Chemical & Process Engineering Novel Material for the Separation of Mixtures of Carbon Dioxide and Nitrogen Mohamed A. M. Elsayed Supervisors : Prof. P. J. Hall & Dr. M. J. Heslop

Chemical & Process Engineering Introduction POROUS CARBON Naturally occurring carbonaceous material Physical or chemical activation Polymer precursor Fewer minerals impurities & controlled pore structure Pyrolysis Sol-gel process

Chemical & Process Engineering Sol-Gel Technologies and their Products

Chemical & Process Engineering OBJECTIVES First stage 1- further developing and modifying resorcinol formaldehyde sol-gel synthesis procedure to make high surface area carbon xerogels with a controlled pore structure. 2- Studying factor affecting on the texture properties and characteristics of the produced material. 4 - Using different techniques for characterization and analysis (BET, TPD, FTIR, TGA, XRD, SEM, etc…) Second stage 3- Further chemical impregnation to produce nitrogen-enriched carbon xerogels 1-Investigation of full binary isotherms for CO 2 and N 2 from composition and flow-rate transient times in chromatographic columns 2- Studying factor affecting on the selectivity of CO 2 and N 2 2- Studying factor affecting on the selectivity of CO 2 and N 2.

Chemical & Process Engineering Experimental Resin synthesisRF-xerogelsCarbon xerogels Active carbon xerogels Carbon characterization N 2 adsorption-desorption techniques Drying Pyrolysis Co 2 gasification

Chemical & Process Engineering Result and discussion Resin analysis Ultimate and Proximate analyses using Elemental and Thermogravimetric analyzer respectively Ultimate and Proximate analyses using Elemental and Thermogravimetric analyzer respectively Nomenclature Ultimate (wt% dry-ash-free basis )Proximate (wt% ) CHNOMoistureVolatileFixed carbon Ash RF-MEA RF-DEA RF-MDEA RF-NH 4 HCO 3 RF-K 2 CO 3 RF-Na 2 CO R/F= 0.5 and R/C = 300 by mole PH=6 and R/W = 0.25 g/cm 3

Chemical & Process Engineering Thermogravimetric analysis of a dried resorcinol- formaldehyde gel

Chemical & Process Engineering FTIR spectra for the synthesis resins with different type of catalytic species -OH -CH 2 - aromatic amides & amines lactamenitrile

Chemical & Process Engineering Carbon xerogels characterization by BET. Effect of changing catalyst species and the catalyst ratios. (a) R/C= 300 by mole with different type of catalytic species (b) MEA was used as a catalyst with different R/C ratio

Chemical & Process Engineering Characteristic pore properties of RF carbon xerogels Nomenclature R/CS BET a (m 2 /g) V t b ( cm 3 /g) V mic c (cm 3 /g) V mes d (cm 3 /g) D p e (nm) Volume fraction % % micro% meso RF-Na 2 CO 3 RF-K 2 CO3 RF-NH 4 HCO3 RF-MEA RF-DEA RF-MDEA RF-MEA a Specific surface area determined from the BET equation. b Total pore volume. c Micropore volume determine by Horvath-Kawazoe equation. d Mesopore volume. e Mean pore diameter.

Chemical & Process Engineering Pore size distribution of the RF carbon xerogels (a) R/C= 300 by mole with different type of catalytic species (b) MEA was used as a catalyst with different R/C ratio R/F=0.5 by mole and R/W=0.25 g/cm 3

Chemical & Process Engineering Effect of R/W on porous structure of carbon xerogels. R/F=0.5, R/C= 100, PH=6 and MEA as a catalyst (a) BET surface area and surface area of micropores (b) Total and micropores volume

Chemical & Process Engineering Effect of pH on the on porous structure of carbon xerogels R/F=0.5 R/C=100 by mole, R/W=0.25 g/cm 3 and MEA as a catalyst. (a) BET surface area and surface area of micropores (b) Total and micropores volume

Chemical & Process Engineering Effect of degree of Burn-off. R/F=0.5 R/C=100 by mole, R/W=0.25 g/cm 3 and MEA as a catalyst. Variation of the BET surface area, pore volume and micropore volume with the burn off level of carbon xerogels gasified in CO 2 at 900°C

Chemical & Process Engineering Structural characterization with scanning electron microscopyanalysis. Structural characterization with scanning electron microscopy analysis. SEM images of cross-section of (a) and (b) samples synthesized under condition pH=6, R/C=300 and R/W=0.25 before and after pyrolysis respectively (c) and (d) carbon xerogels synthesized under condition pH=6, R/C=100 and R/W=0.25 with 0 % and 37% burn-off respectively. (All the samples were prepared using MEA as catalyst) (a) (b) ( c )(d)

Chemical & Process Engineering Conclusion Microporous carbons with high porosity and surface area can be prepared from Resorcinol-Formaldehyde resins The samples evolve from micro-mesoporous solid (RF-Na 2 CO 3 : combination of types I and IV isotherms) with 24.2% micropore to an exclusively microporous material (RF-NH 4 HCO 3 : type I isotherm) with 98.7% micropore. It is possible to tailor the morphology of these materials by varying the initial pH of the precursor’s solution in a narrow range FTIR study shows that samples prepared by MEA, DEA, MDEA and NH 4 HCO 3 contain nitrogenated functional groups High surface area (> 2890 m 2 /g) can be obtained at high burn off levels (>75%). These porous materials with these functional groups are being expected as suitable candidates for acidic gas capture like CO 2 and SO 2, which will be studied in the next stage.

Chemical & Process Engineering Thank-You&Questions