Colloquia

Samenvatting

  One of the most pressing issues nowadays is the rising generation rate of solid waste, which pose one of the enduring environmental, health and economic problems in most developing countries. This category of waste includes industrial, construction and plastic waste, as well as household garbage. Waste tires also belong in this group and have been one of the most prominent waste in recent years.

  Due to the rising demands of the automobile industry, the production of tires is increasing constantly and is expected to reach nearly 23 million tons by 2024. Obviously, this in turn means that the generation of waste tires will also display an upward trend. Annually, approximately 1 billion tires are disposed and are added to the nearly 4 billion tires already in landfills and stockpiles, creating an issue that demands immediate attention.

  Pyrolysis is one of the most effective methods of waste tires utilization, producing three separate products. Within the scope of this thesis project, the post-treatment of the solid product (pyrolytic carbon black (CBp)) was studied. The aim was to determine the optimal conditions in order to reduce the ash content and produce commercial grade carbon black. Firstly, an experimental study of CBp demineralization was conducted, taking into account the effect of several parameters of the process, such as reagent type and concentration, time, temperature and reagent/CBp ratio. Two different feedstocks were utilized, namely passenger car tire and truck tire pyrolytic carbon black, while HCl, H2­SO4 and NaOH were the reagents that were used. The chosen concentration and temperature range was 1-4 M and 20-60 oC respectively, with the reagent/CBp ratio varying between 5 and 20 ml/g. TGA analysis was used to determine the final ash content of the samples, while an XRF and SEM/EDS analysis was conducted to further explore the effects of the treatment on the material.

  Moreover, a feasibility study was conducted on a waste tire pyrolysis unit, coupled with demineralization, aiming to assess its economic performance and define possible setbacks and areas of improvement. The analysis was based on finding the total investment, operating costs and net profits. Additionally, in order to make a more concrete assessment and determine the optimal capacity for the plant, two financial indicators were employed, which were R.O.I (Return on Investment) and P.O.T (Payback Time). Lastly, a sensitivity analysis allowed to examine the effect of different parameters on the feasibility of such an installation.