This study focuses on the synthesis of CoCuFe₂O₄ mixed ferrites supported on nanoporous carbon materials. The carbon supports were derived from two mixtures: a mixture of spent motor oil and pine wood chips (designated as AC-A), and mixture of spent motor oil and crushed coal obtained from the Chukurovo mine (designated as AC-B). Additionally, two types of carbon components – nanodiamond and graphene oxide were used for the synthesis of nanosized ceria-based hybrid nanocomposites. The structural and physicochemical properties of the resulting materials were comprehensively characterized using X-ray diffraction (XRD), nitrogen physisorption, Mössbauer spectroscopy, and temperature-programmed reduction (TPR) analysis. The results revealed that the active phase deposited on the carbon supports consists of a complex mixture of finely dispersed ferrite nanoparticles as well as small CeO₂ crystallites in the hybrid nanocomposites. The dispersion and phase composition were found to be strongly influenced by the textural properties of the respective carbon support. Among the investigated materials, the graphene oxide-modified composites exhibited superior catalytic performance for hydrogen production via methanol decomposition.

The study comprises an in-depth characterization of compositional groups of the liquid by-products obtained from the pyrolysis of swine manure at 500 °C, with the aim of providing an alternative and efficient approach for the valorisation of this waste stream, alongside with the production of biogas and char, the latter of which can be further converted into activated carbon. Two samples were considered: de-watered cake and solid product from anaerobic digestion of swine manure. Biocrude oils were fractionated into weak acidic, strong acidic, alkaline and neutral oil fractions. Subsequently, the neutral oil fraction was separated into paraffinic–naphthenic, slightly polar and polar fractions. All fractions were analyzed by GC–MS. The major identified compositional groups were: (i) for de-watered cake: steroids (40.7%), fatty acids, FAs (23.7%) and n-alkenes/n-alkanes (23.3%); (ii) for solid product from anaerobic digestion: FAs (31.0%), phenols/methoxy phenols (26.6%), n-alkenes/n-alkanes (10.8%) and steroids (10.6%). A variety of short-chain FAs (i.e., linear saturated, mono- and di-unsaturated, cis (i-), trans (ai-), isoprenoid, phenyl alkanoic, amongst others) and methyl esters (FAMEs) were identified as well. FA distribution, nC₁₂–nC₂₀, was similar for both manures studied with nC₁₆ and nC₁₈ as major compounds. FAMEs (nC₁₄–nC₂₈, with even carbon number dominance) in the slightly polar fraction of both samples were accompanied by considerable amounts of oleic (nC_18:1) and linoleic (nC_18:2) acids, and corresponding methyl esters. Hydrocarbons, i.e., n-alkenes/n-alkanes, were in the range of nC₁₅–nC₃₄, with nC₁₈ maximizing. Anaerobically digested manure has resulted in (i) an increase in the portion of longer homologues of hydrocarbons and FAMEs and (ii) the appearance of new FAs series of long chain members nC_22:1–nC_26:1, ω-9. The comprehensive analysis of the biocrude oils obtained from the slow pyrolysis of swine manure indicates their potential for use as biodiesel additives or as feedstock to produce value-added materials.