Mathias Seitz
Hochschule Merseburg
(University of applied science)
Catalytic low temperature conversion of hydrocarbon containing feedstocks
Host: Joaquim Vital
Abstract
The catalytic conversion of hydrocarbon feedstocks is a well established process in oil refining, known as fluid catalytic cracking (FCC). The same improvement can be found in pyrolising lignite catalytically [1] and can also be applied in cracking of polyolefins and fatty biomass. The product distribution of the volatile products is nearly for all feedstocks similar (Fig.1). The main difference occurs with surrogate fuel, which is due to the content of non polyolefin plastics and paper. The catalytic low temperature has the potential to convert coal, polyolefinic waste and biomass according to a fluctuating supply of different hydrocarbon feedstocks and has the opportunity to contribute to close the carbon cycle (recycling of polyolefins). To scale up the process, a broad understanding of the action principle has to be developed. However, the numbers of parameters seem to be too manifold as different feedstocks, many catalyst properties and process parameters influence the behaviour. In the present work, the product generation from different feedstocks, the strategy of identifying the reaction rate and the formulation of a valid model is discussed.
For experiments, several types of zeolites as catalyst and different feedstocks were used for catalytic measurements in a semi-batch rotary kiln reactor. The catalytic measurements were done with between 400 - 600 °C, 1 bar and under inert conditions. Subsequent, an empiric model was developed to determine the significant factors, leading to a scientific model. The results lead to a model, were the properties of the feedstock as well as the type and the shape of the catalyst are essential for conversion. The adsorption of the hydrocarbon species on the catalyst surface was found to be the dominating step in the regarded process window and catalytic cracking occurs according to pore mouth and key-lock catalysis [2]. The enhancement of the temperature leads to increased cracking of long chain hydrocarbons and a hydrocarbon product distribution with a lower molecular weight. The model agrees with the results obtained in a continuous double screw reactor, which was used for validation. According to the results, recommendations to configure a scaled up reactor for catalytic low temperature conversion of hydrocarbon containing feedstocks can be given.
References
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[1] |
Seitz M, Heschel W, Nägler T, Zimmermann J, Stam-Creutz T, Frank W, Appelt J, Bieling S, Meyer B. Influence of catalysts on the pyrolysis of lignites, Fuel 2014, 134, 669-676. |
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[2] |
Martens J A, Vanbutsele G, Jacobs P.A, Denayer J, Ocakoglu R, Baron G, Muñoz Arroyo J.A, Thybaut J, Marin G.B, Catalysis Today 2001, 65, 111–116. |
Short Bio
Mathias Seitz studied in Erlangen Germany Chemical process engineering. He did his PHD in designing catalysts for petrochemical reactions under the direction of Prof. Emig and Prof. Klemm in Erlangen.
During his work in industry for seven years he developed different innovative processes.
Since 2007 he investigates a new method to produce chemicals from lignite by using catalysts.