Biosurfactants' production with substrates from the sugar industry – environmental, cost, market, and social aspects

Abstract

Transforming today's products and production processes towards a more sustainable bio-economy requires the consideration of environmental, cost and market related, as well as social aspects. In this study lab and pilot plant data were extended to industrial scale process chain designs for biosurfactant production. Considering different substrates from the sugar industry (molasses and sugar beet pulp) and different products (rhamnolipids (RL) and mannosylerythritol lipids (MEL)), advantageous process paths and possible specific hotspots were identified. To enable sustainability-oriented process development of microbial biosurfactants, assessment approaches such as Life Cycle Assessment (LCA), product cost analysis (CA) and market analysis were applied. Social aspects were addressed in a more general way. Regarding environmental impacts, the most contributing impact categories (e.g., resource use), process modules (e.g., solvent production) and stages (e.g., extraction stage) were determined. Results for environmental impacts show significant advantages for MEL production, while the choice of the substrate plays a minor role. CA has shown significantly lower costs for MEL production, which can reach the levels of comparable products on the market. The examined market framework and calculated production costs allowed estimations on the competitive position within the market of surfactants. The social aspects have also shown advantages for MEL production and, in the product-dependent variety of results, the importance of taking them into account. In summary, MEL production in an exemplary industrial scale scenario has shown essential advantages, which can be traced back mainly to the higher production yields. However, further design improvements were identified for RL and MEL production.