Home>API standards>API RP 536-2006 pdf free download

API RP 536-2006 pdf free download

API RP 536-2006 pdf free download.Post-Combustion NO x Control for Fired Equipment in General Refinery Services.
3.1.13 cell density: Measurement of hole density in a honeycomb catalyst matrix (cells per sq. cm [sq. in.]). 3.1.14 dilution medium: Fluid (usually air, steam, or water) used to disperse the reactant within the flue gas stream—also referred to as a “carrier.” 3.1.15 injection grid: a series of distribution pipes and injection nozzles located in the flue gas stream to enable effective mixing of the reactant and flue gas. 3.1.16 masking: Condition when the outer surfaces of the catalyst are covered with foreign material rendering the inner active surfaces inaccessible for NO x reduction. 3.1.17 NO x : General term used to describe all oxides of nitrogen including nitric oxide (NO), nitrogen dioxide (NO 2 ), and nitrous oxide (N 2 O). For the purpose of emission calculations, NO x is assumed to be nitrogen dioxide MW = 46.01. 3.1.18 reactant ammonia: Anhydrous or aqueous ammonia used in the majority of post combustion NO x reduction systems. Industrial anhydrous ammonia contains 99.5% minimum by volume ammonia and is injected as a vapor. Aqueous contains about 19% – 29% by weight ammonia solution mixed with water and has to be vaporized or atomized before injecting into the gas stream. 3.1.19 reactant flow control unit: Contains the equipment and instrumentation necessary for control and injection of the reactant (ammonia or urea), including but not limited to vaporizer or atomizer, dilution air fan, mixer, and control valves. 3.1.20 reactant urea: Used in some SNCR processes. Urea is normally used as an aqueous solution containing about 50% urea by weight. 3.1.21 reactor: The housing that contains the catalyst modules and support structure. 3.1.22 reduction efficiency: The percentage of NO x removed from the flue gas by the reduction process. 3.1.23 residence time: The time period the reactant is in contact with the nitrogen oxides and/or catalyst. 3.1.24 sintering: For vanadium and titanium catalysts refers to the irreversible loss of active surface due to the effect of high temperatures.
3.3 UNITS OF EMISSIONS MEASUREMENTS 3.3.1 Analysis of NO x and other emissions are normally measured in ppmvd. Since some sampling instruments measure the wet sample, care should be taken when analyzing results. 3.3.2 The performance of equipment must be compared on a common basis. The amount of NO x and ammonia slip should be corrected back to the standard oxygen levels. For boilers and fired heaters the U.S.A. standard is 3% oxygen (volume dry) in the flue gas, and for gas turbines the standard is 15% oxygen (volume dry). The calculation method for correcting the NO x values is given in Appendix B. 3.3.3 In the United States, the most common unit of reporting emissions is lb/MM Btu liberated. The heat liberation is based upon the higher heating value (HHV) of the fuel. The API standard basis for heat liberation in process heaters is the lower heating value (LHV) of the fuel. Care should be used in expressing the emissions on the correct basis. 3.3.4 In other countries, the units of reporting emissions can be milligrams per Normal cubic meter (mg/Nm 3 ) or parts per mil- lion (ppmvd) based on a different flue gas oxygen reference. See Appendix B for methods of converting the various units. 4 Processes Description, Considerations, and Applications 4.1 SELECTIVE NON-CATALYTIC REDUCTION (SNCR) 4.1.1 General Description The use of Selective Non-Catalytic Reduction (SNCR) units to reduce NO x emissions was pioneered in the early 1970s. These processes use a reactant (ammonia or urea) to react with NO x to form water and inert gas (nitrogen/carbon dioxide). To be effec- tive in reducing NO x emission, the reducing agent must be injected into the fired equipment at a desired temperature point. Although the NO x reduction takes place in the 870ºC – 1370ºC (1600ºF – 2500ºF) temperature range, the temperature window in the SNCR process can be extended down to approximately 700ºC (1300ºF) by the injection of hydrogen or enhanced chemicals along with the reducing agents.

Related PowerPoint Templates

Template Categories
Popular Tags