TGA-DSC: A Screening Tool for the Evaluation of Hydrocracking Catalyst Performance

Abstract

DSC-TGA was used for screening of commercially available and synthesized catalyst for the degradation of polypropylene (PP). In this study, all the runs were performed with 50% load of the catalyst and the results were compared with those of PP + 50% pure silica having no catalytic activity. The degradation behavior of PP using catalyst Zeolyst-713 exhibited much higher degradation activity among the other catalysts used in this study. Moreover, it contributed to lowering of initial stage temperature showing a shape-selective effect. DSC-TGA tools such as Ton, Tmax, T99%, activation energy, enthalpy change in the process and coke content were used for screening. It was concluded that the pore construction and unique acid properties of the Zeolyst-713 as well as proper reaction temperatures were significant influential factors to fully exert this effect. In this work, kinetics of catalytic thermogravimetric degradation of PP used for domestic purposes was investigated using Alumino-silicate catalyst. Zeolyst-713 was observed to lower activation energy and enhances degradation activity in comparison with thermal degradation without a catalyst.

Kinetic Analysis for the Catalytic Pyrolysis of Polypropylene over Low Cost Mineral Catalysts

“…This suggests that NZ can increase the decomposition efficiency of PP at the initial stages, but a much higher heat energy than for a non-catalytic reaction is required for the complete reaction. During the CP of PP, large molecular reaction intermediates can condense in the pores of NZ at a temperature lower than 430 °C and be re-vaporized at higher temperatures, because of the accelerated secondary cracking and efficient vaporization at elevated temperatures [18].…”

“…The DTG curve for the CP of PP over NZ also had a much lower T max than the NCP of PP, but it also had a second DTG peak in the high-temperature region, between 430 and 550 • C. This suggests that NZ can increase the decomposition efficiency of PP at the initial stages, but a much higher heat energy than for a non-catalytic reaction is required for the complete reaction. During the CP of PP, large molecular reaction intermediates can condense in the pores of NZ at a temperature lower than 430 • C and be re-vaporized at higher temperatures, because of the accelerated secondary cracking and efficient vaporization at elevated temperatures [18]. Figure 3 represents the slopes of ln (β) versus 1/T, with different conversions obtained from the TGA of the NCP and CP of PP.…”

Characteristics of Non-Polar Bio-oil Produced by Co-pyrolysis of Corn Cobs and Polypropylene using CO_2 as Carrier Gas

“…At high PP composition of feeds, all biomass particles submerged in thick PP melt and in stirring, there was heat convection from the hot reactor wall through PP melt to biomass particles 19) . In this regime where PP compositions started to exceed biomass compositions in feeds, the heat radiation enhanced by CO 2 gas carrier worked with partial transparency of PP 20) . The high emissivity of CO 2 gas enhanced the primary and secondary pyrolysis of biomass where most of cellulose and hemicellulose decomposition occurred between 270 to 320 o C 21) and high mass decomposition of PP occurred above 400 o C 22) .…”