Metal organic frameworks catalytic co-pyrolysis mechanism of waste wood and rubber for oil preparation

Pyrolysis oil of waste wood exists high viscosity, poor stability, low calorific value, and low H/C ratio. The co-pyrolysis oil derived from waste wood and rubber overcomes the aforementioned drawbacks, with metal-organic frameworks (Ni-MOFs, Mg-MOFs, and Co-MOFs) serving as effective catalysts for enhancing this process. MOFs catalytic co-pyrolysis mechanism of waste wood and rubber for oil production were investigated by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), Gas Chromatograph-Mass spectrograph (GC-MS), infrared flue analyzer (IFA), Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) and molecular simulation. The highest oil yield (52.5 %) was achieved with the addition of Mg-MOFs. Furthermore, catalyst incorporation enhanced both the H/C ratio by over 10 % and the oil yield by at least 15 %. The MOFs catalytic co-pyrolysis mechanism of waste wood and rubber for oil preparation showed that the acid sites on Ni-MOFs and Mg-MOFs and basic sites on Co-MOFs contribute to the conversion of oxygenated compounds to phenols and aromatic hydrocarbons. MOFs catalysts effectively mitigate (>20 %) the release of harmful gases during co-pyrolysis, including volatile organic compounds (C₆H₆), greenhouse gases (CH₄, CO₂), water vapor (H₂O), and acidic pollutants (SO₂). Gas evolution during waste wood and rubber co-pyrolysis occurs in stages: initial dehydration releases H₂O, followed by thermal decomposition yielding CO₂, CH₄, and C₆H₆, with sulfur-containing species (SO₂) emitted last. These five compounds dominate the gaseous emission profile. This study can contribute to take full use of organic wastes and reduce the environmental pollution.