Understanding of synergy in non-isothermal microwave-assisted in-situ catalytic co-pyrolysis of rice husk and polystyrene waste mixtures

• Published in: Bioresource technology 2022-09, Vol.360, p.127589-127589, Article 127589
• Main Authors: Sridevi, Veluru, Suriapparao, Dadi V., Tukarambai, M., Terapalli, Avinash, Ramesh, Potnuri, Sankar Rao, Chinta, Gautam, Ribhu, Moorthy, J.V., Suresh Kumar, C.
• Format: Article
• Language: English
• Subjects: catalysts; Co-pyrolysis; energy; feedstocks; graphene; Microwave; microwave treatment; oils; Polystyrene; polystyrenes; pyrolysis; rice hulls; Rice husk; Synergistic effect; value added
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2022.127589

[Display omitted] •In-situ catalytic co-pyrolysis of Rice husk (RH) and Polystyrene (PS) was conducted.•Pyrolysis index increased (17–445) with the increase of feedstock quantity.•Catalytic co-pyrolysis is rich in aromatic hydrocarbons (92%)•PS promoted the oil yield (70 wt%) and RH enhanced the char yield (34 wt%)•PS and RH interactions caused the positive and negative synergy effect. Rice husk (RH) and polystyrene (PS) wastes were converted into value-added products using microwave-assisted catalytic co-pyrolysis. The graphite susceptor (10 g) along with KOH catalyst (5 g) was mixed with the feedstock to understand the products and energy consumption. RH promoted the char yield (20–34 wt%) and gaseous yields (16–25 wt%) whereas PS enhanced the oil yield (23–70 wt%). Co-pyrolysis synergy induced an increase in gaseous yields (14–53 wt%) due to excessive cracking. The specific microwave energy consumption dramatically decreased in co-pyrolysis (5–22 kJ/g) compared to pyrolysis (56–102 kJ/g). The pyrolysis index increased (17–445) with the increase in feedstock quantity (5–50 g). The obtained oil was composed of monoaromatics (74%) and polyaromatics (18%). The char was rich in carbon content (79.5 wt%) and the gases were composed of CO (24%), H2 (12%), and CH4 (22%).