Improving thermal decomposition process of recycled plastics for sustainable gas and liquid fuel production
Abstract
In the U.S.A., plastic waste is about 12.7 % of the total municipal waste which is
approximately 32 million tons annually. Recovery of plastics is usually done through waste-toenergy
or recycling options. Plastic-to-fuel (PTF) presents a unique opportunity to not only address
environmental issues but also energy crisis. Also, PTF can address a critical problem for low
recyclability rate of plastics. The development of PTF infrastructure can help prevent land-filling of
plastics, extending the lifespan of landfills, reducing plastic loitering, producing synthetic crude oil,
reducing pollutions associated with high sulfur contents in fossil fuels because plastic oil has ultralow
sulfur content, and creating green jobs. In this paper, we reviewed existing methods of
converting plastics into fuel. Additionally, we evaluated various factors, such as operating
temperature, types of reactor and catalyst, plastic to catalyst ratios, and residence time which affect
the conversion efficiency and product quality of plastic feedstock. We used MgSi and Cloisite 30B
as catalysts for the first time for decomposition of different plastics and yielded comparative results
to zeolite as a catalyst. In case of HDPE, oil yield with zeolite was 71% whereas it was 68% and
67% in case of MgSi and Cloisite 30B respectively. Zeolite with PP produced better results as oil
yield was 75% whereas it was 70% and 65% in case of MgSi and Cloisite 30B respectively. Zeolite
with LDPE produced about 70% oil whereas yield was 66% and 65% in case of MgSi and Cloisite
30B. Fourier transform infrared spectroscopy (FTIR), Ultraviolet visible spectroscopy (UV-Vis),
and Gas chromatography (GC) were carried out and spectra results for all the samples were
consistent and were in fuel range.
Description
Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering