Corrosion Mechanisms and Materials Selection for the Construction of

Nov 9, 2017 - With the desire for a clean living environment and the increasing demands for cost competitive energy supply, advanced fuel combustion t...
14 downloads 13 Views 2MB Size
Review pubs.acs.org/IECR

Corrosion Mechanisms and Materials Selection for the Construction of Flue Gas Component in Advanced Heat and Power Systems Yimin Zeng,*,† Kaiyang Li,‡ Robin Hughes,§ and Jing-Li Luo‡ †

Natural Resources Canada, CanmetMATERIALS, Hamilton, Ontario L8P 0A5, Canada Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada § Natural Resources Canada, CanmetENERGY, Ottawa, Ontario K1A 1M1, Canada ‡

ABSTRACT: With the desire for a clean living environment and the increasing demands for cost competitive energy supply, advanced fuel combustion technologies have been proposed and are being developed. The deployment of these technologies has been hindered by unanticipated corrosion damage within core components (such as boilers and flue gas components) at pilotscale demonstration plants. To deal with such materials technology challenges, studies have been carried out, but there is still substantial R&D required to meet the emerging industrial demands. A comprehensive review of open database information regarding the corrosion of flue gas systems in existing combustion plants was therefore conducted in this review. It is anticipated that this information will provide a basis for addressing knowledge gaps in materials technologies and advancing the mechanistic understanding of how alloys corrode in flue gas operating environments. Corrosion modes, the effects of aggressive agents (including CO2, HCl, SOx, and NOx) in flue gas mixtures, and the performance of candidate metallic materials in typical combustion systems are systemically reviewed and discussed. From corrosion and economic points of view, F/M steels (P91 and P92), austenitic stainless steels (SS317, 254SMO, and 654SMO etc.), and duplex steels (2205 and 2507) are likely to be major candidates for the construction of future flue gas systems in the fossil fuel powered industries. Ni-based alloys, particularly Alloy C-276 and Alloy C-22, are more applicable for flue gas components in biomass and waste-to-energy energy combustion systems. late 19th century. In the 1930s, the first flue gas scrubber was built with mild steel and low-alloyed carbon steel in the UK,2 but the scrubber subsequently suffered severe corrosion damage and structural integrity failure due to the underestimation of corrosivity of operating environments.2 The effect of acid gases (SOx, HCl, and NOx) on corrosion of flue gas components in coal-fired power plants have been studied extensively during the last two centuries. Both laboratory tests and field investigations have been carried out to quantitatively measure the corrosion rates of candidate structural materials and formulate a better mechanistic understanding of how steels and alloys perform in related environments. Flue gas desulfurization (FGD) systems in coal-fired power plants are among probably the most widely

1. INTRODUCTION Flue gas, also referred to exhaust waste gas, is generated during the combustion of fuels for steam, heat, and power production. Depending on fuel types (including conventional fossil fuels, renewable biomass, and municipal waste solids), the combustion technology employed, and the types of carbon capture technologies applied (i.e., pre-combustion, postcombustion, and oxy-fuel combustion) in the future, the chemistry of flue gas will vary at different operating plants. Basically, the gas mixture is mainly composed of N2, CO2, H2O, and O2 as well as acidic gases such as SO2/SO3, NO2/NO, HCl, HF, etc.1 It may also contain trace amounts of mercury and fine fly ash particles. Emissions from coal-fired plants have long been a concern, and these concerns were initially the result of smog and acid rain generated by the emission of untreated flue gas. Thus, the acid gases in flue gas mixture had been legally required to be reduced down to acceptable levels before the emission in the © 2017 American Chemical Society

Received: Revised: Accepted: Published: 14141

September 3, 2017 November 8, 2017 November 9, 2017 November 9, 2017 DOI: 10.1021/acs.iecr.7b03664 Ind. Eng. Chem. Res. 2017, 56, 14141−14154

Review

Industrial & Engineering Chemistry Research studied flue gas systems.3 Extensive experience and knowledge regarding the systems have therefore been accumulated. With the desire for a better living environment and the increasing pressure for sustainable development, advanced combustion technologies have been developed during the past decades that are intended to reduce the greenhouse gas emissions from fossil fuel-fired plants. For instance, oxy-fuel technology consists of burning fuel in a mixture of pure oxygen and recirculated flue gas instead of air, leading to a significant increase in CO2 concentration in the flue gas.4 To dispose of the ever increasing waste generated by society, technologies for the incineration of biomedical, municipal, industrial, and hazardous wastes are being developed to not only provide heat and power but to also conserve land from being transformed into waste landfills.5 Despite their economic and/or environmental advantages, new combustion technologies inevitably introduce new materials technology challenges, and it is necessary to understand how to construct flue gas systems in a cost-effective fashion. For example, SOx is the main corrosive agent in power plants using high sulfur-containing coal as fuel, while HCl is likely the dominant corrodant in waste incineration plants due to high chloride content in plastic fuel feedstock. In fact, the service environments of flue gas components are quite complicated and can vary in a wide range due to the variation of fuel types used and combustion methods applied. Therefore, the selection of suitable alloys for flue gas component construction is among the first and most important steps toward increasing the reliability and operating efficiency of combustion technologies. To deal with materials technology barriers, pioneering researches have been carried out, but there is still substantial R&D required to optimize materials performance and to ensure a high level of plant reliability at an acceptable cost. A suite of advanced high pressure combustion technologies, including oxy-pressurized fluid bed combustion (oxy-PFBC),6 high pressure oxy-combustion (HiPrOx),7 and oxy-fuel pressurized generation two (G2) burner systems, are being developed to meet Canada’s greenhouse gas (GHG) regulation requirements while significantly improving energy conversion efficiency in a cost competitive manner. The operating environments of core components (especially flue gas components and boiler tubes) in these systems are quite different from those in conventional fuel combustion plants, leading to technical concerns of how alloys will perform and which alloys are suitable for the construction of key components under such environments. Therefore, the objectives of this paper are to perform a comprehensive review of open and in-house databases to advance mechanistic understanding of corrosion of fuel gas component materials in existing fuel combustion plants, and to identify candidate alloys applicable for flue gas component construction in highpressure oxy-combustion technologies. It is anticipated that this information will provide a basis for advancing materials science required for the successful deployment of these technologies in Canadian and global energy sectors.

steam, and SOx, interact with component materials with corrosion rates as a function of temperature and the concentrations of the corrosive gases. Once the temperature of the gas mixture is close to or less than the condensation temperature of acids, acidic phases (including carbonic, sulfuric and/or nitric acids) start to form small droplets and subsequently coalesce to form a liquid film. These condensed phases cause the formation of a thin acidic film on the component surface, leading to a corrosion process controlled by electrochemical reactions: Anodic reaction: M → Mn + + ne−

(1)

Cathodic reaction: O2 enriched in flue gas: 2H 2O + O2 + 4e− → 4OH−

(2)

O2 depleted in flue gas: 2H+ + 2e− → H 2

(3)

From the corrosion point of view, gases including CO2, HCl, Cl2, SOx, NOx, H2O, and O2, will participate in the above-noted corrosion processes. During hot gas corrosion processes, the presence of oxygen shall enhance the formation of surface oxide scales while its contribution to condensed phase corrosion is to enhance cathodic reaction as described in eq 2. For other typical gases, their roles on corrosion are summarized in the following sections. 2.1. Carbon Dioxide (CO2). In most fuel combustion systems, CO2 is a predominant component in flue gas mixtures and its weight content is typically in the range of 12−15% in conventional coal-fired power plant.8 When present as a hot gas phase, pure CO2 is a non-corrosive species with component temperatures lower than 400 °C.9,10 At higher temperatures, however, the decomposition of CO2 proceeds to produce active carbon atoms that can penetrate into alloys, forming internal carbides which make the alloy suffer embrittlement as well as other mechanical properties degradation.11,12 At temperatures for which condensed phases are formed, the dissolution of CO2 into water films results in the formation of carbonic acid, which can enhance the corrosion of iron-based steels, particularly conventional pipe carbon steels. In the oil and gas industry, this type of corrosion is also referred to as “sweet corrosion”, which occurs primarily in the forms of general corrosion and pitting. This type of corrosion is influenced by many factors, including solution pH, CO2 partial pressure, temperature, impurities, and steel microstructure/ chemical properties.13 2.2. Water (H2O). Water content falls in the range of 4− 20% in typical flue gas mixtures, depending on which combustion technologies are applied.8 At high temperatures, the presence of water vapor increases the oxidation rate of metals. For Fe-Cr alloys with Cr content below 15 wt %, the addition of water vapor at high temperature can increase the oxidation rate more than one magnitude.14 The adsorption and following dissociation of water molecules on metal surfaces account for the formation of porous scales and accelerated oxidation. High-temperature water vapor can destroy the integrity of the Cr2O3 oxide layer, which develops on component surfaces and protects the metal substrate from further attack, through:15

