The performance, selectivity, recovery, and reusability of high metal loading commercial Ni66 ± 5%/SiO2–Al2O3 catalyst were studied in renewable hydrocarbon synthesis from low cost raw material pretreated soapstock (TS) by solvent-free one-pot hydrotreatment (HT). TS was extracted from rapeseed oil chemical refining by-product/waste soapstock (SS) by developed simple treatment method. The catalyst was characterized by FE-SEM, TEM, XRF, XRD, and N2 sorption analysis. Feedstock, liquid, and gaseous products were analyzed by FT-IR, GC-FID, GC-MS, GC-TCD, and CHNS elemental analysis. The effect of initial H2 pressure (2–8 MPa), catalyst amount (3–9%), reaction temperature (280–340 °C), and residence time (15–60 min) on hydrocarbon production were investigated. Combustible gases and pure marketable linear saturated hydrocarbons with high yield 79.1%, calorific value 47.22 MJ/kg, C/H ratio 5.6, and n-C17 content 82.7% were successfully produced from TS using minimum effective catalyst amount and reaction conditions: 5%, 6 MPa, 320 °C, and 30 min.