Analysis articles in the context of chemical engineering

Work at the systems level plays a pivotal part in driving engineering advances. In this Editorial, we discuss the role of the Analysis research article format in accelerating breakthroughs in systems engineering science.

The end of the calendar year is often a time for reflection, particularly at the beginning of a new venture. This is especially true at the journal as we approach the conclusion of our first year in press. In our upcoming January anniversary issue, we will take a more comprehensive look back at the journal’s inaugural year. For now, however, as we enter the final months of 2024, we want to revisit a topic first explored in our February Editorial¹: systems-level thinking, particularly as it relates to our Analysis article format.

Credit: owngarden / Moment / Getty

At Nature Chemical Engineering, our decision to adopt both Article and Analysis as formats for original research papers embraces the systems-level nature of chemical engineering science. While readers will already be familiar with our Article format, the Analysis format might require further introduction — these articles, which are found in many Nature journals, provide substantive and insightful comparative assessments that draw on new or even existing datasets.

At the journal, Analysis articles are a key subset of our research content, highlighting the importance of process- and systems-level thinking in advancing the field. For instance, Analysis articles can provide quantitative pathways to process viability, optimizing over considerations such as technological feasibility, environmental ramifications and economic impact, from individual unit operations to an overall system.

While there is occasional overlap between what constitutes an Article and an Analysis, when we classify original research as an Analysis it is intended to signpost to the community that the work focuses primarily on assessment and/or optimization at the systems level. At the journal, we believe that addressing engineering challenges from both a bottom-up perspective (for example, reaction engineering) and a top-down perspective (for example, process systems engineering) is essential for accelerating scientific progress and scaling up engineering solutions.

Advances from the top down can also drive progress from the bottom up — and vice versa — due to the multiscale nature of chemical engineering science. As one example, an Analysis can identify quantitative design criteria for unit operations and/or their constitutive components, which can then guide future research. Understanding the maximum production cost of a porous sorbent at scale, for instance, may lead to more cost-effective preparation procedures, while awareness of the greenhouse gas emissions from a unit operation could highlight the need for alternative methods.

On the cover of this issue of Nature Chemical Engineering, we feature an Analysis by Venkataraman and co-workers that couples comprehensive process simulations and a techno-economic assessment of the electrochemical production of ethylene from aqueous carbonate feedstocks. The study — spanning CO₂ capture, carbonate concentration, electrolysis, product separation and stream recycling — identifies barriers to the commercial viability of this process, as well as the key advances needed to make it feasible at an industrial scale. For example, the authors highlight the critical need for upstream membrane-based systems to concentrate the carbonate feed under highly alkaline conditions, along with further improvements in bipolar membrane-based electrolyzers to achieve significantly higher Faradaic efficiencies towards ethylene.

As demonstrated in the work by Venkataraman and co-workers, comprehensive process simulations require a detailed, physics-based understanding of individual unit operations. To complement such analyses, the journal has also featured Articles covering bottom-up approaches — in the case of CO₂ electrolysis, ranging from molecular- to cell- and stack-level design. Take, for example, the Article by Li and co-workers, which shows that single-site doping of Cu catalysts with noble metals can influence the selectivity-determining step, enhancing Faradaic efficiency towards ethylene². At the cell level, the Article by Brückner and co-workers provides a diagnostic tool for CO₂-to-CO electrolyzers³ and the work by Lees and co-workers provides a continuum multi-physics model that guides electrolyzer performance⁴. At even larger scales, the Article by Crandall and co-workers showcases a kilowatt-scale tandem CO₂ electrolyzer for enhanced acetate and ethylene production⁵.

As a journal covering all aspects of chemical engineering research, our broad scope enables us to explore diverse strategies for addressing complex challenges in chemical engineering science. Systems-level Analysis articles represent a fundamental part of the discipline, and the inclusion of the Analysis format aims to encourage more submissions in this critical area.