2. OVERVIEW OF CORROSION MECHANISM OF ALLOYS IN FLUE GAS SYSTEMS Two typical corrosion modes, including hot gas corrosion and condensed phase corrosion, are likely to occur on the flue gas components. Before flue gas mixtures cool down to their dew point temperatures, the dominant corrosion process is hot gas chemical reaction in which aggressive agents, such as CO2,

1 3 Cr2O3 + H 2O(g) + O2 (g) → CrO2 (OH)2 (g) 2 4 14142

(4)

DOI: 10.1021/acs.iecr.7b03664 Ind. Eng. Chem. Res. 2017, 56, 14141−14154

Review

Industrial & Engineering Chemistry Research

reaction induced by Cl and O2 from hot flue gas is schematically shown in Figure 1.

As the temperature goes down, increasing moisture content in the flue gas facilitates the formation of condensed water which traps more acidic gases, producing a corrosive environment and high metal loss from condensed phase corrosion processes. 2.3. Chlorine-Containing Compounds. The content of chlorine varies in different fuels. On the basis of a worldwide investigation, the content of chlorine in coals (dry basis) falls in the range of 80−1090 ppm.16 Chlorine concentration in dry biomass fuel generally falls into the range of 0.052−0.72%,17 while that in a waste solid fuel may be more than 1%.8 Detailed information on forms and concentration of chlorine in fuels can be found in several review articles.18,19 Because of their high volatility and reactivity, chlorine and chlorides in the flue gas usually cause serious corrosion. In high-temperature flue gas, chlorine exists in the forms of gaseous Cl2, HCl and alkali chlorides. HCl can react with metals and their oxides through the following means:20,21 MO(s) + 2HCl(g) → MCl 2(s, l, g) + H 2O

(5)

Fe + 2HCl(g) → FeCl 2(g) + H 2(g)

(6)

Figure 1. Possible effects of Cl2 and O2 on active hot gas corrosion.

In addition to active hot gas corrosion at high temperature, the dissolution of chlorides, particularly HCl, in condensed phases can increase the phase acidity and Cl− concentration, leading to a remarkable increase in both general corrosion and pitting. Above certain operating loading stresses of the flue gas components, such dissolution might help initiate stress corrosion cracking.24 The influence of chlorine on pitting has been extensively studied, and several related mechanisms have been proposed.25−28 In general, higher temperature, lower pH, and increased concentration of Cl− shall lead to the accelerated initiation and propagation of pitting. The allowable operating limitations of condensed phase pH and Cl− content in different locations of a flue gas system (coal-fired or gas-fired) have been generally described in references29,30 to help engineers on the cost-effective selection of structural alloys and the optimization of operating conditions. For example, duplex steel 2205 exhibited good corrosion resistance in solutions with Cl− ranging from 9000 to 35000 ppm (mol %). With Cl − concentration increased up to 70000 ppm (mol %), localized pits were found, making the steel unsuitable for long-term use.29 Note that pitting and/or stress corrosion cracking could occur even though the pH and average Cl− content is well controlled. This is possibly due to the localized accumulation of protons and Cl− in condensed phases that can occur on component surfaces, resulting in exceedance of specified limits.29 2.4. Sulfur Oxides (SOx). The typical content of sulfur in coal fuel is usually in the range of 0.5−5 wt %31 with an average value of 1.5−2 wt %,32 which largely depends on the geological depositional environments.33 Table 1 provides the ultimate analysis of a number of North American coals as analyzed at CanmetENERGY. For a more extensive list of coal specifications, the readers can consult a number of sources.34,35 The combustion of coal in an oxidizing environment consequently leads to the formation of sulfur oxides, especially SO2 and SO3 (collectively called SOx), that are able to advance hot gas corrosion and condensed phase corrosion at different locations in the combustion system. In high-temperature flue gas, the presence of SO2 may produce a mixture of oxides and sulfides through the following reactions with components:36 1 2M + SO2 → 2MO + S2 (13) 2

where MO represents a metal oxide. In the presence of excess O2, HCl can be further oxidized into Cl2:20 2HCl(g) + 1/2O2 (g) → H 2O(g) + Cl 2(g)

(7)

with the following accompanying reactions that enhance corrosion:20,22 Fe(s) + Cl 2(g) → FeCl 2(s, g)

(8)

3FeCl 2(g) + 2O2 (g) → Fe3O4 (s) + 3Cl 2(g)

(9)

FeCl 2(g) + O2 (g) + Fe3O4 (s) → 2Fe2O3(s) + Cl 2(g) (10)

Alkali chlorides are thermodynamically unstable and can react with metal oxides in the presence of O2:20,21 2ACl(s, l) + SO2 (g) +

1 O2 (g) + FeO 2

→ A 2SO4 (s, l) + FeCl 2 2ACl(s, l) + Fe2O3(s) +

(11)

1 O2 (g) 2

→ A 2Fe2O4 (s, l) + Cl 2(g)

(12)

where A represents Na or K. Upon exposure to O2, iron will form an oxide layer on its surface. O2 cannot easily penetrate the layer, so the oxide layer serves as a barrier and slows further oxidation of the substrate metal. Gaseous Cl2, however, can penetrate the oxide layer via pores and cracks23 and damage the metal at the interface of metal/oxides by forming metal chlorides. Volatile metal chlorides have a high vapor pressure and will diffuse toward the interface of the scale and the flue gas, where excess O2 from the flue gas will further oxidize the metal chlorides into metal oxides. Cl2 is then released and participates in the next corrosion cycle as a catalyst. The resulting oxides are very porous and non-protective, leaving the substrate metal being prone to further attack by Cl2 and O2. In this way, chlorines and chlorides damage the integrity of flue gas components through cyclic reactions at a quite high rate. This active chemical 14143

M + SO2 → MS + O2

(14)

3M + SO2 → 2MO + MS

(15) DOI: 10.1021/acs.iecr.7b03664 Ind. Eng. Chem. Res. 2017, 56, 14141−14154

Review

Industrial & Engineering Chemistry Research Table 1. Selected North American Coal Ultimate Analyses on an Ash Free Dry Basis rank country C, wt % H, wt % N, wt % S, wt % O, wt % Cl, ppm

