EP3548163A1 - Élimination de l'arsenic des gaz de combustion - Google Patents

Élimination de l'arsenic des gaz de combustion

Info

Publication number
EP3548163A1
EP3548163A1 EP17808482.8A EP17808482A EP3548163A1 EP 3548163 A1 EP3548163 A1 EP 3548163A1 EP 17808482 A EP17808482 A EP 17808482A EP 3548163 A1 EP3548163 A1 EP 3548163A1
Authority
EP
European Patent Office
Prior art keywords
ionic liquid
arsenic
bed
list consisting
process according
Prior art date
Legal status (The legal status 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 status listed.)
Withdrawn
Application number
EP17808482.8A
Other languages
German (de)
English (en)
Inventor
Anne Schmidt
Isabel VERMEULEN
Peter Nockemann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Umicore NV SA
Original Assignee
Umicore NV SA
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 Umicore NV SA filed Critical Umicore NV SA
Publication of EP3548163A1 publication Critical patent/EP3548163A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • 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
    • B01D53/46—Removing components of defined structure
    • B01D53/64—Heavy metals or compounds thereof, e.g. mercury
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/22—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising organic material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28057—Surface area, e.g. B.E.T specific surface area
    • B01J20/28066—Surface area, e.g. B.E.T specific surface area being more than 1000 m2/g
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28069—Pore volume, e.g. total pore volume, mesopore volume, micropore volume
    • B01J20/28073—Pore volume, e.g. total pore volume, mesopore volume, micropore volume being in the range 0.5-1.0 ml/g
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28078—Pore diameter
    • B01J20/28083—Pore diameter being in the range 2-50 nm, i.e. mesopores
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
    • B01J20/3202—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the carrier, support or substrate used for impregnation or coating
    • B01J20/3204—Inorganic carriers, supports or substrates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/30—Processes for preparing, regenerating, or reactivating
    • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
    • B01J20/3231—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the coating or impregnating layer
    • B01J20/3287—Layers in the form of a liquid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2252/00—Absorbents, i.e. solvents and liquid materials for gas absorption
    • B01D2252/30—Ionic liquids and zwitter-ions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/10—Inorganic adsorbents
    • B01D2253/102—Carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/25—Coated, impregnated or composite adsorbents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/30—Physical properties of adsorbents
    • B01D2253/302—Dimensions
    • B01D2253/306—Surface area, e.g. BET-specific surface
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/025—Other waste gases from metallurgy plants
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases
    • 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
    • B01D53/02—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 by adsorption, e.g. preparative gas chromatography
    • B01D53/025—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 by adsorption, e.g. preparative gas chromatography with wetted adsorbents; Chromatography

