Sustainable Production of Aromatics from Biomass- and CO₂-Derived Alcohols over Zeolite-Based Catalysts: A Review

The transformation of biomass- and CO2-derived lower alcohols (methanol, ethanol, and butanol) into value-added aromatics presents a promising strategy to meet the rising global demand for benzene, toluene, and xylenes (BTX). This Review explores renewable production pathways of lower alcohols from biomass and CO2, with a primary focus on their catalytic conversion to BTX aromatics using zeolite-based catalysts. The Methanol to aromatics (MTA), ethanol to aromatics (ETA), and butanol to aromatics (BTA) processes are critically reviewed to understand the rational design of catalytic systems for carbon-efficient aromatics production. Special emphasis is given to the HZSM-5 zeolite, including hierarchical, modified, and metal-incorporated bifunctional catalysts. The influence of zeolite topology, structural modifications, Si/Al ratio, acid site type (Brønsted vs Lewis), mesoporosity, and reaction parameters on aromatic selectivity is thoroughly analyzed. Reaction mechanisms for each alcohol are delineated, highlighting how the molecular structure affects intermediate pathways, cyclization, and hydrogen transfer/dehydrogenation. Catalyst deactivation is also discussed in relation to coke formation, acid site accessibility, and framework stability. Additionally, emerging strategies, such as cofeeding, mixed alcohol conversions, and process intensification, are examined as pathways for improving performance and sustainability. The Review concludes with current challenges and future prospects for developing robust catalytic systems for BTX aromatic production from renewable resources.