Kentucky

Illinois no. 6

Genesee

PRB

Boundary Dam

Poplar River

bituminous USA 80.1 5.6 1.7 3.6 9.0 1302

bituminous USA 80.0 5.5 1.6 3.30 8.6 206

sub-bit Canada 75.9 4.6 1.0 0.3 19.9 16

sub-bit USA 74.6 5.0 1.0 0.4 19.1 SS347HFG > HR3C > Alloy 625, which was in accordance with the Cr contents in these alloys in a descending order. With temperature increasing from 600 to 750 °C, the metal loss of all the alloys presented a “bell-shape” curve. The peak of the curve might be due to the formation of molten alkali iron trisulfates. At the peak point, the molten alkali iron trisulfates resulted in the worst damage to metals, as shown in eq 22. It was found that an increase of SO3 content (from 1300 to 6260 ppm) in the flue gas can shift the corrosion peak temperature to a higher degree due to the stabilizing effect of SO3 on alkali iron trisulfates. The effect of flue gas temperature on corrosion has also been investigated. Field tests in straw-fired power plants in Denmark showed that an increase in flue gas temperature resulted in an increase in corrosion rate, and the tendency became more remarkable at temperatures higher than 540 °C.109 Other field tests on T22, SS310H, and Alloy 625 in a biomass power plant demonstrated that the metals experienced a significant loss of wall thickness due to active corrosion.110 Among the tested alloys, Alloy 625 showed somewhat better performance. Such severe corrosion damage is likely due to the fact that the chlorides or oxy-chlorides of Cr can evaporate from metal surfaces at a higher temperature, resulting in a more porous surface oxide layer without any protection.109 This implies that the temperature of flue gas should be kept below certain points to avoid active corrosion. At low temperatures, both the condensation of acids (including HCl, H2SO4, HF, and HNO3) and ash deposits enhance condensed phase corrosion. First, the condensation of acids can cause severe electrochemical corrosion on component surfaces. Moreover, the ash deposits may contain large amounts of hygroscopic salts, such as ZnCl2 and CaCl2, which can absorb water vapor from the flue gas at temperatures higher than the dew point of water.111 Greater quantities of liquid water subsequently trap more acid gases, making the condensed phase more corrosive to flue gas components. Kish et al.112 tried to select materials for the construction of condensing economizers in a biomass combustion system in which aqueous H2SO4 condensates were the major corrodants in condensed phase corrosion as the flue gas was chloride-free. Candidate alloys, including A179 carbon steel, SS316, duplex steel 2205, and Alloy 20, were exposed to a gas containing 25 vol % H2O + 10 vppm of H2SO4 for 21 days. The corrosion resistances of the tested candidate alloys were ranked: A179 < SS316 < 2205 < Alloy 20. With a corrosion rate of 8.6 mpy, SS316 can be used for system construction as its annual corrosion rate meets operating requirements, while duplex steel 2205 and Alloy 20 are likely to be suitable for more corrosive environments. Vainio et al.113 conducted field tests to explore the possibility of using carbon steels in biomass flue gas containing about 20 vppm of SO2 and 50 vppm of HCl. It was found that the presence of CaCl2 on metal surfaces caused a remarkable increase in corrosion rates up to 1.0 mpy, mainly due to its hygroscopicity and the resulting more corrosive environments.

C, O, and H are the main elements in biomass fuel even though their percentages may vary among different sources.18,99,100 Trace amounts of other elements, including Na, Mg, Si, S, N, P, K, Ca, and Cl, can be found in typical biomass materials.101 Possible Cl content in biomass can reach 2.5 wt %,102 while the content of potassium falls in the range of 0.2− 1.9 wt %. Compared with coal, biomass has a much higher (Na + K + Cl)/S ratio, leading to an ash chemistry dominated by alkali chlorides that may introduce the potential risks of ash deposition, fouling, and severe high-temperature corrosion. Active corrosion induced by chlorine is probably one of the dominant corrosion processes on flue gas components. When condensing on a flue gas component surface, alkali chlorides can react with SO2 and O2 gases to generate elevated concentrations of Cl2 and HCl very near the interface of metals and flue gas by the following reactions:103 2ACl(s, l) + SO2 (g) + O2 (g) → A 2SO4 (s, l) + Cl 2(g) (39)

2ACl(s, l) + SO2 (g) +

1 O2 (g) + H 2O(g) 2

→ A 2SO4 (s, l) + 2HCl(g)

(40)

where A represents Na or K. Gaseous chlorine can be generated through the reactions between alkali chlorides and metal scales:103 2NaCl(s, l) +

5 1 O2 (g) + Cr2O3 4 2

→ NaCrO4 (s, l) + Cl 2(g) 2NaCl(s, l) +

(41)

1 O2 (g) + Fe2O3(s) 2

→ Na 2Fe2O4 (s, l) + Cl 2(g)

(42)

The generated Cl2 can result in higher corrosion rates, internal attack, and voids.104 Cha105 studied the corrosive effect of chlorine on eight superheater candidate materials (10CrMo9, X10, X20, Esshete 1250, TP347H, Sanicro 28, AC 66, Alloy 625) at 535 °C under a controlled atmosphere (H2O + O2 + CO2 + N2 with/without HCl) and with cyclone ashes as deposits. After 360 h, higher metal loss was observed in HCl containing environments than those without HCl. Multiple corrosion layers, mainly consisting of complex oxides and Clcontaining spinels, were grown on all tested alloys. Alloys with a lower content of Ni + Cr tended to form more surface corrosion layers. The corrosion resistance generally follows the sequence of ferritic steels < austenitic steels < Ni-based alloys. Stott et al. confirmed the active oxidation of Fe-28Cr steel by finding FeCl2, CrCl2, and CrO2Cl2 on corrosion scales after an exposure to 0.1−1 vol % HCl at 600 and 700 °C for 42 h.106 Cl-induced corrosion is more obvious when the fuel is straw or other Cl-rich biomass. In several straw-fired power plants in Denmark, field tests found that the alloys, including X3CrNiMoN17-13, 347 steel, DI 59, HCM12, and Esshete 1250, experienced active oxidation in the temperature range of 450−600 °C. Scale spallation and grain boundary attack were also found on the corroded surfaces of all tested alloys.107 Sulfur contributes to corrosion in biomass systems, even though the content of SO2 in flue gas is in the range of 0−70 vppm, much lower than that (400−1200 vppm) in coal-fired systems.8 However, the reactions between chlorides and sulfur oxides, as shown in eqs 39 and 40, can lead to the formation of 14148

DOI: 10.1021/acs.iecr.7b03664 Ind. Eng. Chem. Res. 2017, 56, 14141−14154

Review

Industrial & Engineering Chemistry Research

Figure 5. Schematic of a modern waste-to-energy power plant.

3.4. Waste-to-Energy System. Energy recovery from the combustion of municipal solid waste is one of the most attractive technologies that can not only generate energy from the waste but also decrease the amount of trash destined for landfills as well as reduce GHG emission by offsetting the need for energy production from fossil fuel sources and methane generation from waste landfills. The first waste-to-energy combustion plant was built in the late 19th century.114 After that, numerous types of incinerators were deployed, but little work was done to control water discharges and air emissions from the incinerators until clean air acts were issued to ban uncontrolled waste burning.104,114 With the development of air pollution control equipment, modern incinerators have been developed in North America114 and internationally. Figure 5 is a schematic of a modern incinerator that consists of waste processing system, boiler, and flue gas treatment system. In a modern incinerator for heat/power generation, the municipal wastes can consist of plastics, papers, food waste, leather, and textiles, etc., which provide significant amounts of chlorine, sulfur, alkali metals, lead, zinc, and other heavy metals.44 As a result, HCl, H2SO4, HBr, HNO3, HF, and metals in particulate or droplet form are very likely to be detected in the flue gas. The corrosive nature of these impurities introduces materials technology challenges in controlling corrosion and environmental cracking for the cost-effective construction of flue gas systems. One can expect that the corrosion in waste-toenergy systems is more serious than that occurring in conventional coal-fired systems.44 At high temperatures, fine particles, such as chlorides and sulfides in the flue gas, may accumulate within and on flue gas components. Significant molten salt corrosion can be stimulated by the deposits due to their low melting points. Field inspection of flue gas components at several municipal incinerators showed that the deposits contained high concentrations of Cl and S, moderate concentrations of Na and K, and small amounts of Pb and Zn.115,116 Because of the variation in corrosive components and complexity in corrosion mechanisms, there is still no universal solution to the selection of suitable materials to cost-effectively construct high-temperature parts of flue gas systems. Because of high Cl and alkali contents, Cl-induced active oxidation shall play a key role in the performance of core

components in waste-to-energy power plants. In a 65 MW waste-fired combined heat and power plant,117 corrosion probes with metal test rings made of low-alloyed steels (ST35.8 and 15Mo3), high Cr steel (X20CrMoV121), and high (Ni + Cr) steels (Esshete 1250 and Sanicro 28), respectively, were exposed for about 10 days. It was found that all the candidate alloys experienced great metal loss in the presence of chlorine, and the metal loss of low-alloyed steels could be up to two to three times higher than that of highalloyed steels. Active oxidation was the dominant corrosion mechanism even at the temperature range of 320−470 °C. Such Cl-induced corrosion will be dependent on many factors. One study118 showed that the O/Cl ratio had a great impact on the active oxidation and lower O2 content resulted in higher metal loss.118 The temperature also plays a crucial role. A modeling calculation revealed that it was the flue gas temperature instead of the tube wall temperature that affected the deposition and subsequent corrosion of vapor-condensed Cl from flue gas.119 To mitigate disastrous damage, the superheater outlet steam temperature of most waste-to-energy boilers is limited to below 450 °C.119 The effect of Zn and Pb on corrosion has been studied by several authors considering as heavy metal-induced corrosion.120,121 The total amount of Zn and Pb may be up to 1 wt % from waste solid fuels.122 During combustion, they evaporate and then react with Cl and/or S to form gaseous chlorides and/ or sulfates. Because of the low melting point of these compounds, the gaseous phases can condense on lowtemperature parts of the combustion system as aggressive molten salts, leading to a rapid corrosion of tube materials. For example, a mixture of ZnCl2 and KCl were reported to cause molten salts-induced corrosion on low-alloyed steel at 350 °C.123 Other work showed that the corrosion of SS347 was greatly accelerated in the presence of molten ZnCl2 because the latter could damage the Cr2O3 surface protective layer on the tube surfaces by forming porous PbCrO4.121 As for condensed phase corrosion, variation in chemical compositions of flue gases generates complex condensed liquid films on component surfaces. While HCl is the dominant acid, H2SO4, HBr, HNO3, and HF can also condense and then create a more aggressive environment. Selection of suitable materials is thus a more critical issue in the construction of flue gas 14149

