State-of-the-art Ecomaterials In China

US-China Bilateral Workshop’2008, EVANSTON, USA

State-in-art of Ecomaterials in China Duan Weng, Lei Wang, Rui Ran, Xiaodong Wu Tsinghua University, Beijing 100084, Tel.: 010-6277-2726, E-mail: [email protected]

⇒ Environmental Engineering Materials; ⇒ Environmental-Friendly Materials; ⇒ Environmental Functional Materials;

2008-9-22

⇒ Contribution of materials for the society

Real World

Materials

Energy

Information

Materiality

Driving

Instruction

Materials: one of three supports for modern society!

⇒ Challenges from Resources, Energy & Environment Extreme Global Warming Potential (Temp. 3℃ High, Sea Level 60cm High)

Population 10 billions Food Crisis Population 6.2 billions

Waste

1990

Population Explosion Oil & Natural Gas Exhaust

Mineral Exhaust

Global Warming Potential (Temp. 1℃ High, Sea Level 20cm High)

2000

2050

Duan Weng, “Ecomaterials” (Chinese), Tsinghua University Press, Beijing, 2001, p.17

2100

⇒ Chinese environmental challenges 1900 Urban trash

1940

1980

Microbial pollution, COD

SO2, PM, Photochemical reaction, acid rain, water alimentation, heavy metals, solid waste, etc.

2000 GWP, PM, VOC, acid rain, water alimentation, aerosol, organic metals, POP’s, nuclear scrap, hazardous castoff, etc.

China is facing the most serious and complex pollutions in the world!

⇒ What is ecomaterial Ecomaterials Lower cost

Multi-Function

Functional Materials

Environment-friendly Economy

Materials Performance

Resource

To solve the contradiction between social development and ecological balance!

⇒ Characteristics of Ecomaterials ¾ Better performance;

Environment compatibility in the whole life cycle of materials

¾ No hazardous; ¾ Lower emission;

Functionality Functionality

¾ Higher recycling Application

Production Ecomaterials

Environment Environment

Economy Economy

Disposal

⇒ Framework of Ecomaterials Environmental Impact Assessment (EIA)

Eco-design

Environmental Engineering Materials

Cleaning Production

EnvironmentFriendly Materials

Consumption

Environmental Functional Materials Key Technique for Ecomaterials

Recycling

Waste

⇒ Environmental Engineering Materials

Environmental Engineering Materials

Air Pollution Control

DeNOx; TWC; Photocatalyst;

Water Pollution Control

Absorption; Adsorption; Filtration;

Solid Waste Treatment

Recycling;

⇒ NOx reduction for various technologies

⇒ DeNOx: Selective Catalysis Reduction Baffle

¾ Selective Catalysis Reduction 8NH3 + 6NO2 → 7N2 + 12H2O 4NH3 + 6NO → 5N2 + 6H2O 4NH3 + 4NO + O2 → 4N2 + 6H2O 4HC + 4NO + 3O2 → 2N2 + 2H2O + 4CO2

Flue gas Sediment Plate Catalyst

Stationary DeNOx Catalyst Automotive DeNOx Catalyst

⇒ SCR Catalysts ¾

Zeolite ion-exchange catalyst (Cu-ZSM-5); ¾ Precious metal composite catalyst (Pt/Pd/Rh/Au/Ag); ¾ Transition metal oxide catalyst (CuO, Co3O4, V2O5, Perovskite); Comparison of precious metal composite catalysts

Catalysts Pt-based catalysts

Ag-based catalysts

Characteristics Pt/Pd/Rh; Suitable for SCR with HC as reductant; Outstanding reduction ability, selectivity and at low temperature; Removal of NOX under lean burn condition; Outstanding activity in HC-SCR reaction process; Low cost; The brightest catalyst in the removal of NOx for diesel engine;

Au-based Au particles in nano-size perform Excellent HC-SCR activity; catalysts

⇒ SCR Catalysts: Zeolite Ion-exchange Catalyst ¾ Cu-ZSM-5 exhibited the best deNOx activity, due to the highest oxidative activity. ¾ The presence of 5% water vapor in the reaction system showed distinct negative effect on NO reduction

C3H8-SCR of NO in the absence (open symbols) and presence (solid symbols) of H2O

H2-TPR profiles of Cu-ZSM-5, In-ZSM-5 and La-ZSM-5.