Definitions

  • the present invention concerns a gas cleaning process, specially adapted for the removal of traces of arsenic oxides in exhaust gases, in particular in off-gases from metallurgical smelting processes or coal burning processes.
  • Arsenic is present in many minerals, concentrates, and recycled metal-bearing materials.
  • Arsenic and many arsenic compounds are also relatively volatile at high temperature.
  • Condensation and filtration allow for arsenic abatement down to about 0.2 to 0.8 mg/Nm 3 in the gas phase.
  • Hydrated lime Ca(OH)2 can be injected in the gas, thereby not only serving as condensation surface, but also adsorbing the arsenic by forming a Ca - As precipitate. A further reduction of arsenic down to 0.05 mg/Nm 3 is then typically obtainable.
  • a known process for the further reduction of arsenic is passing the gas through a bed of active carbon. It has been recognized that the effectiveness of arsenic adsorption on active carbon decreases with increasing temperature. The gas stream has therefore to be cooled down to well below 100 °C. Unfortunately, the adsorption kinetics at this temperature are rather slow. A sufficient contacting time between active carbon and gas can only be achieved by using a voluminous bed, which therefore needs to contain a large quantity of active carbon. This results in bulky and expensive equipment. The active carbon is moreover not effectively utilized, as it never gets saturated in arsenic during its normal operational life.
  • US20140001 100 discloses a process for the capture of elemental mercury from a hydrocarbon fluid using ionic liquids.
  • Suitable ionic liquids comprise an organic cation, a metal cation, and an anion.
  • the ionic liquid is believed to perform a dual function.
  • the metal cation part of the ionic liquid oxidizes the mercury.
  • the oxidized mercury, being destabilized in its organic environment, is then efficiently captured in the ionic liquid.
  • US20070123660 similarly concerns a process for the capture of gaseous forms of elemental or oxidized mercury, but also of lead, zinc and cadmium. Use is made of a combination of a ligand and of an ionic liquid. Oxidizing agents are added when elemental species need to be captured.
  • a process is hereby divulged for the removal of arsenic oxides in process exhaust gases, comprising the step of passing the exhaust gases through a supported ionic liquid phase bed, characterized in that the ionic liquid comprises one or more cations from the list consisting of substituted phosphonium, ammonium, imidazolium, pyrrolidinium, and pyridinium, and one or more anions from the list consisting of chloride, bromide, and carboxylate.
  • process exhaust gases are meant gases from metallurgical smelting processes or from other burning processes.
  • the substituted phosphonium cation is according to formula [P m n o ] +
  • the substituted ammonium cation is according to formula [N m n o ] +
  • the substituents are hydrocarbon chains containing m, n, o, and p carbon atoms each, with the proviso that m+n+o+p > 10 when the anion is a halide, and m+n+o+p ⁇ 30 when the anion is a carboxylate.
  • the hydrocarbon chains substituents of the cation are preferably unbranched and saturated.
  • the anions are preferably unbranched, unsaturated monocarboxylates, containing 1 to 8 carbon atoms.
  • the most preferred ionic liquid is [P6 6 6 14] CI. This product is commercially available as
  • the process is most suitable for removing arsenic oxides comprising AS2O3 and/or AS2O5.
  • the supported ionic liquid phase comprises a support phase from the list consisting of alumina, silica, and activated carbon.
  • a support phase having a BET of more than 50 m 2 /g is desired.
  • a weight ratio of support phase to ionic liquid weight between 3 : 1 and 50 : 1 is most suitable.
  • the cleaning apparatus itself can be more compact
  • the investment can therefore be lower than when using active carbon, and the running costs decreased.
  • Such a SILP may also adsorbs elements other than arsenic which may also be present in the gas phase, such as Zn, Hg, Cd, Pb, Sb, and Se, dependent upon the precise ionic liquid selected.
  • the ionic liquid identified as trihexyl-tetradecyl-phosphonium chloride [P6 6 6 14] CI lends itself well for the capture of As, but also of Pb, Cu, Cd, Se and Zn. There is also clear evidence for the uptake of Sb and Se when using 1 -butyl-3-methylimidazolium acetate [C 4 Ciim] [C1CO2].
  • the supporting substrate should be highly porous and should be wetted by the envisaged ionic liquid.
  • Typical candidates are silica, alumina, titanium oxide, zirconium oxides, activated carbon, porous polymers, zeolites, and metal-organic frameworks. When targeting the adsorption of arsenic, ionic liquids susceptible to dissolve significant amounts of it are clearly preferred.
  • the spent SILP can be directly recycled to that process.
  • a capture mechanism ahead of the SILP adsorption step is then needed to avoid the accumulation of the metals captured by the SILP.
  • the recycled SILP could even be considered as a valuable reaction agent. This would be the case, e.g. when dealing with an active carbon substrate and a pyrometallurgical process needing a reducing agent.
  • silica or alumina substrates could usefully be recycled to a process needing fluxing for the formation of a slag.
  • the increase in capacity of the SILP is demonstrated.
  • activated carbon WS 490 from Chemviron Carbon® is used.
  • One part by weight of the ionic liquid is dissolved in nine volume parts of methanol.
  • the solution is added to nine part by weight of activated carbon and left overnight to ensure complete adsorption.
  • the solvent is removed in three steps: 1.5 h at 45 °C and
  • batches of SILP are produced using ionic liquids [P6 6 6 14] CI and [C4Ciim]
  • the BET is measured to characterize the specific surface of the obtained SILP material. From this analysis, the pore volume and the pore size is determined using BJH analysis. These determinations are performed using nitrogen for the untreated activated carbon (AC) as well as for the above-prepared SILP samples. This is reported in Table 1.
  • Ionic liquids are selected according to their capacity to dissolve AS2O3. This list is reported in Table 2, along with the saturation limit as function of temperature. Table 2: AS2O3 solubility in selected ionic liquids
  • the coating layer of the selected ionic liquids is capable of adsorbing about 10 kg of AS2O3 per tonne of SILP.
  • the total capacity of the SILP can be estimated to be double the capacity of the active carbon alone. This increase of capacity is a first advantage of soaking the active carbon in a selected ionic liquid.
  • adsorption columns are prepared, one filled with un-soaked activated carbon to be used as a reference, the filled other with activated carbon soaked in [P6 6 6 14] CI as described in Example 1.
  • Each column comprises a small amount of glass wool at the bottom, followed by a steel mesh and 10 g of adsorption material.
  • Two additional layers of adsorption material are added, each separated by a steel mesh. Each layer has an average height of
  • AS2O3 bearing gas is fed to the columns.
  • a side stream is sampled from the off-gases produced by a lead blast furnace.
  • the gas is divided into three parallel streams.
  • One stream is directly passed through to a cascade of washing bottles for the analysis of the inlet concentrations.
  • the analysis of the AS2O3 in the washing bottles allows for the determination of the input concentration.
  • the other two are passed through the respective adsorption columns.
  • Each column outlet is individually connected to a separate cascade of washing bottles.
  • Each cascade is followed by a drying column and a pump where the gas flow rate is adjusted to 3 L/min for each stream.
  • the temperature of the gas entering the columns is about 140 °C.
  • the experiment is conducted for 48 h.

