Although IGCC fuel gas cleanup equipment efficiently removes more than 95% of the sulfur constituent (as H2S), the residual sulfur in the syngas passes to the combustion turbine where it is oxidized to both SO2and SO3. Installation of SCR in an IGCCs HRSG, for what amounts to NOx polishing, requires consideration of the environmental impacts of ammonia slip. Unfortunately, this further increases parasitic power consumption and raises the cost of the SCR installation. Todd, D. and Battista, R., New Developments in LCV Syngas Combustion / IGCC Experience, General Electric technical paper, 2001. A sweeping new proposed rule published in the Federal Register by the Environmental Protection Agency (EPA) on April 6 establishes new nitrogen oxide (NOx) emissions budgets that will require fossil fuelfired power plants in 25 states to participate in an allowance-based ozone season trading program starting in 2023. During this period, coal-fired generation was responsible for 90% of SO2 emissions and 76% of NOx emissions from the U.S. electric power industry. Short, timely articles with graphics on energy, facts, issues, and trends. NO + O2 NO2 Second, unwanted chemical reactions may negatively impact and interfere with the operation of the plant. It is conceivable that facilities in some states may face added costs by having to dispose of these materials out of state due to a lack of licensed disposal facilities that will handle these materials. 2. This requires the use of licensed transport and disposal facilities and compliance with Resource Conservation and Recovery Act regulations. xref Send your feedback to, Residential Energy Consumption Survey (RECS), Commercial Buildings Energy Consumption Survey (CBECS). Forms EIA uses to collect energy data including descriptions, links to survey instructions, and additional information.
Coal-fired generation for electric power peaked in the United States in 2007 at 2,016 million megawatthours (MWh) and declined to 1,206 million MWh by 2017. Selective Catalytic Reduction (SCR) The proposal, which builds on the agencys existing Cross-State Air Pollution Rule (CSAPR), seeks to implement the EPAs 2015 National Ambient Air Quality Standards (NAAQS) for ozone of 70 parts per billion by imposing federal implementation plans (FIPs) on these states using its authority under the good neighbor requirements of the Clean Air Act. State energy information, including overviews, rankings, data, and analyses. In 1997, each megawatthour of coal-fired electricity generation produced 14.6 pounds of SO2 and 6.4 pounds of NOx. 0000009177 00000 n In addition, NOx (as NO2) is a chronic toxin and an essential precursor to the formation of tropospheric ozone. The catalysts active surface is usually a noble metal, base metal (titanium or vanadium) oxide, or a zeolite-based material. EPA collects detailed sulfur dioxide (SO2), nitrogen oxides (NOX), and carbon dioxide (CO2) emissions data and other information from power plants across the country as part of: The 2021 annual data show a 20 percent increase in SO2emissions compared to 2020, a 6 percent increase in NOXemissions, an 7 percent increase in CO2emissions, and a 13 percent increase in Hg emissions. Atmospheric nitrogen-containing particles decrease visibility. Comprehensive data summaries, comparisons, analysis, and projections integrated across all energy sources. This control method can reduce NOx emissions levels from syngas-fired turbines to approximately 15 ppm (at 15% O2). The decline in emissions between 1997 and 2017 mostly occurred in these 27 states; Ohio, Pennsylvania, and Indiana saw the greatest decline in SO2 emissions between 1997 and 2017, while Ohio, Indiana, and Kentucky saw the greatest decline in NOx emissions. 0000008010 00000 n This responsibility may not be borne by the plant since catalyst suppliers often collect and recycle spent catalyst as part of their contract. Because the regeneration cycle must take place in an oxygen-free environment, the catalyst undergoing regeneration must be isolated from exhaust gases. Financial market analysis and financial data for major energy companies. Not a subscriber or a registered user yet? IGCC applications, with exhaust gas that is relatively free of contaminants, should yield a significantly longer catalyst lifetime than for a conventional coal-fired application. 308 24 PAN and ammonium sulfate, however, are longer-lived and can spread the influence of both NOx and ammonia over a wide area. Ammonia slip is typically limited to less than 5 ppm in most SCR applications, but may be higher when the NOx level entering the catalyst bed is so very low. NOx refers to both nitric oxide (NO) and nitrogen dioxide (NO2). Because the same numbers of sections are always in the regeneration cycle, the production of regeneration gas proceeds at a constant rate. Tags: %%EOF Official websites use .gov
Catalyst is very sensitive to sulfur, including trace quantities that are typically found in IGCC exhaust gas; Reliability of moving parts over time is an operational and maintenance concern; Use of hydrogen for regeneration could be a serious safety concern, since it is hard to contain; SCONOx has about twice the pressure drop of SCR; and. This yields a significant flow rate increase compared with natural gas (~14% more), resulting from the need to maintain a specified heat input to the combustor. 0000009405 00000 n Finally, it is interesting to see the effects of implementation of SCR on NOx and other pollutant species in the context of an IGCC plant. Base-metal catalysts have an operating temperature window for clean fuel applications of approximately 400 to 800 F. The upper range of this temperature window can be increased using a zeolite catalyst to a maximum of 1,100F. CAIR was replaced by the Cross-State Air Pollution Rule (CSAPR) in 2015. Maps by energy source and topic, includes forecast maps.
