Removal Of SOx Research Articles

Simultaneous absorption of SO2 and NOx from simulated flue-gas exploiting the enhancing oxidative ability of aqueous euchlorine as scrubbing solution

This paper reports the performances of a pilot-scale Wet Oxidative Scrubber (WOS) in the treatment of a simulated flue-gas containing 500 ppmv SO2 and 1030 ppmv NOx and operated at 60 °C and 1 atm. The scrubber is fed with an oxidizing solution containing NaClO2 at either 0.75 % or 1 % w/w initially at pH > 9 and then acidified to pH down to 3 with HCl, to obtain the additional oxidative contribution given by euchlorine species during the simultaneous absorption. Further experiments of single-component NOx absorption are performed to better understand the role exerted by SO2 in the simultaneous absorption. These experimental tests are carried out to investigate the effect of the acidity of the chlorite-based scrubbing solution on the simultaneous absorption performance of SO2 and NOx, highlighting the intensification with respect to the bare de-NOx system. Experiments also allow determining the optimal dosages and solution pH for a complete and optimized removal of NOx and SOx also being less energy-intensive. For a scrubbing solution under acid-induced conditions (pH = 3), the retrieved results show that the NaClO2 molar dosage needed for a complete simultaneous removal results 3.6 times greater than the total NOx concentration in the flue-gas. This allows an interesting reduction of 83 % in oxidant consumption and a water-saving of 70 % with respect to the same process applied to the simultaneous NOx absorption but without altering the solution pH. Overall, the results confirm the enhancing role exerted by euchlorine deriving from chlorite acidification and sulfur dioxide presence in the flue-gas.

Combined removal experiment of NOx, SO2 and PM from marine diesel exhaust gas with SCR-DryEGCS system

Pollutants such as nitrogen oxides (NOx), sulfur oxides (SO2), and particulate matter (PM) in ship exhaust have a great impact on human health, environment and climate conditions. Combined selective catalytic reduction technology and dry exhaust gas cleaning technology, a test rig (SCR-DryEGCS system) for WD10C195-15 marine four-stroke high speed diesel engine was established to analyse the removal effect of NOx, SO2, and PM from exhaust gas. The SCR-DryEGCS system removed 89.03%, 99%, and 96% of NOx, SO2, and PM respectively. And also compared with low sulfur oil combined SCR method to verify the feasibility of the SCR-DryEGCS method. It shows that the SCR-DryEGCS system has its own advantages and has a good effect on the removal of NOx, SOx, and PM at the same time.

Actual NOX and SOX removal rates in the atmospheric environment of concrete permeable blocks containing TiO2 powders, coconut shell powders, and zeolite beads

This study examined actual nitrogen oxide (NOX) and sulfur oxide (SOX) removal rates of concrete permeable blocks in the atmospheric environment. To give the concrete permeable block a NOX and SOX removal function, TiO2 submicron particle or coconut shell powder was embedded in the surface layer, and zeolite bead was embedded in the base layer. Using an actual factory production line, concrete permeable block specimens were prepared by adding TiO2 submicron particles and coconut shell powder to the surface layer of the concrete permeable block. The prepared concrete permeable block specimens were placed in a parking lot, and then NOX and SOX removal rates were directly measured for 6 months on the concrete permeable block specimens placed in the parking lot. Test results showed that the clear day removal rates of NOX and SOX for the concrete permeable block specimens embedded with TiO2 submicron particles during the day was 84% and 70%, respectively. Compared to the concrete permeable blocks embedded with coconut shell powder, the NOx removal rate of the specimens embedded with TiO2 submicron particles was 1.45 times higher, while the SOx removal rate was similar. However, during cloudy days and nights, the NOX removal rate of the concrete permeable block specimens embedded with TiO2 submicron particles was zero. On the other hand, NOX and SOX removal rates of the concrete permeable block specimens embedded with coconut shell powder and zeolite bead were maintained at approximately 51% and 77% for 6 months, respectively, in the atmospheric environment regardless of weather and day light conditions. Consequently, the coconut shell powder added to the surface layer of the concrete permeable block is a practically promising material in reducing the NOX in the atmospheric environment regardless of weather and day light conditions.

