Integration of waste biomass thermal processing technology with a metallurgical furnace to improve its efficiency and economic benefit

Abstract

Abstract The article presents innovative technology which integrates a metallurgical pusher-type furnace with a waste heat recovery system that consisted of a reactor for torrefaction and pyrolysis of waste biomass. The technology is designed for utilizing both liquefied and gaseous by-products (torgas, pyrolysis gas and condensate denoted as TPC) obtained from torrefaction and pyrolysis of waste biomass. TPC is considered to be applied as an additional fuel for a metallurgical furnace as an example of effective energy management in metallurgical industry. In detail, the technology contains waste heat recovery unit installed on the furnace smoke stack as the heat source for the pyrolysis/torrefaction reactor. The analysis was carried out for a pusher furnace, fed optionally with either natural gas or coke gas. Share of this gaseous/liquid TPC fuel from waste in the total fuel mixture fed to the furnace was varied from 5 to 15% by volume. Practical usefulness of TPC fuel was tested on a specially constructed test stand. Financial analysis in energy consumption and economy of using the obtained TPC fuel for co-combustion with coke gas in the metallurgical pusher furnace was carried out on the basis of data from a steel sheet roller combined with the pusher furnace located in one of large steel works. It was shown that the use of this TPC fuel derived from thermal treatment of waste biomass and other organic substances can be considered an effective method of reducing production costs in the analyzed steel company and can lead to increase in the attractiveness of their products and thus strengthen their competitiveness on the global market. Graphic abstract