Improving sustainability of energy intensive sectors through multi-objective models

openGlobal energy consumption and the related carbon dioxide emissions, which represent a large share of the overall anthropogenic greenhouse gas production, are continuously increasing since most of the energy needs are still provided by fossil fuels, thus constituting one of the main issues to be addressed in the climate change mitigation agenda. To achieve the Paris Agreement’s ambitious objectives, an energy transition towards sustainable energy systems based on the new smart energy system (SES) paradigm is needed, thus integrating the various energy sources, vectors and needs within the sectors (electricity, heating, cooling, transport, etc.). However, optimal planning, design and management of complex integrated systems such as SES require to make use of proper decision support models based on multi-objective optimization techniques, since a sustainability analysis intrinsically involves environmental, economic and social aspects. Furthermore, a SES project involves several stakeholders, each driven by different and often conflicting objectives, which should be considered within such models, to remove some relevant barriers to the energy transition. Focusing on the improvement of the sustainability of the energy-intensive sectors, the main objective of this thesis is thus the development of a decision support framework based on multi-objective optimization with the aim to support the decision makers in the planning, design and management of integrated smart energy systems, while considering the different involved stakeholders. The proposed model, composed by three main phases (namely investigative, design and decision-making), has been developed by steps via its application on case studies belonging to two main topics concerning the improvement of the sustainability performance of energy-intensive sectors through the implementation of the smart energy system concept. The first main topic is representative of the context of industrial districts and concerns their sustainable energy supply based on technical solutions specifically designed for cluster of firms, allowed by geographical proximity. The other one concerns the synergic integration between industrial and urban areas, through the recovery of waste energy from industrial processes to feed municipal district heating with a carbon-free source. The case studies have been selected, within the opportunities available in the local territorial context, not only because fit for the implementation of the smart energy system concept, but also due to their suitability for the implementation of different phases of the proposed decision support system (DSS).Dottorato di ricerca in Scienze dell'ingegneria energetica e ambientaleopenCiotti, Gelli

Prospective Scenarios on Energy Efficiency and CO2 Emissions in the EU Iron & Steel Industry

This document analyzes on the basis of a detailed bottom-up model the role of technology and its diffusion on energy consumption and CO2 emissions at plant level in the EU-27 Iron & Steel industry. Main current processes of all plants and the cost-effectiveness of their retrofit with Best Available Technologies and Innovative Technologies is analyzed up to 2030. The baseline scenario considers the demand for steel and prices of fuels and resources evolve according to the projection of Primes. Two alternative scenarios vary linearly several times by 2030 some of the main drives of technology change, such us the cost of CO2 allowances, fuels and price of the resources. The reduction ranges for the specific CO2 emissions varies between 14% and 21%. The range for the variation in specific energy consumption goes from 7 to 11%. The higher values rely on the successful market roll-out by 2020 of some key innovative technologies, underlining the importance of the successful conclusion of the research ongoing in those technologies. In the recycling route the results indicate potential improvements between 2010 and 2030 in the specific energy consumption and specific CO2 emissions of about 6% and 11%, respectively.JRC.F.6-Energy systems evaluatio

Material and energy flows of the iron and steel industry: status quo, challenges and perspectives

Integrated analysis and optimization of material and energy flows in the iron and steel industry have drawn considerable interest from steelmakers, energy engineers, policymakers, financial firms, and academic researchers. Numerous publications in this area have identified their great potential to bring significant benefits and innovation. Although much technical work has been done to analyze and optimize material and energy flows, there is a lack of overview of material and energy flows of the iron and steel industry. To fill this gap, this work first provides an overview of different steel production routes. Next, the modelling, scheduling and interrelation regarding material and energy flows in the iron and steel industry are presented by thoroughly reviewing the existing literature. This study selects eighty publications on the material and energy flows of steelworks, from which a map of the potential of integrating material and energy flows for iron and steel sites is constructed. The paper discusses the challenges to be overcome and the future directions of material and energy flow research in the iron and steel industry, including the fundamental understandings of flow mechanisms, the dynamic material and energy flow scheduling and optimization, the synergy between material and energy flows, flexible production processes and flexible energy systems, smart steel manufacturing and smart energy systems, and revolutionary steelmaking routes and technologies

Radiant waste heat recovery from steelmaking and glass industry

This paper tackles the problem of industrial waste heat recovery through an unexploited heat transfer mechanism: thermal radiation. Energy intensive industries have a considerable potential of unused radiant heat, which cannot be recovered through existing methods. That potential energy is quantified for the main identified industries: steel and glassmaking. Then, a radiant heat capturing device allowing high temperature heat capture is designed according to process requirements. Finally, recoverable heat is estimated and potential uses are proposed

A review on CO2 mitigation in the Iron and Steel industry through Power to X processes

In this paper we present the first systematic review of Power to X processes applied to the iron and steel industry. These processes convert renewable electricity into valuable chemicals through an electrolysis stage that produces the final product or a necessary intermediate. We have classified them in five categories (Power to Iron, Power to Hydrogen, Power to Syngas, Power to Methane and Power to Methanol) to compare the results of the different studies published so far, gathering specific energy consumption, electrolysis power capacity, CO2 emissions, and technology readiness level. We also present, for the first time, novel concepts that integrate oxy-fuel ironmaking and Power to Gas. Lastly, we round the review off with a summary of the most important research projects on the topic, including relevant data on the largest pilot facilities (2–6 MW)

Techno-economic optimisation of steel supply chains in the clean energy transition: a case study of post-war Ukraine

