitor. The incorporation of green manure crops notedly increased N₂O emissions. N₂O emission after the incorporation of legumes was especially high. In the container experiments, a diurnal rhythm of the N₂O and NH₃ flows in growing rape and vetch was observed. This indicated a stomatal flow of these gaseous nitrogen forms. N₂O emissions also occurred outside of the vegetation period at temperatures between 0 and 5°C, with the N₂O emissions from the nitrogen fertilized parcels being greater than the emissions from the unfertilized parcels. In container experiments, the N₂O emissions after freeze / thaw cycles were greater from white clover than from perennial rye grass. In fallow soil columns, the N₂O emissions after freeze / thaw cycles were especially high if the content of nitrate and water-soluble organic carbon in the soil was large. The results of this research show that the emission of nitrogen-containing compounds after organic and inorganic fertilization can be reduced through application methods (immediate incorporation), appropriate fertilization technology (addition of nitrification inhibitors), but also through fertilizer application under favourable weather conditions to include seasonal and volume adjustment of the fertilizer based on the growth requirements of the plants. Because high N₂O emissions can also occur at low temperatures, cultivation practices that influence the availability of mineral nitrogen and easily degradable organic substances in the soil during cold weather have a large impact on the N₂O emissions from agricultural land.
Grundlagenuntersuchungen zur Wirkung neuartiger Ureaseinhibitoren in der Nutztierhaltung
(2008) Reinhardt-Hanisch, Annett; Hartung, Eberhard
Due to the agreements held by Germany in international and national programmes to reduce climate and environmental deterioration particularly in relation to ammonia emissions from livestock housing, additional measures have to be taken in order to ensure that international and national objectives will be achieved. Within the framework of a BMBF-funded interdisciplinary research project, new types of urease inhibitors had been tested for application in animal housing. The present work shows the necessary basic studies, which formed the basis for the investigations under conditions similar stall conditions and in practice stall in the second part of the project (LEINKER, 2007). The main objective of the present work was to investigate the effect of different urease inhibitors on urea hydrolysis, and thus to quantify the ammonia release of urea applied on cattle slurry under standardized, reproducible and controlled laboratory conditions and to investigate possible influencing factors (Pre-screening). Subsequent objectives result in the following: development of an appropriate measuring system and implementation of a standardized test, study of various urease inhibitors at different substrate temperatures and inhibitor concentrations, selection of the urease inhibitor which has the best reduction effect, and quantification of other factors influencing the effect of the selected urease inhibitor. In order to assess the inhibitor effect, the protonated ammonium and the available ammonia in slurry should be detected by means of conducting slurry analysis. In addition, the first indications of a long-term effect of the selected urease inhibitor, its impact on biogas accumulation, and its effect on liquid swine manure should be derived. In order to carry out the investigations, a water-tank measuring system had been configured and validated. The 28 measuring tanks of the measurement system, where each tank was filled by 2 l of slurry, worked according to the principle of dynamic chamber and were kept at constant temperature using a water bath. A gas analysis based on NDIR spectroscopy had been used in order to sustain continuous measurement of ammonia concentrations in the measuring device. The standardized test, applied in the main experiments, had been developed in the preliminary experiments. Among the five pre screened urease inhibitors (four new active agents + reference NBTPT active ingredient), the urease inhibitor D is selected for further investigations in the project, as this is the best inhibitor having significant reduction effect, which was in general dependent on the substrate temperature and the inhibitor concentration in terms of ammonia release. For an effective reduction of ammonia release, it seems useful to deploy more often smaller quantities of the inhibitor. The urease inhibitor D showed a significant reduction effect regardless of the origin and the layer thickness of the respective liquid manure. In comparison with the urease inhibitor D treated variants, more urea is significantly converted to ammonia and ammonium-nitrogen at a layer thickness of 4 mm than at a layer thickness of 90 mm. Apart from the ammonia release, the resulting nitrogen balance of all the tests showed no indication of further significant gaseous nitrogen losses, e.g. as nitrous oxide. In the experiments, no significant influence of urease inhibitor D had been detected on the (urea independent) basic release of ammonia from the respective liquid manure resulting from the degradation of organic substances. In practice, this means that the use of urease inhibitors is only reasonable in the presence of urea. The preliminary related investigations showed that the duration effect of the urease inhibitor D is dependent on temperature; no adverse effects caused by the inhibitor D of treated slurry on the biogas accumulation. Similar relations, as in cattle slurry, had been recognized and showed for the urease inhibitor D in pig slurry. As part of the investigations, a urease inhibitor is selected for cattle and pig slurry urea hydrolysis, and thus the ammonia release is significantly reduced. The basic investigations afforded an important contribution to the expansion of knowledge in this area, and lead on the other hand to develop new techniques in order to reduce the ammonia emissions from livestock housing.
