Sugarcane Filter Cake: A Bibliometric Review of Traditional Uses and Its Potential as a Feedstock for Biorefinery and Biofuel Production

Filter cake is a nutrient-rich solid byproduct generated during sugarcane juice clarification, representing both a challenge and an opportunity for the sugar–energy industry. This study presents a systematic bibliometric analysis of global research on filter cake valorization, with a particular focus on its potential for bioenergy and biofuel production. Data were retrieved from the Scopus database and analyzed using VOSviewer, resulting in a dataset of 530 publications up to 2024, of which 485 address recycling and reintegration pathways. The results identify Brazil and India as leading contributors, with research traditionally concentrated on agricultural applications. However, emerging trends highlight the growing interest in thermochemical and biochemical conversion routes, including its use as a substrate for biogas, bioethanol, and other biofuels. The findings demonstrate that filter cake is a promising feedstock for integrated biorefinery systems, contributing to renewable energy generation and resource recovery. Despite this potential, the transition toward advanced biofuel production and high-value energy applications remains limited. This review provides a comprehensive overview of research trends, identifies key gaps, and outlines strategic directions to support the shift from conventional waste management to energy-oriented valorization within a circular bioeconomy framework.