DOI: 10.1021/acs.iecr.7b03664 Ind. Eng. Chem. Res. 2017, 56, 14141−14154

Review

Industrial & Engineering Chemistry Research

at such high temperatures, the damage induced by fireside corrosion is a serious concern as corrosion is remarkably enhanced and the tube materials are at high risk of failure. For biomass-firing and waste-to-energy systems, Cl and S released from the flue gas introduce complicated corrosion processes, including gaseous chemical penetration and molten salt corrosion. For flue gas systems operated at elevated temperatures, austenitic stainless steels shall be the main candidate materials. However, there is a caution on the application of these steels in high Cl− environments because of the risks of pitting and stress corrosion cracking. The steels with higher Mo content may be applicable to such environments.129 This is due to the fact that the alloying elements Mo and Cr together can improve steels resistance to pitting. For example, increasing Mo percentage from 2.5 to 3.75 wt % led to a significant improvement of steels to resist chlorine-induced attacks.59 It was found that SS317LMN with a nominal Mo content of 4.25 wt % was applicable for mildly aggressive environments. Stainless steels with 6 wt % Mo exhibited acceptable corrosion resistance in environments containing 9000−70000 ppm (mol %) Cl− ions.29 Moreover, the addition of element N (0.18−0.35 wt %) makes the steels (named as superaustenitic stainless steels) with improved mechanical strength and corrosion resistance.130 The price of steels can also be reduced with the replacement of Ni by N. These advantages strongly enhance the potential for use of superaustenitic stainless steels in flue gas systems. 6-Mo superaustenitic stainless steel has been widely applied in the flue gas systems.65 7-Mo superaustenitic stainless steel has even exhibited equal corrosion resistance to Alloy C-276 in some cases, indicating its cost-effective application potential for flue gas system construction.30,131 The development of duplex steels enlarges the materials selection window for the construction of flue gas systems at elevated temperatures. Duplex steels are composed of austenite and ferrite through the precise control of alloying elements and processing. These types of materials have the combination of good corrosion resistance and mechanical behavior. However, the steels may experience undesired precipitate formation when exposed to temperatures above 400 °C, leading to a significant decrease in corrosion resistance and mechanical strength.132 Today, grades 2205 and 2507 are commonly used materials in flue gas systems.133 In a sulfur acid solution containing 3 mol % Cl− and 0.02 mol % F−, grade 2205 steel showed better corrosion resistance than SS316L and SS317.63 This work further suggested that super duplex steel 2205 (with N addition up to 0.35 wt %) could be a better choice than SS317 due to its improved corrosion safety margin. Ni-based alloys, such as 740/740H,134 CCA 617,135 and Alloy 263,136 are usually recommended to be used in the most corrosive environments at temperatures above 700 °C. To deal with severe corrosion caused by the combustion of biomass or municipal waste, many Ni-based alloys, including Alloy 625105,108 and Superni-75,137 have been examined. At low temperatures for condensed phase corrosion, Ni-based alloys are needed to fabricate the system parts suffering the most corrosive condensed phase. Currently, Alloy C-276, Alloy C-22, Alloy 625, Alloy 59, Alloy C-2000, Alloy 686, Alloy 926, and Alloy B-10 have been applied to the construction of flue gas systems in coal-fired plants.3,30,58,59,131 Among them, Alloy C276 is the most widely used alloy as it has a nominal content of 16 wt % Cr and 16 wt % Mo to resist environmental attack. Besides, Alloy C-22, with higher Cr but less Mo than those in

systems. Both field and laboratory tests have been performed to study the corrosion behaviors of austenitic stainless steels (SS317, 254SMO, Alloy 24, and 654SMO) and duplex steels (2205 and 2507) in related operating environments.124 Their corrosion rates varied from 0.1 to 4.0 mpy depending on the grade of steels and the testing environments. From a materials science point of view, the steels with higher contents of Cr + Mo + Ni exhibited higher resistance to environmental attack. Among the tested materials, 654MO steel showed the best performance and even could have the potential to replace Alloy C-276 for the construction of flue gas cleaning systems in waste-to-energy power plants, while 254SMO and Alloy 24 should be used for the components operated under mild corrosion environments. 3.5. Selection of Suitable Materials for the Construction of Flue Gas Systems. Most commercial steels and alloys, including low-alloyed steels, ferritic−martensitic (F/M) steels, austenitic stainless steels, Ni-based alloys, Zr alloys, and Ti alloys, have been examined for use in the construction of flue gas systems from the materials and corrosion points of view. The selection of suitable materials relies on a lot of factors, including operating systems, temperatures, and environmental corrosivity. Both laboratory and field investigations show that Zr and Ti alloys have excellent corrosion resistance to some very aggressive service environments when the temperature is below 400 °C, where even Alloy C-276 and Alloy 22 cannot survive.125 However, Ti may experience severe molten salt corrosion at temperatures higher than 400 °C,126 and the high price of Zr and Ti hinders their wider application. They are only recommended to be used in the aggressive environment if needed. Because of their cost advantage, low-alloyed steels (2−3 wt % Cr) instead of stainless steels and Ni-based alloys are sometimes used in mildly corrosive environments where the temperature and environmental chemistry are strictly controlled. For example, some low-alloyed steels can be used in mild corrosive environments for the transportation pipelines of nearly pure CO2 gas46,94 even though it is well-known that a continuous protective oxide layer is unlikely to grow on the steels. Even at operating temperatures below 565 °C, some grades of low-alloyed steels, including T22 and T24, are used for boiler tubes in combustion chambers. However, it is generally accepted that low-alloyed steels are not suitable for the cost-effective construction of flue gas systems in fuel combustion plants. Although the application of low-alloyed steels can reduce capital cost remarkably, this will inevitably lead to higher operation and maintenance costs because of severe corrosion and consequential structural damage of system components. Therefore, the prime candidate materials for flue gas systems are F/M steels, austenitic stainless steels, and duplex stainless steels from materials and economic points of view. For flue gas systems operated at high temperatures, especially in coal-fired plants, F/M steels are widely used as boiler tubes due to their high resistance to stress corrosion cracking and excellent physical properties, including high resistance to thermal fatigue, high thermal conductivity, and high creep strength.127 With 9−12 wt % Cr, P91 and P92 can be used as boiler tubes with a working temperature up to 620 °C.128 Several grades of 300 series austenitic stainless steels, including 304, 316L, and 317L, can be used at temperature up to 675 °C due to their relative high Cr content (10−17 wt %). However, 14150

DOI: 10.1021/acs.iecr.7b03664 Ind. Eng. Chem. Res. 2017, 56, 14141−14154

Review

Industrial & Engineering Chemistry Research Alloy C-276, also has been used for flue gas systems, especially in environments with oxidizing and crevice corrosion risks.3 In general, the corrosion resistance of the steels and alloys described above can be ranked in the following increasing order: low-alloyed steels < austenitic stainless steels < duplex steels < superaustenitic stainless steels < Ni-based alloys. The general trend is due to the fact that the materials with higher Cr, Ni, and Mo contents have the ability to grow a dense and continuous protective surface layer to retard further corrosion damage. Table 2 shows the candidate alloys with the potential

particularly CO2, H2O, O2, Cl, SOx, and NOx, which exhibit their specific roles in two corrosion modes. For conventional coal-fired and oxy-fuel combustion systems, SOx related corrosion is a major risk on flue gas system performance, while corrosion of flue gas components in biomass and waste combustion systems is controlled by SOx, alkali chlorides, and heavy metals. From corrosion and economic points of view, ferritic− martensitic (F/M) steels (P91 and P92), austenitic stainless steels with considerable contents of Mo and N (SS317, 254SMO, and 654SMO, etc.), and duplex steels (2205 and 2507) are prime candidate materials for the construction of flue gas systems in combustion plants. For more aggressive operating environments, Ni-based alloys, particularly Alloy C276 and Alloy C-22, are likely to be applicable choices.