L. Li, N. Guan. Microporous and Mesoporous Materials, Available online 19 July 2008

⇒ SCR Catalysts: Mn/TiO2 catalyst system ¾ NO conversion could be improved by doping Ce from 39% to 84% at 80 ºC

Ce-modified MnOx/TiO2

NO conversion of Ce modified MnOx/TiO2 catalysts at different temperatures. Reaction conditions: 1000 ppm NO, 1000 ppm NH3, 3% O2, 3% water, and balance N2, GHSV = 40,000 h−1 Z. Wu et al. Catalysis Communications 9 (2008) 2217–2220

⇒ Automotive emission control: Three-way catalyst ¾TWC process

HC CO NOx

O2 (O=O) O O

H2O CO2 N2

Catalyst Washcoating Substrate ¾ Application of rare earths in TWC Additive

Application Subject Substrate/ Active layer Structure

Improvement of thermal stability Improvement of mechanical strength Restrain the crystallite growth

Catalyst

Rare earth

Main function

Promotion of uniform distribution Partial or complete replacement of precious metal

Function

Regulation of air-to-fuel ratio Oxygen storage capacity

⇒ Automobile emission control: Ce-based catalyst ¾ The oxygen storage capacity of Ce-based catalysts broadens the TWC operation window; ¾ The addition of oxygen storage materials can decrease the quantity of precious metal and improve the thermal stability and dispersion, and also can modify the reactivity on the interface; ¾ The modification of rare earth or transition metal elements can enhance the oxygen storage capacity;

Sr-modified catalyst

Operation Window

Dynamic OSC values of Sr-modified samples

Jun Fan, Duan Weng et al. Journal of Catalysis 258 (2008) 177–186

⇒ NOx conversion with De-NOx catalyst La1-XSrXMnO3+λ

NO conversion rate/%

80

3# 60

2# 40

4# 5#

20

1#

0 0

100

200

300

400

500

600

T/℃

1# : LaMnO3+λ ,,2#: La0.9Sr0.1MnO3+λ , 3#: La0.7Sr0.3MnO3+λ, 4#: La0.5Sr0.5MnO3+λ , 5#: La0.3Sr0.7MnO3+λ , 750℃

Duan Weng, Hongsheng Zhao, et al, J. Materials Science & Engineering A, 361(2003)173-178

Dynamic OSC of aged Pr doped CZ

Liang Qing, Wu Xiaodong, Weng Duan, Journal of Rare Earth, 2006, 24: 549-553.

CeZr catalyst for cleaning PM in diesel engine

TPO curves of aged K-supported catalysts in (a) tight and (b) loose contact conditions.

Xiaodong Wu, Dongxu Liu, Kai Li, Duan Weng, Catalysis Communications, in press

⇒ Air Pollution Control: Filtration Materials

Ceramics Ceramics

Filtration Filtration Materials Materials

Metals Metals Polymer Polymer Composites Composites

Cordierite (2MgO•2Al2O3•5SiO2), Carbon, Mullite, SiC, ZrO2, TiO2, α/γ-Al2O3, Al2TiO5 FeCrAl, Stainless Steel

PVC

Metal-Ceramic, Organic-Inorganic, Ceramic-Organic Composites

⇒ Diesel Particular Filtration

⇒ Air Pollution Control: Filtration Materials

¾ DPF with catalyst can effectively reduce the emission of CO, HC, NOX and PM;

⇒ VOCs pollution control: Catalytic Combustion ¾ A combustion catalyst of 0.1%Pt-0.5%Pd/stainless steel wire mesh (SSWM) was prepared via anodic oxidation treatment for purifying volatile organic compound (VOC). ¾ The total oxidation temperature for toluene, acetone, and ethyl acetate was at 220, 260, and 280 ºC.

T98 of VOCs on different catalysts

SEM images of different samples (A) 0.1%Pt/SSWM, (B) 0.1%Pt-0.5%Pd/SSWM, (C) the enlargement of 0.1%Pt/SSWM, (D) the enlargement of 0.1%Pt-0.5%Pd/SSWM

Ying Ma et al. Acta Physico-Chimica Sinica, 2008, 24(7): 1132−1136

⇒ Water Pollution Control: Photocatalysts ¾ Environment-friendly ¾ No poisonous; ¾ Lower emission; ¾ Higher stability; ¾ Long life cycle;

Schematic diagram of photocatalysis

TiO2 as a photocatalyst for waste water treatment • production of TiO2 (per 1kg) Fresh water

104kg

V-Ti magnetite

5.58kg

Energy

63.86MJ

Waste acid

6.4kg

Waste water

70kg

CO2

7.87kg

FeSO4·7H2O

3.5kg

Waste solid

10.5kg

Dust

0.3kg

Thin film: less environmental impact

Powder: more efficient (cheap)

It means totally different for material research Environmental information supports decision-making in material research

