Comparison of
This presentation is the property of its rightful owner.
Sponsored Links
1 / 26

연세대학교 화학공학과 이 태 규 PowerPoint PPT Presentation


  • 227 Views
  • Uploaded on
  • Presentation posted in: General

Comparison of Mercury Removal Efficiency from a Simulated Exhaust Gas by Several Types of TiO 2 under Various Light Sources. 연세대학교 화학공학과 이 태 규. 제 4 회 광촉매 연구회 2004 년 2 월 26 일. Introduction. Mercury. Toxic properties High volatility Tendency to bio-accumulate. Emission resources.

Download Presentation

연세대학교 화학공학과 이 태 규

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


4656687

Comparison of Mercury Removal Efficiency from a Simulated Exhaust Gas by Several Types of TiO2 under Various Light Sources

연세대학교 화학공학과

이 태 규

제4회 광촉매 연구회

2004년 2월 26일


Mercury

Introduction

Mercury

  • Toxic properties

  • High volatility

  • Tendency to bio-accumulate

Emission resources

  • 80% of the total emission from the combustors (Coal Combustors, Waste Incinerators, etc.)


Hg emissions control methods

Introduction

Hg Emissions Control Methods

  • Oxidized mercury can be captured relatively easily because of its high solubility in weak acidic solution

  • Elemental mercury is difficult to capture

  • Unusual non-reactivity compared to other metals

    • 5d106s2 closed shell electronic structure for Hg atom

    • extremely slow or no oxidation at high temperatures

    • possible oxidation by strong oxidants (NO2, Cl2)


Introduction

Photocatalyst TiO2

 high removal efficiency for low concentrations of toxic compounds

Hg removal under UV light

Introduction

Hg removal by adsorbents

Activated Carbon

=> most widely used

disadvantage

  • Low applicable

    temperature range

  • Low regeneration rate &

    slow adsorption rate


4656687

Introduction

UV light

  • high energy strength

  • harmful

  • development of improved photocatalysts activating

  • under the visible light!!!

Intermediate

step

Hg removal using a TiO2

under thefluorescent light


Hg capture by tio 2

Theory

Hg capture by TiO2

Light

Hg

TiO2

HgO

O

2

-

O

2

-

e

H

O

2

OH

+

Hg

HgO

+

+

H

TiO2(s) + light → TiO2·OH + Hg(g) → TiO2·HgO(complex)


Apparatus

Experimental

Apparatus


4656687

Light Sources

TiO2 Powder

  • UV black light

  • UV sterilizing light

  • fluorescent light

  • blue light

  • pure anatase (Ishihara co.)

  • P25 (Degussa co.)

  • anatase : rutile = 80 : 20

  • pure rutile (Junsei co.)

Experimental


Wave length

UV-C

UV-B

UV-A

Visible Light

Infrared Ray

Experimental

Wave length


A uv black light

Results

[a] UV black light


B uv sterilizing light

Results

[b] UV sterilizing light


C fluorescent light

Results

[c] fluorescent light


D blue light

Results

[d] blue light


Breakthrough experiment

Results

Breakthrough Experiment


Xrd pattern of tio 2 hg complex

Results

XRD pattern of (TiO2-Hg) Complex


4656687

The removal efficiency was close to 100% under most light sources tested.

More than 99% of initial Hg was removed under all the light sources tested except for the blue light still achieving a Hg removal efficiency close to 80%.

High efficiency was achieved even under the low concentration.

Easily maintainable and cost-effective fluorescent light can be used.

Conclusion


4656687

Future Works

  • Verification of Hg adsorption mechanism under the visible light

  • Verification of Hg removal efficiency with crystallinity, surface area, and particle size

  • Hg removal by TiO2 directly coated on beads

  • Application of TiO2 coated ferro-powder to water treatment

Hg removal by sunlight


Structural effect of in situ generated tio 2 on hg 0 removal in a simulated combustion flue gas

Structural Effect of In Situ Generated TiO2 on Hg0 Removal in a Simulated Combustion Flue Gas

• Furnace 온도가 증가함에 따라 크기가 커지지만

open structure를 가진 입자를 생성

•입자의 크기가 증가할수록 수은의 제거효율 증가

• NH3를 이용하여 TiOx-Ny를 제조, 가시광선에의

반응성 측정 및 촉매 특성 분석


Structural effect of in situ generated tio 2 on hg 0 removal in a simulated combustion flue gas1

Structural Effect of In Situ Generated TiO2 on Hg0 Removal in a Simulated Combustion Flue Gas


Structural effect of in situ generated tio 2 on hg 0 removal in a simulated combustion flue gas2

Structural Effect of In Situ Generated TiO2 on Hg0 Removal in a Simulated Combustion Flue Gas

Ti(OC3H7)4 + 18O2 → TiO2+12CO2 +14H2O


Structural effect of in situ generated tio 2 on hg 0 removal in a simulated combustion flue gas3

Structural Effect of In Situ Generated TiO2 on Hg0 Removal in a Simulated Combustion Flue Gas


Preparation of column shape tio 2 fiber by a diffusion flame reactor

Preparation of Column Shape TiO2 Fiber by a Diffusion Flame Reactor

  • Height above burner (HAB)에 따른

  • particle shape / crystallinity ; fibrous / anatase

  • Raman Spectroscopy


Apparatus1

Apparatus


Sem i

SEM I

<Figure 1. Pure TTIP, HAB=3cm>

<Figure 2. Pure TTIP, HAB=5cm>


Sem ii

SEM II

<Figure 3. Pure TTIP, HAB=7.5cm>

<Figure 4. Pure TTIP, HAB=10cm>


4656687

The End


  • Login