Table 2. Candidate Alloys for the Construction of Flue Gas Component in Advanced Heat and Power Systems combustion systems conventional coal-fired

oxy-fuel combustion

typical corrosive agents in flue gas high SOx%

high CO2%, H2O%, and SOx%

biomass combustion

high alkali chlorides

waste-to-energy

high chlorine, sulfur, alkali metals, and heavy metals



promising candidate alloys • F/M steels (P91 and P92) • austenitic stainless steels (SS316L and SS317L) • duplex steels (2205 and 2507) • Ni-based alloys (Alloy C276 and Alloy 59) • austenitic stainless steels (SS316L and SS347) • duplex steel (2205) • Ni-based alloys (Alloy C276, Alloy C-22, and Alloy 625) • austenitic stainless steels (HR3C and SS347) • duplex steel (2205) • Ni-based alloys (Alloy 625 and Alloy 20) • austenitic stainless steels (654MO and 254SMO)

AUTHOR INFORMATION

Corresponding Author

*Tel: (905) 645-0819. E-mail: [email protected]. ORCID

Yimin Zeng: 0000-0003-2685-7048 Jing-Li Luo: 0000-0002-2465-7280 Notes

The authors declare no competing financial interest.



ACKNOWLEDGMENTS This research work was sponsored and funded by the PERD (Program for Energy Research and Development) program of Natural Resource Canada, Government of Canada, and Natural Sciences and Engineering Research Council of Canada.



REFERENCES

(1) Aaron, D.; Tsouris, C. Separation of CO2 from flue gas: a review. Sep. Sci. Technol. 2005, 40 (1−3), 321−348. (2) Snis, M.; Beckers, B.; Bergquist, A.; Torsner, E., Modern materials in flue gas cleaning applications: corrosion properties in artificial scrubber environment, field tests and service experience. In CORROSION 2007, Nashville, Tennessee, March 11−15, 2007; NACE International: Houston, TX, 2007. (3) Agarwal, D. C.; Ford, M., FGD metals and design technology: past problems/solution, present status and future outlook. In CORROSION 98, San Diego, California, March 22−27, 1998; NACE International: Houston, TX, 1998. (4) Zheng, L. Oxy-fuel Combustion for Power Generation and Carbon Dioxide (CO2) Capture; Elsevier: New York, 2011. (5) Kawahara, Y. Development and application of high-temperature corrosion-resistant materials and coatings for advanced waste-toenergy plants. Mater. High Temp. 1997, 14 (3), 261−268. (6) Follett, W., Fitzsimmons, M., Pisupati, S., Sonwane, C., Jovanovic, S., Manley, T., Hiraoka, D., Yows, S., Development of a pilot scale coal powered oxy-fired pressurized fluidized bed combustor with CO2 capture. In Power-Gen Europe Conference, Amsterdam, June 9−11, 2015; 2015. (7) Cairns, P. E.; Clements, B. R.; Hughes, R.; Herage, T.; Zheng, L.; Macchi, A.; Anthony, E. J. High-Pressure Oxy-Firing (HiPrOx) of Fuels with Water for the Purpose of Direct Contact Steam Generation. Energy Fuels 2015, 29 (7), 4522−4533. (8) Kaczmarczyk, R.; Mlonka-Mędrala, A. In Chloride corrosion in biomass-fired boilersFe-O-Cl system thermodynamic analysis. First International Conference on the Sustainable Energy and Environment Development (SEED 2016); E3S Web of Conferences; EDP Sciences: London, 2016; Vol. 10, p 00060. (9) Thomas, D. C.; Benson, S. M. Carbon Dioxide Capture for Storage in Deep Geologic FormationsResults from the CO2 Capture Project: Vol

• Ni-based alloy (Alloy 24)

to be used for the construction of fuel gas component in the combustion systems based on our extensive review of public database. Note that further tests are still needed to demonstrate their application viability in the systems to achieve the most cost-effective operations.

4. SUMMARY With increasing demand for GHG emissions control and sustainable energy supply in a cost-effective fashion, advanced combustion technologies using different fuel feedstocks (including coal, gas, biomass materials, and municipal solid waste) have been in development for the past several decades. However, the commercial deployment of these technologies has been significantly hindered by unanticipated severe corrosion and even degradation failures of core components (such as boilers and flue gas components) in pilot-scale plants. This paper provides a comprehensive review on open and inhouse databases to fill some knowledge gaps in materials technologies and advance the understanding of how materials corrode in flue gas operating environments to meet the emerging industrial demands of cost-effective construction on combustion power plants. Depending on the operating temperatures, hot gas corrosion and condensed phase corrosion can occur on fuel gas components. The corrosivity of flue gas mixtures is coherently related to the contents of several typical aggressive agents, 14151

DOI: 10.1021/acs.iecr.7b03664 Ind. Eng. Chem. Res. 2017, 56, 14141−14154

Review

Industrial & Engineering Chemistry Research 2. Geologic Storage of Carbon Dioxide with Monitoring and Verification. Elsevier: New York, 2015. (10) Mohitpour, M. Pipeline Transportation of Carbon Dioxide Containing Impurities. ASME Press: New York, 2012. (11) Raj, A.; Goswami, B.; Kumar, S.; Krishna, G.; Roy, N.; Ray, A. K. Damage analysis of service exposed reformer tubes in petrochemical industries. High Temp. Mater. Processes 2014, 33 (3), 201−216. (12) Agüero, A.; Gutiérrez, M.; Korcakova, L.; Nguyen, T.; Hinnemann, B.; Saadi, S. Metal dusting protective coatings. a literature review. Oxid. Met. 2011, 76 (1−2), 23−42. (13) Mishra, B.; Al-Hassan, S.; Olson, D.; Salama, M. Development of a predictive model for activation-controlled corrosion of steel in solutions containing carbon dioxide. Corrosion 1997, 53 (11), 852− 859. (14) Wright, I. G.; Dooley, R. A review of the oxidation behaviour of structural alloys in steam. Int. Mater. Rev. 2010, 55 (3), 129−167. (15) Saunders, S.; Monteiro, M.; Rizzo, F. The oxidation behaviour of metals and alloys at high temperatures in atmospheres containing water vapour: A review. Prog. Mater. Sci. 2008, 53 (5), 775−837. (16) Vassilev, S.; Eskenazy, G.; Vassileva, C. Contents, modes of occurrence and origin of chlorine and bromine in coal. Fuel 2000, 79 (8), 903−921. (17) Jenkins, B.; Baxter, L.; Miles, T. Combustion Properties of Biomass, Biomass Usage for Utility and Industrial Power; Utah Education Engineering Foundation Conferences, 1996. (18) Vassilev, S. V.; Baxter, D.; Andersen, L. K.; Vassileva, C. G.; Morgan, T. J. An overview of the organic and inorganic phase composition of biomass. Fuel 2012, 94, 1−33. (19) Tillman, D. A.; Duong, D.; Miller, B. Chlorine in solid fuels fired in pulverized fuel boilers-Sources, forms, reactions, and consequences: A literature review. Energy Fuels 2009, 23 (7), 3379−3391. (20) Grabke, H.; Reese, E.; Spiegel, M. The effects of chlorides, hydrogen chloride, and sulfur dioxide in the oxidation of steels below deposits. Corros. Sci. 1995, 37 (7), 1023−1043. (21) Cutler, A.; Halstead, W.; Laxton, J.; Stevens, C. The role of chloride in the corrosion caused by flue gases and their deposits. J. Eng. Power 1971, 93 (3), 307−312. (22) Pîşa,̆ I.; Rădulescu, C.; Lăzăroiu, G.; Negreanu, G.; Zamfir, S.; Văireanu, D. The evaluation of corrosive effects in co-firing process of biomass and coal. Environ. Eng. Manage. J. 2009, 8 (6), 1485−1490. (23) Riedl, R.; Dahl, J.; Obernberger, I.; Narodoslawsky, M. Corrosion in fire tube boilers of biomass combustion plants. In Proceedings of the China International Corrosion Control Conference, Beijing, October 26−28, 1999, 1999. (24) Lu, B. T.; Chen, Z. K.; Luo, J. L.; Patchett, B. M.; Xu, Z. H. Pitting and stress corrosion cracking behavior in welded austenitic stainless steel. Electrochim. Acta 2005, 50 (6), 1391−1403. (25) Hoar, T. P.; Mears, D. C.; Rothwell, G. P. The relationships between anodic passivity, brightening and pitting. Corros. Sci. 1965, 5 (4), 279−289. (26) Sato, N. A theory for breakdown of anodic oxide films on metals. Electrochim. Acta 1971, 16 (10), 1683−1692. (27) Kolotyrkin, J. M. Pitting corrosion of metals. Corrosion 1963, 19 (8), 261t−268t. (28) Soltis, J. Passivity breakdown, pit initiation and propagation of pits in metallic materials−review. Corros. Sci. 2015, 90, 5−22. (29) Phull, B. S.; Mathay, W. L.; Ross, R., Corrosion Resistance of Duplex and 4−6% Mo-Containing Stainless Steels in FGD Scrubber Absorber Slurry Environments. In CORROSION 2000, Orlando, Florida, March 26−31, 2000; NACE International: Houston, TX 2000. (30) Audouard, J. P.; Charles, J.; Verneau, M., Metallic Answers for FGD Systems. In CORROSION 98, San Diego, California, March 22− 27, 1998; NACE International: Houston, TX 1998. (31) Chou, C.-L. Sulfur in coals: A review of geochemistry and origins. Int. J. Coal Geol. 2012, 100, 1−13. (32) Moskovits, P. Low-temperature boiler corrosion and deposits a literature review. Ind. Eng. Chem. 1959, 51 (10), 1305−1312.

