Pyrolysis of hyphaene thebaica shell over ceramic tile dust-derived catalysts and assessment of the produced bio-oil

• ZSM-5 zeolite with hierarchical mesopores was synthesised from ceramic tile dust. • Biomass pyrolysis with the ZSM-5 and its metal oxide composites was performed. • The catalytic pyrolysis enhanced the fuel quality of the pyrolysis bio-oils. • Phenolic compounds, hydrocarbons, and esters were increased in the bio-oils. • The extent of coking on the ZSM-5 and its composites was established. The purpose of this study is to demonstrate the potential of ceramic tile dust (CTD)-derived ZSM-5 zeolite (CZ) and its monodispersed composite with metal oxides (MgO and Fe 2 O 3 ) in the catalytic pyrolysis of hyphaene thebaica shell (HTS). The HTS was pyrolysed in a Fixed-bed reactor at 400–600 °C, and 100–300 mL/min N 2 flowrate. The maximum bio-oil production of 32 % was obtained at 500 °C and 150 mL/min N 2 flowrate, with bio-oils containing 50 % acid and octadecenoic acids, as well as esters, phenols, aldehydes, ketones, ethers, aromatics, and hydrocarbons. A carboxymethyl cellulose templating agent was employed for the mesoporous zeolite synthesis from CTD. This resulted in the mesoporous zeolite with a predominant ZSM-5 crystal phase, exhibiting pore diameters ranging from 1.8-6 nm, 229 m 2 /g surface area and 1145 μmol/g total acidity. The catalytic pyrolysis of HTS was conducted using the ZSM-5 zeolite (CZ) and metal-oxide (MgO, Fe 2 O 3 , and Fe 2 O 3 /FeO) modified CZ, as monodispersed composite catalysts. Under best thermal pyrolysis conditions, CZ-Fe 2 O 3 , CZ-MgO, and CZ-Fe 2 O 3 /MgO demonstrated 22–23 % bio-oil yields. Notably, the CZ-Fe 2 O 3 /MgO catalyst exhibited the highest hydrocarbon yield at 16 %, while the CZ-MgO favoured the production of phenolics, esters, and alcohols. CZ-MgO also displayed the highest coking level at 7.5 %, indicating faster deactivation than the other catalysts. The synthesised catalysts exhibited remarkable catalytic activity, resulting in a notable improvement in the quality of bio-oils obtained from the intermediate pyrolysis of hyphaene thebaica shells in a fixed-bed reactor.