Sustainable Photocatalytic Valorization of Pork Lard to Fatty Acids and Glycerol through Energy-Efficient Hybrid Irradiations: LCIA and Cost Analysis

Abstract

The upsurge in global pork meat consumption leading to surplus generation of byproducts, namely, inedible pork lard (IPL), necessitates a sustainable valorization technique for synthesis of industrially valuable fatty acids (FA) and glycerol (GL). An energy-efficient hybrid "UV and quartz iodine (QI) -irradiated batch reactor" (UVQIIBR) were deployed in the presence of heterogeneous acid-photocatalysts, specifically, Amberlyst 15 and nano-TiO₂, for photocatalytic hydrolysis of IPL. The optimal process rendered 98.2% IPL conversion (α_IPL) at 180 min, 70 °C, 1:80 IPL:water mol/mol, and 10 wt % catalyst concentration. A comparative study among electromagnetically irradiated reactors revealed an augmented 98.2% IPL conversion in UVQIIBR compared to 90.2% in the UV and silicon carbide (SC) (far-infrared)-irradiated batch reactor, 85% in the UV-irradiated batch reactor, 78.02% in the QI-irradiated batch reactor, 70.46% in the SC-irradiated batch reactor, and a remarkably lower conversion (55%) in the conventionally heated (CH) batch reactor (CHBR). A significant 62.28% energy savings could be achieved in UVQIIBR as compared to CHBR. The optimal product was composed of FA (77.91%) and GL (22.09%). Furthermore, the LCIA ascertained superior sustainability of IPL-conversion in UVQIIBR over CHBR in terms of a profound 69.007% reduction in GWP and the cost of FA (29.68%) and GL (40%).