Combined strategy and Ni NPs/SiO2 aerogel catalyst for cracking hydrocarbon fuels

Abstract

The endothermic hydrocarbon fuel catalytic cracking as an active cooling technology for aircraft engines needs to provide a higher heat sink to absorb more heat and at the same time produce less carbon deposits to ensure the continuous operation of the aircraft. In this paper, Ni nanoparticles embedded into SiO2 aerogel is achieved by two different method, col-gel (Ni-co) and after impregnation (Ni-after) and firstly introduced to achieve high heat adsorption capability and low coke generation in the fuel cracking process through ethanol-assisted and TiN coating technology. The Fourier transform infrared spectroscopy (FTIR) and contact angle test results show that aerogel catalysts are modified successfully with excellent hydrophobicity and lipophilicity which indicates that aerogel catalysts could be well dispersed in n-decane. According to the SEM and N2 adsorption-desorption, Ni-after remains similar three-dimensional structure with SiO2 aerogel and shows better pore structure which result in higher cracking activity (4.04 MJ/kg at 750 °C, 3.5 MPa) than Ni-co. Furthermore, the most efficient coke inhibition in supercritical catalytic cracking of n-decane is achieved by incorporating a little ethanol over TiN coating and high catalytic activity could be maintained within 50 min at 750 °C, 3.5 MPa and the coke generation is decreased by more than 90.0% (9.67–0.42 mg/cm2·g) compared with Ni-after catalytic cracking.