Economic and environmental analyses of biomass torrefaction for injection as pulverized material in blast furnaces

Abstract

Biomass was the first material used as a fuel by humanity, being replaced by fossil fuels after the industrial revolution. With the growing of environment discursions and the effects of CO 2 emissions, biomass has been gaining strength as a potential alternative to fossil fuels, especially for steelmaking, which is responsible for about 5 to 10% of all CO 2 emitted. It is known that biomass, compared to fossil fossils, has a higher volatile content, high moisture and lower calorific value. On the other hand, it has a higher hydrogen content and lower sulfur content (important for the steel industry), in addition it is considered neutral in CO 2 emissions. Torrefaction, heating biomass at a temperature between 200-280°C in an oxygen free atmosphere, is an interesting treatment to adapt biomasses for use in the steelmaking processes, mainly in the pulverized material injection into the blast furnace. PCI is an extremely important process for the production of iron in the blast furnace, due to its ability to reduce coke consumption and optimize the operation of the reactor. This article comes with the purpose of presenting a bibliographic review about PCI technique, torrefaction process, biomasses and its applicability in the steel industry. In addition, an economic and environmental analysis of the possible use of biomass in steelmaking processes will be presented. Results shows that the use of torrefied biomass in the injection process is interesting, generating savings of 10 dollars and reduction of 264kg in CO 2 emissions per ton of hot metal, with a replacement of 50% of the coal used by biomass.

Methods and Validation Techniques of Chemical Kinetics Models in Waste Thermal Conversion Processes

“…Efforts are being made worldwide to promote the energy use of waste through combustion [1], gasification [2], pyrolysis [3] and torrefaction [4] as a strategy that fits, among others, into the idea of a circular economy [5,6]. These activities focus on finding sustainable alternatives for the effective use of waste, which loses the status of "rubbish" and becomes a valuable raw material for other processes [1].…”