Many companies now have strategic targets to reduce their impact on the climate, with the amount of carbon dioxide that the business emits as a common measurement. It is not always simple to measure this, as the emissions often occur a long way away from the core activities, and are difficult to estimate.
This text is for those of you who are curious about the impact that use of metalworking fluid has on the climate, and how to calculate it yourself.
Climate impact – common measurements
Before calculating how much impact something has, it is important to determine how you want to present the answers. There are many variants where the consumption of water or energy is one measurement and emissions of carbon dioxide or other greenhouse gases another.
In this calculation we will use so-called carbon dioxide equivalents that measure how much carbon dioxide is produced and released in the different parts of the metalworking fluid's life cycle. Carbon dioxide equivalents are a standard recommended by the UN's IPCC (International Panel on Climate Change).
Carbon dioxide emissions – over the entire life cycle
A metalworking fluid doesn't actally produce any emissions once it is in use and in its container. However, it has taken a number of steps for it to get there, and what will happen after it has been used? When working on climate analyses it is very important that the framework is well defined as on many occasions minor changes can produce far-reaching effects. One example is whether you decide to include consumption of packaging material, and if you do, whether you should include production of the barrel? The associated question becomes whether production of the metal that makes up the barrel should also be included? You see, it can quickly feel a very long way away from your own operation.
It is important to use the same delimitations for all calculations, otherwise it is not possible to compare them with each other.
The life-cycle stages that we have included in these kinds of calculations are:
- Emissions from production of raw materials (oil or polymers)
- Emissions from transportation to / from plants
- Emissions from destruction at the end of lifetime
The calculation – a simple method
Calculating carbon dioxide emissions is relatively simple, and often follows a standard formula:
The amount of a substance produced/destroyed * emission factor per amount of substance
An example:
An ordinary metalworking fluid system of 10,000 litres is changed twice a year. The fluid is an emulsion with 40% oil in the concentrate, which is mixed to 5% in water when used. The production site is located 15 km from the waste destruction plant.
The amount of oil that has to be produced for refill, 3 times/year (600 litres concentrate):
- 148 kg carbon dioxide from production of mineral oil
As the bulk of the oil production is powered by the crude oil or the natural gas that is produced at the same time, it is the carbon dioxide emissions from these fuels that we include.
Metalworking fluid that is destroyed (2x20,000 litres):
- 1,485,225 kg carbon dioxide from evaporation of the fluid
- 2,640 kg carbon dioxide from gasification of the mineral oil
The fact that the waste disposal plant is energy efficient and also powered by biofuel can significantly improve the impact on the environment, however evaporating large amounts of water is extremely energy-intensive, regardless of energy source.
Transport of metalworking fluid for destruction:
- 144 kg carbon dioxide from transportation to the waste disposal plant
Summary
- 1,488 tonnes carbon dioxide/year for an ordinary plant of 10,000 litres which has to be destroyed twice a year.
- In comparison, this corresponds to the same truck drive system's with 10,000 liters on board from Lulea to Gothenburg 1000 times. If instead the metalworking fluid was changed once a year, emissions would have been reduced to 50%.
To view the components from the calculation: CO2 emission calculation
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