Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Combining HC-SCR over Ag/Al2O3 and hydrogen generation over Rh/CeO2-ZrO2 using biofuels: An integrated system approach for real applications
Chalmers Tekniska Högskola.
KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.ORCID iD: 0000-0001-9601-1959
Chalmers Tekniska Högskola.
Show others and affiliations
2015 (English)In: Applied Catalysis B: Environmental, ISSN 0926-3373, E-ISSN 1873-3883, Vol. 162, 583-592 p.Article in journal (Refereed) Published
Abstract [en]

Abstract We report on a high NOx reduction activity over Ag/Al2O3 catalysts, using hydrogen produced in a fuel reformer. The focus of the study is to evaluate the performance of a hydrocarbon selective catalytic reduction (HC-SCR) catalyst in real conditions. Initially, the catalytic materials for the fuel reformer (Rh/CeO2-ZrO2) and the HC-SCR (Ag/Al2O3) were evaluated in separate bench-scale reactor setups. These two setups were subsequently joined into an integrated bench-scale reactor setup with the aim to evaluate the influence of the reformate on the HC-SCR activity in a controlled environment. In the final phase of the study a 4 wt.% Ag/Al2O3 catalyst doped with 100 ppm(w) Pt was scaled up and tested in a pilot-scale reactor setup. The pilot-scale reactor setup enabled evaluation of the HC-SCR activity in real exhaust gases generated by a single cylinder engine (genset) together with a hydrogen-rich gas supplied from a fuel reformer. Commercial biodiesel (NExBTL) was used as reducing agent for the HC-SCR as well as fuel in the fuel reformer for both the bench-scale and pilot-scale experiments. This study gives an excellent link between evaluations of the catalytic materials, controlled bench-scale experiments and applied engine experiments, proving a viable concept for lean NOx reduction together with onboard hydrogen production. A NOx conversion of above 70% was reached at temperatures below 250 °C, in bench-scale experiments when hydrogen produced in the fuel reformer is added.

Place, publisher, year, edition, pages
2015. Vol. 162, 583-592 p.
Keyword [en]
HC-SCR fuel reformer integrated system, Ag/Al2O3, Rh/CeO2-ZrO2, Biofuels, Diesel engine
National Category
Chemical Engineering
Identifiers
URN: urn:nbn:se:kth:diva-149332DOI: 10.1016/j.apcatb.2014.07.036ISI: 000343686900067Scopus ID: 2-s2.0-84905367908OAI: oai:DiVA.org:kth-149332DiVA: diva2:739173
Funder
Mistra - The Swedish Foundation for Strategic Environmental ResearchSwedish Energy AgencyKnut and Alice Wallenberg Foundation, Dnr KAW 2005.0055
Note

QC 20140902

Available from: 2014-08-20 Created: 2014-08-20 Last updated: 2017-12-05Bibliographically approved
In thesis
1. Fuel Reforming for Hydrogen Production in Heavy-Duty Vehicle Applications
Open this publication in new window or tab >>Fuel Reforming for Hydrogen Production in Heavy-Duty Vehicle Applications
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The depletion of fossil fuels together with growing environmental concerns have created incitement for developing a more energy-efficient and environmentally-friendly vehicle fleet. The development towards cleaner heavy-duty vehicles started already in the 80’s with the introduction of emission legislations. Initially, engine optimization was enough for reaching the legislated levels of emissions. However, at present engine optimization is not enough but exhaust aftertreatment has become an essential part of heavy-duty vehicles, in order to meet the emission standards. Today, the total emissions are targeted which means that there is an interest in decreasing the idling emissions as well as the emissions during operation. To reduce the overall emissions several states in the USA have introduced idling legislations. Due to the limitations in idling time alternative solutions for power generation during rests are requested. A possible alternative is a fuel cell auxiliary power unit, combining a fuel cell with a fuel reformer (FC-APU). 

The focus of this thesis is the development of the fuel reformer for an FC-APU, in which the hydrogen to the fuel cell is generated from diesel in a high-temperature catalytic process. The produced hydrogen can also be used in other heavy-duty vehicle applications i.e. selective catalytic reduction of NOx (HC-SCR), where addition of hydrogen is essential for reaching high conversion at low temperatures. The effect of using hydrogen from a fuel reformer in HC-SCR is included in this work. The catalytic material development is focused on developing promoted materials with lower rhodium content but with catalytic activity comparable to that of materials with higher rhodium content. This includes evaluation and extensive characterization of both fresh and aged promoted materials. The work also includes reactor design where a micro reactor with multiple air inlets is evaluated.

This work has contributed to increased knowledge of catalytic materials suitable for reforming of diesel. By changing the support material from the traditionally used alumina to ceria-zirconia, increased H2 yield was achieved. In addition, the ceria-zirconia supported material was less prone to coke. By promoting the material with cobalt or lanthanum it was possible to decrease the rhodium content by 2/3 with enhanced catalytic performance. It was also discovered that promotion with lanthanum decreased the tendency for coking even further. Additionally, the lanthanum-promoted material had higher thermal stability as well as a stable highly dispersed rhodium phase.

Furthermore, the work has contributed to an increased knowledge concerning the fuel reformer’s effect on HC-SCR. The work displays clear evidence of benefits with using hydrogen-rich gas from a fuel reformer instead of pure hydrogen. The benefits are derived from the content of low molecular weight hydrocarbons present in the hydrogen-rich gas, which are strong reducing agents increasing the NOx reduction. This finding proves that fuel reforming in combination with HC-SCR is a viable option for NOx abatement.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. xi, 66 p.
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2015:6
Keyword
aging · autothermal fuel reforming · CeO2-ZrO2 · characterization · diesel · H2-assisted HC-SCR · micro reactor · monolith
National Category
Chemical Engineering
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-159423 (URN)978-91-7595-412-7 (ISBN)
Public defence
2015-02-27, Kollegiesalen, Brinellvägen 8, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Funder
Mistra - The Swedish Foundation for Strategic Environmental Research
Note

QC 20150202

Available from: 2015-02-02 Created: 2015-01-29 Last updated: 2015-02-02Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopusSciencedirect

Authority records BETA

Granlund, Moa. Z.

Search in DiVA

By author/editor
Granlund, Moa. Z.Pettersson, Lars. J.
By organisation
Chemical Technology
In the same journal
Applied Catalysis B: Environmental
Chemical Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 241 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf