# Continuous Synthesis of 2‐Methoxyhydroquinone from Vanillin in a Taylor‐Couette Disc Contactor

## TL;DR

The paper presents a continuous method to synthesize a redox-active compound from vanillin for use in sustainable energy storage.

## Contribution

A scalable and efficient continuous synthesis of 2-methoxyhydroquinone from vanillin is demonstrated using a Taylor-Couette disc contactor.

## Key findings

- The Taylor-Couette disc contactor achieved an 83% yield of 2-methoxyhydroquinone.
- The product reached 93.8% purity and a production rate of 0.55 kg h−1.
- The synthesized compound is suitable for single-cell redox flow battery performance and stability tests.

## Abstract

Organic redox flow batteries are a promising sustainable technology for large‐scale storage of surplus energy in the grid. However, the main challenge lies in scaling up the synthesis of redox‐active molecules from sustainable sources, as either the synthesis is complex or renewable feedstock is not available at a large scale. This challenge is addressed by employing vanillin, a fine chemical widely available from lignin, as a starting material for the synthesis of redox‐active hydroquinones. The use of a continuously operating column reactor, known as the Taylor‐Couette disc contactor, is demonstrated to generate redox‐active 2‐methoxyhydroquinone in high yields and purity. Production rates of ≈0.55 kg h−1 of 2‐methoxyhydroquinone are achieved, with sufficient purity for use in single‐cell redox flow battery performance and short‐stack stability tests.

This study investigates continuous synthesis of 2‐methoxyhydroquinone (MHQ) from vanillin in a Taylor‐Couette disc contactor (TCDC). The TCDC, a stirred column reactor utilizing Taylor vortices for intense mixing, achieved efficient phase separation and hydraulic stability. With an 83% yield, 93.8% purity, and a production rate of 0.55 kg h−1 of MHQ, the product proves suitability for redox flow batteries.© 2025 WILEY‐VCH GmbH