Technological solutions for NOx, SOx, and VOC abatement: recent breakthroughs and future directions.

NOx, SOx, and carbonaceous volatile organic compounds (VOCs) are extremely harmful to the environment, and their concentrations must be within the limits prescribed by the region-specific pollution control boards. Thus, NOx, SOx, and VOC abatement is essential to safeguard the environment. Considering the importance of NOx, SOx, and VOC abatement, the discussion on selective catalytic reduction, oxidation, redox methods, and adsorption using noble metal and non-noble metal-based catalytic approaches were elaborated. This article covers different thermal treatment techniques, category of materials as catalysts, and its structure-property insights along with the advanced oxidation processes and adsorption. The defect engineered catalysts with lattice oxygen vacancies, bi- and tri-metallic noble metal catalysts and non-noble metal catalysts, modified metal organic frameworks, mixed-metal oxide supports, and their mechanisms have been thoroughly reviewed. The main hurdles and potential achievements in developing novel simultaneous NOx, SOx, and VOC removal technologies are critically discussed to envisage the future directions. This review highlights the removal of NOx, SOx, and VOC through material selection, properties, and mechanisms to further improve the existing abatement methods in an efficient way.

Seawater bittern recovery system for CO2, SOx and NOx removal using microbubble scrubber

In salt production, a considerable amount of seawater bittern is discharged, which contains valuable metal ions such as K+ and Mg2+. These metal ions react with sulfate and carbonate ions and can be used to isolate air pollutants. Here, this work developed a seawater bittern recovery process using a novel microbubble scrubber with the aim of CO2, SOx, and NOx reduction. The low equipment cost and compactness of the microbubble scrubber makes it highly compatible to industrial applications. In addition, it removes air pollutants using only distilled water, which is environmentally and economically desirable. To design the proposed system, a process model is developed based on the experimental results for the developed microbubble scrubber. The suggested process comprises the following four procedures: (1) metal ion separation for KOH and Mg(OH)2 production, (2) CO2 capture using the produced KOH, (3) SOx and NOx capture using the microbubble scrubber, and (4) sulfurization and carbonation using the generated Mg(OH)2. The experimental results show that 98 % and 99 % of the CO2 and SOx can be captured and utilized as CaCO3 and CaSO4, respectively. Finally, the payback period (PBP) of the proposed process is determined to be 0.5 y, confirming its economic feasibility.

Nano Pt/TiO2 photocatalyst for ultrafast production of sulfamic acid derivatives using 4-nitroacetanilides as nitrogen precursor in continuous flow reactors

The design of reactors based on high performance photocatalysts is an important research in catalytic hydrogenation. In this work, modification of titanium dioxide nanoparticles (TiO2 NPs) was achieved by preparation of Pt/TiO2 nanocomposites (NCs) through photo-deposition method. Both nanocatalysts were used for the photocatalytic removal of SOx from the flue gas at room temperature in the presence of hydrogen peroxide, water, and nitroacetanilide derivatives under visible light irradiation. In this approach, chemical deSOx was achieved along with protection of the nanocatalyst from sulfur poising through the interaction of the released SOx from SOx-Pt/TiO2 surface with p-nitroacetanilide derivatives to produce simultaneous aromatic sulfonic acids. Pt/TiO2 NCs have a bandgap of 2.64 eV in visible light range, which is lower than the bandgap of TiO2 NPs, whereas TiO2 NPs have a mean size of 4 nm and a high specific surface area of 226 m2/g. Pt/TiO2 NCs showed high photocatalytic sulfonation of some phenolic compounds using SO2 as a sulfonating agent along with the existence of p-nitroactanilide derivatives. The conversion of p-nitroacetanilide followed the combination processes of adsorption and catalytic oxidation–reduction reactions. Construction of an online continuous flow reactor–high-resolution time-of-flight mass spectrometry system had been investigated, realizing real-time and automatic monitoring of completion the reaction. 4-nitroacetanilide derivatives (1a-1e) was converted to its corresponding sulfamic acid derivatives (2a–2e) in 93–99% isolated yields of within 60 s. It is expected to offer a great opportunity for ultrafast detection of pharmacophores.

