Properties and Combustion Characteristics of Bio-Oils from Catalytic Co-Pyrolysis of Grape Seeds, Polystyrene, and Waste Tires

Abstract

This work aims to study the bio-oils obtained from the catalytic co-pyrolysis of waste polymers and a residual biomass (grape seeds, GS). For that purpose, the organic liquid fractions produced in an auger reactor were thoroughly characterized in two steps, obtaining in the first place their main physicochemical properties as well as their chemical compositions, and second, their droplet combustion behaviors. Both the polymer type (waste tires or polystyrene, WT and PS, respectively) and the nature of the low-cost, calcium-based catalyst used (Carmeuse limestone, calcined dolomite, or an inert material such as sand) were studied. A significant improvement in the physicochemical properties of the bio-oils was obtained when using a catalyst, with lower viscosity, density, and oxygen content. These beneficial effects were more marked for the bio-oil produced with the Carmeuse catalyst, presumably due to the higher prevalence of aromatization and hydro-deoxygenation reactions. When changing the polymer source from WT to PS, a considerable increase in the aromatic content and a viscosity reduction were noted. The droplet combustion tests revealed the consistent occurrence of microexplosions for all of the studied bio-liquids, these bursting events being more violent for the GS−PS oil. Regarding the evaporation behavior, this liquid also yielded significantly higher burning rates during the initial heatup phase, in agreement with its richer composition in volatile compounds such as styrene. These results point to this fuel as the one with the best global combustion behavior from all of the explored bio-oils. The GS−WT liquids showed much closer features among them, although with noticeable differences depending on the catalyst used. A more volatile behavior was observed for GS−WT Carmeuse, followed by GS−WT dolomite and GS−WT sand, strengthening thus the previously reported improvements in physicochemical properties. Finally, the propensity to form soot of these bio-oils was characterized through a soot probe, which revealed a higher soot yield for the bio-liquids produced with the Carmeuse catalyst.

A Thermo-Catalytic Pyrolysis of Polystyrene Waste Review: A Systematic, Statistical, and Bibliometric Approach

“…However, catalytic co-pyrolysis increased solid-phase CO 2 formation by up to 3 wt.% in the presence of 10 wt.% of PS. Another study on co-pyrolysis of grape seeds and PS was performed by Muelas et al [ 145 ], using Carmeuse as a catalyst, differentiating it from the previous one mentioned. Their experiments were performed at a GS: PS ratio of 80:20 in an auger reactor; the authors found that a significant improvement in the physicochemical properties of the bio-oils was obtained when using a catalyst with lower viscosity, density, and oxygen content.…”

Advances in Computational Fluid Dynamics Modeling for Biomass Pyrolysis: A Review

“…With the rise in interest in biomass pyrolysis, numerical modeling studies have been conducted to investigate the process at different scales. These scales range from the molecular level and reaction kinetics to the reactor level for estimating product compositions [81][82][83]. Although multi-scale investigations are crucial, the input parameters from the molecular and particle scales are elementary and require integration with reactor levels for designing, scaling up, and optimizing industrial applications.…”

Review and Perspectives of End-of-Life Tires Applications for Fuel and Products

“…Recovering these wries will lead to more than 1 million tons of recycled steel each year globally, helping to conserve 1.1 million tons of iron ore, 0.6 million tons of coking coal, and 0.05 million tons of limestone . More examples of TDP include new tires, rubber walkways, playground mulch, synthetic turf, and sports surfaces. − The second category is energy recovery or tire-derived fuels (TDF), where ELT are used as an alternative fuel source . The third category of ELT recovery is civil engineering, where ELT are repurposed for applications such as breakwaters and coastal protection, erosion barriers, ground improvement, landfill construction (as a lightweight backfill in gas venting systems, in leachate collection systems and operational liners, and for capping and daily cover), slope stabilization and retaining walls, , sound barriers and insulation applications, stormwater infiltration galleries, railroad ties, and roads …”