State of the art of adsorbent optimization for thermochemical

storage of heat

J. Jänchen and H. Stach*TFH Wildau (University of Applied Sciences), Germany

* ZeoSys GmbH, Berlin-Adlershof, Germany

Content

Demands resulting from the thermochemical cyclePorous materials for thermochemical storageMethods of modificationAchievements within the Annex 17Acknowledgement

Demants resulting from the storage cycle

Temp. level for charging, Temp. level in the condenser

(solar < weast heat) (heat removal, vapor pressure)

Temp. level for discharging Temp. level of the evaporator

(low temp. Heating < hot water) (heat supply, vapour pressure)

Porous materials for thermochemical StorageZeolites of type A, X, Y, Chabazite, (microporous, with large pore volumes),AlPO‘s, MeAPO‘s, SAPO‘s (microporous, with large pore volumes),Silica gel (mesoporous, large pore and small poretypes),MCM-41 (mesoporous, aluminosilicates)Composites, hygroscopic salt hydrates in a porous material (Aristov, Russia) such as- silica gel, aluminosilicate, activated carbon with - CaCl2 nH2O, MgSO4 nH2O, Na3PO4 nH2O.

Methods of modificationZeolites:- ion exchange with divalent ions (Ca, Mg)- changes of Si/Al ratio, dealumination of the frame

workAlPO‘s:- changes of lattice compositionSilica gel:- modification of surface chemistry and pore sizeComposits:- changes of the hygroscopic salts and the hosts

Structure of the materials

Zeolite X, Y

Chabazite

Activated carbon

Zeolites:

LiLSX, NaLSX, (FAU)

CaNaA-Mo (LTA)

AlPO‘s:

AlPO-5 (AFI), SAPO-34 (CHA).

Composits: CaCl2 in attapulgite, activated arbon silica gel.

Zeolite A Silica gel

AFICHA

MCM-41

Water isotherms (and heat curves) on LiLSX, NaLSX, SAPO-34,AcCarbon/CaCl2, Attapulgite/CaCl2, at 313 K

FAM-Z01 and FAM-Z02FAM-Z01 and FAM-Z02

0

0.1

0.2

0.3

0.4

0 0.1 0.2 0.3 0.4 0.5

Relative Pressure [-]

Amount of Adsorbent [kg-H2/kg-Adsorbent]

Almino-Silicate Zeolite

Silica Gel

ＦＡＭ－Ｚ０２

Activated Carbon

ＦＡＭ－Ｚ０１

30 micron

Crystal of FAM(SEM photograph)

We explored AlPOs and selected optimum structure and controlled surface hydrophobicity.We have succeeded in developing FAM-Z01 and FAM-Z02 for desired adsorbents.

Mitsubishi Chemical

Comparison of the Storage temperatures for LiLSX, NaLSX, SAPO, ActCarb/CaCl2, silica gel

Achievements within the Annex 17Products available: (potential) Manufacturer:

- LiLSX, NaLSX, Tricat Zeolites GmbH, Bitterfeld, Ger.

CWK Bad Köstritz, Germany

- CaNaA- 60-Mo Südchemie, Germany

- FAM Z-01, Mitsubishi Chemicals, Japan

- FAM Z-02 Mitsubishi Chemicals, Japan

- SAP Tricat Zeolites GmbH, Bitterfeld, Ger.

- Poolkohle/CaCl2 CarboTech, Germany

- Attapulgite/CaCl2 Südchemie, Germany

Acknowledgements

The authors are grateful to D. Ackermann, E. Weiler, W. Brösicke and U. Hellwig for the kind colaboration in the past and at present.The financial support by the Federal Ministry of Economics and Labour (BMWA, Germany), grant number 0329525 D, is acknowledged.