TW469163B - The apparatus for, and a method of, combatting air pollution - Google Patents

The apparatus for, and a method of, combatting air pollution Download PDF

Info

Publication number
TW469163B
TW469163B TW088106730A TW88106730A TW469163B TW 469163 B TW469163 B TW 469163B TW 088106730 A TW088106730 A TW 088106730A TW 88106730 A TW88106730 A TW 88106730A TW 469163 B TW469163 B TW 469163B
Authority
TW
Taiwan
Prior art keywords
catalyst
patent application
scope
nox
during
Prior art date
Application number
TW088106730A
Other languages
English (en)
Chinese (zh)
Inventor
Guy Richard Chandler
Raj Rao Rajaram
Claus Friedrich Goersmann
Valerie Anne Self
Original Assignee
Johnson Matthey Plc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Johnson Matthey Plc filed Critical Johnson Matthey Plc
Application granted granted Critical
Publication of TW469163B publication Critical patent/TW469163B/zh

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9495—Controlling the catalytic process
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9404—Removing only nitrogen compounds
    • B01D53/9409—Nitrogen oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion
    • F01N3/206—Adding periodically or continuously substances to exhaust gases for promoting purification, e.g. catalytic material in liquid form, NOx reducing agents
    • F01N3/2066—Selective catalytic reduction [SCR]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
    • F01N2570/18—Ammonia
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N2610/00—Adding substances to exhaust gases
    • F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Health & Medical Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Biomedical Technology (AREA)
  • Toxicology (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust Gas After Treatment (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)
  • Catalysts (AREA)
TW088106730A 1998-04-28 1999-04-27 The apparatus for, and a method of, combatting air pollution TW469163B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GBGB9808876.8A GB9808876D0 (en) 1998-04-28 1998-04-28 Combatting air pollution

Publications (1)

Publication Number Publication Date
TW469163B true TW469163B (en) 2001-12-21

Family

ID=10830994

Family Applications (1)

Application Number Title Priority Date Filing Date
TW088106730A TW469163B (en) 1998-04-28 1999-04-27 The apparatus for, and a method of, combatting air pollution

Country Status (12)

Country Link
US (1) US6713030B1 (enExample)
EP (1) EP1083979B1 (enExample)
JP (1) JP4357742B2 (enExample)
KR (1) KR100604131B1 (enExample)
CN (1) CN1201854C (enExample)
AU (1) AU741813B2 (enExample)
CA (1) CA2329994C (enExample)
DE (1) DE69918435T2 (enExample)
GB (1) GB9808876D0 (enExample)
PL (1) PL343689A1 (enExample)
TW (1) TW469163B (enExample)
WO (1) WO1999055446A1 (enExample)

