MW ohřev v chemické recyklaci PET – Ing. Radek TOBOLÍK

Anotace:

Literární rešerše Zhodnocení možností využití MW v chemické recyklaci a volba vhodného reakčního systému Experimentální studie vlivu MW ohřevu na rychlost a výtěžek solvolytické reakce Zhodnocení výsledků a doporučení pro další výzkum a praxi

Abstract:

PET is a condensation polymer, formed by combining one molecule of TPA (terephthalic acid) and one molecule of EG (ethylene glycol) which are polycondensed to form PET. The polycondensation reactions are reversible, so adding of proper solvents to PET under the right conditions of temperature and catalysis depolymerizes PETE to form raw monomers TPA and EG. TPA production requires hydrolysis as an unevitable reaction step. Some procedures offer post-consumer PET recyclation to form another feedstock for polycondensation BHET (bis-hydroxyethyl terephthalate) via a glycolysis process. If methanol is used in solvolysis, the dimethyl ester of terephthalic acid (DMT) would be formed along with EG. Polyols (APP), which can be recovered from PET in a relatively easy and cheap manner, can be used not only for recycled PET production, but also mainly for other products like for use in new polyurethane manufacture. Almost all methods of chemical recycling of PET require significant capital equipment for the reaction chemistry and purifications, energy consumptions and operational complexity and as such require large scale to be economically attractive. Introduction of any improvement cutting effectively the energy costs of recycling process would enhance the competitiveness of recovery method under consideration on the market. Generally, introduction of MW enhanced synthesis/decomposition significantly saves time and power needed for conventional processes requiring heating during operations as well as MW enhance reaction and diffusion rates of species having polar functional groups. The aim of the project is to reveal the effect of MW irradiation on selected chemical recycling processes in a laboratory scale. As the conversion efficiency of conventional processes is usually very high, the work will be focused on the reaction kinetics. General parameters for evaluation of effectiveness of examined MW process in compare with conventional recovery will be the reaction time, introduced power, energy losses, process convenience, energy content in products as well as consumption of supplementary chemicals. The problem can be addressed in a few months on basic level, but the theme could be extended into a broader study. Experimental set-up and evaluation procedures are available. …víceméně