The influence of feed space velocity and pressure on the cold flow properties of diesel fuel

Abstract This study investigates the influence of hydroisodewaxing process parameters, specifically pressure and feed space velocity, on the performance characteristics of diesel fuel, including the cold filter plugging point and pour point. The experiments were performed using bifunctional catalysts – Ni/MAS-H-bentonite, Mo/MAS-H-bentonite, and Ni–Mo/MAS-H-bentonite – developed for this purpose. The process was carried out at a fixed temperature of 320°C, with feed space velocity varying from 0.5 to 2.0 h −1 and pressure ranging from 1.0 to 3.0 MPa. Among the tested catalysts, the bimetallic Ni–Mo/MAS-H-bentonite exhibited superior performance, achieving an optimal balance between product yield and low-temperature properties under operating conditions of 2.0 MPa and a feed space velocity of 1.0 h −1 . These findings highlight the potential of the Ni–Mo/MAS-H-bentonite catalyst for enhancing the cold flow properties (CFPs) of diesel fuel while maintaining high efficiency in hydroisodewaxing processes. This study highlights significant environmental and practical benefits by introducing cost-effective, environmentally friendly catalysts. Utilizing locally sourced bentonite from Kazakhstan reduces reliance on imports and minimizes the carbon footprint. By employing inexpensive and abundant nickel and molybdenum as promoters for the catalysts, the optimized hydroisodewaxing process enhances CFPs of diesel fuels and minimizes yield losses, improving fuel efficiency and lowering maintenance costs.