# Sustainable Valorization of Palm Fatty Acid Distillate into Green Diesel Using Ni–Co Catalysts Supported on Zeolite from Kaolin Waste under Solvent- and Hydrogen-Free Conditions

## TL;DR

This study shows how to convert palm oil waste into green diesel using low-cost catalysts made from kaolin waste, without needing solvents or hydrogen.

## Contribution

A sustainable method for green diesel production using waste-derived Ni–Co/zeolite catalysts under solvent- and hydrogen-free conditions.

## Key findings

- Catalytic deoxygenation achieved 86% diesel-range hydrocarbons with NiZ catalyst.
- Cobalt-based catalysts improved deoxygenation selectivity and reduced secondary cracking.
- The process produced 60–65% organic liquid products with 77–83% hydrocarbons in the C8–C17 range.

## Abstract

The use of low-cost,
nonedible feedstocks has proven
to be a promising
route for catalytic deoxygenation reactions aimed at producing diesel-like
hydrocarbons. In this study, palm fatty acid distillate, a byproduct
of crude palm oil refining, was converted into green diesel via thermal
and catalytic deoxygenation using zeolite-supported Ni, Co, and NiCo
catalysts (10 wt % metal, synthesized from kaolin residue). The reactions
were carried out at 250–350 °C for 30 min without solvent
or hydrogen. The process was evaluated using thermogravimetric analysis,
and kinetic parameters were estimated via the Coats–Redfern
method. Both the thermal and catalytic routes yielded 60–65%
organic liquid products, with 77–83% hydrocarbons in the C8–C17 range. The catalytic route resulted
in high yields of diesel-range hydrocarbons (C15–C17), with 86% for NiZ, 75% for CoZ, and 65% for NiCoZ, whereas
the thermal route reached only 45%. Thermodynamic evaluation further
demonstrated that cobalt-based catalysts enhanced deoxygenation selectivity
while limiting secondary cracking. This study presents a sustainable
and scalable approach. This study presents a sustainable and scalable
approach for converting industrial waste into high-quality green diesel
using waste-derived catalysts under mild, hydrogen-free conditions.