Families Citing this family (59)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001303934A (ja) * 1998-06-23 2001-10-31 Toyota Motor Corp 内燃機関の排気浄化装置
DE10100420A1 (de) * 2001-01-08 2002-07-11 Bosch Gmbh Robert Verfahren und Vorrichtung zur Steuerung eines Abgasnachbehandlungssystems
DE10112444A1 (de) * 2001-03-13 2002-10-02 Krupp Uhde Gmbh Verfahren zur Verringerung des Gehalts von N¶2¶O und NO¶x¶ in Gasen
US6742326B2 (en) 2001-08-09 2004-06-01 Ford Global Technologies, Llc High efficiency conversion of nitrogen oxides in an exhaust aftertreatment device at low temperature
US6698191B2 (en) 2001-08-09 2004-03-02 Ford Global Technologies, Llc High efficiency conversion of nitrogen oxides in an exhaust aftertreatment device at low temperature
US6928359B2 (en) 2001-08-09 2005-08-09 Ford Global Technologies, Llc High efficiency conversion of nitrogen oxides in an exhaust aftertreatment device at low temperature
EP1458960B1 (en) 2001-12-20 2011-02-09 Johnson Matthey Public Limited Company Improvements in selective catalytic reduction
JP3951774B2 (ja) * 2002-03-29 2007-08-01 三菱ふそうトラック・バス株式会社 内燃機関のＮОｘ浄化装置
GB0220645D0 (en) 2002-09-05 2002-10-16 Johnson Matthey Plc Exhaust system for a lean burn ic engine
EP1644619A2 (en) * 2003-06-12 2006-04-12 Donaldson Company, Inc. Method of dispensing fuel into transient flow of an exhaust system
DE102004018648A1 (de) * 2004-04-16 2005-11-10 Hte Ag The High Throughput Experimentation Company Verfahren zur Reduktion von Stickoxiden mit einem Abgasnachbehandlungssystem
US7117669B2 (en) * 2004-05-05 2006-10-10 Eaton Corporation Temperature swing adsorption and selective catalytic reduction NOx removal system
US20050247050A1 (en) * 2004-05-05 2005-11-10 Eaton Corporation Adsorption based ammonia storage and regeneration system
US7213395B2 (en) * 2004-07-14 2007-05-08 Eaton Corporation Hybrid catalyst system for exhaust emissions reduction
JP4267535B2 (ja) 2004-07-23 2009-05-27 日野自動車株式会社 排気浄化装置のＮＯｘ低減率測定方法
EP1812146A1 (en) * 2004-10-29 2007-08-01 Philip Morris USA Inc. Reducing agent metering system for reducing nox in lean burn internal combustion engines
WO2006066043A1 (en) * 2004-12-15 2006-06-22 Donaldson Company, Inc. Control for an engine exhaust treatment system
US7178328B2 (en) * 2004-12-20 2007-02-20 General Motors Corporation System for controlling the urea supply to SCR catalysts
US7585490B2 (en) * 2005-04-15 2009-09-08 University Of Iowa Research Foundation Synthesis and use of nanocrystalline zeolites
US8115373B2 (en) 2005-07-06 2012-02-14 Rochester Institute Of Technology Self-regenerating particulate trap systems for emissions and methods thereof
US7485272B2 (en) * 2005-11-30 2009-02-03 Caterpillar Inc. Multi-stage system for selective catalytic reduction
US20100166628A1 (en) 2006-02-15 2010-07-01 Nicola Soeger Catalyst for reducing nitrogen-containing pollutants from the exhaust gases of diesel engines
CN100425325C (zh) * 2006-06-26 2008-10-15 马春强 一种高尘复合scr烟气脱硝工艺及脱硝催化反应装置
JP5082361B2 (ja) 2006-09-27 2012-11-28 東ソー株式会社 ＳＣＲ触媒用β型ゼオライト及びそれを用いた窒素酸化物の浄化方法
AU2007338356B2 (en) * 2006-12-23 2011-12-08 Alzchem Trostberg Gmbh Method for the selective catalytic reduction of nitrogen oxides in exhaust gases of vehicles
DK2150328T5 (da) 2007-04-26 2015-06-29 Johnson Matthey Plc SCR-fremgangsmåde og system med Cu/SAPO-34 zeolitkatalysator
US8001769B2 (en) * 2007-08-20 2011-08-23 Caterpillar Inc. Control of SCR system having a filtering device
DE102008010330A1 (de) * 2008-02-21 2009-09-03 Süd-Chemie AG SCR-Katalysator mit Ammoniak-Speicherfunktion
US8074445B2 (en) * 2008-04-30 2011-12-13 Cummins Ip, Inc. Apparatus, system, and method for reducing NOx emissions on an SCR catalyst
US8281572B2 (en) 2008-04-30 2012-10-09 Cummins Ip, Inc. Apparatus, system, and method for reducing NOx emissions from an engine system
US8505278B2 (en) 2009-04-30 2013-08-13 Cummins Ip, Inc. Engine system properties controller
US8201394B2 (en) 2008-04-30 2012-06-19 Cummins Ip, Inc. Apparatus, system, and method for NOx signal correction in feedback controls of an SCR system
US8256208B2 (en) * 2008-04-30 2012-09-04 Cummins Ip, Inc. Apparatus, system, and method for reducing NOx emissions on an SCR catalyst
US8181450B2 (en) 2008-04-30 2012-05-22 Cummins IP. Inc. Apparatus, system, and method for reducing NOx emissions on an SCR catalyst using ammonia storage and slip control
US8141340B2 (en) 2008-04-30 2012-03-27 Cummins Ip, Inc Apparatus, system, and method for determining the degradation of an SCR catalyst
US8161730B2 (en) 2008-04-30 2012-04-24 Cummins Ip, Inc. Apparatus, system, and method for reducing NOx emissions on an SCR catalyst
US8109079B2 (en) * 2008-04-30 2012-02-07 Cummins Ip, Inc. Apparatus, system, and method for controlling ammonia slip from an SCR catalyst
WO2009135071A2 (en) * 2008-04-30 2009-11-05 Cummins Ip, Inc. Apparatus, system, and method for reducing nox emissions from an engine system
BRPI0912247B1 (pt) * 2008-05-07 2019-04-16 Umicore Ag & Co. Kg Processo para a redução de óxido de nitrogênio em gases de escape, contendo hidrocarbonetos, mediante emprego de um catalisador scr na base de um crivo molecular.
US8071037B2 (en) * 2008-06-25 2011-12-06 Cummins Filtration Ip, Inc. Catalytic devices for converting urea to ammonia
US7858060B2 (en) * 2008-07-30 2010-12-28 Gm Global Technology Operations, Inc Current storage estimation for selective catalytic reduction catalysts
US8061126B2 (en) * 2008-07-30 2011-11-22 GM Global Technology Operations LLC Nitrogen oxide estimation downstream of a selective catalytic reduction catalyst
WO2010065963A2 (en) * 2008-12-05 2010-06-10 Cummins Ip, Inc. Apparatus, system, and method for estimating an nox conversion efficiency of a selective catalytic reduction catalyst
US8356471B2 (en) * 2008-12-05 2013-01-22 Cummins Ip, Inc. Apparatus, system, and method for controlling reductant dosing in an SCR catalyst system
KR101809040B1 (ko) 2009-04-17 2017-12-14 존슨 맛쎄이 퍼블릭 리미티드 컴파니 질소 산화물의 환원에 대한 희박/농후 노화에 대해 내구적인 소기공 분자 체 지지된 구리 촉매
DE112010003613T5 (de) * 2009-09-10 2012-11-08 Cummins Ip, Inc. Niedertemperatur-Katalysator für die selektive katalytische Reduktion sowie dazugehörige Systeme und Verfahren
US8671666B2 (en) 2010-03-11 2014-03-18 Cummins Inc. System and apparatus for enhancing exhaust aftertreatment startup emissions control
JP5119289B2 (ja) 2010-04-06 2013-01-16 トヨタ自動車株式会社 内燃機関の排気浄化装置
US8733083B2 (en) 2010-04-26 2014-05-27 Cummins Filtration Ip, Inc. SCR catalyst ammonia surface coverage estimation and control
JP5002040B2 (ja) * 2010-07-07 2012-08-15 トヨタ自動車株式会社 内燃機関の排気浄化装置
US8987161B2 (en) 2010-08-13 2015-03-24 Ut-Battelle, Llc Zeolite-based SCR catalysts and their use in diesel engine emission treatment
CN102266702A (zh) * 2011-06-03 2011-12-07 清华大学 一种捕集工业废气中氨气的方法和设备及其应用
DE102015209988A1 (de) 2014-06-02 2015-12-03 Johnson Matthey Public Limited Company Beschichtete Artikel mit hohen KNOx/KSOx-Verhältnissen für die selektive katalytische Reduktion
JP2018525214A (ja) * 2015-07-03 2018-09-06 ハルドール・トプサー・アクチエゼルスカベット 触媒酸化反応における温度制御のための方法およびシステム
CN108786457A (zh) * 2017-05-02 2018-11-13 中国石油化工股份有限公司 烟气脱硝方法及脱硝反应器
CN108786439A (zh) * 2017-05-02 2018-11-13 中国石油化工股份有限公司 一种烟气脱硝方法及脱硝反应器
CN117345381A (zh) 2019-05-09 2024-01-05 康明斯排放处理公司 用于分流式紧密联接催化剂的阀门装置
US11732628B1 (en) 2020-08-12 2023-08-22 Old World Industries, Llc Diesel exhaust fluid
WO2024142568A1 (ja) * 2022-12-26 2024-07-04 株式会社クボタ 排気ガス浄化システム

