Avaliação de Ciclo de Vida (ACV)

Hello green curios! All right with you? I'm back with another topic for us to talk about here this time it's the Life Cycle Assessment (acv) or in English Life Cycle Assessment (lca) this is being talked about a lot.

And why is it so important? You've probably heard that discussion about plastic bags or using a paper bag, using a glass bottle, or using an aluminum can? and then what is better, what are we going to base this decision on?

so life cycle assessment comes as a way to assist in decision making and allow this analysis to be done based on data. But Larissa, how did it come about? Where did this whole idea come from?

The first effective life cycle assessment was carried out by Coca-Cola to assess the impact of glass bottles compared to the impact of plastic bottles. So this was the first public life assessment study and from then on other studies were being developed Who today gives the guidelines for these studies are the ISOs so the ISO 14040 family are those that define some strategies for life cycle assessment , so based on that many studies began to be developed, how do these studies work? basically you define what you want to study, then what you want to assess.

Your production of bottles, PET bottles for example So this study has three possibilities: you can evaluate your bottle production from oil extraction to the plastic production arriving at the factory gate or your plastic production to the production of bottle arriving at the gate of the factory that will be filled, and these two would be known as cradle to gate. So you take it from where you extract this raw material to the gate of the factory that will use that product. Or you have another option which would be the cradle to grave, where you analyze from the extraction of the raw material to the disposal of the final material, considering the process, for example, an example of the PET bottle from the extraction of oil to the production of Plastic , bottle injection, bottle blowing, use in fillings and then post-consumer disposal.

So there you have cradle as grave as it would be from the cradle or the grave. Another option is the cradle to cradle, which is from cradle to cradle. In this case, it goes from raw material extraction, injection, use, disposal and recycling, which produces a new raw material that can return to this process.

So these are the three main study options and the studies they can be attributional or consequential. What does Larissa mean? the attributional ones will basically evaluate the cycle of your product, it is a more common study so I will study the cycle of a PET bottle.

So, I'm going to study the entire cycle and the attribution of the associated emissions in that cycle. When I talk about the consequential, what does that mean? I am studying changing a certain parameter and how it will affect this cycle of mine that is already known.

So those are the two main types of everything within those three categories that I presented to you and how should this study be done? there are four main topics: the first one is the objective and scope in this you need to define which audience you are presenting this study to, what is the area of ​​interest of this study? what are you going to rate?

What is your functional unit? So I'm going to evaluate the packaging emissions needed to store 10,000 liters of soda, for example, so to store 10,000 liters of soda, I'm going to see the impact of my plastic packaging and my glass packaging, and then I can make a comparison. It guarantees that the studies are comparable, that I can compare banana with banana, orange with orange and have a more effective result.

In addition, you need to define your study system, which would basically be the scope, so in your system you need to put everything you are going to evaluate. So I'm going to look at transport, I'm going to evaluate production, I'm going to evaluate the distance it's traveling to define what I consider and what I'm failing to consider. So, the type of life assessment is a very interesting process, but it still has its limitations, because you can consider what is more viable for you, so many studies are biased precisely because it considers some steps and do not consider others that are important for the environmental impact.

So basically the objective and scope it works for you to define your study and present to your reader what is really being evaluated. And then we move on to our second part, which would be inventory analysis. So in the Inventory Analysis (LCI) we are going to collect all the data associated with our system.

And then, give all the inputs and outputs of our process So everything that comes out of our process, so that in the end we can go to the third stage, which is the impact assessment, this stage basically constitutes the evaluation impact associated with this process. So, based on some methods, there are a number of methods that can be used for this purpose. And then you choose the method that best suits your process?

And what is the impact of your process on the final product so it will basically give you some impact categories which are: Impact on climate, acidification, nitrification, depletion of the ozone layer So there are several categories that are included in this impact assessment after that we go to the last stage which would be the interpretation of the study and then this point is very important because the life cycle assessment involves a series of uncertainties what are these uncertainties? these uncertainties are variability during the analysis, the data today is a bit limited so you can have primary sources and secondary sources of data. The primary sources are those that you take from your own process, getting a more real study of your own process, but when you don't have 100% of these data you rely on databases that are secondary sources.

So these secondary data sources, they will take examples from different processes around the world and will give you an average of that location that you choose, so basically there are a lot of uncertainties in this data, so what happens when you choose a data it has already been carrying a series of uncertainties. This needs to be taken into account at the end of the study, so at the end of the study a statistical analysis is necessary for you to assess the real impact of this uncertainty in your data on your final result. So when you compare two different products using life cycle assessment even though they are using exactly the same standards and you are comparing bananas with bananas you need to take into account these uncertainties related to the data and these uncertainties are not related to the data but also the methods, they must be taken into account when you compare your two bananas, so for example I compared a glass container with a plastic container.

I saw there that plastic emits 20% less than glass, but what is my uncertainty involved in the analyzed data, so this needs to be taken into account when making a comparison using the life cycle assessment, so guys It's a complex world of life, it's very interesting, but for the elaboration of the review and also for the use of the data, a more complete study is necessary so that you understand exactly these uncertainties and how to evaluate the statistics behind the whole process. So, whenever you see a life cycle analysis, look carefully See if the methods are comparable, if the data systems are also favorable, and what is the uncertainty involved in this study ok The life cycle assessment is extremely important for you to take a decision on which packaging to use, which product is best for you , what is the impact of this product on the environment .