Selective catalytic reduction cost
Graph, source: eucg Inc.
And Boward,., "Economic Evaluation of Controls for.s - A Case Study In Proceedings: epri-DOE-EPA Combined Utility Air Pollution Control Symposium: The Mega Symposium: NOX and Multi-Pollutant Controls, epri, Palo Alto, CA,.S.
1, commercial selective catalytic reduction systems are typically found on large utility boilers, industrial boilers, and municipal solid waste boilers and have been shown to reduce NO x by 70-95.
Srivastava, is gratefully acknowledged.DEF tanks range in size from 5 to 22 gallons depending on the truck's application.By MW at the time of the study) owned by eight large utilities from SIP Call states located in the East and Midwest.(A2) in (A4 (NH3)i (ppm NOx)r (ppm) 1 x (ppm 786.88 NOx)r (lb/106 Btu) (A5) (NOx)r (lb/106 Btu) B (lb/106 Btu C/100 (A6) where B NOX (lb/106 Btu) at the inlet of SCR reactor C NOx removal efficiency (percent) Substituting Eqn.A nationwide DEF distribution infrastructure has rapidly expanded to meet the needs of a growing SCR technology marketplace.Personal Communication with.Equation (2) assumes this average degree of difficulty.Gas turbines, cars, and diesel engines all have a period during a start-up where exhaust temperatures are too cool for NOx reduction to occur.This factor is dependent upon the number of hours a unit is assumed to operate per year.All those three reductants are widely available in large quantities.Given the importance of catalyst cost, changing factors over a broad range can result in a significantly increased (or decreased) estimate for variable O M cost.
These engines require the periodic addition of diesel exhaust fluid (DEF, a urea solution) to enable the process.
Another facet of tuning involves determining the proper ammonia flow for all process conditions.
Honeycomb configurations are smaller than plate types, but have higher pressure drops and plug much more easily.
The cost equations and variables used in the methodology are based on information obtained from SCR system suppliers and reflect experience gained from over 200 SCR applications.
However, the estimates that this methodology can provide cannot replace the detailed site-specific engineering cost studies or cost"tions.First, in general, there has been less of a demand for achieving low NOX removal efficiencies (i.e., below 70-75 percent) with SCR.13'14'15'16 This is because, typically, SCR systems with higher NOX removal efficiencies are more cost effective.DEF is carried in an onboard tank which must be periodically replenished by the operator based on vehicle operation.Ammonia slip is also an issue with SCR technology used in power plants.The DEF sets off a chemical reaction that converts nitrogen oxides into nitrogen, water and tiny amounts of carbon dioxide (CO2 natural components of the air we breathe, which is then expelled through the vehicle tailpipe.In another economic analysis by Gaikwad and Boward,6 for SCR retrofits on 300 and 500 MW boilers to reduce NOX by 80-85 percent, combined O M costs were estimated to be between.6 million/yr and.2 million/yr.Some of these poisons include: halogens, alkaline metals, arsenic, phosphorus, antimony, chrome, copper.The cost distribution for 72 units with SCR installed shows expected economies of scale.Another catalyst based on activated carbon was also developed which is applicable for the removal of NOx at low temperatures.Some 41 of the units surveyed in the 600- to 900-MW range are close to navigable waters, versus 76 of units larger than 900.
The costing methodology presented in this report can be used to estimate budgetary costs of SCR application over the spectrum of boiler sizes and types.
For example, recent literature reflects a range of 55 to 140 /kW as being characteristic of retrofit SCR system capital cost for all types of utility boilers.