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3825206A1 (de) * 1988-07-25 1990-02-01 Degussa Verfahren zur katalytischen entstickung von abgasen mittels eines reduktionsmittels
DE4117143C2 (de) 1991-05-25 1995-04-20 Daimler Benz Ag Verfahren zur selektiven katalytischen Reduktion von Stickoxiden in Abgasen aus Kraftfahrzeugdieselmotoren
DE4217552C1 (enExample) 1992-05-27 1993-08-19 Mercedes-Benz Aktiengesellschaft, 7000 Stuttgart, De
DE4315278A1 (de) 1993-05-07 1994-11-10 Siemens Ag Verfahren und Einrichtung zur Dosierung eines Reduktionsmittels in ein stickoxidhaltiges Abgas
JP3568566B2 (ja) * 1993-11-24 2004-09-22 バブコック日立株式会社 二酸化窒素と一酸化窒素を含有する排ガス用脱硝装置の使用方法
US5482692A (en) * 1994-07-07 1996-01-09 Mobil Oil Corporation Selective catalytic reduction of nitrogen oxides using a ferrocene impregnated zeolite catalyst
ES2122602T3 (es) 1994-08-10 1998-12-16 Siemens Ag Procedimiento para la conversion catalitica de oxidos de nitrogeno contenidos en el gas de escape de un motor de combustion interna.
JPH09133032A (ja) * 1995-11-10 1997-05-20 Toyota Motor Corp 内燃機関の排気浄化装置

