Electric Arc Furnace

Contents

Overview | Asset Structure | Flow Equations | Input File (Standard Format) | Types - Asset Structure | Constructors | Examples

Overview

In Macro, Electric Arc Furnace (EAF) refers to standalone steelmaking facilities where steel scrap is melted and refined into crude steel using electric arc furnaces. These assets are specified via input files in JSON or CSV format, located in the assets directory, and are typically named with descriptive identifiers such as standalone_scrap_electric_arc_furnace.json or standalone_scrap_electric_arc_furnace.csv.

Asset Structure

An EAF plant is made of the following components:

• 1 Transformation component, representing the EAF.
• 6 Edge components:
  • 1 incoming SteelScrap Edge, representing the steel scrap supply.
  • 1 incoming Electricity Edge, representing the electricity supply.
  • 1 incoming NaturalGas Edge, representing the natural gas supply.(used in natural gas burners that pre-heat scrap and reduce electricity consumption)
  • 1 incoming CarbonSource Edge, representing the carbon source supply. (minimal amount added to adjust the carbon content of the steel, reduce iron oxide losses, and add chemical energy. The carbon source can be metallurgical coal, charcoal, etc.).
  • 1 outgoing CrudeSteel Edge, representing crude steel production.
  • 1 outgoing CO2 Edge, representing CO2 emitted into the atmosphere.

Here is a graphical representation of a scrap-fed EAF asset:

Flow Equations

The ElectricArcFurnace asset follows these stoichiometric relationships:

\[\begin{aligned} \phi_{steelscrap} &= \phi_{crudesteel} \cdot \epsilon_{steelscrap\_consumption} \\ \phi_{elec} &= \phi_{crudesteel} \cdot \epsilon_{elec\_consumption} \\ \phi_{elec} &= \phi_{crudesteel} \cdot \epsilon_{natgas\_consumption} \\ \phi_{elec} &= \phi_{crudesteel} \cdot \epsilon_{carbonsource\_consumption} \\ \phi_{co2} &= \phi_{crudesteel} \cdot \epsilon_{emission\_rate} \\ \end{aligned}\]

Where:

• $\phi$ represents the flow of each commodity.
• $\epsilon$ represents the stoichiometric coefficients defined in the Conversion Process Parameters section.

Input File (Standard Format)

The easiest way to include a standalone scrap-EAF asset in a model is to create a new file (either JSON or CSV) and place it in the assets directory together with the other assets.

your_case/
├── assets/
│   ├── sstandalone_scrap_electric_arc_furnace.json    # or standalone_scrap_electric_arc_furnace.csv
│   ├── other_assets.json
│   └── ...
├── system/
├── settings/
└── ...

This file can either be created manually or using the template_asset function, as shown in the Adding an Asset to a System section of the User Guide. The file will be automatically loaded when you run your Macro model. An example of an input JSON file is shown in the Examples section.

The following tables outline the attributes that can be set for an Electric Arc Furnace asset.

Transform Attributes

Essential Attributes

Conversion Process Parameters

General Attributes

Investment Parameters

Economic Parameters

Constraints Configuration

ElectricArcFurnace assets can have different constraints applied to them, and the user can configure them using the following fields:

For example, if the user wants to apply the BalanceConstraint to the transformation component and the MaxCapacityConstraint to the output edge, the constraints fields should be set as follows:

{
    "transform_constraints": {
        "BalanceConstraint": true
    },
    "edges":{
        "crudesteel_edge": {
            "constraints": {
                "MaxCapacityConstraint": true
            }
        }
}

Users can refer to the Adding Asset Constraints to a System section of the User Guide for a list of all the constraints that can be applied to the different components of an ElectricArcFurnace asset.

Default constraints

To simplify the input file and the asset configuration, the following constraints are applied to the ElectricArcFurnace asset by default:

• Balance constraint (applied to the transformation component)
• Capacity constraint (applied to the output crude steel edge)

Types - Asset Structure

The ElectricArcFurnace asset is defined as follows:

struct ElectricArcFurnace{T <: Commodity} <: AbstractAsset
    id::AssetId
    eaf_transform::Transformation
    crudesteel_edge::Edge{CrudeSteel}
    elec_edge::Edge{Electricity}
    steelscrap_edge::Edge{SteelScrap} 
    naturalgas_edge::Edge{NaturalGas}
    carbonsource_edge::Edge{T}
    co2_edge::Edge{CO2}
end

Here, T denotes the carbon source, which may be metallurgical coal, charcoal, etc.

Constructors

Factory constructor

make(asset_type::Type{ElectricArcFurnace}, data::AbstractDict{Symbol,Any}, system::System)

Stochiometry balance data

eaf_transform.balance_data = Dict(
    :electricity_consumption => Dict(
        crudesteel_edge.id => get(transform_data, :electricity_consumption, 0.0),
        elec_edge.id => 1.0,
    ),
    :steelscrap_consumption => Dict(
        crudesteel_edge.id => get(transform_data, :steelscrap_consumption, 0.0),
        steelscrap_edge.id => 1.0
    ),
    :naturalgas_consumption => Dict(
        crudesteel_edge.id => get(transform_data, :naturalgas_consumption, 0.0),
        naturalgas_edge.id => 1.0,
    ),
    :carbonsource_consumption => Dict(
        crudesteel_edge.id => get(transform_data, :carbonsource_consumption, 0.0),
        carbonsource_edge.id => 1.0,
    ),
    :emissions => Dict(
        crudesteel_edge.id => get(transform_data, :emission_rate, 0.0),
        co2_edge.id => -1.0,
    ) 
)

Examples

This example illustrates a basic standalone electric arc furnace configuration in JSON format, featuring standard parameters in a three-zone case. In the example below, the carbon source is assumed to be metallurgical coal.