(33) Simms, N. J.; Sumner, J.; Hussain, T.; Oakey, J. E. Fireside issues in advanced power generation systems. Mater. Sci. Technol. 2013, 29 (7), 804−812. (34) Quality Guidelines for Energy System Studies, Detailed Coal Specifications (DOE/NETL-401/012111); NETL: Pittsburgh, PA, January 2012. (35) Methodology and Specifications Guide; S&P Global Platts: New York, 2017. (36) Young, D. High Temperature Corrosion and Oxidation of Metals. Elsevier, Amsterdam, 2008. (37) Singh, P.; Birks, N. Mechanism of sulphur transport through preformed oxide scales. Mater. Corros. 1980, 31 (9), 682−688. (38) Alcock, C. B.; Hocking, M. G.; Zador, S. The corrosion of Ni in O2+SO2 atmospheres in the temperature range 500−750 °C. Corros. Sci. 1969, 9 (2), 111−122. (39) Lai, G. Y. High-Temperature Corrosion and Materials Applications; ASM International: Materials Park, OH2007. (40) Viswanathan, R.; Spengler, C. Corrosion of 85 Ni-15 Cr Alloy at 1600 F in Controlled Atmospheres Containing O2, SO2, SO3, H2S, and N2. Corrosion 1970, 26 (1), 29−41. (41) Stein-Brzozowska, G.; Maier, J.; Scheffknecht, G. Impact of the oxy-fuel combustion on the corrosion behavior of advanced austenitic superheater materials. Energy Procedia 2011, 4, 2035−2042. (42) Ståhl, K.; Balic-Zunic, T.; da Silva, F.; Eriksen, K. M.; Berg, R. W.; Fehrmann, R. The crystal structure determinations and refinements of K2S2O7, KNaS2O7 and Na2S2O7 from X-ray powder and single crystal diffraction data. J. Solid State Chem. 2005, 178 (5), 1697−1704. (43) Rademakers, P.; Hesseling, W.; Van de Wetering, J. Review on Corrosion in Waste Incinerators, And Possible Effect of Bromine; TNO Industrial Technology: Eindhoven, The Netherlands, 2002; pp 18−25. (44) Albina, D. O.; Millrath, K.; Themelis, N., Effects of feed composition on boiler corrosion in waste-to-energy plants. In 12th Annual North American Waste-to-Energy Conference, Savannah, Georgia, May 17−19, 2004, American Society of Mechanical Engineers: New York, 2004; pp 99−109. (45) Srivastava, S.; Godiwalla, K.; Banerjee, M. Fuel ash corrosion of boiler and superheater tubes. J. Mater. Sci. 1997, 32 (4), 835−849. (46) Kranzmann, A.; Neddemeyer, T.; Ruhl, A. S.; Hünert, D.; Bettge, D.; Oder, G.; Neumann, R. S. The challenge in understanding the corrosion mechanisms under oxyfuel combustion conditions. Int. J. Greenhouse Gas Control 2011, 5, S168−S178. (47) Miller, J. A.; Bowman, C. T. Mechanism and modeling of nitrogen chemistry in combustion. Prog. Energy Combust. Sci. 1989, 15 (4), 287−338. (48) Huijbregts, W.; Leferink, R. Latest advances in the understanding of acid dewpoint corrosion: corrosion and stress corrosion cracking in combustion gas condensates. Anti-Corros. Methods Mater. 2004, 51 (3), 173−188. (49) Toftegaard, M. B.; Brix, J.; Jensen, P. A.; Glarborg, P.; Jensen, A. D. Oxy-fuel combustion of solid fuels. Prog. Energy Combust. Sci. 2010, 36 (5), 581−625. (50) Farber, M.; Darnell, A. J.; Ehrenberg, D. M. High Temperature Corrosion Rates of Several Metals with Nitric Oxide. J. Electrochem. Soc. 1955, 102 (8), 446−453. (51) Takasu, Y.; Matsuda, Y. High Temperature Oxidation of Metals and Alloys in Nitrogen Monoxide. Boshoku Gijutsu 1982, 31 (3), 148− 155. (52) Paschke, B.; Kather, A. Corrosion of Pipeline and Compressor Materials Due to Impurities in Separated CO2 from Fossil-Fuelled Power Plants. Energy Procedia 2012, 23, 207−215. (53) Dugstad, A.; Halseid, M.; Morland, B., Experimental techniques used for corrosion testing in dense phase CO2 with flue gas impurities. In CORROSION 2014, San Antonio, Texas, March 9−13, 2014; NACE International: Houston, TX, 2014. (54) Kofstad, P. High Temperature Corrosion;Elsevier Crown House: Linton Road, Barking, Essex IG 11 8 JU, UK, 1988. (55) Hatt, R. M. Fireside deposits in coal-fired utility boilers. Prog. Energy Combust. Sci. 1990, 16 (4), 235−241. 14152

