Cold DeNOx development for oxyfuel power plants

Winkler, Florian; Schoedel, Nicole; Zander, Hans‐Jörg; Ritter, Roland

doi:10.1016/j.ijggc.2011.05.007

Cited by 16 publications

(9 citation statements)

References 5 publications

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“…It is well-accepted that the gas-phase reaction of NO x species is complex, and the major species in the gas phase include NO, NO 2 , N 2 O 4 , and N 2 O 3 . Winkler et al 36 suggested that N 2 O 3 could be excluded to be present in the gas phase with regard to the thermal dynamic equilibrium of the different NO x species. N 2 O 4 exists as the dimer of NO 2 as a result of the chemical equilibrium but plays a minor role in Hg 0 removal.…”

Section: Methodsmentioning

confidence: 99%

Effect of Acid Gases on Elemental Mercury Removal in an Oxy-fuel CO₂ Compression Process

Huang

Luo

et al. 2017

Energy Fuels

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Oxy-fuel combustion is considered as one of the most promising options for capturing CO2 from coal-fired power plants. Oxy-fuel flue gas contains traces of gaseous elemental mercury (Hg0) impurity, which accumulate in the CO2 compression units, causing severe damage to the aluminum heat exchangers. It is of great interest that the co-capture of flue gas impurities, such as nitrogen oxide (NO x ) and elemental mercury, could be achieved in a CO2 compression system at a high pressure. Currently, most of the studies associated with Hg0 removal were conducted on traditional gas-cleaning devices at atmospheric pressure. It has been demonstrated that both NO x and SO2 from flue gas played a significant role in Hg0 reactions at atmospheric pressure in O2/CO2 (oxy-combustion) or O2/N2 (air-fired) conditions. However, the effect of those acidic gases on elemental mercury removal in the oxy-fuel compression system at high pressures was unclear. In this work, gas-phase Hg0 oxidation by NO x and SO2 was experimentally performed at the simulated O2/N2 and O2/CO2 atmospheres at pressures up to 2.5 MPa. It was found that Hg0 removal was dependent upon the concentration of NO2 in flue gas and primarily achieved by gas-phase reactions between Hg0 and NO2. High pressure dramatically enhanced the oxidation of NO to NO2. Thus, the flue gas impurity Hg0 could be efficiently removed through reacting with NO2 in the CO2 compression purification units. SO2 hardly reacted with Hg0 but affected the reaction of Hg0 and NO2. The presence of SO2 inhibited mercury removal especially at high pressures because of the decreased NO2 concentration through the reaction with SO2 and the decomposition of HgO to Hg0 by SO2. The presence of CO2 made the Hg0 removal rate less dependent upon the pressure. The removal behavior of Hg0 in the O2/CO2 atmosphere was similar to that in the O2/N2 atmosphere at pressures lower than 1.0 MPa. With the increasing pressure, the removal rate of Hg0 in the O2/CO2 atmosphere was lower than that in the O2/N2 atmosphere.

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Section: Methodsmentioning

confidence: 99%

Effect of Acid Gases on Elemental Mercury Removal in an Oxy-fuel CO₂ Compression Process

Huang

Luo

et al. 2017

Energy Fuels

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“…Oxy-fuel combustion has a great potential to directly reduce CO 2 emission from a coal-fired power plant − and produces a CO 2 -rich stream that contains nitrogen oxides (NO x ) and sulfur oxides (SO 2 ). , Depending on the specifications of the CO 2 transportation and utilization/storage, NO x and SO 2 in a CO 2 -rich stream have to be removed accordingly. − …”

Section: Introductionmentioning

confidence: 99%

“…6−9 Generally, the mature technology is used to remove the SO 2 in the flue gas under atmospheric pressure, and then the NO x is removed under high pressure. Linde 6 proposed using FGD to remove 95−99% of the SO 2 in the flue gas. After pressurization, NO in the flue gas is oxidized to produce soluble NO 2 and then absorbed by ammonia solution to form ammonium nitrite, which is heated to 120 °C to decompose into N 2 .…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Absorption of NO_x and SO₂ into Water and Acids under High Pressures