Designing direct redox reaction chemically coupling NO and SO2 removal

A novel simultaneous removal strategy for NO and SO2 was proposed to meet the increasingly strict emission requirements, i.e. triggering the direct redox reaction between two pollutants (SO2 + NO + O2− = SO42− + 1/2N2), which chemically couples SOx and NOx removal and prevents the possible competition between DeNOx and DeSOx reactions. In this fundamental study, we tailor-made an efficient Pd-La1.5Co0.5O3 catalyst that accelerated the designed reaction to an industrially applicable level, achieving a prominent SO2 adsorption capacity of 2465.2 μmol g−1 and NO reduction capacity of 1891.3 μmol g−1 over 60 min when SO2 and NO are simultaneously fed at 680 °C. Over this catalyst, SO2 adsorbed on the La site underwent disproportionation via sulfite intermediate into oxysulfate and sulfide, which gave access to NO reduction. Co in the catalyst played a complex role. The active oxygen species binding to Co3+ in perovskite competed with NO in SO2 oxidation. However, this generated Co2+ that was found to take part in sulfite disproportionation through forming Co9S8, which accelerated the disproportionation and NO reduction. The catalyst is promising to be industrially applied as an additive of the FCC catalyst or flue gas aftertreatment catalyst and exhibited 45 % higher DeNOx efficiency and 28 % higher DeSOx efficiency in a simulated catalytic cracking/coke combustion cycle than the commercial additives. The findings open a new avenue for the development of novel environmentally benign and cost-effective simultaneous removal technology.

Advances in air pollution control for key industries in China during the 13th five-year plan

Industrial development is an essential foundation of the national economy, but the industry is also the largest source of air pollution, of which power plants, iron and steel, building materials, and other industries emit large amounts of pollutants. Therefore, the Chinese government has promulgated a series of stringent emission regulations, and it is against this backdrop that research into air pollution control technologies for key industrial sectors is in full swing. In particular, during the 13th Five-Year Plan, breakthroughs have been made in pollution control technology for key industrial sectors. A multi-pollutant treatment technology system of desulfurization, denitrification, and dust collection, which applies to key industries such as power plants, steel, and building materials, has been developed. High-performance materials for the treatment of different pollutants, such as denitrification catalysts and desulfurization absorbers, were developed. At the same time, multi-pollutant synergistic removal technologies for flue gas in various industries have also become a hot research topic, with important breakthroughs in the synergistic removal of NOx, SOx, and Hg. Due to the increasingly stringent emission standards and regulations in China, there is still a need to work on the development of multi-pollutant synergistic technologies and further research and development of synergistic abatement technologies for CO2 to meet the requirements of ultra-low emissions in industrial sectors.

A direct contact cooler design for simultaneously recovering latent heat and capturing SOx and NOx from pressurized flue gas

Integrated SOx and NOx removal technology using a direct contact cooler is a promising alternative for cleaning coal combustion flue gas, especially for pressurized combustion systems. Past investigations of integrated SOx and NOx removal have been limited to low-temperature processes, where the flue gas has been cooled upstream of the removal unit, and the moisture in the flue gas has been condensed out. This work presents a novel design that recovers the flue gas heat while simultaneously removing SOx and NOx in a single reactive-absorption column – direct contact cooler. A validated model was used to evaluate different direct contact cooler designs. Modeling results suggested that a counter-current column with a single water inlet can scrub 83% of the NOx and 96.5% of the SOx in 115 s, while an optimized design with multiple water inlets enhances the scrubbing of NOx by 9 percentage points and SOx by 3.5 percentage points, due to a 34% increase in residence time. It is also observed that the liquid-phase reaction between absorbed SOx and NOx plays a significant role in the removal of SO2 from the flue gas for high-temperature scrubbing compared with low-temperature scrubbing. The design reinforces the potential of high-temperature SOx-NOx removal and heat recovery and suggests a means of reducing capital costs for such columns.

