Inherent Safety Analysis of a Cascade Biorefinery for the Utilization of Avocado Hard Waste from the South Colombian Region

Cascade biorefineries have demonstrated potential due to their ability to further valorize a wide variety of waste, including agricultural residues such as avocado hard waste. The intrinsic safety aspects of these technologies have been scarcely studied. Therefore, an inherent safety analysis was applied to identify and assess the risks of an avocado cascade biorefinery in the Amazon region. Several available databases (online) were used to determine the safety data of the substances in the process, such as CameoChemicals, INCHEM, and NIOSH. Additionally, data from extended mass and energy balance (based on the literature) were collected to assess the process operating conditions. The results show that the process is slightly unsafe, with an overall inherent safety score of 25, and that it achieved a performance of 96% relative to the neutral operating point (24). Chemical risks represented the most critical challenges of the process, with a score of 16, with exothermic reactions, hazardous substances, and dangerous chemical interactions being the most significant sources of risks. On the other hand, the process safety indicator scored 9, indicating that these aspects are not a major source of risk, as the process had mostly low operating conditions (near-environment temperatures and pressures; low inventory), with equipment being the only significant risk factor. Nonetheless, the safety structure subindex for this process was 2, as no clear and recognizable risks existed (at least in the literature) for this type of scheme at the scale analyzed (small scale). This score needs to be studied to properly assess the risks in bioprocesses like cascade biorefineries. Finally, replacing acid hydrolysis with enzymatic hydrolysis, along with another method for bioactive extraction, is recommended to reduce the inherent risks.