Thermal distributive blast furnace gas characterisation, a steelworks case study

Blast furnace gas (BFG) is a dynamic by-product gas produced in large quantities with a composition comprising typically 18–23% CO, 1–5% H2 and balance of N2 and CO2. Industrial operations lead to fluctuations in gas characteristics over short time periods. This can dissuade engineers from using the gas in increasingly complex technologies with perceived efficiency improvements such as gas turbines, a trait exacerbated by the ‘dirty’ nature synonymous with industrial process gases. This body of work used the Tata Port Talbot integrated steelworks as a case study to analyse variation in gaseous composition, as a foundation for evaluation of the combustion dynamics associated with BFG. Varying levels of compositional fluctuation were observed, with H2 providing the most significant contributing factor to fuel characteristic. Particulate contamination was also studied as the gas cools and is distributed around the works, utilising condensate analyses at multiple distances from source. Particulate loading analyses yielded values of 0.04–0.1 mg Nm−3 at a distance of over 1.5 km from source, with results implying BFG is thermally scrubbed of contaminant matter through a mechanism of gas cooling and the amalgamation of condensate. The work performed therefore suggests the location of any installed equipment offers a significant contributory factor to performance.