During the regeneration cycle, these louvers close and a valve opens allowing regeneration gas into the section. The hydrogen reacts with nitrites and nitrates to form water and elemental nitrogen. Several critical issues associated with the use of this technology are: In 1997, the EPA monitored the application of SCONOx on a natural gas-fired turbine at the Federal Cogeneration facility in Los Angeles, where it established a 3.5 ppm (at 15% oxygen on a 3-hour rolling average) standard for NOx. The quantity of waste associated with SCR is quite large, although the actual amount of active material in the catalyst bed is relatively small. Web Policies, FOIA/Privacy Act 0 Reports requested by congress or otherwise deemed important. By 2017, those rates had fallen to 2.4 pounds per megawatthour (lbs/MWh) and 1.5 lbs/MWh, respectively.
The contribution of NOx or ammonia emissions from a single facility to any of these environmental problems is primarily determined by existing levels of NOx and ammonia in the area and the concentration of other pollutants in the atmosphere that react with the NOx or NH3.
The regeneration of the catalyst is accomplished by passing a dilute hydrogen reducing gas across the surface of the catalyst in the absence of oxygen. In 2005, the Clean Air Interstate Rule (CAIR) addressed regional interstate transport of contributors to ground-level ozone (smog) by requiring 27 eastern states to file implementation plans to reduce SO2 and NOX emissions. Subscribe to feeds for updates on EIA products including Today in Energy and What's New. 2NO2+ K2CO3 CO2+ KNO2+ KNO3. The ammonium sulfate, if not deposited with any bisulfate formed, is discharged to the atmosphere as fine particulate matter (PM2.5), since no particulate control is typically installed downstream of the HRSG.
Available combustion-based NOx control options for syngas-fired turbines are more limited than those available for natural gas-fired turbines. Small levels of ammonia (NH3) and hydrogen cyanide (HCN) are produced, however, and must be removed during the syngas cooling process. International energy information, including overviews, rankings, data, and analyses. U.S. A few manufacturers have guaranteed NOx emissions in the range of 9 ppm (e.g., GE).
In 2020, sources in both the Cross-State Air Pollution Rule (CSAPR) NOXannual program and the ARP together emitted 0.78 million tons, a reduction of 5.1 million tons, or 87 percent, from 1995 levels. An oxygen-blown, entrained-flow IGCC plant will typically produce syngas with a heating value ranging from 250 to 400 Btu/ft3(HHV basis), which is considerably lower than the 1000 Btu/ft3for natural gas. An important factor that affects the performance of SCR is the operating temperature.
0000002065 00000 n The use of a diluent to lower flame temperature, such as nitrogen or steam, is currently the preferred method for minimizing NOx generation from a syngas-fired turbine. During this time period, electric generation from these power plants decreased by 5 percent. ET) , to start a free trial, get pricing information, order a reprint, or post an article link on your website.
Annual U.S. electric power industry emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) have declined by 88% and 76%, respectively, between their peaks in 1997 and 2017. The broad 181-page proposed rule stems from a finding the EPA will make if the rule is finalized that interstate transport of ozone precursor emissions from 26 upwind stateswhich include the 25 states listed above plus Californiais significantly contributing to downwind nonattainment or interfering with maintenance of the 2015 ozone NAAQS in other states, based on projected NOx emissions in the 2023 ozone season.. For eight states currently covered by the 2016-established CSAPR NO, The broad 181-page proposed rule stems from a finding the EPA will make if the rule is finalized that interstate transport of ozone precursor emissions from 26 upwind stateswhich include the 25 states listed above plus Californiais significantly contributing to downwind, nonattainment or interfering with maintenance of the 2015 ozone NAAQS in other states, based on projected, emissions limitations beginning in 2026 for other industrial stationary sources (referred to as non-EGUs in the proposal)marking the first.
Unlike SCR, it does not require the use of ammonia injection, and the active NOx removal reagent is potassium carbonate. Cross-State Air Pollution Rule (CSAPR), seeks to implement the EPAs 2015 National Ambient Air Quality Standards (NAAQS) for ozone of 70 parts per billion by imposing federal implementation plans (FIPs) on these states using its authority under the good neighbor requirements of the Clean Air Act. General Electric (GE) is currently targeting development of combustors to reliably achieve below 10 ppm NOx with syngas, which would be comparable to the NOx emission levels achieved through use of the lean-premix technology on gas turbines firing natural gas. The NOx reacts with NH3and O2to form N2and H2O, primarily according to the following equations: 4NH3+ 4NO + O2 4N2+ 6H2O For the following figures, please select a pollutant: Tools to customize searches, view specific data sets, study detailed documentation, and access time-series data.