⇒ Water Pollution Control: Membrane Materials Microfiltration

Suspended particles

Ultrafiltration

Macromolecular organic compounds Carbohydrate etc. Divalent salt or multivalent salt

Nanofiltration reverse osmosis

Monovalent salt H2O

⇒ Environment-Friendly Materials

Bio-degradable materials; Environmental -Friendly Materials

Green packaging materials; Alternatives for hazard elements like Pb, Hg & Organics; Cleaning production;

⇒ Environment-friendly materials: Degradable plastics White Pollution Plastic pollution in China Plastic pollution

Other pollution

Weight percentage

7%

93%

Volume percentage

20%

80%

Degradable plastics photodegradable plastics Degradable plastics

microbial synthesis chemical synthesis

biodegradable plastics photo-biodegradable plastic

natural polymer blending type

⇒ Environment-friendly materials: Green Packaging Materials Category

Content

To replace aluminum with steel; To replace aluminum plating with silicon plating; Green substitute To replace wood with bamboo; packaging materials To replace pulp paper with recycled paper; To replace plastic with edible wrapping paper; To replace ordinary plastic with biodegradable plastic; Green modified packaging materials

Plastic modified material; Glass modified material; Foldable container; Mildew bags; Modified steel drums;

New green packaging materials

Natural packaging materials; The comprehensive utilization of natural chitin; Edible packaging materials; Green packaging printing inks;

⇒ Environment-friendly materials: Comprehensive utilization of rice chaff Rice chaff: 18～22％ of rice weight; Process 1: Chaff

Hydrolization for xylitol

Vacuum burn

Ecological building materials

Power/heating

Activated carbon & soluble glass Rinsing

Pure SiO2

• 2 tons chaff ~ 1 ton coal

Disposable green tableware

• 1.0 kg chaff ~ 2.6 steam • ~2.5 kg chaff ~ 1 KWh power

Process 2: Chaff ash

Reaction

Filtration

Washing pickling solid

NaOH

Dry & active Activated carbon

water liquild

⇒ Environmental Functional Materials

Self-cleaning Materials; Environmental Functional Materials

Phase Change Materials; Smart Materials for building;

⇒ Environmental functional materials: Low emissivity glass ¾ Double-layer glass, low emissivity

LOW-E

9 Higher the visible light transmission; 9 Low solar energy transmission; 9 Lower U-value; SnO2~40nm

Ag~10nm

⇒ Environmental functional materials: ETFE ¾ ETFE ( Ethylene –Tetrafluoethylene copolymer) 9 Easy processing 9 Tolerance of dissolution and radiation Better antifracture tear strength

Anti-aging natural ability

Transmittance > 95%

Tolerance of corrosion and abrasion resisting

Low surface tension Fire-retardant property and insulation

Water Cube

⇒ Environmental functional materials: Phase Change Materials (PCM)

¾ Phase change floor is made of high-density polyethylene packaging between paraffin and concrete;

¾ When the outdoor temperature in 5 ~ 20ºC, the indoor temperature can be controlled at 15 ~ 20 ºC. This applies to the use of cold winter weather.

⇒ Environmental functional materials: Phase Chang Materials (PCM) ¾ SSPCM plates could decrease the daily maximum temperature by up to 2ºC due to the cool storage at night.

Indoor temperature of the room with and without SSPCM plates (1 May–30 September).

G. Zhou et al. Applied Energy 86 (2009) 52–59

Indoor temperature history with different thermal conductivity of SSPCM (8–12 June).

⇒ Environmental Functional Materials Energy Storage Materials

Self-cleaning coating The r radi mal atio n

Energy Storage Materials

Long -la Lumi sting nesce Sunlight nce Luminescence excitation coating moisture H2O absorption low emissivity glass, Th light controlling coating rad erma iat l ion To prevent the heat To prevent the thermal dissipation inside radiation outside

Energy Storage & humidity controlling materials Water release

Energy Storage & humidity controlling material

Heat Heat adsorption

Energy saving room without light, power supply, belching and air-conditioning

⇒ Summary ¾ Catalyst, photocatalyst, filtration, adsorption and absorption materials were concentrated for environmental engineering materials at moment; ¾ Biomass resource, bio-degradable polymer and green packaging materials were developed for environment-friendly materials in China; ¾ Self-cleaning materials, phase change materials and smart materials for building were hot-spots of environmental functional materials for our development;

⇒ Acknowledgement ¾ It is grateful to NSFC for the financial support in the project 50572045; ¾ We would like to thank NSF to host this Workshop; ¾ Thanks a lots for Prof. Chang and MRI colleagues from Northwestern University to organize the Workshop;

谢 谢！ Thank You for Your Attention!