Conversión de los vapores de pirólisis de polietileno de alta densidad en combustibles usando catalizadores de zeolitas impregnados de ni

Abstract

High-density polyethylene (HDPE) is one of the most common polymers in plastic waste. The objective of this research was to obtain the liquid fraction through the pyrolysis process, through the use of metal/zeolite catalysts: Ni /HZSM-5 and Ni-Zn/HZSM-5. HDPE plastic was used as raw material in the Batch reactor at the laboratory level in order to obtain a liquid fraction similar to fuel. Variables were controlled, quantitative data was collected, as well as the amount of gaseous, solid and liquid products. Having a research focus on the liquid fraction, the influence of the various experimental parameters was analyzed, such as the temperature and hydrogen flow variables, and the chemical characterization of the liquid fraction obtained. Nitrogen gas was injected through the valves into the reactor at a pressure of 1 to 2 MPa, with a water cooling system at 10°C, the HDPE pyrolysis temperature was 425°C and the conversion of the pyrolysis gases in the Ni/HZSM-5 and Ni-Zn/HZSM-5 catalysts it was 250°C. Chromatography techniques (GC-MS), FT-IR spectrometry, API degrees, density, viscosity, ASTM distillation and ANOVA analysis of each of them were analyzed in the liquid fraction obtained, complying with the respective standards for each technique. As a result of the processes, a mixture of aliphatic hydrocarbons was obtained, being alkanes, alkenes and alkynes in the composition of the liquid fractions, having a yield of 53.5% in the use of the monometallic Ni/HZSM-5 catalyst and a yield of 45.5 with the bimetallic Ni-Zn/HZSM-5 catalyst, concluding that the first liquid fraction obtained a higher yield, however, more studies should be carried out controlling the variables to obtain a higher quality product.