Life Cycle Assessment Notes

Scope Emissions

• Scope One Emissions:
  • Emissions from inside the company.
  • Directly part of the company's operation, production, etc.
• Scope Two Emissions:
  • Greenhouse gas emissions related to electricity consumed.
  • Indirectly related issues.
• Scope Three Emissions:

Global Carbon Budget

• The global carbon budget is a certain amount.
• Current anthropogenic emissions are using up that budget.
• Time is running out to maintain a 66% chance of staying within a 1.5 degrees Celsius temperature increase.
• Atmospheric scientists compare $CO_2$ concentrations to country reports and find moderate agreement.

Carbon Accounting

• Developed countries require major emitters to report emissions.
• Carbon accounting is a potential job area.

Life Cycle Assessment (LCA)

• A method to help companies make decisions related to environmental impacts.
• Companies need to make decisions about technology to reduce greenhouse gas emissions.

Components of Commercial LCA Packages

• Database:
  • Contains environmental impacts of materials and processes.
  • Mainly greenhouse gas emissions and other relevant impacts.
  • Commercial databases (some free, most require payment).
• Interface:
  • Allows setting up the problem (e.g., a factory).
  • Input raw material usage, electricity sources, diesel vehicles, etc.
• Packages can be bought complete or components can be chosen separately.
• Some databases are particularly good for certain industries

Examples of LCA Software

• OpenLCA: Free, but may lack support.
• SimaPro:
  • Approximately $15,000.
  • Single-user license available.
  • QUT has this capability.
  • Can be bundled with databases.
• Sphera: Can be combined with their in-house database.
• Brightway2: It is a free Python library.
• GaBi: Can interact with Excel and has a large database (82,000,000 data points).
• Ecoinvent: Commercial single-user license costs approximately 4,000 British pounds
• QUT has multi-user licenses for some LCA software.
• LCA should be context-specific (e.g., celery in Australia vs. Vietnam).
• Certification from an independent organization is needed for claims of low emissions.
• Overview is meant to supplement the lecture on LCA.

Non-Assessable Quiz Review

• A quiz was given to test knowledge of LCA.

Key Points from Quiz Review:

• Primary Purpose of LCA: Assess environmental impacts associated with a product or service.
• Not Typically Included in LCA: Marketing strategies.
• Goal of Life Cycle Inventory Phase: Quantify energy and raw material inputs and environmental releases.
• Benefit of Conducting LCA: Identifying opportunities for product improvement.
• Cradle to Grave Approach: Encompasses the entire life cycle.
• Common Environmental Impact Category: Water consumption.
• Purpose of Sensitivity Analysis: Identify key parameters or "hotspots" with significant environmental impact.
• Need for Engineering Background: Understanding the industry context is crucial; specialized knowledge may be needed for specific industries (e.g., aluminum).
• Limitation of LCA: Can be time-consuming and resource-intensive.
• ISO Standard for LCA: ISO 14040 series.
• Interested Stakeholder Group: Government regulators (though environmental advocacy groups and individual companies also have interest).

Simplified LCA Example: Product P in Country C

• Industry B produces one tonne of product P per year.
• Goal: Determine environmental impacts in terms of "eco points."

Stages and Inputs

• Stage 1: Details about the life cycle of P and required inputs.
• Stage 2: Additional inputs and emissions.

Impact Assessment

• Emission factors provided for X, Y, and Z (global warming and acid rain impacts).
• Country C gives three times more importance to acid rain than greenhouse gas emissions.

Identifying Environmental Hotspots

• Process flow diagram outlines stages and material flows.
• Calculations involve inputs, gases, and $CO_2$ equivalents.
• Normalization and weighting used to calculate total eco points.
• Sensitivity analysis identifies hotspots by focusing on inputs with the largest impact.

Sustainable Approaches to Energy Supply

• Review of efficiency, energy, and power concepts.

Key Definitions:

• Efficiency: Work out / Work in
• Energy: Capacity for doing work (Joules)
• Power: Energy per unit time (Watts)

Common LCA Calculations (Power Stations)

• Calculations are relevant to LCA databases.
• Example problem: Calculating $CO<em>2$ produced per year and $CO</em>2$ emission factor for a power station.

Example Problem:

• Power station operates by transferring heat to the boiler from coal combustion.
• Calorific value of coal: 30 MJ/kg.
• Emission: 2.5 kg $CO_2$/kg coal.
• Overall efficiency: 40%.
• Plant output: 337 MW per year.

Solution Outline:

• Definition of efficiency: electricity generated/calorific or energy content of the coal
  $\text{Efficiency} = \frac{\text{Electricity Generated}}{\text{Calorific Content of Coal}}$
• Calculate coal energy per second (842 MJ/s).
• Calculate coal required to produce the heat required (28 kg/s).
• Calculate $CO_2$ production (70 kg/s or 2.2 x $10^9$ kg/year).
• Calculate emission factor (0.75 kg $CO_2$/kWh).

CO2 Emission Factor

• Kilograms of $CO_2$ per kilowatt hour (kg CO2/kWh)

National Greenhouse Accounting Factors (2020 Data)

• Typical value: 0.78 kg $CO_2$ equivalent/kWh (varies by state).
• Variations due to different types of coal and electricity generation methods.

Example: Australian Coal

• Queensland has good quality coal.

LCA: Factors to be Considered

• This also comes in to play when considering whether a company is using renewable sources. If they are the emission factor will be lower.

Is LCA a comparison tool?

• It is a decision making tool but countries can review each other's processes and emission factors.