DOI: 10.1021/acs.iecr.7b03664 Ind. Eng. Chem. Res. 2017, 56, 14141−14154

Review

Industrial & Engineering Chemistry Research (56) Harb, J.; Smith, E. Fireside corrosion in PC-fired boilers. Prog. Energy Combust. Sci. 1990, 16 (3), 169−190. (57) Shoemaker, L.; Crum, J. R., Experience in Effective Application of Metallic Materials for Construction of FGD Systems; Special Metals: Huntington, WV, 2010. (58) Herda, W.; Rockel, M.; Grossmann, G.; Starke, K. High Specialty Stainless Steels and Nickel Alloys for FGD Dampers; NACE International: Houston, TX, 1997. (59) White, F.; Grossmann, G.; Decking, H.; Agarwal, D. C. Experience with the Use of Alloy 59 (UNS N06059) in Industrial Applications; NACE International: Houston, TX, 1996. (60) Kohler, M.; Kirchheiner, R.; Stenner, F. Alloy B-10, a New Nickel-Based Alloy for Strong Chloride-Containing, Highly Acidic and Oxygen-Deficient Environments; NACE International: Houston, TX, 1998. (61) Tossey, B. M.; Padgett, B. N.; Shingledecker, J., Field Testing of Ten Corrosion Resistant Alloys in Wet Flue Gas Desulfurization Absorber Slurries. In CORROSION 2014, San Antonio, Texas, March 9−13, 2014; NACE International: Houston, TX, 2014. (62) Beckers, B.; Bergquist, A.; Snis, M.; Torsner, E. Modern materials in flue gas cleaning applications; corrosion properties in artificial scrubber environment, field tests and service experience. In CORROSION 2007, Nashville, Tennessee, March 11−15, 2007; NACE International: Houston, TX, 2007. (63) Peultier, J.; Barrau, F.; Audouard, J. P., Corrosion Resistance of Duplex and Superduplex Stainless Steels in Halide Containing Sulfuric Acid Media. In CORROSION 2006, San Diego, California, March 12− 16, 2006; NACE International: Houston, TX, 2006. (64) Ellis, P. Quantitative Tool for FGD Alloy Selection Based on pH and Chloride; NACE International, Houston, TX, 1998. (65) Shoemaker, L. E.; Crum, J. R.; Eisinger, N. C.; Hazeldine, D. P. Super-Austenitic Stainless Steels Offer Performance, Reliability and Economy in Wet FGD Air Pollution Control Systems. In AIRPOL 2007, Louisville, Kentucky, June 26−28, 2007; NACE International: Houston, TX, 2007. (66) Abraham, B.; Asbury, J.; Lynch, E.; Teotia, A. Coal-oxygen process provides CO2 for enhanced recovery. Oil Gas J. 1982, 80, 11. (67) Carrasco-Maldonado, F.; Spörl, R.; Fleiger, K.; Hoenig, V.; Maier, J.; Scheffknecht, G. Oxy-fuel combustion technology for cement production - State of the art research and technology development. Int. J. Greenhouse Gas Control 2016, 45, 189−199. (68) Stanger, R.; Wall, T.; Spoerl, R.; Paneru, M.; Grathwohl, S.; Weidmann, M.; Scheffknecht, G.; McDonald, D.; Myöhänen, K.; Ritvanen, J.; Rahiala, S.; Hyppänen, T.; Mletzko, J.; Kather, A.; Santos, S. Oxyfuel combustion for CO2 capture in power plants. Int. J. Greenhouse Gas Control 2015, 40, 55−125. (69) Zebian, H.; Gazzino, M.; Mitsos, A. Multi-variable optimization of pressurized oxy-coal combustion. Energy 2012, 38 (1), 37−57. (70) Hagi, H.; Nemer, M.; Le Moullec, Y.; Bouallou, C. Towards second generation oxy-pulverized coal power plants: energy penalty reduction potential of pressurized oxy-combustion systems. Energy Procedia 2014, 63, 431−439. (71) Tumsa, T. Z.; Mun, T. Y.; Lee, U.; Yang, W. Effects of coal characteristics to performance of a highly efficient thermal power generation system based on pressurized oxy-fuel combustion. Int. J. Energy Res. 2017, 41 (1), 127−138. (72) Guedea, I.; Lupiañez, C.; Romeo, L. M. Exergetic comparison of different oxyfuel technologies. Int. J. Energy Environ. Eng. 2011, 2 (3), 35−47. (73) Czakiert, T., Zuwala, J., Lasek, J., Oxy-fuel combustion: The state of the art. In The 12th International Conference on Fluidized Bed Technology, Krakow, Poland, May 23-26, 2017, 2017. (74) White, V.; Fogash, K. In Purification of Oxyfuel-derived CO2: Current Developments and Future Plans. In First Oxy-fuel Combustion Conference, September 7-11, 2009, Cottbus, Germany, 2009. (75) Kanniche, M.; Gros-Bonnivard, R.; Jaud, P.; Valle-Marcos, J.; Amann, J.-M.; Bouallou, C. Pre-combustion, post-combustion and oxycombustion in thermal power plant for CO2 capture. Appl. Therm. Eng. 2010, 30 (1), 53−62.

(76) Hong, J.; Field, R.; Gazzino, M.; Ghoniem, A. F. Operating pressure dependence of the pressurized oxy-fuel combustion power cycle. Energy 2010, 35 (12), 5391−5399. (77) Gopan, A.; Kumfer, B. M.; Axelbaum, R. L. Effect of operating pressure and fuel moisture on net plant efficiency of a staged, pressurized oxy-combustion power plant. Int. J. Greenhouse Gas Control 2015, 39, 390−396. (78) Hetland, J., Flue gas processing: strategies for water managment. Water removal and moisture control via dew point modelling. In Third Oxyfuel Combustion Conference, September 9−13, 2013, Ponferrada, Spain, 2013. (79) Terrien, P.; Dubettier, R.; Leclerc, M.; Meunnier, V. Engineering of Air Separation and Cryocap units for large size plants. In Third Oxyfuel Combustion Conference, September 9−13, 2013, Ponferrada, Spain, 2013. (80) Stiegel, G. J.; Bose, A.; Armstrong, P. Development of Ion Transport Membrane (ITM) Oxygen Technology for Integration in IGCC and Other Advanced Power Generation Systems; NETL: Pittsburgh, PA, 2013. (81) Allam, R. J. Improved oxygen production technologies. Energy Procedia 2009, 1 (1), 461−470. (82) Woycenko, D.; Van de Kamp, W.; Roberts, P. Combustion of Pulverized Coal in a Mixture of Oxygen and Recycled Flue Gas; Elsevier: Waltham, MA, 1992; Vol. 1995. (83) Chandra, K.; Kranzmann, A.; Neumann, R. S.; Rizzo, F. Comparative study on high temperature oxidation of T92 steel in dry and wet oxyfuel environments. Oxid. Met. 2015, 84 (3−4), 463−490. (84) Syed, A. U.; Simms, N. J.; Oakey, J. E. Fireside corrosion of superheaters: Effects of air and oxy-firing of coal and biomass. Fuel 2012, 101, 62−73. (85) Mathekga, H.; Oboirien, B.; North, B. A review of oxy-fuel combustion in fluidized bed reactors. Int. J. Energy Res. 2016, 40 (7), 878−902. (86) Yang, X. Sulfation Behavior of Calcium-Based Sorbents under Oxy-combustion Conditions at High Pressures. Master Thesis. The Pennsylvania State University, 2015. (87) Serpa, J.; Morbee, J.; Tzimas, E., Technical and Economic Characteristics of a CO2 Transmission Pipeline Infrastructure; EUR 24731 EN; European Commission Joint Research Centre, Institute for Energy: Petten, The Netherlands, 2011;10.2790/30861 (88) Forbes, S. M.; Verma, P.; Curry, T. E.; Friedmann, S. J.; Wade, S. M. CCS Guidelines for Carbon Dioxide Capture, Transport and Storage; World Resources Institute: Washington, DC, 2008. (89) CO2 Pipeline Infrastructure; 2013/8; IEAGHG: Cheltenham, UK, January 2014. (90) Verhoff, F.; Banchero, J. Predicting dew points of flue gases. Chem. Eng. Prog. 1974, 70 (8), 71−72. (91) Kiang, Y. H. Predicting dewpoints of acid gases. Chem. Eng. 1981, 88 (3), 127−127. (92) George, D. L.; Barajas, A. M.; Burkey, R. C. The need for accurate hydrocarbon dew point determination. Pipeline Gas J. 2005, 232 (9), 32−34. (93) Okita, N. Dew Point for Flue Gas of Power-Plant Exhaust; ICRN23; IAPWS: Yokohama, Japan, 2008. (94) Ruhl, A. S.; Kranzmann, A. Investigation of corrosive effects of sulphur dioxide, oxygen and water vapour on pipeline steels. Int. J. Greenhouse Gas Control 2013, 13, 9−16. (95) Levina, E.; Bennett, S.; McCoy, S. Technology Roadmap: Carbon Capture and Storage; International Energy Agency: Paris, 2013. (96) Tanaka, N. Technology Roadmap: Biofuels for Transport; International Energy Agency: Paris, 2011. (97) O’Connor, D. Advanced Biofuels−GHG Emissions and Energy Balances; Report T39-T5; International Energy Agency: Paris, May 25, 2013. (98) Demirbas, M. F.; Balat, M.; Balat, H. Potential contribution of biomass to the sustainable energy development. Energy Convers. Manage. 2009, 50 (7), 1746−1760. 14153