Modelling of particulate matter and ammonia emissions from German agriculture
(2016) Beletskaya, Olga; Zeddies, Jürgen
Agricultural production comes along with numerous environmental effects, such as contribution to climate change, harmful to health emission impacts as well as eutrophication and acidification of soils and waters. Political regulations and environmental protection measures at the national and international level shall support development of sustainable agriculture. The intention of this work is to analyze the alterations of particulate matter, ammonia, and greenhouse gas losses from German agriculture arising due to adaptations in agricultural and environmental policy, and to find out efficient PM and NH3emission abatement options. To show, how certain economic and political conditions and their adjustment over time do affect amount of NH3, PM, and GHG released from agriculture and to evaluate emission mitigation options, economic-ecological static integer linear model, EFEM (Economic Farm Emission Model), has been developed. Following exogenous parameters have been integrated into the model: emission factors and the activities data stemming from FADN (Farm Accountancy Data Network) and census databases. In EFEM farm structure, production activities and extrapolation tool are represented in the system of interrelated modules for five farm types, i.e., arable farms, forage-growing, mixed and intensive livestock farms (one with the emphasises on pig husbandry and another one specializing in poultry production). The modelling is done for three German counties and each of them has focus regions, which are exemplary for important sources of PM, NH3, and GHG emissions in agriculture. Thus, following study regions have been chosen: Baden-Württemberg characterized by forage growing prevailing there, Lower Saxony marked by intensive livestock productions and Brandenburg due to its sandy arable sites at risk of erosion. The individual scenarios analyse abatement and financial efficiency of the adjustments of emission sources. Emission sources are adjusted in the framework of the emission relevant agricultural production practice, as exclusion of urea from mineral fertilization practices, switching from slurry to solid manure based livestock housing systems, introduction of crude protein reduced feeding by pigs and poultry, environmentally friendly slurry storage and land application, reduced tillage, and installation of exhaust air treatment systems in pig barns. Relatively efficient abatement of NH3 results from the exclusion of urea from fertilization practice at farms and in regions with higher land endowments, the switch from liquid to solid manure based housing system for cattle and the injection of liquid manure into the soil and covering manure storage with granulate at farms and in regions with comparatively high livestock density. Efficient PM and GHG emission reductions, mainly due to carbon sequestration, follows the introduction of the reduced tillage. Installation of Exhaust Air Treatment Systems, such as one-stage and multiple-stage chemical scrubbers, results in relatively expensive but more efficient measure for the reduction of both NH3 and PM losses. Net benefit, as the difference between reduced costs of damage for human health and environment and mitigation costs, gives the insight into the effect of abatement measure for the overall economy. Among all scenarios analysed in this study, the emission abatement options assuring maximal net benefits and emissions reduction are combined together and suggested as the abatement strategy at the farm and policy level. The scenario results are compared with national emission abatement ratios proposed by the European Commission for the years between 2020 and 2029. However, this efficiency of each individual abatement measure varies for study regions due to their individual conditions. Increasing attention to environmental problems at the regional and global level requires higher contribution of scientists from all over the world to the definition of pollution and emission abatement status. This study demonstrates the relevance of further investigation of PM and NH3 emissions in and from agriculture and of the ways to abate them.
