CO 2 adsorption using CaO and its potential integration with - PowerPoint PPT Presentation

CO 2 adsorption using CaO and its potential integration with hydrogen production from biomass gasification Dr Chunfei Wu University of Hull 25/10/2017

Outline Introduction Experimental Results and discussions Conclusion

Introduction - background U.S. National Climate Assessment (2014)

CO 2 capture using CaO-based materials CO 2 adsorption  CaCO 3 CO 2 desorption  CaO 400 - 600 º C ~800 º C • High temperature required for regeneration • Material movement is required, thus better mechanical strength needed • Still have challenges for the treatment of the adsorbed CO 2

Our approaches Ca-based composite catalyst CO 2 adsorption  CaCO 3 CO 2 desorption  CaO <400 º C ~400 º C Renewable Hydrogen H 2 CH 4 , CO etc. energy storage o System integration o No material movement o CO 2 utilised

Introduction - CO 2 solid adsorbent high theoretical adsorption capacity low cost The application of different types of adsorbents at different temperature ChemSusChem.2009,2:796-854.

Introduction – deactivation of CaO CaCO 3 CaO Schematic description of the transformation of a calcium oxide adsorbent in recarbonation/decomposition cycles AIChE Journal.2007,53:2432-2442. Ind. Eng. Chem. Res. 2006, 45, 8846 – 8851.

Methods to improve CaO-based adsorbents Energy Environ. Sci., 2014, 7 , 3478-3518

Objectives and experimental work Detailed analysis of CO 2 capture using CaO adsorbent CaCO 3 product layer thickness investigation Focused ion beam (FIB)/SEM energy-dispersive X-ray spectroscope (EDXS)

Results-Porosity analysis 0.20 -1 STP 100 CaO CaO 0.16 sol-gel 3 ·g -1 80 sol-gel CaO 3 ·g Quantity Adsorbed/cm dv/dlog(w)/cm 0.12 60 0.08 40 0.04 20 0 0.00 0.0 0.2 0.4 0.6 0.8 1.0 1 10 100 P / P 0 dp / nm S BET S micro S meso V p V micro V meso Samples (m 2 g -1 ) (m 2 g -1 ) (m 2 g -1 ) (cm 3 g -1 ) (cm 3 g -1 ) (cm 3 g -1 ) CaO 20.96 3.70 17.26 0.0314 0.0014 0.0331 sol-gel CaO 38.51 8.51 30.01 0.1527 0.0035 0.1511

SEM analysis CaO sol-gel CaO

TEM analysis CaO sol-gel CaO

Fixed bed adsorption (1) 25 50 CaO sol-gel CaO 20 800 o C 40 800 o C 15 30 CO 2 % CO 2 % 10 20 600 o C 400 o C 5 600 o C 10 400 o C 0 0 0.0 2.0k 4.0k 6.0k 8.0k 10.0k 12.0k 14.0k -2.0k 0.0 2.0k 4.0k 6.0k 8.0k 10.0k 12.0k 14.0k Time / s Time / s CO 2 capture performance of different adsorbents in the fixed bed test (left: CaO, right: sol-gel CaO) under 15% CO 2

Fixed bed adsorption (2) 60 60 CaO sol-gel CaO 50 50 40 40 CO 2 % CO 2 % o C 800 o C o C 600 800 o C 400 30 o C 30 600 o C 400 20 20 10 10 0 1000 2000 3000 4000 5000 0 1000 2000 3000 4000 5000 Time / s Time / s CO 2 capture performance of different adsorbents in the fixed bed test (left: CaO, right: sol-gel CaO) under 40% CO 2

TGA adsorption (1) 150 150 CaO t-s CaO t-f 135 135 weight / % weight / % 120 120 105 105 90 90 75 75 0 200 400 600 800 1000 0 200 400 600 800 1000 o C o C Temperature / Temperature / 150 150 sol-gel CaO t-s sol-gel CaO t-f 135 135 weight / % weight / % 120 120 105 105 90 90 75 75 0 200 400 600 800 1000 0 200 400 600 800 1000 o C Temperature / o C Temperature / TGA test of CO 2 capture performance at temperature fixed and temperature swing process （ CO 2 partial pressure: 15% ）

TGA adsorption (2) 150 150 CaO t-f CaO t-s 135 135 weight / % 120 weight / % 120 105 105 90 90 75 75 0 200 400 600 800 1000 0 200 400 600 800 1000 o C o C Temperature / Temperature / 150 150 sol-gel CaO t-f sol-gel CaO t-s 135 135 weight / % weight / % 120 120 105 105 90 90 75 75 0 200 400 600 800 1000 0 200 400 600 800 1000 o C o C Temperature / Temperature / TGA test of CO 2 capture performance at temperature fixed and temperature swing process （ CO 2 partial pressure: 100% ）