{
    "StandaloneScrapElectricArcFurnace": [
        {
            "type": "ElectricArcFurnace",
            "global_data":{
                "transforms": {
                    "timedata": "Electricity",
                    "constraints": {
                            "BalanceConstraint": true
                    }
                },
                "edges":{
                    "crudesteel_edge":{
                        "type": "CrudeSteel",
                        "unidirectional": true,
                        "has_capacity": true,
                        "can_expand": true,
                        "can_retire": true,
                        "integer_decisions": false,
                        "constraints": {
                            "CapacityConstraint": true
                        }
                    },
                    "steelscrap_edge":{
                        "commodity": "SteelScrap",
                        "unidirectional": true,
                        "has_capacity": false
                    },
                    "elec_edge":{
                        "commodity": "Electricity",
                        "unidirectional": true,
                        "has_capacity": false
                    },
                    "naturalgas_edge": {
                        "commodity": "NaturalGas",
                        "unidirectional": true,
                        "has_capacity": false
                    },
                    "carbonsource_edge": {
                        "commodity": "MetCoal",
                        "unidirectional": true,
                        "has_capacity": false
                    },
                    "co2_edge": {
                        "commodity": "CO2",
                        "unidirectional": true,
                        "has_capacity": false,
                        "end_vertex": "co2_sink"
                    }
                }
            },
            "instance_data":[
                {
                    "id": "SE_scrap_eaf",
                    "transforms": {
                        "steelscrap_consumption": 1.14,
                        "electricity_consumption": 0.63,
                        "naturalgas_consumption": 0.41,
                        "carbonsource_consumption": 0.02,
                        "emission_rate": 0.16
                    },
                    "edges": {
                        "crudesteel_edge": {
                            "end_vertex": "crudesteel_SE",
                            "existing_capacity": 0.0,
                            "investment_cost": 2097144,
                            "fixed_om_cost": 41943,
                            "variable_om_cost": 72
                        },
                        "steelscrap_edge": {
                            "start_vertex": "steelscrap_source"
                        },
                        "elec_edge": {
                            "start_vertex": "elec_SE"
                        },
                        "naturalgas_edge": {
                            "start_vertex": "natgas_SE"
                        },
                        "carbonsource_edge": {
                            "start_vertex": "metcoal_source"
                        }
                    }
                },
                {
                    "id": "MIDAT_scrap_eaf",
                    "transforms": {
                        "steelscrap_consumption": 1.14,
                        "electricity_consumption": 0.63,
                        "naturalgas_consumption": 0.41,
                        "carbonsource_consumption": 0.02,
                        "emission_rate": 0.16   
                    },
                    "edges": {
                        "crudesteel_edge": {
                            "end_vertex": "crudesteel_MIDAT",
                            "existing_capacity": 0.0,
                            "investment_cost": 2097144,
                            "fixed_om_cost": 41943,
                            "variable_om_cost": 72
                        },
                        "steelscrap_edge": {
                            "start_vertex": "steelscrap_source"
                        },
                        "elec_edge": {
                            "start_vertex": "elec_MIDAT"
                        },
                        "naturalgas_edge": {
                            "start_vertex": "natgas_MIDAT"
                        },
                        "carbonsource_edge": {
                            "start_vertex": "metcoal_source"
                        }
                    }
                },
                {
                    "id": "NE_scrap_eaf",
                    "transforms": {
                        "steelscrap_consumption": 1.14,
                        "electricity_consumption": 0.63,
                        "naturalgas_consumption": 0.41,
                        "carbonsource_consumption": 0.02,
                        "emission_rate": 0.16
                    },
                    "edges": {
                        "crudesteel_edge": {
                            "end_vertex": "crudesteel_NE",
                            "existing_capacity": 0.0,
                            "investment_cost": 2097144,
                            "fixed_om_cost": 41943,
                            "variable_om_cost": 72
                        },
                        "steelscrap_edge": {
                            "start_vertex": "steelscrap_source"
                        },
                        "elec_edge": {
                            "start_vertex": "elec_NE"
                        },
                        "naturalgas_edge": {
                            "start_vertex": "natgas_NE"
                        },
                        "carbonsource_edge": {
                            "start_vertex": "metcoal_source"
                        }
                    }
                }
            ]
        }
    ]
}

See Also

• Edges - Components that connect Vertices and carry flows
• Transformations - Processes that transform flows of several Commodities
• Nodes - Network nodes that allow for import and export of commodities
• Vertices - Network nodes that edges connect
• Assets - Higher-level components made from edges, nodes, storage, and transformations
• Commodities - Types of resources stored by Commodities
• Time Data - Temporal modeling framework
• Constraints - Additional constraints for Storage and other components