The steelmaking industry is the largest energy consuming manufacturing sector in the world and is responsible for 5-7% of anthropogenic CO2 emissions. It is therefore necessary to increase energy efficiency and reduce greenhouse gases emissions in these industries. COG, a by-product of coking plants, is one of the key ways to achieve these goals. COG, which is used as fuel in different processes of the steelmaking plants, is a H-2-rich gas with a high energetic potential. However, there is a significant surplus that usually is burnt away in torches, and even directly emitted into the air. With the aim of tackling this wasting of resources and energy inefficiency, several alternatives have been proposed during recent years. In the present work, these alternatives are reviewed and their main advantages and drawbacks are discussed. (C) 2012 Elsevier B.V. All rights reserved.