The synthesis of diphosphine compounds 1 and 2, derived from a terphenyl backbone, and their corr... more The synthesis of diphosphine compounds 1 and 2, derived from a terphenyl backbone, and their corresponding cis coordination in platinum complexes is described. Subtle but significant differences are noted in the solid-state structures, with bite angles P1-Pt-P2 of ...
Theoretical calculations were performed in order to determine, a priori, which in a range of smal... more Theoretical calculations were performed in order to determine, a priori, which in a range of small-to-medium pore zeolites would be the most effective at suppressing hydride transfer reactions by estimating the magnitude of steric hindrance. Steric hindrance was estimated as the difference between the enthalpies of adsorption of the transition-state complex and those of the two reacting hydrocarbons, calculated using
PYROLYSIS OF BIOMASS Guray Yildiz, Frederik Ronsse, Kevin van Geem, Ruben van Duren, Sascha R. A.... more PYROLYSIS OF BIOMASS Guray Yildiz, Frederik Ronsse, Kevin van Geem, Ruben van Duren, Sascha R. A. Kersten, Wolter Prins Department of Biosystems Engineering, Ghent University, Coupure Links 653, B9000, Ghent, Belgium, (Guray.Yildiz@UGent.be) Laboratory for Chemical Technology (LCT), Ghent University, Technologiepark 918, B-9052 Ghent, Belgium Albemarle Catalysts Company BV, Nieuwendammerkade 1–3, P.O. Box 37650, 1030 BE Amsterdam, The Netherlands Sustainable Process Technology Group, Faculty of Science and Technology, University of Twente, Postbus 217, 7500AE Enschede, The Netherlands
A short historical overview of hydroformylation in general is presented in this chapter. Subseque... more A short historical overview of hydroformylation in general is presented in this chapter. Subsequently this is narrowed down to the platinum catalyzed hydroformylation, as this will be the focus of the research collected in this thesis. Because of the importance of the reaction mechanism in this work an account on this topic is given for platinum-catalyzed hydroformylation. Since the tin(II)chloride addition in platinum catalyzed hydroformylation is essential in the conversion of olefins to aldehydes, the role of this additive is elaborately discussed. Finally, this chapter closes with the aim of this research and the outline of this thesis.
Fast pyrolysis is a thermochemical process that contributes to the conversion of biomass into a v... more Fast pyrolysis is a thermochemical process that contributes to the conversion of biomass into a variety of fuels and chemicals. The process aims to produce a liquid mixture of organic molecules called bio-oil. To improve the quality of crude bio-oil in relation to biofuel applications, biomass fast pyrolysis can be carried out in the presence of suitable catalysts. Catalyst particles can be introduced to the reactor (in situ) for the removal of oxygen and the catalytic cracking of high molecular weight compounds in the pyrolysis vapours. The primary goal of this work was to investigate the effects of a repeatedly regenerated ZSM-5 based FCC catalyst on the fast pyrolysis product yields (e.g. organics, water, carbonaceous solids and non-condensable gases), non-condensable gas compositions, bio-oil compositions and the elemental distribution over various pyrolysis products and to gain an insight of the underlying mechanisms. Experiments were performed in a newly designed laboratory sc...
ABSTRACT Fast pyrolysis experiments of pine wood have been performed in a continuously operated m... more ABSTRACT Fast pyrolysis experiments of pine wood have been performed in a continuously operated mechanically stirred bed reactor at 500 °C. The effects of the pine wood ash were studied by comparing non-catalytic and catalytic experiments (using a ZSM-5 based catalyst) with their ash-added counterparts. To show the case of ash accumulated from the biomass feeding, the results of catalytic fast pyrolysis obtained after eight reaction/catalyst regeneration cycles were included as well. The objective was to distinguish between the ash-catalyst interactions and the catalyst deactivation. The latter may be caused by thermo-mechanical, chemical and/or structural changes in the catalyst; such as poisoning, fouling, and attrition, as well as by coke deposition. Ash concentrations up to ca. 3 wt.% relative to the amount of pine wood fed, and ca. 0.002 wt.% relative to the amount of bed material, were found to be sufficient to change the distribution and the composition of pyrolysis products. The addition of ash to the catalytic fast pyrolysis, caused a reduction in the yields of both the organics and coke by 2 wt.% (on feed basis), while increases of 1 wt.% and 4 wt.% in the water and non-condensable gases were observed, respectively. The total yield of CO plus CO2 was boosted by more than 10%, while the CO2 production (decarboxylation reactions) was favoured clearly. Moreover, the presence of added-ash suppressed the conversion of sugars and acids – these were more pronounced in the case of accumulated-ash – as well as of the phenols. The catalyst deactivation during the reaction/regeneration cycles is not only related to the presence of ash but also to changes in the structure and composition of the catalyst. To overcome the drawbacks of biomass ash in catalytic fast pyrolysis, either the biomass feedstock has to be leached (ash removal) before being introduced to the process, or the char (which contains a vast majority of the biomass ash) has to be physically removed from the catalyst before the regeneration step.