Abstract

La présente invention concerne un procédé d'élimination d'oxydes d'arsenic des gaz d'échappement de procédé, comprenant l'étape consistant à faire passer les gaz d'échappement à travers un lit de phase liquide ionique supporté, caractérisé en ce que le liquide ionique comprend un ou plusieurs cations de la liste constituée par le phosphonium substitué, l'ammonium, l'imidazolium, le pyrrolidinium et le pyridinium, et un ou plusieurs anions de la liste consistant en chlorure, bromure et carboxylate. Par rapport à un lit de charbon actif, le lit de charbon actif imbibé de liquide ionique selon l'invention permet un doublement estimé de la capacité d'adsorption d'arsenic du lit, tout en améliorant considérablement la cinétique d'adsorption.
EP17808482.8A 2016-12-05 2017-12-05 Élimination de l'arsenic des gaz de combustion Withdrawn EP3548163A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP16202195 2016-12-05
PCT/EP2017/081435 WO2018104257A1 (fr) 2016-12-05 2017-12-05 Élimination de l'arsenic des gaz de combustion

Publications (1)

Publication Number Publication Date
EP3548163A1 true EP3548163A1 (fr) 2019-10-09

Family

ID=57530500

Family Applications (1)

Application Number Title Priority Date Filing Date
EP17808482.8A Withdrawn EP3548163A1 (fr) 2016-12-05 2017-12-05 Élimination de l'arsenic des gaz de combustion

Country Status (8)

Country Link
EP (1) EP3548163A1 (fr)
JP (1) JP2019535511A (fr)
KR (1) KR20190087630A (fr)
CN (1) CN110177611A (fr)
AU (1) AU2017371115A1 (fr)
CA (1) CA3043671A1 (fr)
EA (1) EA201991235A1 (fr)
WO (1) WO2018104257A1 (fr)