Porous Ceramics Adsorbents Based on Glass Fiber-Reinforced Plastics for NOx and SOx Removal.

To reuse waste glass fiber-reinforced plastics (GFRPs), porous ceramics (i.e., GFRP/clay ceramics) were produced by mixing crushed GFRP with clay followed by firing the resulting mixture under different conditions. The possibility of using ceramics fired under a reducing atmosphere as adsorbent materials to remove NOx and SOx from combustion gases of fossil fuels was investigated because of the high porosity, specific surface area, and contents of glass fibers and plastic carbides of the ceramics. NO2 and SO2 adsorption tests were conducted on several types of GFRP/clay ceramic samples, and the gas concentration reduction rates were compared to those of a clay ceramic and a volcanic pumice with high NO2 adsorption. In addition, to clarify the primary factor affecting gas adsorption, adsorption tests were conducted on the glass fibers in the GFRP and GFRP carbides. The reductively fired GFRP/clay ceramics exhibited high adsorption performance for both NO2 and SO2. The primary factor affecting the NO2 adsorption of the ceramics was the plastic carbide content in the clay structure, while that affecting the SO2 adsorption of the ceramics was the glass fiber content.

Recent Breakthroughs and Advancements in NOx and SOx Reduction Using Nanomaterials-Based Technologies: A State-of-the-Art Review.

Nitrogen and sulpher oxides (NOx, SOx) have become a global issue in recent years due to the fastest industrialization and urbanization. Numerous techniques are used to treat the harmful exhaust emissions, including dry, traditional wet and hybrid wet-scrubbing techniques. However, several difficulties, including high-energy requirement, limited scrubbing-liquid regeneration, formation of secondary pollutants and low efficiency, limit their industrial utilization. Regardless, the hybrid wet-scrubbing technology is gaining popularity due to low-costs, less-energy consumption and high-efficiency removal of air pollutants. The removal/reduction of NOx and SOx from the atmosphere has been the subject of several reviews in recent years. The goal of this review article is to help scientists grasp the fundamental ideas and requirements before using it commercially. This review paper emphasizes the use of green and electron-rich donors, new breakthroughs, reducing GHG emissions, and improved NOx and SOx removal catalytic systems, including selective/non-catalytic reduction (SCR/SNCR) and other techniques (functionalization by magnetic nanoparticles; NP, etc.,). It also explains that various wet-scrubbing techniques, synthesis of solid iron-oxide such as magnetic (Fe3O4) NP are receiving more interest from researchers due to the wide range of its application in numerous fields. In addition, EDTA coating on Fe3O4 NP is widely used due to its high stability over a wide pH range and solid catalytic systems. As a result, the Fe3O4@EDTA-Fe catalyst is projected to be an optimal catalyst in terms of stability, synergistic efficiency, and reusability. Finally, this review paper discusses the current of a heterogeneous catalytic system for environmental remedies and sustainable approaches.

SOx removal and emission characteristics of WFGD system applied in ultra-low emission coal-fired power plants

In this paper, SOX (SO2 and SO3) removal and emission characteristics of wet limestone-gypsum flue gas desulfurization (WFGD) are investigated based on the data collected from 95 ultra-low emission coal-fired power units. The study shows that the overall removal efficiency of single-absorber is above 97.5%, in which the SO3 removal efficiency is between 31% and 70%. When the inner structures are installed into the spray absorber, the correlation between the inlet SO2 concentration and SOX removal efficiency becomes more obvious, however, with a tray absorber, the maximum SO2 removal efficiency of double-absorber reaches 99.74%, in which the SO3 removal efficiency is between 27% and 81%. With a normal spray absorber, the higher inlet concentration, the higher removal efficiency it reaches, while with a tray absorber, the result is opposite. With a single-absorber, there is little correlation between flue gas temperature drop and SO2 removal efficiency. Large temperature drop harms the improvement of overall SO2 removal efficiency but is beneficial to SO3 removal. By the calculation of SOX emission performance model, average emission performances of SO2 and SO3 are acquired, which are about 90–107 mg/(kW·h) and 81–97 mg/(kW·h), respectively.

Yellow phosphorus and Potash for SOX and NOX removal

ABSTRACT Flue gases emitted from the industries and other emission sources are considered the main atmospheric issues. The main Flue gases emitted are sulfur oxides SOX and Nitrogen oxides NOX. The study was about methods of removing SOX and NOX from emitted gases and the possibility of deriving useful byproducts. The process for removing was investigated using different absorbers, process conditions, and phosphorus allotropes. The yellow phosphorus (P4) was applied for removal accompanied by Potash. The simultaneous removal achieved higher removing efficiency for SOX than NOX. Yellow phosphorus emulsion proved to be one of the effective SOX and NOX removal techniques. Byproducts produced from SOX and NOX proved to contain the complete fertiliser Nitrogen Phosphorus Potassium NPK. The obtained results showed that several useful byproducts can be derived from SOX and NOX removal process.

A kinetic evaluation and optimization study on NOx reduction by reburning under pressurized oxy-combustion

Pressurized oxy-combustion is an emerging and more efficient technology for carbon capture, utilization, and storage than the first generation (atmospheric) oxy-combustion. NOx is a major conventional pollutant produced in pressurized oxy-combustion. In pressurized oxy-combustion, the utilization of latent heat from moisture and removal of acid gases (NOx and SOx) are mainly conducted in an integrated direct-contact wash column. Recent studies have shown that NOx particular inlet concentration should be maintained before direct contact wash column to remove NOx and SOx efficiently. As a result, minimizing NOx for environmental reasons, avoiding corrosion in carbon capture, utilization, and storage, and achieving effective NOx and SOx removal in direct contact wash columns are crucial. Reburning is a capable and affordable technology for NOx reduction; however, this process is still less studied at elevated pressure, particularly in pressurized oxy-combustion. In this paper, the kinetic evaluation and optimization study on NOx reduction by reburning under pressurized oxy-combustion was conducted. First, the most suitable mechanism was selected by comparing the results of different kinetic models with the experimental data in literature at atmospheric and elevated pressures. Based on the validated mechanism, a variety of parameters were studied at high pressure, i.e., comparing the effects of oxy and the air environment, different reburning fuels, residence time, H2O concentration, CH4/NO ratio, and equivalence ratio on the NO reduction. The results show that de-NOx efficiency in an oxy environment is significantly enhanced compared to the air environment. Improvement in the de-NOx efficiency is considerably higher with a pressure increase of up to 10 atm, but the effect is less prominent above 10 atm. The formation of HCN is significantly reduced while the N2 formation is enhanced as the pressure increases from 1 to 10 atm. The residence time required for the maximum NO reduction decreases as the pressure increases from 1 atm to 15 atm. At the higher pressure, the NO reduction rises prominently when the ratio of CH4/NO increases from 1 to 2; however, the effect fades after that. At higher pressure, the NO reduction by CH4 reburning decreases as the H2O concentration increases from 0 to 35%. The optimum equivalence ratio and high pressure for maximum NO reduction are 1.5 and 10 atm, respectively. This study could provide guidance for designing and optimizing a pressurized reburning process for NOx reduction in POC systems.