The synthesis of diphosphine compounds 1 and 2, derived from a terphenyl backbone, and their corr... more The synthesis of diphosphine compounds 1 and 2, derived from a terphenyl backbone, and their corresponding cis coordination in platinum complexes is described. Subtle but significant differences are noted in the solid-state structures, with bite angles P1-Pt-P2 of ...
Theoretical calculations were performed in order to determine, a priori, which in a range of smal... more Theoretical calculations were performed in order to determine, a priori, which in a range of small-to-medium pore zeolites would be the most effective at suppressing hydride transfer reactions by estimating the magnitude of steric hindrance. Steric hindrance was estimated as the difference between the enthalpies of adsorption of the transition-state complex and those of the two reacting hydrocarbons, calculated using
PYROLYSIS OF BIOMASS Guray Yildiz, Frederik Ronsse, Kevin van Geem, Ruben van Duren, Sascha R. A.... more PYROLYSIS OF BIOMASS Guray Yildiz, Frederik Ronsse, Kevin van Geem, Ruben van Duren, Sascha R. A. Kersten, Wolter Prins Department of Biosystems Engineering, Ghent University, Coupure Links 653, B9000, Ghent, Belgium, (Guray.Yildiz@UGent.be) Laboratory for Chemical Technology (LCT), Ghent University, Technologiepark 918, B-9052 Ghent, Belgium Albemarle Catalysts Company BV, Nieuwendammerkade 1–3, P.O. Box 37650, 1030 BE Amsterdam, The Netherlands Sustainable Process Technology Group, Faculty of Science and Technology, University of Twente, Postbus 217, 7500AE Enschede, The Netherlands
A short historical overview of hydroformylation in general is presented in this chapter. Subseque... more A short historical overview of hydroformylation in general is presented in this chapter. Subsequently this is narrowed down to the platinum catalyzed hydroformylation, as this will be the focus of the research collected in this thesis. Because of the importance of the reaction mechanism in this work an account on this topic is given for platinum-catalyzed hydroformylation. Since the tin(II)chloride addition in platinum catalyzed hydroformylation is essential in the conversion of olefins to aldehydes, the role of this additive is elaborately discussed. Finally, this chapter closes with the aim of this research and the outline of this thesis.
Fast pyrolysis is a thermochemical process that contributes to the conversion of biomass into a v... more Fast pyrolysis is a thermochemical process that contributes to the conversion of biomass into a variety of fuels and chemicals. The process aims to produce a liquid mixture of organic molecules called bio-oil. To improve the quality of crude bio-oil in relation to biofuel applications, biomass fast pyrolysis can be carried out in the presence of suitable catalysts. Catalyst particles can be introduced to the reactor (in situ) for the removal of oxygen and the catalytic cracking of high molecular weight compounds in the pyrolysis vapours. The primary goal of this work was to investigate the effects of a repeatedly regenerated ZSM-5 based FCC catalyst on the fast pyrolysis product yields (e.g. organics, water, carbonaceous solids and non-condensable gases), non-condensable gas compositions, bio-oil compositions and the elemental distribution over various pyrolysis products and to gain an insight of the underlying mechanisms. Experiments were performed in a newly designed laboratory sc...
ABSTRACT Fast pyrolysis experiments of pine wood have been performed in a continuously operated m... more ABSTRACT Fast pyrolysis experiments of pine wood have been performed in a continuously operated mechanically stirred bed reactor at 500 °C. The effects of the pine wood ash were studied by comparing non-catalytic and catalytic experiments (using a ZSM-5 based catalyst) with their ash-added counterparts. To show the case of ash accumulated from the biomass feeding, the results of catalytic fast pyrolysis obtained after eight reaction/catalyst regeneration cycles were included as well. The objective was to distinguish between the ash-catalyst interactions and the catalyst deactivation. The latter may be caused by thermo-mechanical, chemical and/or structural changes in the catalyst; such as poisoning, fouling, and attrition, as well as by coke deposition. Ash concentrations up to ca. 3 wt.% relative to the amount of pine wood fed, and ca. 0.002 wt.% relative to the amount of bed material, were found to be sufficient to change the distribution and the composition of pyrolysis products. The addition of ash to the catalytic fast pyrolysis, caused a reduction in the yields of both the organics and coke by 2 wt.% (on feed basis), while increases of 1 wt.% and 4 wt.% in the water and non-condensable gases were observed, respectively. The total yield of CO plus CO2 was boosted by more than 10%, while the CO2 production (decarboxylation reactions) was favoured clearly. Moreover, the presence of added-ash suppressed the conversion of sugars and acids – these were more pronounced in the case of accumulated-ash – as well as of the phenols. The catalyst deactivation during the reaction/regeneration cycles is not only related to the presence of ash but also to changes in the structure and composition of the catalyst. To overcome the drawbacks of biomass ash in catalytic fast pyrolysis, either the biomass feedstock has to be leached (ash removal) before being introduced to the process, or the char (which contains a vast majority of the biomass ash) has to be physically removed from the catalyst before the regeneration step.
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Papers by Ruben Van Duren