Qian

Liu

et al. 2020

Energy Fuels

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Scrubbing of SO2 and NO x from oxy-fuel combustion flue gas under a high pressure has been well recognized as an effective technique for flue gas purification. Experiments were performed in a bubbling column under high pressure to explore the absorption products and the SO2 selectivity during simultaneous absorption of SO2 and NO x . The main absorption product in liquid phase at pH > 1 was identified as hydroxylamine disulfonic acid (HADS), which was then quantified by the Raman spectroscopy. The N2O concentration in gas phase was estimated by the nitrogen mass balance across the system. Results showed that N2O and HADS were produced dominantly by the reaction between HNO2 and HSO3 – at pH > 1, and this followed the Raschig mechanism. However, the absorption of SO2 was promoted while the absorption of NO x was inhibited, and this followed the lead chamber mechanism. Based on the quantification of the nitrogen and sulfur related products in both gas and liquid phase, about 48%–56% NO x and 14%–17% SO2 were consumed by the Raschig mechanism, and 15%–23% SO2 was consumed by the lead chamber mechanism in the pH range 1.09–1.72. For simultaneous absorption of NO x and SO2, SO2 was completely absorbed in different solutions except in the 18.4 mol/L H2SO4. A high concentration of H2SO4 suppressed the absorption of NO x but cannot achieve selective absorption of SO2 without absorbing NO. HNO3 concentration did not have appreciable effect on NO x absorption efficiency in the concentration range 0.1–1 mol/L. When the concentration of HNO3 was 15 mol/L, NO x was no longer absorbed into liquid solution. The mixed acids produced by the simultaneous absorption of NO x and SO2 can cause severe corrosion to a 316L stainless steel tube.

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“…Air Products proposed a two-stage scrubbing process with the low pressure (1.5 MPa) and high pressure (3 MPa) stage to remove SO 2 and NO separately in the forms of H 2 SO 4 and HNO 3 [13]. Similarly, Linde also proposed a twostage method with the first stage (atmospheric pressure) to remove SO 2 as CaSO 4 , and second stage (1.8 MPa) to remove NO as NH 4 NO 3 [14]. In addition, Air Liquide proposed using a sodium solution to remove SO 2 in the atmospheric caustic scrubber, and using a four-stage compression process (at a final pressure of 2.4 MPa) to remove NO in the condensates in the form of HNO 3 [15].…”

Section: Introductionmentioning

confidence: 99%

Removal and recovery of SO₂ and NO in oxy-fuel combustion flue gas by calcium-based slurry

Cai

Ding

et al. 2020

E3S Web Conf.

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This study investigates the use of calcium-based slurry for simultaneous removal NO and SO2 from oxy-fuel combustion flue gas, and recovery of the sulfur and nitrogen species in resulting solutions. The experiments were performed in a bubbling reactor in a transient mode under the pressure of 20 bar. The various influencing factors including the CaO amount, carrier gas (N2/CO2), and absorption time on the simultaneous NO and SO2 removal process, and the solution products were studied comprehensively. The results show that the NO2 removal efficiency can be improved by the presence of CO2, and the gas phase HNO2 produces in this process. The addition of CaO has positive effects not only on the NO2 removal efficiency but also on the formation of stable HNO3. With the presence of CO2, CaCO3 is formed in a solution initially. With the decrease of pH, CaCO3 is gradually converted to CaSO4, and in particular CaCO3 can be fully avoided through decreasing the pH of an absorption solution to 1.14. At the same time, the formation of unstable S(IV) and NO2- can be prevented when the solution pH is lower than 1.37. The nitrogen and sulfur compounds in the absorption solution (at pH 1.14) were further separated by the addition of different amounts of CaO. In particular, 95% of SO42- finally can be recovered in the form of CaSO4.2H2O with nitrogen in solution existing as NO3- by controlling the Ca/S ratio at 4.70. The effectiveness of calcium-based slurry on the removal and recovery of SO2 and NO is confirmed.

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Cold DeNOx development for oxyfuel power plants

Cited by 16 publications

References 5 publications

Effect of Acid Gases on Elemental Mercury Removal in an Oxy-fuel CO₂ Compression Process

Effect of Acid Gases on Elemental Mercury Removal in an Oxy-fuel CO₂ Compression Process

Simultaneous Absorption of NO_x and SO₂ into Water and Acids under High Pressures

Removal and recovery of SO₂ and NO in oxy-fuel combustion flue gas by calcium-based slurry

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Cold DeNOx development for oxyfuel power plants

Cited by 16 publications

References 5 publications

Effect of Acid Gases on Elemental Mercury Removal in an Oxy-fuel CO2 Compression Process

Effect of Acid Gases on Elemental Mercury Removal in an Oxy-fuel CO2 Compression Process

Simultaneous Absorption of NOx and SO2 into Water and Acids under High Pressures

Removal and recovery of SO2 and NO in oxy-fuel combustion flue gas by calcium-based slurry

Contact Info

Product

Resources

About

Effect of Acid Gases on Elemental Mercury Removal in an Oxy-fuel CO₂ Compression Process

Effect of Acid Gases on Elemental Mercury Removal in an Oxy-fuel CO₂ Compression Process

Simultaneous Absorption of NO_x and SO₂ into Water and Acids under High Pressures

Removal and recovery of SO₂ and NO in oxy-fuel combustion flue gas by calcium-based slurry