Production of the complete fertilizer with simultaneously removing sulfur oxides and nitrogen oxides using yellow phosphorus

Flue gases proved to have several human and environmental problems. Although they are many, SOX and NOX are the most famous, due to their direct human, animal, and plant effect. Thus, their removal represents one of the main concerns worldwide. Whereas there are several available techniques for this task, herein we applied a unique method through the white/yellow phosphorus (P4). Our target was to achieve the simultaneous removal together with obtaining the complete fertilizer Nitrogen, Phosphorus, Potassium (NPK). The removal efficiency investigated with and without the ozone, SOX and NOX removal reach 100% at a faster time with the ozone existence. Also, examining the optimal P4 weight that was 0.5 g, furthermore, the optimum stirring intensity proves to be 1083 rpm, additionally, the optimum temperature was 55 °C, finally, it was compared with the most famous absorbers. The system efficiency was tested in a special experiment, furthermore, the reaction mechanism was identified together with testing the solid precipitate using Raman spectroscopy and X-Ray Diffraction (XRD).

Pilot-scale testing of direct contact cooler for the removal of SOx and NOx from the flue gas of pressurized oxy-coal combustion

To attain the purity standard for carbon sequestration, SOx and NOx must be removed from the flue gas of pressurized oxy-combustion of coal. Studies suggest that at high pressure SOx and NOx can be simultaneously removed in a single column, with water as the working fluid. Additionally, in pressurized oxy-combustion the moisture in the flue gas can be recovered at high temperature. However, to date, experimental investigations in pressurized oxy-combustion environments have been largely limited to laboratory scale and room temperature. This work demonstrates the operation and parametric testing of an experimental pilot-scale direct contact column with a diameter and packing height of 0.2 m and a 2.3 m, respectively, over a temperature range from 24 to 202 °C, O2 concentration from 1 to 4% v/v, and S/N ratio from 0 to 2. Additionally, a model of the direct contact column is developed and simulated in Aspen Plus to complement and interpret the experimental results. The study reveals that NO oxidation is the controlling reaction in the overall scrubbing of SOx and NOx at gas temperatures up to 200 °C. The NOx scrubbing efficiency depends on residence time in the column, with higher than 90% removal at a residence time of 120 s. Oxygen concentration has little effect above a concentration of 1% v/v. At high temperature, the total NOx scrubbing efficiency is reduced by approximately 10%, as compared to room temperature. SOx removal is higher than 93% under all conditions. Scrubbing efficiency at different S/N ratios demonstrate the importance of NOx in sulfur scrubbing and confirm that a low NOx concentration in the flue gas can lead to a significant reduction in SOx scrubbing.

NO X and SO X Flue Gas Treatment System Based on Sulfur-Enriched Organic Oil in Water Emulsion.

Nitrogen (NOX) and sulfur (SOX) oxides, the major gaseous pollutants emitted from fossil fuel combustion, have significant health and environmental concerns. Environmental regulations limit these pollutant emissions to tolerable levels. Currently, these pollutants are treated by flue gas desulfurization (SOX removal) and selective catalytic reduction (NOX removal) processes. However, these technologies require large footprints, use expensive catalysts, and operate under high working temperatures. A new catalyst is reported herein, based on sulfur-enriched oil emulsified with water, where the active catalytic species are sulfur-based oxides. The catalyst has been developed using O2 as the oxidation reagent in a low-temperature wet scrubber rather than H2O2 or O3 that are presently used. The catalytically oxidized pollutants are converted to produce ammonium fertilizers by NH4OH addition. As a result of treatment with this novel catalyst, we observed reductions in emissions of SOX and NOX of >85% and 23%, respectively. The catalyst production and the wet scrubbing process are discussed in detail.

