**9. Business case**

A business case consists of several components that determine whether or not it is attractive for industry. Most critical factor is economic profitability. Can products be sold for a price that is attractive for the market and leaves a profit for the manufacturing company? There is also an increasing demand for products that are sustainable, this aspect must also be taken into account as non-sustainable products could be excluded in the future. In the Netherlands from 2023 the policy of the government is to purchase only sustainable products.

Product sustainability can be achieved by using raw materials with a low carbon footprint, for example: recycled or re-used materials. The use of materials with a low carbon footprint alone is not enough to ensure sustainability. The energy needed for production and the CO2 production that is related to the production of the new product must also be included.

The economical profitability of structural re-use of EoL thermoset composites for retaining walls was considered. During the production of the infra-structural demonstrators it had become apparent that manual production was too costly for economic profitability. Trials were carried out with our industry partners using the automated production technique of pultrusion, with a very positive outcome. Following that success, the pultrusion company Krafton in The Netherlands installed a compounder to mix re-used EoL composite flakes with resin and injects this into the core of pultrusion profiles. This is an efficient continuous production process that involves very little labour.

A financial tool was developed to analyse the profitability of a factory that produces these profiles with a pultrusion-based continuous process at a production speed of 15 m/hour [18]. Costs for the production are based on raw material costs, energy consumption, labour costs, depreciation of machinery, rent of production

#### **Figure 16.**

*Annual profit for a model production plant for profiles with EoL composite core [3].*

#### *Industrial Re-Use of Composites DOI: http://dx.doi.org/10.5772/intechopen.99452*

space and overhead. Based on price discussions with local councils and water municipalities in The Netherlands, a factor of 1.3 was applied to the sales price of identical profiles made of tropical hard wood (azobé).

A factor of 1.3 means that a product made of re-used EoL thermoset composite can be sold for a 30% higher price than the traditional tropical hard wood profile. This higher sales price was found acceptable by the water municipalities based on the longer life span in wet conditions and the circular characteristics of the product.

Variables in the tool are the weight percentage of EoL material in the profile and the number of production lines. **Figure 16** shows the annual profit of the model factory as a function of weight percentage of EoL material in pultruded profiles, for production facilities with 1, 2 and 4 production lines respectively.

From the analysis it can be seen that already with one production line the facility becomes profitable when the content of EoL material in the profiles reaches at least 62% by weight. With more production lines the profitability becomes higher as the number of persons working in the pilot plant weighs heavily within the calculation. From the trials by the industry partners using a pultrusion set-up it was found that an EoL content of 70% by weight is possible in the profile under consideration.

For the same profile also the CO2 footprint was analysed. For this, the ECO-Calculator of EuCIA was used [19]. This tool evaluates the CO2 footprint of composite products 'from cradle to gate', which means it considers the effect of the raw materials used and the production process. Using this tool the CO2 emission per kg of product was calculated for two percentages of EoL composite material content (50 wt% and 70 wt%, respectively). Moreover, the CO2 emission per meter profile was analysed when the profile with the same mechanical performance was made using only virgin raw materials, either as a profile made with an RTM-process with a PET-foam core or as a hollow profile with shear webs inside made with a pultrusion process. Cross-sections of the four profiles are presented in **Figure 17**.

The results of the analysis is given in the graph in **Figure 18**. Obviously the amount of CO2 for the production of a meter profile is strongly related to the percentage of re-used EoL thermoset composite used. This is mainly connected to the amount of virgin resin that is used to embed the EoL composite flakes. Comparing virgin based profiles with EoL composite material containing profiles, the carbon footprint of the latter becomes advantageous when the amount of re-used EoL thermoset composite is at least 70 wt% or higher.

#### **Figure 17.**

*Profile types with identical mechanical performance analysed for their CO2 – footprint. From left to right: 50% EoL, 70% EoL, virgin RTM, virgin pultrusion.*

**Figure 18.**

*Graph of CO2 footprint per meter profile for different profile build up [3].*
