Kraft lignin-based Vanillin production - Process modification, techno-economic evaluation, and energy analysis

This correspondence outline specific modifications implemented in the vanillin production process derived from kraft lignin, with the primary objective of minimizing the release of chemical substances into the environment and optimizing facility utilization. The processes were meticulously designed using Aspen Plus V12.1 software, followed by a sensitivity analysis conducted on the specifications of the main distillation column for each process. Subsequently, the obtained results underwent techno-economic evaluation and energy analysis, employing Aspen Process Economic Analyzer V12 and Aspen Energy Analyzer V12.1. The calculations reveal that increasing the purity of methanol and water from 95 to 99 wt % during methanol recycling effectively reduces chemical releases into the environment but significantly raises utility costs, thereby diminishing the Net Present Value. Furthermore, the energy analysis demonstrates that the implemented modifications markedly reduce energy consumption, exerting a direct impact on economic parameters. In the process design phase, while Aspen Plus software showed no errors in the results, Aspen Energy Analyzer detected errors in the modified scenario in two heat exchangers because of high temperature at the shell outlet based on its respective criteria, necessitating increasing the cooling flowrates to cover this issue.