DOI: 10.1021/acs.iecr.7b03664 Ind. Eng. Chem. Res. 2017, 56, 14141−14154

Review

Industrial & Engineering Chemistry Research

temperature on lead chloride induced high temperature corrosion. Fuel 2017, 196, 241−251. (121) Bankiewicz, D.; Enestam, S.; Yrjas, P.; Hupa, M. Experimental studies of Zn and Pb induced high temperature corrosion of two commercial boiler steels. Fuel Process. Technol. 2013, 105, 89−97. (122) Pedersen, A. J.; Frandsen, F. J.; Riber, C.; Astrup, T.; Thomsen, S. N.; Lundtorp, K.; Mortensen, L. F. A full-scale study on the partitioning of trace elements in municipal solid waste incineration Effects of firing different waste types. Energy Fuels 2009, 23 (7), 3475− 3489. (123) Spiegel, M. Salt melt induced corrosion of metallic materials in waste incineration plants. Mater. Corros. 1999, 50 (7), 373−393. (124) Pettersson, R.; Bergquist, A.; Ekman, S.; AB, O. S.; KIMAB, J. F. S.Corrosion of austenitic and duplex stainless steels in flue gas cleaning systems for waste combustion processes. In CORROSION 2013, Orlando, Florida, March 17−21, 2013; NACE International: Houston, TX, 2013. (125) Ali, M.; Al-Beed, A., Performance of selected materials in flue gas environment. In CORROSION 98, San Diego, California, March 2227, 1998; NACE International: Houston, TX, 1998. (126) Anuwar, M.; Jayaganthan, R.; Tewari, V.; Arivazhagan, N. A study on the hot corrosion behavior of Ti−6Al−4V alloy. Mater. Lett. 2007, 61 (7), 1483−1488. (127) Zeng, Y.; Guzonas, D. Corrosion Assessment of Candidate Materials for Fuel Cladding in Canadian SCWR. JOM 2016, 68 (2), 475−479. (128) Viswanathan, R.; Sarver, J.; Tanzosh, J. M. Boiler materials for ultra-supercritical coal power plantsSteamside oxidation. J. Mater. Eng. Perform. 2006, 15 (3), 255−274. (129) Pardo, A.; Merino, M.; Coy, A.; Viejo, F.; Arrabal, R.; Matykina, E. Pitting corrosion behaviour of austenitic stainless steels− combining effects of Mn and Mo additions. Corros. Sci. 2008, 50 (6), 1796−1806. (130) Reed, R. P. Nitrogen in austenitic stainless steels. JOM 1989, 41 (3), 16−21. (131) Muro, R.; Neighbor, M.; Shoemaker, L.; Crum, J., An Advanced Super-Austenitic Stainless Steel Offers Economical And Technical Advantages Over Nickel-Base Corrosion-Resistant Alloys In The Process Industries. In CORROSION 2010, San Antonio, Texas, March 14−18, 2010; NACE International: Houston, TX, 2010. (132) Chan, K. W.; Tjong, S. C. Effect of secondary phase precipitation on the corrosion behavior of duplex stainless steels. Materials 2014, 7 (7), 5268−5304. (133) Cui, Z.; Wang, L.; Ni, H.; Hao, W.; Man, C.; Chen, S.; Wang, X.; Liu, Z.; Li, X. Influence of temperature on the electrochemical and passivation behavior of 2507 super duplex stainless steel in simulated desulfurized flue gas condensates. Corros. Sci. 2017, 118, 31−48. (134) Sarver, J.; Tanzosh, J. Steamside oxidation behaviour of candidate USC materials at temperatures between 650 and 800°C. Energy Mater. 2007, 2 (4), 227−234. (135) Nair, A.; Kumanan, S. In Newer Materials for Supercritical Power Plant Components−A Manufacturability Study. Proceedings of the International Conference on Advances in Production and Industrial Engineering, 2015; p 326. (136) Stein-Brzozowska, G.; Flórez, D. M.; Maier, J.; Scheffknecht, G. Nickel-base superalloys for ultra-supercritical coal-fired power plants: Fireside corrosion. Laboratory studies and power plant exposures. Fuel 2013, 108, 521−533. (137) Singh, H.; Sidhu, T. High temperature corrosion behavior of Ni-based superalloy Superni-75 in the real service environment of medical waste incinerator. Oxid. Met. 2013, 80 (5−6), 651−668.

(99) Vassilev, S. V.; Baxter, D.; Andersen, L. K.; Vassileva, C. G. An overview of the chemical composition of biomass. Fuel 2010, 89 (5), 913−933. (100) Faaij, A.; van Doorn, J.; Curvers, T.; Waldheim, L.; Olsson, E.; van Wijk, A.; Daey-Ouwens, C. Characteristics and availability of biomass waste and residues in the Netherlands for gasification. Biomass Bioenergy 1997, 12 (4), 225−240. (101) Vassilev, S. V.; Braekman-Danheux, C.; Laurent, P. Characterization of refuse-derived char from municipal solid waste: 1. Phasemineral and chemical composition. Fuel Process. Technol. 1999, 59 (2− 3), 95−134. (102) Simms, N.; Kilgallon, P.; Oakey, J. Fireside issues in advanced power generation systems. Energy Mater. 2007, 2 (3), 154−160. (103) Antunes, R. A.; de Oliveira, M. C. L. Corrosion in biomass combustion: A materials selection analysis and its interaction with corrosion mechanisms and mitigation strategies. Corros. Sci. 2013, 76, 6−26. (104) Mudgal, D.; Singh, S.; Prakash, S. Corrosion Problems in Incinerators and Biomass-Fuel-Fired Boilers. Int. J. Corros. 2014, 2014, 1−14. (105) Cha, S. High temperature corrosion of superheater materials below deposited biomass ashes in biomass combusting atmospheres. Corros. Eng., Sci. Technol. 2007, 42 (1), 50−60. (106) Stott, F.; Shih, C. High-Temperature Corrosion of Iron− Chromium Alloys in Oxidizing−Chloridizing Conditions. Oxid. Met. 2000, 54 (5), 425−443. (107) Montgomery, M.; Karlsson, A.; Larsen, O. H. Field test corrosion experiments in Denmark with biomass fuels. Part 1: Strawfiring. Mater. Corros. 2002, 53 (2), 121−131. (108) Hussain, T.; Syed, A.; Simms, N. J. Trends in fireside corrosion damage to superheaters in air and oxy-firing of coal/biomass. Fuel 2013, 113, 787−797. (109) Montgomery, M.; Jensen, S.; Borg, U.; Biede, O.; Vilhelmsen, T. Experiences with high temperature corrosion at straw-firing power plants in Denmark. Mater. Corros. 2011, 62 (7), 593−605. (110) Kish, J.; Reid, C.; Singbeil, D.; Seguin, R. Corrosion of HighAlloy Superheater Tubes in a Coastal Biomass Power Boiler. Corrosion 2008, 64 (4), 356−366. (111) Retschitzegger, S.; Brunner, T.; Obernberger, I. Lowtemperature corrosion in biomass boilers fired with chemically untreated wood chips and bark. Energy Fuels 2015, 29 (6), 3913−3921. (112) Kish, J.; Stead, N.; Singbeil, D.; Preto, F.; Jetté, F., Some aspects of materials selection for condensing economizers. In CORROSION 2008, New Orleans, Louisiana, March 16-20, 2008; NACE International: Houston, TX, 2008. (113) Vainio, E.; Kinnunen, H.; Laurén, T.; Brink, A.; Yrjas, P.; DeMartini, N.; Hupa, M. Low-temperature corrosion in cocombustion of biomass and solid recovered fuels. Fuel 2016, 184, 957−965. (114) Vehlow, J. Air pollution control systems in WtE units: an overview. Waste Manage. 2015, 37, 58−74. (115) Klenowicz, Z.; Darowicki, K. Waste incinerators: Corrosion problems and construction materials-A review. Corros. Rev. 2001, 19 (5−6), 467−492. (116) Lee, S.-H.; Themelis, N. J.; Castaldi, M. J. High-Temperature Corrosion in Waste-to-Energy Boilers. J. Therm. Spray Technol. 2007, 16 (1), 104−110. (117) Persson, K.; Broström, M.; Carlsson, J.; Nordin, A.; Backman, R. High temperature corrosion in a 65 MW waste to energy plant. Fuel Process. Technol. 2007, 88 (11−12), 1178−1182. (118) Krumm, L.; Galetz, M. C. Chlorine Attack of Carbon Steel Between 350 and 500°C and Its Importance Regarding Corrosion in Waste Incineration. Oxid. Met. 2017, 87 (5−6), 757−766. (119) Otsuka, N. A thermodynamic approach on vapor-condensation of corrosive salts from flue gas on boiler tubes in waste incinerators. Corros. Sci. 2008, 50 (6), 1627−1636. (120) Kinnunen, H.; Hedman, M.; Engblom, M.; Lindberg, D.; Uusitalo, M.; Enestam, S.; Yrjas, P. The influence of flue gas 14154

DOI: 10.1021/acs.iecr.7b03664 Ind. Eng. Chem. Res. 2017, 56, 14141−14154