IKFT 05-20 Masterthesis: Inspecting the efficiency of the use of several applicable quench media in recovering products of interest from pyrolysis condensates in a fractionated condensation system
Institute of Catalysis Research und Technology (IKFT)
Fast pyrolysis decomposes lignocellulosic biomass at temperatures of around 500 ⁰C in an inert environment to produce char (containing inorganics), pyrolysis oil (bio-oil), and permanent gases, each of which can be used for fuel and chemical applications. This process is investigated at KIT within the scope of the bioliq® concept to valorise agricultural wastes as a step towards attaining zero or limited dependence on fossil fuels, which have been associated with increased net carbon emissions into the atmosphere.
Following thermal decomposition of biomass in a twin-screw reactor, pyrolysis vapours and char are produced. Char is then separated using cyclones and vapours are usually condensed into two separate fractions, the organic rich condensate (ORC) the Aqueous condensate (AC). A quench cooling condensation system where pyrolysis volatiles come into direct contact with the quench media is used to optimise the recovery of condensable products. The ORC mostly contains heavy organic products such as phenolic oligomers and sugars whereas the AC is primarily made up of water (about 85 wt.%) with traces of light molecular weight compounds such as carboxylic acids, acetol and furanics. The ORC condensate due to its comparatively richer energy content has found significant fuel applications. The AC is currently just being flared. However, it is also being investigated as input material for other process chains such as microbial conversion since compounds including acetic acid (a carboxylic acid) have been reported to promote the growth of microbes. Sugars present in ORC have also been reported to find suitable applications in downstream microbial conversions. The type of quench media used in condensing pyrolysis vapours have been reported to affect final pyrolysis product distribution. This has therefore prompted the need in inspecting the efficiency of the use of several applicable quench media (including water, ethanol, ethylene glycol, etc.) in recovering products of interest from pyrolysis condensates in the fractionated condensation system.
In this study, the effects of the use of some selected quench media (including water, ethanol, ethylene glycol, etc.) on composition of pyrolysis condensates will be investigated theoretically and validated on our Process Development Unit (PDU). Already developed thermodynamic models in the group will be used and extended to cover the effects of using different quench media.
Practical aspects of study include:
Application of already developed thermodynamic models (GCA-EoS - Group Contribution Association - Equation of State, Dortmund Modified UNIFAC) to investigate the effects of the use of the selected quench media on condensable product composition.
Optimise condensation conditions based on this model, including considerations around the amount of quench medium required/ feasible.
Experimentally validating key optimal conditions (maximum two conditions) of theoretical models on the PDU.
as soon as possible
Chemical/Process Engineering or other related field
Contact person in line-management
Mr. George Kofi Parku, IKFT
Please apply online using the button below for this vacancy number IKFT 05-20.
Ausschreibungsnummer: IKFT 05-20
If qualified, severely disabled persons will be preferred.
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