April 16
@
4:00 PM
–
5:00 PM
Jungho Jae
Department of Chemical Engineering
Pusan National University
Busan, Korea
Heterogeneous Catalytic Technologies to Decarbonize Plastic Industry
Decarbonization of chemical industry has been increasingly emphasized due to the worsening of global warming and climate change. Especially, plastics are said to be one of the biggest contributors to increasing carbon emission due to their daily and single-use culture as well as the massive use of fossil fuels to produce them. Two potential solutions to this plastic problem are: to recycle the plastic to its original monomers to be re-used for the synthesis of plastics and to produce plastic monomers from the carbon-neutral feedstock such as biomass, called bio-based polymer. In this presentation, I will discuss specific two catalytic technologies to decarbonize plastic use.
First, the acrylic acid (AA) production by the gas-phase dehydration of lactic acid (LA) and the design of new solid acid catalyst based on zeolites for high AA selectivity (>90%) will be discussed. Lactic acid (LA) is a key C3 biorenewable platform molecule, which can be mass-produced via the fermentation of biomass-derived cellulose at nearly theoretical yields, while AA is a high volume (~8×106 tons/year) and multipurpose plastic monomers for adhesives, coatings, and absorbent polymers and currently produced from petroleum-derived propylene. Due to the structural similarity between LA and AA, the dehydration of LA to AA has received considerable attention for the sustainable AA production. However, achieving high AA selectivity remains challenging, because high reactivity of the carboxyl groups adjacent to the hydroxyl groups leads to various side reactions. Alkali-exchanged zeolites can be an ideal candidate material for selectivity control in LA to-AA reaction due to their tunable acid-base properties and hydrophobic/hydrophilicity as well as the shape selectivity. I will discuss recent new findings on the site requirement for the high AA selectivity obtained from the controlled zeolite synthesis and in-situ IR spectroscopy.
Second, I will talk about the catalytic hydrogenolysis of polyethylene terephthalate (PET) to aromatic chemicals or cyclic fuels. PET can be depolymerized and deoxygenated directly into gasoline- and jet-fuel range cycloalkanes in nearly quantitative yield (~99%) on Ru/TiO2 catalyst in water/dodecane bi-phasic medium. The hydrophilicity of the catalyst and the related Pickering emulsion formation are the key catalytic descriptors to dictate the overall PET conversion and aromatic selectivity. I will discuss how these oil/water emulsion interface meditated by the catalyst particles can be manipulated by the reaction parameter and catalyst properties, eventually turning the product selectivity toward the more desired and unsaturated products of benzene, toluene, xylenes (BTX) in >90% selectivity.