Oona Korhonen, Project Manager at Measurlabs, specialized in biomass

Read below a guest article by Oona Korhonen from Measurlabs. 

How well do you know the amount of bio-based content in the raw materials you use? Have you measured it yourself? 

There are two big reasons to do so. Firstly, as fossil-based materials are becoming less attractive, and politics are restricting the use of fossil-based raw materials, it is increasingly important to know the real composition of the raw materials you use. Secondly, as bio-based materials can be chemically identical to their petroleum-based counterparts, identifying the origin of the chemicals is essential. Oona Korhonen from Measurlabs is an expert in this area and shares here her knowledge about determining the amount of bio-based content in materials. 

How to measure the amount of bio-based components 

One of the most accurate ways to study a material’s bio-based vs. petroleum-based composition is to analyse the carbon in the product. Bio-based carbon originating from plants is radioactive, whereas carbon originating from fossils no longer is. The amount of radioactive carbon in the sample can thus be used to determine the amount of bio-based content in the material.  

The radio activeness of the bio-based carbon originates from the atmosphere and photosynthesis. The content of radiocarbon in the atmosphere is relatively stable, and thus living plants have the same radioactive carbon content as air. When the plant is alive, it continuously absorbs carbon from the air during photosynthesis. Once the plant dies, the radioactive carbon it has absorbed starts to deteriorate with a known rate, called “half-life”. This way, the age of biomass based components can be evaluated based on their content of radioactive carbon. 

The content of radioactive carbon in the organic material can be determined using accelerator mass spectrometry (AMS) by measuring the different carbon isotopes in the sample. This method is commonly used for evaluation of the age of the organic material, but it can also be used to evaluate how much of the carbon in the material is originating from renewable biomass and how much from fossil origin.  

Avoid the risk of misinterpretation 

There are standardised methods for the determination of biobased carbon, and the amount can be expressed as a fraction of the total organic carbon or total carbon in the sample. If the sample contains a high amount of inorganic carbon (which is neither biomass- nor petroleum-based), it will impact how bio-based the material seems.  

Let’s take an example: If all organic carbon in a material is biomass-based, the amount of bio-based carbons of the total organic carbons will be 100%. However, if the material also includes inorganic carbons, the amount of bio-based carbons of the total carbons will be less than 100%. The different measurements may result in misinterpretations of the materials origin, which is why it is important to specify how the biobased carbon content was determined. 

The main standard methods used for determining th