Simultaneous removal of CO2, NOx and SOx using single stage absorption column

Capturing flue gases often require multiple stages of scrubbing, increasing the capital and operating costs. So far, no attempt has been made to study the absorption characteristics of all the three gases (NO, SO2 and CO2) in a single stage absorption unit at alkaline pH conditions. We have attempted to capture all the three gases with a single wet scrubbing column. The absorption of all three gases with sodium carbonate solution promoted with oxidizers was investigated in a tall absorption column. The absorbance was found to be 100% for CO2, 30% for NO and 95% for SO2 respectively. The capture efficiency of sodium carbonate solution was increased by 40% for CO2 loading, with the addition of oxidizer. Absorption kinetics and reaction pathways of all the three gases were discussed individually in detail.

Understanding the effect of CaO on HCN conversion and NOx formation during the circulating fluidized combustion process using DFT calculations

Hydrogen cyanide (HCN) is an important intermediate during the conversion of fuel nitrogen to NOx. The mechanism of HCN oxidation to NO, N2, and N2O on the CaO (100) surface model was investigated using density functional theory calculations to elucidate the effect of in-furnace SOx removal on HCN oxidation in circulating fluidized bed boilers. HCN adsorption on the CaO (100) surface releases as high as 1.396 eV and the HC bond is strongly activated. The CaO (100) surface could catalyze the oxidation of CN radical to NCO with the energy barrier decreasing from 1.560 eV for the homogeneous case to 0.766 eV on the CaO (100) surface. The succeeding oxidation of NCO by O2 forming NO is catalyzed by the CaO (100) surface with the energy barrier decreasing from 0.349 eV (homogeneous process) to 0.026 eV on the CaO (100) surface, while the reaction between NCO and NO forming either NO or N2 is prohibited in comparison with corresponding homogeneous routes. The rate constants of these reactions under fluidized bed combustion temperature range are provided, and the calculation results lead to the conclusion that CaO (100) surface catalyzes the HCN conversion and improves the NO selectivity during HCN oxidation in the HCN/O2/NO atmosphere, which could well explain previous experimental observations. Kinetic parameters of HCN oxidation on the CaO (100) surface are provided in the Arrhenius form for future kinetic model development.

Kinetic study and optimization on SNCR process in pressurized oxy-combustion

Pressurized Oxy-combustion is one of the most promising technologies for carbon capture, utilization, and storage (CCUS) of coal utilization. In pressurized oxy-combustion, the removal of acid gas pollutants and the latent heat of moisture condensation are mainly carried out by an integrated direct-contact wash column (DCC). Recent studies have shown that the inlet concentration of NOx in the column is important for the combined removal of NOx and SOx, therefore, it is essential to control the NOx emissions before the DCC. Selective non-catalytic reduction (SNCR) is a promising and economical technology of NOx reduction; however, no study has been conducted on SNCR at elevated pressure, especially in pressurized oxy-combustion. In this paper, kinetic modeling is carried out to explore and optimize the NOx reduction by SNCR in pressurized oxy-combustion. First, the detailed mechanism used in this study is validated by the experimental results in literature. Based on the validation of the detailed mechanism, the effects of different parameters including temperature, oxygen concentration, moisture content, NH3 concentration, and SO2 concentrations on the SNCR performance are analyzed at higher pressures in oxy-combustion atmosphere. The modeling results show that by increasing the pressure from 1 atm to 15 atm, the SNCR de-NOx efficiency increased by 2–3%. The width of the optimum temperature window for maximum De-NOx is broadened from 1250K to 1450K with increasing the pressure from 1 atm to 10 atm. The increase of pressure has no significant effect on thermal de-NOx efficiency with increasing the NH3/NO ratio. At higher pressure (10 atm) the increase in O2 concentration from 1 to 20% the de-NOx efficiency decreases almost twice as much as at 1 atm. The increase of SO2 and moisture contents at high pressure have no significant effect on the de-NOx efficiency. Rate of production (ROP) and sensitivity analysis are performed to determine the dominant reaction paths of de-NOx in pressurized-oxy SNCR process. This study can provide guidance for the process optimization of de-NOx by SNCR in pressurized oxy-combustion.