Extended hierarchical decomposition approach for the synthesis of biorefinery processes.

• Extended Douglas's hierarchical approach for biorefinery process synthesis • Various limitations for the synthesis of biorefinery processes are overcome • Additional tasks to assist reaction pathways screening at early design stage • Solid recovery system and material integration are added to the model Synthesis of biorefinery processes have been of great interest in the research community and industrial practitioners for the past two decades. However, there is a lack of systematic insight-based approach for the synthesis of biorefinery processes, especially at the conceptual design level. This paper presents an extension on the systematic hierarchical decomposition approach (commonly known as the "Douglas's hierarchical approach") for the synthesis of biorefinery processes. Note that the Douglas's hierarchical approach was originally developed for the synthesis of conventional chemical processes, and hence has various limitations when it is applied directly for the synthesis of biorefinery processes. These include unknown reaction stoichiometry, wide varieties of biomass feedstock, alternative conversion platforms, uncertain characteristic of biomass feedstock, etc. These challenges are now being addressed in the extensions proposed in this work for biorefinery process synthesis. Besides, additional tasks are included to assist reaction pathways screening at the early stage of design, while solid recovery system and material integration are being considered within the extended approach to maximise resource conservation and to minimise waste generation. The extended Douglas's approach is demonstrated with a case study on the synthesis of palm-based biorefinery processes. [ABSTRACT FROM AUTHOR]