Chemical recycling of municipal packaging waste by pyrolysis

[EN]The present doctoral thesis centers on studying pyrolysis as a chemical recycling technique for rejected packaging waste fractions coming from separation and sorting plants. The pyrolysis experiments have been carried out in a lab-scale installation equipped with a 3.5 L semi-batch reactor and a condensation and collection system for the liquids and gases generated. In the present thesis, an experimental study on the conventional pyrolysis process applied to the aforementioned waste fractions has been conducted, as well as the study of non-conventional or advanced pyrolysis processes such as catalytic and stepwise pyrolysis. The study of the operating parameters has been carried out using a mixed plastics simulated sample, the composition of which is similar to that found in real fractions, and subsequently the optimized process has been applied to real packaging waste. An exhaustive characterization of the solids, liquids and gases obtained in the process has been made after each experiment and their potential uses have been established. Finally, an empirical model that will predict the pyrolysis yields (% organic liquid, % aqueous liquid, % gases, % char, % inorganic solid) as a function of the composition of the initial sample has been developed. As a result of the experimental work done, the requirements have been established for an industrial packaging waste pyrolysis plant that aims to be sufficiently versatile as to generate useful products regardless of the nature of the raw material.

Numerical Research on Liquid Spray in Supersonic Cross Flow

Numerical simulation was conducted to characterize the kerosene spray injecting into supersonic cross flow, especially focusing on the aerodynamic secondary breakup effect of the supersonic cross flow on the initial droplets. It was revealed that the initial parent drops were broken up into small drops whose diameter is about O(10) micrometers soon after they entered into the supersonic cross flow. During the appropriate range of initial drop size, the parent droplets would be broken up into small drops with the same magnitude diameter no matter how large the initial drops SMD was.

Numerical Study on Kerosene Spray in Supersonic Flow

Numerical simulation was conducted to study the kerosene spray characteristics injecting into supersonic cross flow. The verification of the simulation was carried out by experimental Schlieren image, and the agreement was obtained by compared the spray plume pictures. Furthermore, the aerodynamic secondary breakup effect of the supersonic cross flow on the initial droplets was investigated. It was revealed that the initial parent drops were broken up into small drops whose diameter is about O(10) micrometers soon after they entered into the supersonic cross flow. During the appropriate range of initial drop size, the parent droplets would be broken up into small drops with the same magnitude diameter no matter how large the initial drops SMD was.

The pyrolysis of n-butane

A study of the pyrolysis of n-butane was carried out using an all-gold tubular reactor. The initial rate of decomposition of the n-butane was of 1.50-order with respect to the partial pressure of the n-butane. A free radical mechanism, similar to that originally proposed by Rice, accounted satisfactorily for the distribution of products. Oxygen was rigorously excluded from the pyrolysis gases. The surfaces of the gold reactor had been acid-treated to remove oxide impurities. Some preliminary experiments were performed in the partial oxidation of n-butane.

Optimization of the pyrolysis process for the production of a biomass derived reducing agent and hydrogen-rich gases

221 p.

Valorization of scrap tires pyrolysis oil (STPO) through a 2-stage hydrotreating-hydrocracking strategy. Process variables and kinetic modeling

232 p.