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4908191A (en) * 1987-07-21 1990-03-13 Ethyl Corporation Removing arsine from gaseous streams
FR2668465B1 (fr) * 1990-10-30 1993-04-16 Inst Francais Du Petrole Procede d'elimination de mercure ou d'arsenic dans un fluide en presence d'une masse de captation de mercure et/ou d'arsenic.
US8118916B2 (en) 2005-10-21 2012-02-21 The University Of Cincinnati High capacity materials for capture of metal vapors from gas streams
KR20100042110A (ko) * 2008-10-15 2010-04-23 한국과학기술연구원 인 함유 이온성 액체를 이용한 기체 흡수제
GB2484301B8 (en) 2010-10-05 2017-11-22 The Queen's Univ Of Belfast Process for removing metals from hydrocarbons
DE202011106028U1 (de) * 2011-08-14 2012-08-17 BLüCHER GMBH Neue Konzepte für die Gasbehandlung und Gasreinigung
JP6616928B2 (ja) * 2013-06-19 2019-12-04 カルゴン カーボン コーポレーション 活性炭からの重金属浸出の軽減方法
FR3009204B1 (fr) * 2013-07-31 2015-07-24 IFP Energies Nouvelles Procede de captation d'un metal lourd contenu dans un gaz humide avec dilution du gaz humide pour controler l'humidite relative du gaz.
CN103877844B (zh) * 2014-03-13 2016-01-13 华能国际电力股份有限公司 一种脱汞吸收液
WO2016148735A1 (fr) * 2015-03-16 2016-09-22 University Of Wyoming Procédés et compositions pour l'élimination du mercure dans des gaz

Also Published As

Publication number Publication date
EA201991235A1 (ru) 2020-01-16
CN110177611A (zh) 2019-08-27
JP2019535511A (ja) 2019-12-12
KR20190087630A (ko) 2019-07-24
CA3043671A1 (fr) 2018-06-14
AU2017371115A1 (en) 2019-05-30
WO2018104257A1 (fr) 2018-06-14

Similar Documents

Publication Publication Date Title
Li et al. Sulfur abundant S/FeS2 for efficient removal of mercury from coal-fired power plants
Vidic et al. Vapor-phase elemental mercury adsorption by activated carbon impregnated with chloride and chelating agents
JP2602361B2 (ja) 液体炭化水素から水銀を除去するための新規な製品／方法／用途
US4233274A (en) Method of extracting and recovering mercury from gases
Uddin et al. Role of SO 2 for elemental mercury removal from coal combustion flue gas by activated carbon
EP1357999B1 (fr) Procede d'extraction de mercure d'un courant gazeux
CN1033689C (zh) 净化由燃烧设备排出的有负载的废气的方法
EP1308198B1 (fr) Procédé et dispositif pour l'élimination de mercure
Qu et al. Regenerable sorbent with a high capacity for elemental mercury removal and recycling from the simulated flue gas at a low temperature
US20080041227A1 (en) Process for Removal of Mercury from Gas Stream
CN110252255B (zh) 一种气态汞吸附剂的制备方法和应用
Aktas et al. Platinum recovery from dilute platinum solutions using activated carbon
RU2352383C2 (ru) Способ улавливания тяжелых металлов из дымовых газов
RU2139752C1 (ru) Способ непрерывного и одновременного сбора и осаждения ртути из содержащих ее газов
Wan et al. Removal of mercury from flue gas using coal gasification slag
KR100376899B1 (ko) 가스로부터 금속 카르보닐 및 수분의 제거 방법 및 장치
US20090200207A1 (en) Absorption Composition and Process for Removing Mercury
WO1996009884A1 (fr) Compositions ceramiques chimiquement actives et possedant une fraction hydroxyquinoleine
EP0527000A2 (fr) Procédé d'élimination de soufre
Qin et al. Selective removal of Hg2+ from acidic wastewaters using sulfureted Fe2TiO5: Underlying mechanism and its application as a regenerable sorbent for recovering Hg from waste acids of smelters
Lanaridi et al. Liquid‐and Solid‐based Separations Employing Ionic Liquids for the Recovery of Platinum Group Metals Typically Encountered in Catalytic Converters: A Review
Saha et al. Metal sorption performance of an activated carbon after oxidation and subsequent treatment
EP2635529A1 (fr) Sorbant à base de manganèse pour l'élimination d'espèces de mercure à partir de fluides
EP3548163A1 (fr) Élimination de l'arsenic des gaz de combustion
EP2433708A1 (fr) Sorbant de sulfide d'argent supporté

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20190705

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20200128