Analyse of landfill gas composition and optimization of its production and exploitation at landfill sites

This PhD thesis results from collaboration between Centre SITE, Ecole Nationale Superieure des Mines de Saint-Etienne, France and Faculty of Chemistry, Jagiellonian University in Cracow, Poland (international thesis), as well as with two industrial partners: society Satrod and Elyo which manage landfill site and landfill gas utilization at Borde-Matin, and Miejskie Przedsiebiorstwo Oczyszczania in Cracow (Municipal Company of Purification) which manages landfill site Barycz. This PhD thesis aims to understand and explain the process dynamics of the landfill gas (LFG). In order to propose an assistance to the optimisation of the LFG exploitation and using, the behaviour of LFG in the mass of the waste (transfer, composition, influences and variations...) and the relationships with external parameters (meteorological and exploitation parameters, operators interventions) have been investigated. Landfill gas utilization implies collecting and processing of LFG generated during anaerobic fermentation of organic waste. LFG utilization aims at energy production and environment protection by reduction of greenhouse gas emissions (methane), elimination of odors and explosion hazard. One of the techniques of LFG utilization implies the production of electric energy in power units consisting of LFG engines coupled with electricity generators. In order to reach optimum efficiency of using the biogas it is of big importance that LFG production and composition be constant. However, a lot of factors are able to affect or afford the concentration of the different LFG components and the volume of its production. These are, among others, meteorological parameters (precipitation, atmospheric pressure, temperature and air humidity), the age and type of the waste as well as the method of its disposal. This work investigates the LFG generation process dynamics at different landfill sites in relation to various external parameters (meteorological and operational). Various types of models have been studied according to the time horizon concerned: short-, mean-term and global view. The short-term models (hours, days) could have an interest in the management 'from day-to-day' whereas the global models could provide a decision making assistance to the landfill management on the horizon of several years. (author)