Aluminum Refining

Contents

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

Overview

In Macro, the Aluminum Refining asset represents a facility that transforms electricity and aluminum scrap into refined aluminum. This process is less energy-intensive than primary aluminum smelting, consuming approximately 2.0 MWh per tonne of aluminum (compared to 13.3 MWh per tonne for smelting). The process uses aluminum scrap as a feedstock and produces refined aluminum with no direct CO₂ emissions.

These assets are defined using either JSON or CSV input files placed in the assets directory, typically named with descriptive identifiers like aluminum_refining.json or aluminum_refining.csv.

Asset Structure

An Aluminum Refining plant is made of the following components:

• 1 Transformation component, representing the aluminum refining process.
• 3 Edge components:
  • 1 incoming Electricity Edge, representing electricity consumption (approximately 2.0 MWh per tonne of aluminum).
  • 1 incoming AluminumScrap Edge, representing aluminum scrap supply (approximately 1.05 tonnes per tonne of aluminum, including 5% loss).
  • 1 outgoing Aluminum Edge, representing refined aluminum production.

Here is a graphical representation of the Aluminum Refining asset:

Flow Equations

The Aluminum Refining asset follows these stoichiometric relationships:

\[\begin{aligned} \phi_{elec} &= \phi_{aluminum} \cdot \epsilon_{elec\_aluminum\_rate} \\ \phi_{aluminumscrap} &= \phi_{aluminum} \cdot \epsilon_{aluminumscrap\_aluminum\_rate} \\ \end{aligned}\]

Where:

• $\phi$ represents the flow of each commodity
• $\epsilon$ represents the stoichiometric coefficients defined in the Conversion Process Parameters section.
• Note: Aluminum and AluminumScrap flows are in tonnes, while Electricity is in MWh.

Input File (Standard Format)

The easiest way to include an Aluminum Refining 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/
│   ├── aluminum_refining.json    # or aluminum_refining.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 Aluminum Refining asset.

Transform Attributes

Essential Attributes

Conversion Process Parameters

General Attributes

Investment Parameters

Economic Parameters

Constraints Configuration

Aluminum Refining 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 CapacityConstraint to the output edge, the constraints fields should be set as follows:

{
    "transform_constraints": {
        "BalanceConstraint": true
    },
    "edges":{
        "aluminum_edge": {
            "constraints": {
                "CapacityConstraint": 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 Aluminum Refining asset.

Default constraints

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

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

Types - Asset Structure

The Aluminum Refining asset is defined as follows:

struct AluminumRefining <: AbstractAsset
    id::AssetId
    aluminum_transform::Transformation
    elec_edge::Edge{<:Electricity}
    aluminumscrap_edge::Edge{<:AluminumScrap}
    aluminum_edge::Edge{<:Aluminum}
end

Constructors

Factory constructor

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

Stoichiometry balance data

aluminumrefining_transform.balance_data = Dict(
    :elec_to_aluminum => Dict(
        elec_edge.id => 1.0,
        aluminumscrap_edge.id => 0.0,
        aluminum_edge.id => get(transform_data, :elec_aluminum_rate, 0.0)
        ),
        :aluminumscrap_to_aluminum => Dict(
            elec_edge.id => 0.0,
            aluminumscrap_edge.id => 1.0,
            aluminum_edge.id => get(transform_data, :aluminumscrap_aluminum_rate, 0.0)
    )
)

Examples

This example illustrates a basic Aluminum Refining configuration in JSON format:

{
    "AluminumRefining": [
        {
            "type": "AluminumRefining",
            "global_data":{
                "nodes": {},
                "transforms": {
                    "timedata": "Aluminum"
                },
                "edges":{
                    "aluminum_edge": {
                        "commodity": "Aluminum",
                        "unidirectional": true,
                        "has_capacity": true,
                        "can_retire": true,
                        "can_expand": true,
                        "integer_decisions": false
                    },
                    "elec_edge": {
                        "commodity": "Electricity",
                        "unidirectional": true,
                        "has_capacity": false
                    },
                    "aluminumscrap_edge": {
                        "commodity": "AluminumScrap",
                        "unidirectional": true,
                        "has_capacity": false
                    }
                }
            },
            "instance_data":[
                {
                    "id": "aluminum_refining_1",
                    "transforms":{
                        "elec_aluminum_rate": 2.0,
                        "aluminumscrap_aluminum_rate": 1.05
                    },
                    "edges":{
                        "aluminum_edge": {
                            "end_vertex": "aluminum_node_1",
                            "existing_capacity": 0.0,
                            "investment_cost": 2400000,
                            "fixed_om_cost": 420000,
                            "variable_om_cost": 123
                        },
                        "elec_edge": {
                            "start_vertex": "elec_node_1"
                        },
                        "aluminumscrap_edge": {
                            "start_vertex": "aluminumscrap_node_1"
                        }
                    }
                }
            ]
        }
    ]
}

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
• Aluminum Smelting - Primary energy-intensive aluminum production process
• Alumina Plant - Alumina production from bauxite