• Development of a novel SnO₂/Chitosan nanocatalyst via co-precipitation techniques. • Achieved 94.5% biodiesel yield with dominant FAMEs: methyl oleate (50.91%) and methyl linoleate (26.27%). • The catalyst demonstrated excellent reusability, maintaining high performance over five cycles. • An innovative lab-scale reactor design ensured uniform heat distribution and efficient methanol recovery. • FTIR, XRD, SEM, and BET analyses confirmed the catalyst's unique structural and surface characteristics. This paper reports the synthesis and characterisation of a new type of heterogeneous nanocatalyst for biodiesel production from soybean oil. This catalyst was synthesised from tin oxide and chitosan in a novel hybrid configuration, with the aim of developing an efficient, structurally integrated catalytic system that minimises nanoparticle agglomeration and metal leaching, and promotes long-term stability relative to previously developed hybrid nanocatalysts. The nanocatalyst was synthesised using a controlled ‘co-precipitation’ process, which enhanced nanoparticle dispersion and structural stability, while enabling catalyst recyclability. A custom-designed laboratory scale reactor with improved thermal management, enhanced heat transfer, improved vapour condensation and recovery, and enhanced mixing facilitated increased biodiesel conversion and efficient thermal management during transesterification of soybean oil (methanol-to-oil ratio = 12:1, catalyst loading = 3 wt%, temperature = 60–65°C, reaction time = 90 min). The resulting cassiterite-phase (tin) oxide/chitosan nanocatalyst comprised uniform spherical nanoparticles with Sn–O bonding and a high-surface-area mesoporous structure (260.15 m 2 /g, pore volume = 0.67 cm 3 /g, average pore size = 9.56 nm). The cassiterite-phase SnO₂/chitosan nanocatalyst achieved a maximum biodiesel yield of 94.5%, exceeding the yields achieved using pure tin oxide nanocatalysts (85.3–89.2%). The final biodiesel product met all international fuel specifications and was verified to have exhibited the following properties: density = 0.889 kg/m 3 , viscosity = 3.9 mm 2 /s, flash point = 114°C, and cetane number = 53.7. Using gas chromatography-mass spectrometry (GC-MS), it was confirmed that the biodiesel was primarily made up of fatty acid methyl esters (FAMEs). The two primary components comprised methyl oleate (50.91%) and methyl linoleate (26.27%). The cassiterite-phase tin oxide/chitosan nanocatalyst showed great activity for five reaction cycles and was able to maintain about 85 percent conversion after the fifth cycle.
Ridha et al. (Wed,) studied this question.