Nitrogen-rich and lignocellulosic biomass for biogas production : methane yield potentials, process stability and nutrient management
(2023) Morozova, Ievgeniia; Lemmer, Andreas
A sustainable energy supply and bio-based economic processes are of central importance for the future development of many Eastern European countries. Due to the large agricultural potentials of these countries, bioenergy systems can make a significant contribution to sustainable electricity and heat production if they are reasonably integrated into an energy supply structure based on various renewable energy sources. This requires the use of regenerative starting products and the complete utilisation of all by-products of the overall process. With such a cradle-to-cradle approach, biogas technology can be a central component of future energy systems. The focus of this study is on Ukraine. In the future, bioenergy villages can make a decentralised contribution to a sustainable energy supply in this country. This study aims to determine the methane yield potential of various energy crops from Ukraine, investigate the process stability during fermentation in biogas plants and derive concepts for optimized digestate management. Seven different crops with a total of 22 varieties were investigated for their specific biomass yields, methane yields and areal methane yields. The crops were cultivated in Ukraine. The biogas production potential of the collected crop samples was determined using the Hohenheim Biogas Test in Germany. The Ukrainian variety “Osinnii zoretsvit” of miscanthus, “Giganteus” species, from the 8th year of vegetation, harvested at the stem elongation stage, resulted in the highest areal methane yield of 7404.55 ± 199.00 m3*ha-1 and the lowest N requirement per unit methane produced (23.41 ± 7.18 gN*m-3) among all the studied crops. The maize variety "Svitanok MV" (FAO 250) had the highest value of areal methane yield of 6365.67 ± 55.49 m3*ha-1 among the annual crops when harvested at the stage of wax maturity; remarkable was its unusually high specific methane yield of 0.41 ± 0.00 m3*kg-1VS. The Ukrainian sugar sorghum variety "Favoryt", harvested at the beginning of flowering, had an areal methane yield of 5968.90 ± 82.70 m3*ha-1, making it an attractive alternative energy crop for Ukraine. In the second part of the work, experimental investigations were carried out to test how N-rich substrates influence the stability and efficiency of the biogas process. For this purpose, different variants with various N-increase rates of the input materials at two initial concentrations were evaluated in the laboratory. The continuous trials were conducted over a period of 33 weeks. The modelling procedure was applied to evaluate the effects of TAN (total ammonia nitrogen) and FAN (free ammonia nitrogen) on the degree of methane production inhibition for all scenarios studied. It was concluded that the higher the N-increase rate in the feeding regime, the more methane production is inhibited. The maximum nitrogen concentration in the digestate achieved during stable fermentation processes in this study was 11.5 g*kg-1FM, which corresponded to the values of TAN and FAN of 9.07 g*kg-1FM and 0.85 g*kg-1FM, respectively. These values are much higher than those reported up to now in the literature. At the same time, process efficiency decreased with increasing nitrogen concentrations. As a final step, the technology for nutrients recovery from digestate was developed and tested in this work. First, the digestate separation with a screw press separator was carried out as a "benchmark" at the research biogas plant "Unterer Lindenhof" on a technical scale. Subsequently, a methodology for digestate separation at laboratory scale was developed based on a tincture press, which corresponds to the technology used in practice. The effect of pretreatment of digestate with various biocoal-based additives was studied. In this study, six variants of biocoals synthesized at either 350 °C or 600 °C and partially impregnated with Mg or Ca before pyrolysis were produced. Different reaction times and conditions between the biocoals and the digestate were tested. The results on nutrient removal showed that the biocoals impregnated with Mg prior to pyrolysis had a positive effect on nutrient removal efficiency. The Mg-impregnated biocoal synthesised at 600 °C showed removal efficiencies for NH4+, P and K of 56.04%, 66.66% and 51.77%, respectively. These values were much higher than those for the control variant and much higher than the values found up to now in the literature. By using the nutrient-rich solid fraction of the digestate as fertiliser to cultivate bioenergy crops for further use in biogas production, the production cycle is closed, and the cradle-to-cradle approach is achieved.
