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INSTITUTUL NAŢIONAL DE
CERCETARE DEZVOLTARE PENTRU TEHNOLOGII IZOTOPICE SI MOLECULARE Str. Donat 67-103, 400293, Cluj-Napoca, Romania Tel: +40-264-584037; Fax: +40-264-420042 Email: itim@itim-cj.ro, web: www.itim-cj.ro |
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INSTITUTUL NAŢIONAL DE
CERCETARE DEZVOLTARE PENTRU TEHNOLOGII IZOTOPICE SI MOLECULARE Str. Donat 67-103, 400293, Cluj-Napoca, Romania Tel: +40-264-584037; Fax: +40-264-420042 Email: itim@itim-cj.ro, web: www.itim-cj.ro |
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Design by MM
Deadline: December 2013
Title of Phase 2: Hydrogen production by catalytic steam reforming of bioethanol obtained from wood waste: raw bioethanol physico-chemical characterization, catalysts activity and selectivity for raw ethanol SR; modeling and simulation of the process, model validation.
Results:
(1) crude bio-ethanol prepared from fir-wood sawdust;
(2) analytic method for analysis of crude bio-ethanol (fermentation product);
(3) method and installation for hydrogen production by ethanol/bio-ethanol steam reforming using Me1-Me2/oxide1-oxide2 catalysts;
(4) samples of hydrogen prepared from crude bio-ethanol;
(5) kinetic study of ethanol/bio-ethanol steam reforming;
(6) scientific and technical report containing experimentation reports for preparation and analysis of bio-ethanol and catalytic studies of ethanol/bio-ethanol steam reforming.
Dissemination:
- 4 published papers;
- 1 published abstract;
- 1 accepted paper;
- 2 papers presented at internat. conferences;
- 1 paper presented at national conference;
- 1 master thesis.
(1) Fir-wood sawdust was used as raw material for the preparation of bio-ethanol. The fermentation product, obtained by two different enzymatic hydrolysis methods, was analyzed for the determination of chemical composition. Three types of analysis were employed function of type and structure of compound of interest. For both hydrolysis methods, beside water, the crude bio-ethanol contains mainly ethanol and acetic acid; in lower concentrations other alcohols and acids are present. Traces of aldehydes and esters were also found.
(2) In order to establish the optimum reaction conditions and catalysts for bio-ethanol steam reforming, a (ethanol-water) mixture of 9 wt.% ethanol, was first used for catalytic tests.
- Ni-Au, Ni-Ag, Ni-Cu; support = Al2O3, ZrO2, CeO2–Al2O3, La2O3–Al2O3, CeO2–ZrO2, La2O3–ZrO2;
- reaction conditions: temperature 150–350°C; atmospheric pressure; carrier gas flow: 35–133 ml/min, (ethanol+water) flow 0,1–1 ml/min.
Ethanol conversion was calculated. The maximum values (close to 100%) were obtained at 350°C for all studied catalysts, except Ni/ZrO2 and Ni-Me/ZrO2.
- The addition of Cu, Ag and Au to Ni/Al2O3 improve the ethanol conversion especially at high reagents flow.
- The addition of La2O3 to alumina and CeO2 and La2O3 to zirconia decreases significantly the temperature at which the ethanol conversion reaches the maximum value.
Hydrogen production had maximum value for Ni/ La2O3-ZrO2 catalyst.
Catalyst stability was very good for 24 h time on stream and low reagents flow, but decreases significantly with increasing the liquid reagents flow.
(3) Bio-ethanol catalytic steam reforming studies were made using a bio-ethanol sample of ~ 3.5 % ethanol and 1.6 % acetic acid concentrations, at 350°C and bio-ethanol flow between 0.1 and 1 ml/min. In these conditions, both ethanol and acetic acid are reformed.
- ethanol and acetic acid conversion is close to 100 %, except acid conversion at 1 ml/min bio-ethanol flow. Main reaction products are H2, CH4, CO si CO2.
- catalysts stability was good for 4 h time on stream and low reagents flow, but decreases significantly with increasing the liquid reagents flow.
- hydrogen production is improved by the presence of acetic acid.
(4) For modeling and simulation of hydrogen production from bio-ethanol, a kinetic study regarding the catalytic steam reforming of ethanol on Ni/Al2O3, at 250-350°C and water:ethanol mol ratio 30:1, was performed. The rate constants were calculated, and also the variation of reactants concentration during the process were obtained from optimization process. The model was validated by a good correlation obtained with the experimental data.
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