The following essential work has been performed:
preparation and characterisation of catalytic systems of bulk mixed oxide catalysts and mechanical mixtures thereof,
testing and analysis of catalyst activity and selectivity, focused mainly on isopentane and also on n-pentane feedstock, and the selection of the most promising catalyst systems,
study of impact of experimental conditions on catalyst activity and selectivity,
evaluation of the performance of the promising catalysts for the OXD of C5 alkane - olefin mixtures, including the catalyst sensitivity to changes in experimental conditions, the influence of water and catalyst deactivation.
The main conclusions that can be shown from the research program are:
the homogeneous (uncatalysed) reaction plays an important role in the conversion of the C5 paraffins, and is enhanced by an increase in temperature and in oxygen to paraffin feed ratio,
a most promising catalytic system has been selected, and the influence of composition, the preparation methods, the texture modification and external phases on the catalytic performance of the selected system has been studied,
metal dopes have been shown to increase catalytic performance and selectivity in olefins and in diolefins,
the selected catalysts are highly selective to total dehydrogenation and to isoprene, particularly at high temperatures and at low conversions. Industrially acceptable levels of isopentane conversion can be obtained with good selectivities,
the catalytic effect on the OXD of a mixture of isopentane and isopentene is additive on both reactions and overall isoprene selectivities around 40 % were obtained with yields of isoprene over 10 % per pass.
The present proposed project is aimed at developing precompetitive knowledge for the design of new catalysts for the selective oxidative activation of C5 paraffins. The increasing demand for C5 olefins and the current limited availability from catalytic and thermal cracking processes are forcing refiners to look at alternative routes for producing these olefins. On the other hand, paraffins are largely abundant in refinery streams but, currently, their use is limited, except for n-butane and i-butane, to energy carriers for combustion. The objective of the proposed research would therefore be to develop new, metal oxide catalysts for the oxidative dehydrogenation (OXD) of a refinery C5 paraffinic fraction. This research programme will be carried out by two academic laboratories, in close collaboration with two industrial partners. The laboratories A and B will be responsible for the lab scale design, characterization and catalytic screening of potentially interesting catalysts for the OXD of both model C5 paraffins and mono-olefins and (eventually) an industrial refinery C5 fraction. The industrial partners C and D will evaluate the lab scale performance of the promising catalysts for the OXD of refinery C5 fractions, in order to assess the technico-economical feasibility for a scale up to pilot (and industrial) scale (after the successful completion of this project).
Funding SchemeCSC - Cost-sharing contracts