Diplomová práce se zabývá spalováním zemního plynu při využití vzduchu s vyšším obsahem kyslíku (21–46 % kyslíku ve spalovacím vzduchu), tzv. kyslíkem obohaceným spalováním (OEC). Technologie OEC nalezla uplatnění v průmyslu, kde se jsou nároky na zvýšenou produktivitu, dosažení vyšší tepelné účinnosti, zlepšení vlastností plamene, snížení náklady, či zlepšení kvality výsledného produktu. Ačkoliv OEC přináší řadu výhod, je nutné zmínit i nevýhody jako: poškození zařízení, nestejnoměrné zahřívání, narušení plamene, zvýšené emise anebo zpětný zášleh plamene. Zkoušky proběhly na zkušebně hořáků, která umožňuje testovat hořáky nejen na plynná a kapalná paliva, ale i hořáky navržené pro kombinované spalování při maximálním výkonu hořáku 1 800 kW. Při zkouškách byl použit plynový „low-NOx“ hořák se stupňovitým přívodem paliva. V diplomové práci je popsán vliv obsahu kyslíku ve spalovacím vzduchu na emise oxidů dusíku (NOx), teplotu plamene, přenos tepla ze spalin do stěn spalovací komory, a také vlastnosti plamene, zvláště pak jeho stabilitu, tvar a rozměry. Zkoušky proběhly při výkonech 300 kW, 500 kW a 750 kW, přičemž pro výkon 750 kW proběhly testy jak při jednostupňové, tak dvoustupňové konfiguraci.

Studiens syfte var att studera en ombyggnation av SNCR-anläggningen i Filbornaverket, enavfallseldad rosterpanna, på uppdrag av Öresundskraft Kraft & Värme AB. Anledningen var attse om en minskning av NOx-utsläpp var möjlig då det innebär en minskning av försurning avskog och mark. Naturvårdsverket har som mål att minska mängden NOx-utsläpp genom attanvända sig av ekonomiska styrmedel.Filbornaverket är en panna på cirka 60 MW fjärrvärmeeffekt och 18 MW eleffekt. Metodensom användes var en jämförande metod. Ombyggnationen ledde till en minskning av NOxutsläppunder perioden oktober till november 2018 på 5,45% jämfört med samma period2017. Detta innebar en årlig besparing på cirka 250 000 kr i minskade NOx-avgifter tillNaturvårdsverket för Öresundskraft Kraft & Värme AB. Mängden insprutad ammoniak blev igenomsnitt 4,73% lägre 2018 jämfört med 2017. / This study examined the reconstruction of the SNCR equipment in Filbornaverket, a wasteburning grate boiler, on behalf of Öresundskraft Kraft & Värme AB. The purpose was to see ifa reduction of NOx was possible. A reduction of NOx means a reduction in acidification offorest and land. Naturvårdsverkets goal is to reduce the amount of NOx by using economiccontrol means.Filbornaverket is a boiler of about 60 MW district heating power and 18 MW electrical power.A comparative method was used in this study. The reconstruction lead to a reduced amountof NOx during the period October to November 2018 of 5,45% compared to same period2017. This means an annual saving of around 250 000 kr in reduced NOx-fees toNaturvårdsverket for Öresundskraft Kraft & Värme AB. The amount of injected ammonia wasin average 4,73% lower during 2018 compared to 2017.

One major aspect of environmental pollution affecting human life and climate is air pollution. The harmful pollutants in the air include mostly hydrocarbons, carbon monoxide, carbon dioxide, nitrogen oxides as well as soot and other particulate matter. These pollutants result in several damaging effects on environment and living beings which include acid rain, photochemical smog, global warming and various health hazards in human beings even cancer. Major contribution of these pollutants is from man-made sources such as industrial and automotive emissions that employ fossil fuels. In our country, diesel constitutes more than 40% of the fossil fuel consumption. Studies show that diesel engine emissions contribute to 80% of nitrogen oxides amongst other air pollutants. In the context of stringent emission regulations being implemented all over the world, exhaust emission control, in general and nitrogen oxide emission in particular, is gaining significant importance. A review of recent literature indicates the significance and popularity of electrical discharge based non thermal plasma for exhaust cleaning applications in general, and NOx cleaning in particular. While the existing pre-combustion and catalyst based post-combustion nitrogen oxides (NOx) abatement techniques have inherent disadvantages owing to short shelf life, saturated engine modifications, cost concerns etc., the electrical discharge based non- thermal plasma techniques offer certain advantages in terms of cost and life factors. Several non-thermal plasma techniques viz., pulsed plasma, surface plasma, dielectric barrier discharge plasma etc., have been studied under different laboratory conditions. Interestingly, due to the high oxidizing environment that prevails in the discharge plasma zone, complete reduction of NOx by the plasma alone is becoming a challenging task. This has led the researchers to utilize additional processing techniques in cascade with discharge plasma. This additional gas cleaning technique may involve the use of adsorbents, catalysts or some other secondary treatment for eliminating the nitrogen oxides produced due to oxidizing reactions in the plasma chamber. One such additive can be an adsorbent, which can be commercially obtained or prepared from industrial wastes. In this thesis the adsorption properties of two industrial wastes were explored for the first time in conjunction with discharge plasma. The synergistic effect of plasma combined with an adsorbent shows promising results in NOx removal thus offering an effective solution to two environmental issues namely air pollution and open waste dumping. While the plasma, generally, refers to direct plasma treatment of exhaust, it can also be used for generation of ozone in a separate reactor which can subsequently be injected into the exhaust stream resulting in indirect plasma treatment. The current work focuses on both direct and indirect dielectric barrier discharge plasma treatment for NOx reduction in diesel engine exhaust cascaded with either oyster shells, a mariculture waste or lignite ash from lignite coal fired plant. Instead of conventional petro-diesel, biodiesel produced from the seeds of pongamia pinnata is used as the fuel. This biofuel, on one hand, causes considerable reduction in volatile organic compounds, particulate matter, soot, oil mist etc., but on the other hand may have higher concentrations of nitrogen oxides, an aspect that has motivated us to take up the research work envisaged in this thesis. It was observed in the laboratory environment that for a given power, both direct and indirect plasma treatments have resulted in NOx removal to the tune of 85 to 95% when cascaded with the adsorbents studied.

The thesis is focused on the experimental investigation of the oxygen enhanced combustion technology (OEC), which uses the combustion air with higher concentration of oxygen, i.e. more than 21 %. The OEC technology is used in those industrial applications, which requires higher thermal efficiency, increased productivity, improved character of the flame, reduced equipment cost, lower volume of exhaust gases and improved product quality. Although this technology involves a number of advantages, it is appropriate to mention some of its disadvantages such as refractory damage, inconsistent heating, increased pollutant emission or flame disturbance and/or flashback. The combustion tests of OEC were carried out at the burners testing facility that enables to test many types of burners (gaseous, liquid, or combined). The two-staged low-NOx burner fired by natural gas was used during the tests. The observed parameters include the effect of oxygen concentration in the combustion air on the NOx emissions, heat flux into the wall of the combustion chamber, in-flame temperature distribution in the horizontal symmetry plane of the combustion chamber and also the shape and dimensions of the flame. The combustion tests of the air-enrichment, air-oxy/fuel and O 2 lancing OEC methods were carried out at the burner thermal input of 750 kW and air excess of 1,1 for two combustion regimes, namely one-staged and two-staged fuel supply.