Change search
ReferencesLink to record
Permanent link

Direct link
Syngas conversion to ethanol over a mesoporous Cu/MCM-41 catalyst: Effect of K and Fe promoters
KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology. UMSA Universidad Mayor de San Andrés, Bolivia.
KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
Show others and affiliations
2016 (English)In: Applied Catalysis A: General, ISSN 0926-860X, E-ISSN 1873-3875, Vol. 526, 77-83 p.Article in journal (Refereed) Published
Abstract [en]

Transportation fuels such as ethanol can be obtained through thermochemical processing of biomass. Interest in the development of more selective catalysts for the conversion of biomass-derived syngas (H2 + CO) to ethanol is increasing in both academia and industry. In this work, we have evaluated the performances of K and Fe as metal promoters of a mesoporous Cu/MCM-41 catalyst and their effects on the product selectivity and especially on ethanol formation. The metal loading was 29 wt.% Cu, 2 wt.% Fe and 1.6 wt.% K. The catalysts were tested at 300 °C, 20 bar and gas-hourly-space-velocities in the range of 1500–30000 mlsyngas/gcat h; under these conditions the syngas conversion level was between 2 and 11%. The non-promoted Cu/MCM-41 catalyst showed interesting selectivity toward oxygenated compounds, mostly methanol. The addition of K as promoter increases the selectivity toward methanol even more, while the addition of Fe as promoter favors the formation of hydrocarbon compounds. When both K and Fe as promoters are incorporated into the Cu/MCM-41 catalyst, the reaction rate to oxygenated compounds is notably increased, especially for ethanol. The space time yield for ethanol for the Cu/MCM-41 catalyst is 0.3 × 10−5 carbon-mol/gcath which increases to 165.5 × 10−5 carbon-mol/gcath for the Cu-Fe-K/MCM-41 catalyst. From XPS analysis, the Cu-Fe-K/MCM-41 catalyst was found to have the following atomic composition: Cu0.34Fe0.08K0.08Si1.00. The promoting effect of both K and Fe, may be related to an increased reaction rate toward CO non-dissociation and CO-dissociation paths, respectively, which is beneficial for the ethanol formation. Further catalytic results, catalyst characterization and discussion of results are presented in this work.

Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 526, 77-83 p.
Keyword [en]
Copper, Ethanol, Mesoporous MCM-41, Promoters, Syngas, Catalysts, Copper compounds, Dissociation, Ethanol fuels, Hydrocarbon refining, Iron compounds, Mesoporous materials, Methanol, Reaction rates, Synthesis gas, Catalyst characterization, Gas hourly space velocities, Hydrocarbon compounds, Product selectivities, Syn-gas, Thermochemical processing, Catalyst selectivity
National Category
Chemical Engineering
Identifiers
URN: urn:nbn:se:kth:diva-195315DOI: 10.1016/j.apcata.2016.08.006ISI: 000384865600010ScopusID: 2-s2.0-84981263991OAI: oai:DiVA.org:kth-195315DiVA: diva2:1045574
Note

QC 20161110

Available from: 2016-11-10 Created: 2016-11-02 Last updated: 2016-11-25Bibliographically approved
In thesis
1. Catalytic conversion of syngas to ethanol and higher alcohols over Rh and Cu based catalysts
Open this publication in new window or tab >>Catalytic conversion of syngas to ethanol and higher alcohols over Rh and Cu based catalysts
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

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.
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2017:2
Keyword
thermochemical process, ethanol, higher alcohols, mesoporous catalysts, rhodium, copper, metal promoters
National Category
Chemical Engineering
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-196808 (URN)978-91-7729-206-7 (ISBN)
Public defence
2017-01-27, Q2, Osquldas väg 10, Våning 2, Stockholm, 10:00 (English)
Opponent
Supervisors
Funder
Sida - Swedish International Development Cooperation Agency
Note

QC 20161125

Available from: 2016-11-25 Created: 2016-11-22 Last updated: 2016-12-05Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Lopez, LuisKušar, HenrikBoutonnet, MagaliJärås, Sven
By organisation
Chemical Technology
In the same journal
Applied Catalysis A: General
Chemical Engineering

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 17 hits
ReferencesLink to record
Permanent link

Direct link