The processes of iron and steel making are energy intensive and consume large quantities of electricity and fossil fuels. In order to meet future climate targets and energy prices, the iron and steel industry has to improve its energy and resource efficiency. For the iron and steel industry to utilize its energy resources more efficiently and at the same time reduce its CO2 emissions a number of options are available. In this paper, opportunities for both integrated and scrap-based steel plants are presented and some of the options are electricity production, fuel conversion, methane reforming of coke oven gas and partnership in industrial symbiosis. The options are evaluated from a system perspective and more specific measures are reported for two Swedish case companies: SSAB Strip Products and Sandvik AB. The survey shows that both case companies have great potentials to reduce their CO2 emissions.

Industrial excess heat is a large untapped resource, for which there is potential for external use, which would create benefits for industry and society. Use of excess heat can provide a way to reduce the use of primary energy and to contribute to global CO2 mitigation. The aim of this paper is to present different measures for the recovery and utilization of industrial excess heat and to investigate how the development of the future energy market can affect which heat utilization measure would contribute the most to global CO2 emissions mitigation. Excess heat recovery is put into a context by applying some of the excess heat recovery measures to the untapped excess heat potential in Gavleborg County in Sweden. Two different cases for excess heat recovery are studied: heat delivery to a district heating system and heat-driven electricity generation. To investigate the impact of excess heat recovery on global CO2 emissions, six consistent future energy market scenarios were used. Approximately 0.8 TWh/year of industrial excess heat in Gavleborg County is not used today. The results show that with the proposed recovery measures approximately 91 GWh/year of district heating, or 25 GWh/year of electricity, could be supplied from this heat. Electricity generation would result in reduced global CO2 emissions in all of the analyzed scenarios, while heat delivery to a DH system based on combined heat and power production from biomass would result in increased global CO2 emissions when the CO2 emission charge is low. 

Awareness of climate change and the threat of rising energy prices have resulted in increased attention being paid to energy issues and industry seeing a cost benefit in using more energy-efficient production processes. One energy-efficient measure is the recovery of industrial excess heat. However, this option has not been fully investigated and some of the technologies for recovery of excess heat are not yet commercially available. This paper proposes three technologies for the generation of electricity from low-temperature industrial excess heat. The technologies are thermoelectric generation, organic Rankine cycle and phase change material engine system. The technologies are evaluated in relation to each other, with regard to temperature range of the heat source, conversion efficiency, capacity and economy. Because the technologies use heat of different temperature ranges, there is potential for concurrent implementation of two or more of these technologies. Even if the conversion efficiency of a technology is low, it could be worthwhile to utilise if there is no other use for the excess heat. The iron and steel industry is energy intensive and its production processes are often conducted at high temperatures. As a consequence, large amounts of excess heat are generated. The potential electricity production from low-temperature excess heat at a steel plant was calculated together with the corresponding reduction in global CO2 emissions.

Today, climate change is at the top of the political agenda. The European Commission has set atarget to reduce greenhouse gas emissions by 20 % by 2020, compared to 1990 levels. The steelindustry contributes significantly to industrial CO2 emissions, and thus it is important for thissector to find options to reduce its CO2 emissions. One alternative is to substitute fossil fuelswith biomass derived fuels; a promising option is to replace LPG (Liquefied Petroleum Gas) used asfuel in heating furnaces with bio-syngas produced through the gasification of biomass. This paperis a feasibility study of the implementation of this concept at a Swedish scrap-based steel plant.The results have been obtained through a case study approach with interviews and literaturesurveys. The study shows that if a fuel gas mixture of 50 vol% bio-syngas and 50 vol% LPG would beused, the global CO2 emissions would be reduced by 5,400 tonnes/year. Moreover, a full-scale fuelsubstitution would result in reduced emissions by 68,600 tonnes/year. In the case of a partial fuelsubstitution, a 4 MWth High Temperature Agent Gasifier (HTAG) is a suitable choice while a 45 MWthindirectly heated Circulating Fluidised Bed Gasifier (CFBG) would be suitable for a full-scale fuelsubstitution. In the case of a fuel switch, the lower heating value of syngas, compared to LPG, notonly implies that a different combustion technology must be used, but also that the exhaust gasflows will be substantially larger, and consequently the exhaust gas cleaning system must bedesigned with dimensions suitable for larger flows. Excess heat from the gasifier can be used forspace heating, but if the excess heat replaces district heating from a Combined Heat and Power(CHP) plant, the global CO2 emissionsreductions would be less than if the excess heat is not recovered.

Climate change is of great concern for society today. Manufacturing industries and construction account for approximately 20% of global CO2 emissions and, consequently, it is important that this sector investigate options to reduce its CO2 emissions. One option could be to substitute fossil fuels with renewable alternatives. This paper describes a case study in which four future energy market scenarios predicting 2030 were used to analyse whether it would be profitable for a steel plant to produce bio-SNG (bio-synthetic natural gas) in a biomass gasifier and to substitute LPG (liquefied petroleum gas) with bio-SNG as fuel in reheating furnaces. The effects on global CO2 emissions were analysed from a perspective in which biomass is considered a limited resource. The results from the analysis show that investment in a biomass gasifier and fuel conversion would not be profitable in any of the scenarios. Depending on the scenario, the production cost for bio-SNG ranged between 22 and 36 EUR/GJ. Fuel substitution would reduce global CO2 emission if the marginal biomass user is a producer of transportation fuel. However, if the marginal user of biomass is a coal power plant with wood co-firing, the result would be increased global CO2 emissions.

The iron and steel industry is an energy-intensive industry that consumes a significant portion of fossil fuel and electricity production. Climate change, the threat of an unsecure energy supply and rising energy prices have emphasised the issue of improved energy efficiency in the iron and steel industry. However, an energy-efficiency gap is well recognised, i.e. cost-efficient measures are not implemented in practice. This study will go deeper into why this gap occurs by investigating energy-management practices at 11 iron and steel companies in Sweden. Energy managers at the steel plants were interviewed about how they perceived their own and their companies’ efforts to improve energy efficiency and how networking among energy managers influenced the efforts to improve energy efficiency. Reported barriers to improved energy efficiency were, for example, too long payback period, lack of profitability, lack of personnel, risk of production disruption, lack of time and lack of commitment. Only three out of the eleven companies had assigned a person to work full time with energy management, and some of the energy managers were frustrated with not having enough time to work with energy issues. Generally, the respondents felt that they had support from senior management and that energy issues were prioritised, but only a few of the companies had made great efforts to involve employees in improving energy efficiency. Networking among Swedish steel companies was administered by the Swedish Steel Producers’ Association, and their networking meetings contributed to the exchange of knowledge and ideas. In conclusion, Swedish steel companies regard improved energy efficiency as important but have much work left to do in this area. For example, vast amounts of excess heat are not being recovered and more efforts could be put into engaging employees and introducing a culture of energy efficiency.