Control-oriented model paves the way for efficient hydrogen production from ammonia

Researchers have developed a novel computational framework to monitor and optimize proton ceramic electrochemical reactors for green hydrogen generation.

A team of scientists from the Universitat Politècnica de Catalunya (UPC) and the Instituto de Tecnología Química (ITQ, UPV-CSIC) has unveiled a new control-oriented model that could significantly enhance the safety, efficiency, and scalability of next-generation hydrogen production technologies.

Their study, titled “Control-oriented modeling and observation of a single cell proton ceramic electrochemical reactor for single-stage ammonia cracking to compressed hydrogen,” published in the International Journal of Hydrogen Energy, focuses on the modeling and observation of proton ceramic electrochemical reactors (PCERs) for single-stage ammonia cracking to compressed hydrogen.

As hydrogen becomes a cornerstone of the global energy transition, efficient and cost-effective production methods are urgently needed. Ammonia, due to its high hydrogen density and established infrastructure, is considered one of the most promising hydrogen carriers. However, conventional hydrogen extraction from ammonia typically requires multi-stage processes—combining catalytic cracking, separation, and compression—that suffer from significant energy losses.

The new PCER concept, developed in the SINGLE project, revolutionizes this approach by integrating ammonia dehydrogenation, hydrogen separation, and electrochemical compression into a single, streamlined step. This eliminates the need for external heat sources and mechanical compressors, drastically improving overall energy efficiency.

Despite its potential, PCER operation involves highly complex interactions between electrical, chemical, and thermal phenomena, making control and monitoring particularly challenging. Addressing this, the research team developed a computationally efficient, control-oriented model capable of describing the dynamic behavior of a single reactor cell.

This simplified model enables real-time implementation of advanced control algorithms, ensuring stable operation while preventing performance degradation. The design and development of such controllers is currently in progress, aiming to further enhance system performance.

The study also introduces a “soft sensor” algorithm based on observer theory, designed to estimate in real time key internal variables such as hydrogen partial pressure and membrane resistance—critical for optimizing performance and preventing catalyst degradation.

“Through the fusion of models and data, soft sensors and observers convert uncertain, noisy electrochemical signals into reliable state information, enabling deeper insight and effective control,” explains Dr. Andreu Cecilia, one of the main authors of the study.

The proposed model was validated against a high-fidelity multi-physics simulation, demonstrating strong agreement in key performance metrics such as hydrogen extraction efficiency, ammonia conversion, and temperature dynamics. Crucially, the simplified model can simulate reactor behavior in real time—a critical feature for future industrial implementation.

This work is part of the SINGLE project, which aims to develop next-generation technologies for hydrogen production, purification, and compression directly from ammonia in a single, integrated step. The key technology component of PCER is the electrochemical cell, which is engineered to function both as a durable ammonia dehydrogenation (ADH) catalyst and as a voltage-driven membrane for hydrogen separation and compression.

By integrating all four process steps—catalytic cracking, separation, purification, and compression—into a single reactor, the technology achieves unprecedented energy efficiencies while directly delivering high-purity, pressurized hydrogen. SINGLE will demonstrate this breakthrough approach at a 10 kg H₂/day scale, providing a clear pathway for future scale-up.