The EPAs existing CSAPR ozone-season NOx program limits NOx emissions from fossil fuelfired electric generating units (EGUs) in 22 states during the ozone season, which runs from May 1 through September 30. Such operation may require more excess ammonia than is typically used. Uranium fuel, nuclear reactors, generation, spent fuel. Metal-based catalysts are typically applied as a coating over a metal or ceramic substrate, while zeolite catalysts are typically a homogeneous material that forms both the active surface and the substrate. 0000001167 00000 n 0000016269 00000 n Selective catalytic reduction (SCR) is a fully commercial technology that has been applied to natural gas-fired turbines to minimize NOx, while the EMx (SCONOx) process is a newer, non-ammonia based technology which competes with SCR.
However, in either case, emissions of all regulated pollutants are well below the permit-specified limits. Sulfur dioxide emissions have fallen since 1990. Sign up for email subcriptions to receive messages about specific EIA products. ", CO + O2 CO2
The effective operating temperature range is 280-750F, with 500-700F being the optimum range for NOx removal. In coal gasification-based processes, NOx can be formed downstream by the combustion of syngas with air in electricity-producing gas turbines. Differences between syngas and natural gas composition and combustion characteristics are the source of the problem. SCR selectively reduces NOx emissions by injecting NH3into the exhaust gas upstream of a catalyst. Nitrogen is usually available from the cryogenic air separation unit, so it can conveniently be employed in the IGCC process.
0000001348 00000 n Includes hydropower, solar, wind, geothermal, biomass and ethanol. The CO is oxidized to CO2by the platinum catalyst.
At any given time eighty percent of these sections are in the oxidation/absorption cycle, and twenty percent are in the regeneration cycle. News & Technology for the Global Energy Industry. NO is oxidized to NO2and then reacts with the potassium carbonate coating on the catalyst to form potassium nitrites and nitrates at the surface of the catalyst. Maps, tools, and resources related to energy disruptions and infrastructure. For eight states currently covered by the 2016-established CSAPR NOx Ozone Season Group 2 Trading Program that are already covered under state implementation plans or FIPs, the EPA proposes to issue new FIPs for two states (Alabama and Missouri) and amend existing FIPs for six states (Arkansas, Mississippi, Oklahoma, Tennessee, Texas, and Wisconsin) to transition power plants in those states from the Group 2 program to the revised Group 3 trading program, beginning with the 2023 ozone season. There are two major operational impacts resulting from the installation of an SCR system in the HRSG of an IGCC plant.
According to law firm Hunton Andrews and Kurth, while the EPA applies the same basic four-step process that it developed and used in previous CSAPR rulemakings, the proposed rule deviates from the EPAs previous methodology in certain important ways.
The nitrogen found in coal typically takes the form of aromatic structures such as pyridines and pyrroles.
The South Coast Air Quality Management District designated SCONOx as the Best Available Control Technology (BACT) for natural gas-fired turbine engines. The costs for training, meeting appropriate Federal, State and local safety codes, and the preparation and approval of the RMP and Emergency Preparedness Plan must be taken into consideration when assessing the technology. This resulted in being designated as having achieved a LAER (lowest achievable emission rate) at 3.5 ppmv, which set the standard for future control technology for similar facilities per Section 173(a)(2) of the Clean Air Act. The initial capital cost is about three times the cost of SCR, although this may come down once there are more systems in operation. Vanadium pentoxide, the most commonly used SCR catalyst, is on the EPA list of Extremely Hazardous Materials.
Defense Daily subscriber and registered users, please log in here to access the content. These chemical reactions, shown below, are referred to as the "Oxidation/Absorption Cycle. Exploration and reserves, storage, imports and exports, production, prices, sales. The exhaust gases from a gas turbine flow into the reactor and react with potassium carbonate that is impregnated onto the platinum catalyst surface. This unreacted ammonia is known as ammonia slip. NOx can deteriorate water quality by overloading the water with nutrients causing an overabundance of algae. 1991-1994 data are not available for Nitrogen Oxides. xb```b`` bl, SCR catalysts degrade over time, which changes the quantity of NH3slip.
Permit applicants need to be aware of ammonia safety concerns as an issue, which in itself may mitigate the benefit of using SCR to control NOx. In terms of the range of influence or potential for long-range transport, nitric acid or organic nitrate (peroxyacetylnitrate, PAN) derived from NOx emissions, and ammonia have similar lifetimes in the atmosphere and, thus, similar potential for long-range transport. 0000016112 00000 n
Energy-Related Carbon Dioxide Emissions, Energy-Related Carbon Dioxide Emissions at the State Level, Monthly Solar Photovoltaic Module Shipments Report, Annual Solar Photovoltaic Module Shipments Report, Midwest and Rocky Mountain Transportation Fuels Markets, East Coast and Gulf Coast Transportation Fuels Markets, Changes in coal sector led to less SO2 and NOx emissions from electric power industry, decline in electric power sector coal-fired generation.