CENTRAL

Introduction 

Aniline finds applications in more than 300 different end products with a global production of 10.4 MTA in 2024 which is expected to reach > 16.1 MTA by 2033. Aniline production currently occurs via three consecutive steps: (1) HNO₃ production, (2) nitration of (fossil-sourced) benzene with HNO₃/H₂SO₄ mixture, and (3) hydrogenation of nitrobenzene using grey H₂. This fossil-based production of aniline has a large CO₂ footprint amounting to 6.0 kg CO_2,eq/kg aniline, consumes 300 PJ (petajoule) of non-renewable energy due to the harsh and energetically voracious Haber-Bosch and Ostwald processes and releases large amounts of acid sludge. Apart from the environmental impact, replacing the fossil-based aniline production with an electrified alternative has an industrial relevance because of the large cluster of the aniline industry located in Belgium (BASF, Covestro). 

Goal 

The overarching goal of the CENTRAL project is to decouple aniline production from the Haber-Bosch and Ostwald processes (producing NH₃ and HNO₃ respectively) by using N₂, benzene, water and renewable electrons. CENTRAL aims at the development and lab scale validation of a fully electrified, continuous aniline synthesis process. The focus will be on the development of both electrode processes, integration in an electrochemical flow-cell, and proof-of-concept on TRL3. Technoeconomic assessment of the CENTRAL technology will be carried out aimed at target setting for economic viability and steering future R&D directions. 

Approach 

In the CENTRAL project, a combined electrochemical nitration and reduction is proposed to produce aniline at near-ambient reaction conditions. In situ nitration is performed by electro-oxidation of N₂ to NO_x^(-) and classical hydrogenation is replaced by electro-reduction of nitrobenzene. First, the anodic/anolyte and cathodic/catholyte processes are investigated separately, supported by the development of a kinetic-/transport model that describes the individual reactions and interactions between relevant species in the anodic chamber. Afterwards, the integrated system will be designed and validated on the lab-scale. 

Expected impact and valorization 

The CENTRAL electrification platform addresses several stakeholders in the (mostly Flemish) value chain e.g. technology suppliers, component providers, electrolyzer technology providers and the energy sector by enabling flexible, intermittent renewable energy utilization. The valorisation strategy aims to connect relevant players across different sectors into new value chains:  industrial players producing aniline and companies using aniline, HNO₃, or NO_x as feedstock for their processes (e.g. production of MDA, isocyanates, caprolactam, MDI, TDI, BTX). The valorisation approach of the CENTRAL project is threefold: (1) IP transfer and follow-up projects; (2) Industrial perspective from Industrial Advisory Board; (3) dissemination of project results, promoting the project to attract more companies.