A Review of the Gasification of Organic Waste Obtained from Wastewater
Umama Minahil1, Marcelo Fossa da Paz2*
1Department of Chemistry, University of Agriculture Faisalabad, Pakistan
2Faculty of Biological and Environmental Sciences, Federal University of Grande Dourados, Brazil
Submitted: 22-01-2026; Accepted: 27-05-2026; Published: 01-07-2026
Abstract
Gasification of sewage sludge provides a renewable solution to the problem of organic waste, transforming it into useful products in the form of syngas and biochar, and other forms of energy carriers. The objective of this review is a detailed study of sewage sludge gasification with an emphasis on the variety of technologies, the mechanisms of the reaction, and the difficulties inherent in the process. The review starts with a discussion of the physicochemical characteristics of sewage sludge and its gasification phenomenon. It subsequently discusses some of the methods of gasification, such as fluidized bed, entrained flow, and supercritical water gasification, the efficiency, merits, and disadvantages of the methods. The paper also explores the chemical reactions that rule the process of gasification and the process of producing syngas and how temperature, pressure as well as the catalyst help improve yields. The main issues of sludge gasification which are discussed in the review include the formation of tar, the behavior of ash, and the prevention of heavy metal emission. Lastly, it comments on the possibilities of incorporating sewage sludge gasification into the framework of a circular economy, which provides future research and technological prospects. The aim of this review is to become a useful source for academics, engineers and policymakers in the development of sustainable management of sewage sludge by use of gasification.
Keywords: sewage sludge, syngas, fluidized bed gasification, thermochemical conversion, gasification techniques.
Review article *Corresponding Author, e-mail: marcelopaz@ufgd.edu.br; https://doi.org/10.71111/1-26-4-4-st-1