Untersuchungen zum Emissionsgeschehen von Ammoniak und Methan in der Mastschweinehaltung
(2017) Gronow-Schubert, Stephanie; Gallmann, Eva
The growing of feed crops, the production of farm livestock and the processing of livestock products, along with the associated use of farmland for this entire production chain, all engender greenhouse gases on a worldwide scale. In this respect, ammonia and methane emissions are directly associated with livestock farming including the feeding of pigs for slaughter. The main aim of the work presented in this thesis was investigation of emissions produced in this way, and into selected strategies applied for reducing ammonia and methane release, particularly in management of liquid manure inside a fattening unit. In this context, the paper focusses on the three approaches – measuring, analysing and modelling - which are accordingly established as the following part-targets: • Applying emission reduction strategies as part of liquid manure management in a conventional fattening unit and comparing the resultant emissions with those from a reference system where no emission reduction actions had been taken. The selected emission reduction strategies should be practicable and sustainably applicable in existing livestock housing systems. • Analysing the main factors of influence on emissions throughout the fattening period during different seasons of the year, with special consideration of time series effects and regressions. • Examining the possibilities of substance flow modelling, application to own measurement data rather or for assessing the potential of emission reduction methods as well as evaluation of the selected approach for substance flow modelling. In-barn liquid manure management with fattening pigs markedly influences ammonia and methane emissions whereby the concrete reduction potentials are not yet sufficiently clarified. Within this study, a first work package compares, through a case control approach, the liquid manure management strategies - weekly emptying of the liquid manure channel as well as covering of the underfloor stored liquid manure surface as well as the addition of Effective Microorganisms to the liquid manure – with the strategies tested for emission reduction potential and compared over a feeding cycle in each case with the stored manure method as reference. The pig housing used in the trial was divided into two compartments (experimental and reference compartment) each holding 50 animals. In quasi-continuous measurement, incoming air, compartment and exhaust air ammonia and methane concentrations, temperatures of incoming air, compartment and exhaust air, and the temperature and pH of the liquid manure, were all recorded. Additionally, liquid manure samples were analysed in 14-day rhythm and the level of liquid manure measured as well as the degree of dirtiness of pen floors. Also recorded were pig weights and performance or feeding data. No further differences in terms of feeding, ventilation or management existed between trial and reference compartments. The applied reduction strategies were able to partially reduce ammonia and methane emissions (weekly emptying of liquid manure channel: methane emission rates reduced by 39 % based on emission rate in grams per day and livestock unit; liquid manure cover: 13.8 % ammonia emission rates reduction in grams per day and livestock unit), had in part no effect, or even a negative influence on the emissions (weekly emptying of the liquid manure channel: no effect on ammonia emissions; liquid manure cover: 119.9 % rise in methane emission rates in terms of grams per day and livestock unit). The selected interval of one week between emptying the liquid manure channel was not sufficient as a reduction strategy. With covering of the liquid manure surface underfloor, it is important to consider that the almost airtight sealing of the liquid manure surface delivered favourable conditions for methanogenesis. The influence of the addition of Effective Microorganisms to the liquid manure on the emissions of ammonia and methane was marginal. The emissions of ammonia increased of 8.3 % and the emissions of methane of 5.9 %. The evaluations (time series and regression analyses) of the data from the reference compartments from a total of four feeding cycles (two summer and two winter cycles) comprised the second work package. The time series analysis enabled insight into the relationships between the ammonia and methane emissions in terms of time, and insights into the influential factors affecting release and transport of the gases. For example, the time-related influences of high temperatures on the system “fattening unit” and on the release of emissions, could be graphically shown. The time series analysis gave indications as to how dynamic, or how stable, climatic conditions can be in pig housing. The regression analyses clearly showed that the emission process, with ammonia as well as with methane, is influenced particularly through the amount of liquid manure involved, the temperature and the air volume flow. In the same way, the distance between the liquid manure surface and the slatted flooring (‘headspace’) was found to have direct influence on the release of ammonia and methane from the liquid manure. A larger ‘headspace‘ correlated with reduced emissions and vice versa. Following recording and statistical evaluation of the emission data, the contribution that can be made through substance flow modelling of ammonia emissions towards increasing knowledge on the emission process and on methods for its reduction within pig housing was examined as a third work package. This involved the transfer of selected recorded data into the substance flow model. Serving as basis was the model from CORTUS et al. (2010a) adapted in three steps to take account of the conditions in the pig housing being used. The constructional outline of the trial livestock housing served as system limit. Berkeley Madonna 8.3.18 software was used for numerical integration of the differential equation system. Own data was applied for calibration and validation, in each case taken from the reference compartment of two different feeding cycles. In principle, the adapted model was capable of modelling ammonia concentrations and emissions. In addition, the influence of the liquid manure temperature and pH value of the liquid manure could be depicted. However, the model generally reacted sensitively to temperature and pH values. Because of this, the model underestimated and overestimated recorded values, in part substantially. An important influence on the model accuracy appeared to be related to the submodel considering urine puddles. For the purposes of own modelling, this submodel was cut out of the main model during its adaptation according to the recorded data. Compared to recordings, modelling of gas concentrations and emissions offers the advantage of cost-efficient and time-saving estimations of emission potential for different housing systems, e.g. for feeding pig production. Calibration and validation, as well as adaptation to suit the type of application requires, however, particular care and expertise. Through the various methods for measurement, analysis and modelling that were applied, the work reported here contributes to better understanding of the emission process and the reduction of emissions, particularly in the case of liquid manure management in feeding pig production.