CaO作为高温 CO2吸附剂的文献调研报告

Lijing Fan2013.8.16

Contents

Brief background information

Work plan

Different structure material

CaO nanopod

CaO hollow sphere

Hollow CaCO3 Microspheres

Background

BP2030 World Energy Outlook

Carbon dioxide emission

Billion tonCO2

Billion ton oil

CO2 capture and storage (CCS)

High efficiency Low costRegenerable

First, any chemical employed to capture CO2 will rapidly exhaust its global supplies if it is used in a once-through manner;

Second, any chemical produced from CO2 as a reactant will rapidlysaturate global markets for that chemical

CaO-Based adsorbents

CaO advantages:Wide availability Low costEasy handlingHigh initial adsorption quantity

1. The choice of the precursor2. The preparation methods3. Change the morphology and structure4. Chemical treatments and reactivation5. Use of additives

CaO Nanopods CaO Hollow Sphere Hollow CaCO3 Microspheres

surfactant template biomimetic

The critical layer thickness of the product CaO+CO2 CaCO⇄ 3

Hollow structure?

Step1:fast surface reactionStep2:slow diffusion

20-50nm

CaO Hollow Nanopods

Ind. Eng. Chem. Res.2009， Synthesis and Characterization of CaO Nanopods for High Temperature CO2 Capture.

Tri-block copolymer, P123(PEO20PPO70PEO20)

TEM image of the “nanopod” CaCO3Schematic diagram of a slurry bubble column used for the synthesis of CaCO3 nanopods.

Adsorption capacity

Material BET surfacearea [m2/g]

total porevolume [cm3/g]

CaO nanopods 16.92 0.24 CaO

commercially available

9.19 0.10

The role of PEO20PPO70PEO20

CaCO3nanopods prepared in the presence of P123 surfactant CaCO3 prepared without P123

The role of PEO20PPO70PEO20

CaO derived from A CaO derived from B

P123 (PEO20PPO70PEO20)- tri-block copolymer surfactant, helps to stabilize the CO2 bubbles, which form a template for the assembly of the CaCO3 nanopods.

CaO Hollow Sphere

J. Mater. Chem. A, 2013, 1, Synthesis, characterization, and high temperature CO2 capture of new CaO based hollow sphere sorbents.

Diagram of the formation mechanism of the CaO/Ca12Al14O33 hollow spheres

Mesoscopic CaO/Ca12Al14O33 hollow nanospheres

Template:core (interior polystyrene core)–shell (sulfonated hydrogel shell) gel particles

Precursors : calcium chloride dihydrate : aluminum isopropoxide =85:15 in weight ratio

Material characterization

Higher-magnification SEM image

TEM image of hollow spheres

XRD patterns of hollow sphere sorbents with different CaO/Ca12Al14O33 ratios

Adsorption capacity

CO2 adsorption capacity at experimental condition. Inset: the rate of CO2 adsorption

CO2 capture capacity as a function of the cycle number

Reasons for high adsorption capability

void space in hollow structures

mesoscopic sorbentsThe inert Ca12Al14O33 binders

Theoretical maximum possible capacity： 0.59g CO2/g adsorbent

1. According to the literature ,repeating the experiment of synthesizing hollow CaCO3 nanopod and investigating its adsorption capacity.

2. Adding aluminum isopropoxide to improve the cycle stability of nanopod CaO.

3. Consulting more literature about CaO-based adsorbent with different structure such as CaCO3 hexagonal plates, rod-like particles, and multi-branched hierarchical structures.

Work plan

Thanks for your attention!

CaCl2(aq) + 2NH4OH (aq) + CO2(g) CaCO3(s) + 2NH4Cl(aq) + H2O

Hollow CaCO3 Microspheres

4-（ 2-乙胺基）苯 -1,2-二酚CaCO3 crystalline phases

calcite

aragonitevaterite

J. Mater. Chem., 2011, Bio-inspired mineralization of CO2 gas to hollow CaCO3 microspheres and bone hydroxyapatite/polymer composites

Hollow CaCO3 Microspheres

Schematic illustration of the experimental procedure for conversion of CO2 gas to hollow vaterite

Bio-inspired Hollow CaCO3 Microspheres

SEM image Confocal microscopic image

Experimental scheme

. HCl +Tris-base

Tris-HCl

Dopamine

CaCl2(aq) + 2NH4OH (aq)

CO2

calcinationCaCO3 CaO

Existing problems:

1.The bio-inspired simulation is hard to realize

2.Material size: BET surface area-6.18m2/g, pore volume- 0.021cm3/g

3.Crystal phase transition