Deriving Economic Potential and GHG Emissions of Steel Mill Gas for Chemical Industry

Abstract

To combat global warming, industry needs to find ways to reduce its carbon footprint. One way this can be done is by re-use of industrial flue gasses to produce value-added chemicals. Prime example feedstocks for the chemical industry are the three flue gasses produced during conventional steel production: blast furnace gas (BFG), basic oxygen furnace gas (BOFG), and coke oven gas (COG), due to their relatively high CO, CO2, or H2 content, allowing the production of carbon-based chemicals such as methanol or polymers. It is essential to know for decision-makers if using steel mill gas as a feedstock is more economically favorable and offers a lower global warming impact than benchmark CO and H2. Also, crucial information is which of the three steel mill gasses is the most favorable and under what conditions. This study presents a method for the estimation of the economic value and global warming impact of steel mill gasses, depending on the amount of steel mill gas being utilized by the steel production plant for different purposes at a given time and the economic cost and greenhouse gas (GHG) emissions required to replace these usages. Furthermore, this paper investigates storage solutions for steel mill gas. Replacement cost per ton of CO is found to be less than the benchmark for both BFG (50–70 €/ton) and BOFG (100–130 €/ton), and replacement cost per ton of H2 (1800–2100 €/ton) is slightly less than the benchmark for COG. Of the three kinds of steel mill gas, blast furnace gas is found to be the most economically favorable while also requiring the least emissions to replace per ton of CO and CO2. The GHG emissions replacement required to use BFG (0.43–0.55 tons-CO2-eq./ton CO) is less than for conventional processes to produce CO and CO2, and therefore BFG, in particular, is a potentially desirable chemical feedstock. The method used by this model could also easily be used to determine the value of flue gasses from other industrial plants.

Comparative Lifecycle Assessment of Methanol and Urea Produced from Steel Mill Gases

“…The assessment of a product-specific footprint is possible if the environmental impact of SMG, which is the CCU feedstock, is determined. Several methodologies were proposed for its determination [37,38]. Therefore, further study should consider the evaluation of footprint of SMG, and its influence on the footprint of the produced chemical.…”

Upcycling the carbon emissions from the steel industry into chemicals using three metal oxide loops

“…Since the majority of the energy input for cryogenic distillation is required by pumps and compressors, the difference between the energy transfer duty (which includes the energy consumption from pumps and compressors) and heat duty is assumed to be the electrical energy (electrical energy E exergy) input to drive the separation. The exergy efficiency (Z exergy,distillation ) of the cryogenic distillation column is given by eqn (14), where the denominator indicates the minimum reversible work required to bring about the separation and the subscripts ''feed'' and ''products'' refer to the mole fraction of the ith component in the feed and product. 46 The minimum reversible work displayed in the denominator of eqn ( 14) is used for determining the energy required for separating H 2 O from the product mixture of rWGS, i.e., it is assumed that separation of H 2 O from the mixture has an exergy efficiency of 100%.…”

“…Among the gases produced in the steel industry, the blast furnace gas (BFG) is primarily targeted. 14 With approximately 5% H 2 , 24% CO, 24% CO 2 , and the rest inert (mostly N 2 ) on a molar basis, the BFG is the most abundant steel mill gas and also the most difficult to use for applications other than combined heat and power generation. 7,15 The combined use of CaO and Fe 3 O 4 has already been successfully demonstrated for CO 2 capture and conversion for super-dry reforming of methane, which combines catalytic dry reforming and reverse water-gas shift.…”

“…Among the gases produced in the steel industry, the blast furnace gas (BFG) is primarily targeted. 14 With approximately 5% H 2 , 24% CO, 24% CO 2 , and the rest inert (mostly N 2 ) on a molar basis, the BFG is the most abundant steel mill gas and also the most difficult to use for applications other than combined heat and power generation. 7,15…”

Preferential Oxidation of H2in CO-Rich Streams over a Ni/γ-Al2O3Catalyst: An Experimental and First-Principles Microkinetic Study

“…The selective removal of H 2 from CO-rich gas streams is another technically challenging and scientifically interesting application of PROX. This can be applied to blast furnace gas (BFG), an economically favorable CO/CO 2 -rich process gas from steel production, as a first step before its upgrading to high-value intermediates for the polymer industry. − The residual amounts of H 2 (1–8 vol %) in these streams entail a technical and safety challenge for the upgrading of CO and CO 2 to polyether-ester polyols and polyether-carbonate polyols, respectively. , Carbon-rich industrial flue gases provide an alternative feedstock that contributes to the concept of carbon circularity, encouraging industrial symbiosis practices. ,, The removal of H 2 can be done via physical separation or via a catalytic process. Physical separation, such as membrane or cryogenic separation, is expensive and energy-intensive, while the rWGS is thermodynamically limited, even at high temperatures.…”