KBBPPS Knowledge Based Bio-based Products` Pre-Standardization - Verification of method for total carbon recovery (CEN TS 16640) - ruggedness test - Final report

Determination of the biogenic carbon of a finished product includes three steps: 1 – obtaining a representative sample, 2 – sample pretreatment and 3 – C14 analysis of the sample. Our review on sampling standards was given in Deliverable 3.1. The method to determine total carbon and biobased carbon content was reviewed in Deliverable 3.2 that is converted into the technical specifications CEN/TS 16640 "Bio-based products — Determination of the bio based carbon content of products using the radiocarbon method”. Deliverable 3.3 pre-sented the first stage of the verification of the method on the total carbon determination. Deliverable 3.3 described the intermediate stage, approximately half of the challenging prod-ucts were tested - volatile paints, volatile liquids, paint components, sun lotion and all its con-stituents. Since the C14 determination techniques are very accurate and extensively tested, we verified only the total carbon recovery method which is based on complete combustion of a material. The results obtained on the total carbon fractions in each of the analysed materials were in good agreement with theoretical data (when known) and with data provided by products suppliers (when available). The results of our measurements indicated a very good repeata-bility. Deliverable 3.4 of the European KBBPPS project presents the final results of evalutation of the method for the total carbon recovery in various products. Present document is a continu-ation of the intermediate report that was published as Deliverable 3.3. Current report includes the results of the ruggedness test on the next set of challenging products including bio-composites, bio-textile, boards made from wheat straw and gaseous samples. The known C14 determination techniques are already standardized and exhibit a very high accuracy. Therefore a verification is needed only for the total carbon recovery method which is based on a complete combustion of a material. In relation to this, given report focuses ex-clusively on the ruggedness test that aims to check the method which is used to retrieve all available carbon from different materials and concerns only the treatment part and aims to check if it is possible to extract all available carbon (via conversion to CO2) for different types of materials or products. Extraction of available carbon can be evaluated via determining the combustion recovery, as it was explained in Deliverable 3.3 and will be repeated in Para-graphs 4 and 5 of this report. For most tested materials, the CO2 conversion results indicate a very high carbon recovery rate and thus prove the reliability of total carbon determination by the combustion and titration method. All performed measurements indicate a very good repeatability and a good agreement with data provided by sample suppliers (when available). As a recommendation, special attention shall be paid to those materials or products which contain volatile components since omitting the carbon from the volatile part can lead to incor-rect value for the total carbon content. When a special enhancer is used to ignite a product, it is of importance to know the carbon content that is added to the system from the enhancer. Inhomogeneity, as it was illustrated by one of the analyzed materials, can lead to several percents difference in the carbon content. In case a material is suspected to be inhomoge-neous and a preparation of a representative sample is therefore of difficulty, it is better to analyze such material as a whole (when possible), or if possible, to analyze each component seperately.