Structured packed bubble column reactor for continuous production of vanillin from Kraft lignin oxidation

In this work we have studied the lignin oxidation with oxygen to produce vanillin in a continuous gas–liquid co-current bubble column reactor. Using Mellapak structured packings within the reactor, it was possible to increase in 35% the oxygen transfer to liquid phase. A simulation study was performed to gather the effect of different operating conditions (gas and liquid flow rates, temperature, pressure and oxygen mass transfer rate) to achieve improved operating conditions to increase reactor performance. This study allowed us to propose a set of operating conditions that can approach the maximum vanillin conversion obtained in a batch reactor. It was verified that the oxygen mass transfer constant should be significantly increased. This can represent an opportunity to develop new tailored internals for this application.