The steel industry's clean energy transition can enable new market creation and economic growth stimulation. Yet, the most efficient and feasible pathway to decouple the sector from fossil fuels remains unclear, particularly within developing nations and unstable socio-political contexts. Here, a blueprint for reconfiguring plant locations and reallocating resources is developed through a Ukrainian case study under two scenarios, which capture potential post-war conditions. Framed by regrowth of Ukraine's export-oriented steel industry and prospective European Union accession, green iron and steel trade strategies are devised. A steel supply chain optimisation model underpins the techno-economic, spatially granular analysis of energy and material flows, which utilises the inputs from a separate cost-minimised renewable energy, green hydrogen, and green ammonia production model. Results show that optimal supply chain configurations rely on mixed emissions-free energy profiles, the emergence of new steelmaking sites nearby high-quality renewables, regional alliances for green iron and steel market creation, and multi-billion-dollar investment. Mature nuclear and hydro power critically reduce costs in the near-term, whilst the rapid expansion of solar and wind energy infrastructure underpins production system scale-up. To simultaneously rebuild the 22 million-tonnes-a-year Ukrainian steel industry and transition to near-zero emissions by 2050, infrastructure investment surmounts to $62 billion, given full liberation of Ukrainian territory. Near-term investment is necessary to ease the pace of change, and although mobilising capital of this magnitude will be challenging, convincing carbon prices favour decarbonisation efforts

The new steel map: reconfiguring supply chains around renewable resources

Steel is an indispensable component of our physical environment and the most consumed metal on earth at 2 billion tonnes per annum. Continuance of this consumption and production pattern is incongruent with climate change mitigation; steel production is deeply dependent on fossil fuels with the sector emitting about one-tenth of energy-related global greenhouse gas emissions. Decarbonisation must commence immediately to reach near zero-emissions by 2050 and not exceed the allocated 30-year carbon budget aligned to a 1.5°C global warming trajectory. This presents a hefty challenge given the fundamental change in energy inputs required, consequent modification of metallurgical processes, and restructuring of the supporting supply chains. Yet, a significant opportunity lies in transitioning the industrial sector towards electrification with zero-carbon electricity inputs. In terms of physical pathways to near zero-emissions, the current literature body focuses on process level improvements, whilst supply chain assessments from raw materials to markets are largely absent. The energy paradigm shift introduces multiple novel supply chain elements worth exploring, including green hydrogen and iron trade, matching variable renewables with processes of varying flexibility, and opening of green markets under carbon policies. This literature gap is addressed in this thesis through mathematical modelling and geospatial analysis at multiple scales, spanning individual processes to the complete supply chain, and applied in local, regional, and global contexts. The systems-based, locational research agenda allows exploration and evaluation of novel configurations for renewables-based steel supply chains. The technological focus is on hydrogen-based direct reduction of iron followed by the electric arc furnace, which reduces emissions to near zero and is rapidly reaching commerciality. The most significant tangible contributions of this thesis are the facility-level and supply chain optimisation models, which can be applied in any locality or region of interest. However, only through the meaningful case study analyses did critical insights emerge, of particular interest: (i) it is economically and energetically rational to reconfigure steel supply chains around high-quality renewables and iron ore deposits; (ii) co-locating hydrogen and iron production, and dislocating iron and steel production through green iron trade, introduces a valuable trade paradigm that takes advantage of upstream renewables whilst maintaining downstream market strongholds, (iii) iron ore producers have an integral part to play in the green steel transition, and a significant opportunity exists for these nations to transition from predominantly extractive to manufacturing economies, (iv) regional trade alliances and carbon policies are critical to green steel transitions, and (v) sectorial decoupling from fossil fuels requires well-timed investments and low-carbon energy system integration. Resource reallocation in the steel industry calls for supply chain restructuring; carrying over of fossil-based legacies will be a lost opportunity

Effect of strengthened standards on Chinese ironmaking and steelmaking emissions

China has produced roughly half of the world’s steel in recent years, but the country’s iron and steel industry is a major source of air pollutants, especially particulate matter, SO2 and NOx emissions. To reduce such emissions, China imposed new emission standards in 2015 and promoted ultralow emission standards in 2019. Here we use measurements from China’s continuous emissions monitoring systems (covering 69–91% of national iron and steel production) to develop hourly, facility-level emissions estimates for China’s iron and steel industry. In turn, we use this data to evaluate the emission reductions related to China’s increasingly stringent policies. We find steady declines in emission concentrations at iron- and steelmaking plants since the 2015 standards were implemented. From 2014 to 2018, particulate matter and SO2 emissions fell by 47% and 42%, respectively, and NOx increased by 3%, even as the production increased by 14%. Moreover, we estimate that if all facilities achieve the ultralow emission standards, particulate matter, SO2 and NOx emissions will drop by a further 50%, 37% and 58%, respectively. Our results thus reveal the substantial benefits of the Chinese government’s interventions to curb emissions from iron and steel production and emphasize the promise of ongoing ultralow emission renovations

two innovative modelling approaches in order to forecast consumption of blast furnace gas by hot blast stoves

Abstract The online optimization of the use of process off gases in integrated steelworks can greatly contribute to increase the sustainability of the steel production. A correct management of these gases could allow both the reduction of natural resources exploitation (e.g. natural gas) and of the facility's environmental impact. However, in order to achieve an almost complete use of these gases, it is fundamental to forecast their production and consumption according to the production plan and to use such forecasting to optimize the gases distribution inside the network by considering possible interactions. According to these needs, this paper presents two models, which allow forecasting the consumption of blast furnace gas by some major consumers: the hot blast stoves. Due to the almost regular operation of these plants, two kinds of models can be applied: an Echo State Network-based model, which is more complex and sensitive to the variations of the operating practices and a simpler switch model, which does not require training and is very easy to use. Both models provide good results and the user can interchangeably exploit them