Counterfactual sustainability screening - the definition and undertaking of a sustainability screening method for the assessment of defossilised supply chains

With the monumental shift in industrial interest towards sustainable, defossilised supply chains in response to the climate crisis, the understanding of alternative supply chain viability has never been more vital. As part of their Clean Future initiative, Unilever Home Care has committed to the phasing out of fossil carbon sources from their supply chains. To better assess the viability of these prospective supply chains within a quick timeframe, a counterfactual screening method has been developed which pits the performance of eleven selected sustainability indicators against a success baseline, returning a results array on the sustainability performance of these routes. This paper briefly introduces the initiatives laid out by Unilever Home Care, before undertaking a concise review on existing sustainability screening methods from the literature, with the key limitations of these methods outlined. In response to these limitations, a new methodology is then defined, with a case study of defossilised Linear Alkylbenzene Sulfonate (LAS)-appropriate olefins being applied. This study both illustrates the functionality of the methodology, as well as provides an insight into the viability of the assessed supply chains. Within the study, 18 technologies forming 18 routes were assessed, spanning green (“from plants”), grey (“from plastic waste”) and purple (“from CO2”) feedstocks (according to the Carbon Rainbow). General results trends suggest that green and grey routes hold much greater viability than the purple routes, given their relatively lower capital and operating costs, as well as their superior likelihood of being commercially viable by 2030. Plans for further research are also provided, with plans for results validation included.