Catalytic Co-Pyrolysis of Formic Acid Pretreated Nypa Fruticans Fronds and PET for Sustainable Bio-Oil Production

Universitas Riau, Chemical Engineering Department, 28293 Pekanbaru, Indonesia

^* Corresponding author: sunarno@lecturer.unri.ac.id

Abstract

The growing global energy demand has accelerated the search for sustainable and environmentally friendly alternatives, among which bio-oil has emerged as a potential candidate. Bio-oil is a liquid fuel derived from the pyrolysis of biomass, a thermal decomposition process at high temperatures (>300 °C) in the absence of oxygen, resulting the formation of biochar, gases, and liquid fractions. Co-pyrolysis, involving the simultaneous pyrolysis of biomass with other feedstocks, has gained attention due to its potential to improve yield and quality of bio-oil. This study investigates the effect of formic acid pretreatment of Nypa fruticans fronds (NFFs), the role of polyethylene terephthalate (PET) addition, and the influence of NiO-CuO/biochar catalyst loading on bio-oil production. Experiments were conducted at 500 °C for 60 minutes with varying formic acid (FA) concentrations (0%, 10%, and 20% w/w), NFFs-to-PET ratios (100:0, 75:25, 50:50, 25:75, and 0:100), and catalyst loadings (5%, 10%, and 15% w/w). The best performance was achieved under combined conditions of 10% FA pretreatment, a 25:75 NFFs-to-PET ratio, and 10% catalyst loading, resulting in a bio-oil yield of 39.33% w/w with calorific value of 33.71 MJ/kg, viscosity of 21.74 cSt, and density of 0.95 g/cm³. These findings demonstrate the effectiveness of co-pyrolysis with PET and NiO-CuO/biochar catalysts in producing higher yields and improved bio-oil quality, highlighting its potential as an alternative renewable fuel.