Carbon neutral methanol from pulp mills towards full energy decarbonization: an inside perspective and critical review

Abstract

This work provides a critical review of the potential of integrating green methanol production processes in pulp mills. It identifies the current challenges, available synergies and future trends, whilst considering the inside perspective of current experts on implementing biorefinery processes and projects in this industry. The performed analysis shows that green methanol can be a key material in various decarbonization strategies, and pulp mills are natural frontrunners to establish production plants due to their suitability to implement biorefinery processes and the local existence of large flowrates of biogenic CO₂. Three potentially integrable pathways were identified and discussed: (i) e-methanol from captured CO₂ and green H₂, (ii) biomethanol from the gasification of Kraft pulping byproducts and (iii) biomethanol from the purification of stripper off gases. However, several challenges and drawbacks must be tackled, such as insufficient low-cost renewable electricity, transmission grid issues, complex process implementation, difficult synergy seizing, low maturity of the technology start-to-end chain and unclear legislation, that ultimately result in excessive production costs and lack of stakeholder's confidence. The inability to address these challenges can lead to the failure or postponement of projects, consequently reducing the potential role that green methanol and hydrogen strategies can have towards full energy decarbonization.