Also Published As

Publication number Publication date
CA2329994C (en) 2007-07-10
KR100604131B1 (ko) 2006-07-25
JP4357742B2 (ja) 2009-11-04
KR20010043138A (ko) 2001-05-25
EP1083979B1 (en) 2004-06-30
GB9808876D0 (en) 1998-06-24
PL343689A1 (en) 2001-08-27
WO1999055446A1 (en) 1999-11-04
JP2002513110A (ja) 2002-05-08
CN1306455A (zh) 2001-08-01
DE69918435T2 (de) 2005-08-18
CA2329994A1 (en) 1999-11-04
EP1083979A1 (en) 2001-03-21
US6713030B1 (en) 2004-03-30
DE69918435D1 (de) 2004-08-05
AU3616499A (en) 1999-11-16
CN1201854C (zh) 2005-05-18
AU741813B2 (en) 2001-12-13

Similar Documents

Publication Publication Date Title
TW469163B (en) The apparatus for, and a method of, combatting air pollution
JP5259707B2 (ja) 非ゼオライト卑金属ｓｃｒ触媒
US5543124A (en) Process for reducing nitrogen oxides
JP5528195B2 (ja) リーンバーンエンジン用排気機構
US7485273B2 (en) Method for the reduction of NOx and NH3 emissions
US7585477B2 (en) Catalyst and method for catalytic reduction of nitrogen oxides
US20050069476A1 (en) Selective catalytic reduction
EP2650496A2 (en) Catalysed wall-flow filter
US7666375B2 (en) Method for catalytic reduction of nitrogen oxides
TW200401746A (en) Selective non-catalytic reduction of NOx
CA2318136A1 (en) Combatting air pollution
US7175822B2 (en) Method for catalytic reduction of nitrogen oxides
CN106413856A (zh) 减少启动用于生产硝酸的系统时氮氧化物的排放
JP2003236343A (ja) 排気ガスの浄化方法および低温脱硝装置
JP3560147B2 (ja) 排気ガス浄化システム
US11208928B2 (en) Passive NOx adsorption and decomposition
JP2004074139A (ja) 排ガス浄化触媒及び浄化方法
JP3368920B2 (ja) 天然ガスの燃焼方法及び天然ガス用燃焼器
JP2004008977A (ja) 窒素酸化物を接触的に除去するための方法とそのための装置
KR102142862B1 (ko) 질소산화물 저감을 위한 펄스 제어 시스템, 이를 사용한 질소산화물 저감방법, 및 이를 포함한 내연기관
KR101126247B1 (ko) 희토류 금속을 함유하는 배기가스내 질소 산화물의 선택적 환원용 촉매 및 이의 제조방법
MXPA00010599A (en) Process and apparatus for reducing the nitrogen oxide content in exhaust gases by the controlled addition of nh3
JP2004261754A (ja) 排ガス浄化触媒及び浄化方法
CZ20003983A3 (cs) Způsob snižování obsahu oxidů dusíku ve výfukových plynech řízeným přidáváním amoniaku a zařízení k jeho provádění
JPH04349938A (ja) 排ガス浄化用触媒及びこれを使用した排ガスの浄化方法

Legal Events

Date Code Title Description
GD4A Issue of patent certificate for granted invention patent
MM4A Annulment or lapse of patent due to non-payment of fees