INFORM April 2026

EXTRACTS & DISTILLATES INFORM 39

PROCESSING ARTICLES PICKED BY RESEARCHERS This column highlights articles from non-AOCS journals to complement the AOCS member benefit of access to full journal articles .

Bryan Yeh has over 30+ years of senior leader experience in agribusiness,

oils into SAF while reducing the energy requirement when compared to conventional HEFA processes. The third article reports on the performance of low-cost deoxygenation catalysts on oils derived from black soldier fly larvae, sardine waste and squid waste. APPROACHES TO CONDITIONING OF VEGETABLE OIL FEEDSTOCK FOR HYDROTREATING TO PRODUCE RENEWABLE DIESEL Pérez-Rangel, N., et al. , Fuel , 383, 133897, 2025. The hydrotreating (HDT) process is increasingly implemented due to its versatility in producing renewable diesel and its flexibility with various raw materials. Impurities in vegetable oils can disrupt the HDT process, necessitating a pretreatment stage to ensure optimal performance, catalyst and equipment preservation, and achieve high yields. While laboratory-scale studies often overlook pretreatment due to minimal impacts on production costs and the use of pre-refined oils, industrial processes are designed

and tailored to optimize the purification step for efficiency and cost-effectiveness. This study discusses the effect of impurities such as phospholipids, metals, and free fatty acids (FFA) on HDT and outlines effective pretreatment methods. Removing impurities is critical as they can deactivate sulfur-based catalysts, promote coke formation, and initiate oligomerization. The introduction of dimethyl disulfide (DMDS) and co processing with sulfur containing petroleum fractions are examined for their effectiveness in mitigating catalyst deactivation. The two stage HDT, or pre-HDT, which is emphasized for lowering coke formation and increasing hydrogen availability, is also covered. The study emphasizes the importance of tailored pretreatment strategies for different raw material, including used cooking oil (UCO), to enhance HDT efficiency and extend catalyst life.

biofuels, energy, food, management consulting, renewable chemicals, synthetic biology, and water industries. He is based in Walnut Creek, California. With over 5 billion gallons per year of hydrotreating capacity in North America alone, the topic of both how to pretreat waste oils and how to source waste oils has been constantly evolving. Producers of renewable diesel (RD) and sustainable aviation fuel (SAF) through the hydrotreated esters and fatty acids (HEFA) pathway are constantly discovering characteristics of their feedstock that adversely affects their process. The first article is a recent overview of how to pretreat feedstock for the HEFA pathway. Going forward, it will be necessary to have processes that address a way to produce RD and SAF using alternative wastes that are currently not being exploited. The second article explores the use of photothermal coupling catalysts to convert waste