Techno-economic assessment of BTX production from bio-based waste feedstocks via Integrated Cascading Catalytic Pyrolysis

Abstract

Achieving the Paris Agreement’s climate goals also requires the transformation of the chemical industry. The patented BioBTX production pathway converts mixed waste plastics into BTX via pyrolysis with catalytic upgrading. This thesis assesses five potential bio-based alternatives (UCO and lignin with pre-treatment or chat post-processing) for BTX production under a NetZero carbon constraint.

From a technical standpoint, the UCO pathway requires minimal adaptations to the BioBTX base case process as it is already an established feedstock in other production processes for biofuels. However, its economic viability is constrained by high feedstock costs, requiring significant BTX/oil yield improvements or policy interventions to be competitive. Lignin-based pathways face even greater challenges. Although pre-treatment can increase BTX yield and consequently economic viability, this technology is still at a low maturity. Additional post-processing steps such as char combustion, gasification or char sales to the agricultural sector are technologically feasible, but economically unviable without significant yield improvements. The NetZero constraint could be feasible in the mixed plastic base case, but is only recommended if a suitable end-user for the product gas is identified.

This research is limited due to the use of assumptions and lack of validated data for BTX production from UCO and lignin. Future work should prioritize pilot testing of UCO pathways, technological advancement of lignin pre-treatment and life cycle assessments to evaluate environmental impacts. From a policy perspective, enhancing the economic viability of UCO-based BTX production will require targeted subsidies or utilization quotas, combined with sufficient feedstock availability and strict regulations for UCO supply chains to avoid price inflation and fraud. Finally, public investment in research and development is essential to scale up emerging technologies like lignin pre-treatment.

In conclusion, continued experimental research, data validation and supportive policy frameworks will be essential to advance the assessed bio-based BTX production pathways and move closer to a carbon-neutral chemical industry.