Catalytic conversion of syngas to ethanol and higher alcohols over Rh and Cu based catalysts
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
The thermochemical process converts almost any kind of biomass to a desired final product, i.e. gaseous or liquid transportation fuels and chemicals. The transportation fuels obtained in this way are renewable biofuels, which are alternatives to fossil fuels. During the last few years, thermochemical plants for the production of bioethanol have been launched and another is under construction. A total of about 290 million liters of ethanol are expected to be processed per year, mostly using municipal solid waste. Considerable efforts have been made in order to find a more selective catalyst for the conversion of biomass-derived syngas to ethanol.
The thesis is the summary of five publications. The first two publications (Papers I and II) review the state of the art of ethanol and higher alcohols production from biomass, as well as the current status of synthetic fuels production by other processes such as the Fischer-Tropsch synthesis. Paper III analyses the catalytic performance of a mesoporous Rh/MCM-41 (MCM-41 is a hexagonal mesoporous silica) in the synthesis of ethanol which is compared to a typical Rh/SiO2 catalyst. Exhaustive catalytic testing including the addition of water vapor and modifying the hydrogen partial pressure in the syngas feed-stream which, in addition to the catalyst characterization (XRD, BET, XPS, chemisorption, TEM and TPR) before and after the catalytic testing, have allowed concluding that some water vapor can be concentrated in the pores of the Rh/MCM-41 catalyst. The concentration of water-vapor promotes the occurrence of the water gas shift reaction, which in turn induces some secondary reactions that change the product distribution, as compared to results obtained from the typical Rh/SiO2 catalyst. These results have been verified in a wide range of syngas conversion levels (1-68 %) and for different catalyst activation procedures (catalyst reduction at 200 °C, 500 °C and no-reduction) as shown in Paper IV. Finally, similar insights about the use of mesoporous catalyst have been found over a Cu/MCM-41 catalyst, shown in Paper V. Also in Paper V, the effect of metal promoters (Fe and K) has been studied; a noticeable increase of ethanol reaction rate was found over Cu-Fe-K/MCM-41 catalyst as compared to Cu/MCM-41.
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2017. , 98 p.
TRITA-CHE-Report, ISSN 1654-1081 ; 2017:2
thermochemical process, ethanol, higher alcohols, mesoporous catalysts, rhodium, copper, metal promoters
Research subject Chemical Engineering
IdentifiersURN: urn:nbn:se:kth:diva-196808ISBN: 978-91-7729-206-7OAI: oai:DiVA.org:kth-196808DiVA: diva2:1048937
2017-01-27, Q2, Osquldas väg 10, Våning 2, Stockholm, 10:00 (English)
Montes Ramírez, Mario
Boutonnet, Magali, Associate Professor
FunderSida - Swedish International Development Cooperation Agency
QC 201611252016-11-252016-11-222016-12-05Bibliographically approved
List of papers