XRD analysis   CaO   CaO  CaCO3   CaCO3      FB-des    sol-gel FB-des  Intensity / a.u. Intensity / a.u.    FB-600        sol-gel FB-600        FB-400 sol-gel FB-400 CaO sol-gel CaO 0 10 20 30 40 50 60 70 80 0 10 20 30 40 50 60 70 80 2Theta / degree 2Theta / degree XRD patterns of CaO adsorbents obtained after reaching highest reaction rate at different temperatures (left: CaO, right: sol-gel CaO).

FIB-SEM analysis (1) 80 nm SEM-EDX of CaO obtained at 600 ºC

FIB-SEM analysis (2) CaO SEM-EDX of sol-gel CaO obtained at 600 ºC

CaO/KIT-6 -1 ) STP 50 CaO/KIT-6 0.5-1 40 CaO/KIT-6 1-1 3 g Quantity absorbed / (cm CaO/KIT-6 2-1 Intensity 30 CaO/KIT-6=0.5:1 20 CaO/KIT-6=1:1 CaO/KIT-6=2:1 10 0 0.0 0.2 0.4 0.6 0.8 1.0 0 10 20 30 40 50 60 70 80 P / P 0 2 Theta/degree S BET / S micro / S meso / V p / V micro / V meso / d ave / Samples (m 2 /g) (m 2 /g) (m 2 /g) (cm 3 /g) (cm 3 /g) (cm 3 /g) nm KIT-6 545.83 265.42 280.41 0.4066 0.1105 0.2892 29.8 CaO/KIT/6 0.5-1 16.43 1.96 14.47 0.0768 0.0012 0.0773 18.7 CaO/KIT/6 1-1 8.29 1.78 6.51 0.0291 0.0008 0.0288 14.0 CaO/KIT/6 2-1 2.12 0.64 1.48 0.0001 0.0003 0.0008 0.28

CaO/KIT-6 for CO 2 capture 16 108 CaO/KIT-6=0.5:1 CaO/KIT-6=2:1 CaO/KIT-6=1:1 106 CaO/KIT-6=2:1 15 o C o C 400 600 Weight / % 104 CO 2 / % 14 102 13 100 12 98 0 10 20 30 40 50 0 400 800 1200 1600 t / min Time / min Two temperature windows for CO 2 adsorption are observed 10 stable cycles of CO 2 adsorption/desorption

Ni-CaO-based composite catalyst Excess Syngas Biomass CO 2 capture electricity or (~600°C) gasification (~400 °C ) Wind farm CO 2 saturated Regenerated material material High purity Energy storage CO 2 release & hydrogenation and clean H 2 processes (~350 °C ) syngas

Ni-CaO/KIT-6 catalyst 100 -1 ) STP Ni/CaO/KIT-6 0.5-1 80 3 g Ni/CaO/KIT-6 1-1 Quantity absorbed / (cm Ni/CaO/KIT-6 2-1 60 Intensity Ni/CaO/KIT-6 0.5-1 40 Ni/CaO/KIT-6 1:1 Ni/CaO/KIT-6 2:1 20 0 0 10 20 30 40 50 60 70 80 0.0 0.2 0.4 0.6 0.8 1.0 2 Theta / degree P / P 0 Pore volume XRD 104 Ni/CaO/KIT-6 0.5:1 Ni/CaO/KIT-6 1:1 100 Ni/CaO/KIT-6 2:1 96 weight / % 92 88 84 TPR 80 0 200 400 600 800 1000 1200 temperature / o C

Methanation of adsorbed CO 2 0.35 4.5 CH 4 0.30 H 2 4.0 3.5 0.25 H 2 % CH 4 % 3.0 0.20 2.5 0.15 2.0 0.10 1.5 0 500 1000 1500 2000 2500 3000 Time / s

Conclusions  Porous structure is beneficial for CO 2 capture  CaO-based adsorbents have two temperature windows for CO 2 capture – 400 and 600 ºC  Measured thickness of the CaCO 3 layer is between 80 and 170 nm for the first stage fast adsorption  Developing nano-CaO with dimension less than the critical thickness will be promising. The sintering of CaO needs to be considered  Integrate CO 2 capture and utilisation could be promising

Thank you for your attention!