Engine and Power Plant Combustion Technologies for Sustainability

The special collection on Engine and Power Plant Combustion Technologies for Sustainability is available in the ASCE Library (https://ascelibrary.org/page/jleed9/engine_power_plant_combustion).

In putting this special collection together, we were motivated by the need to respond to what we see as the development of a misconception and the concern that this may develop into a trend that may lead to counter-productive attitudes toward the environmental challenges that modern society faces. In particular, the misconception seems to be developing among the general public and parts of the scientific community that somehow combustion and sustainability are incompatible, that a sustainable future power and transportation portfolio will not and should not include combustion technologies.

In our view, nothing could be further from the truth in terms of technological reality for the foreseeable future. Exploitation of fossil fuels, even the most challenging ones from an environmental perspective, will be part of the energy portfolio for the next century or so, not least because they are economically attractive for the developing world. Impoverished societies that sit on reserves of fuel that can cost as little as $10 a ton will use this commodity, and this is simply an inescapable fact. Given the universal nature of contemporary environmental challenges, the real question is not whether fossil fuels will be used for power generation and transportation in the foreseeable future but whether the engineering and scientific community can provide the technologies that will allow utilization of these resources to proceed in a manner that will not add to the quite substantial burden that modern industrial activity has put on the environment.

In this sense, we think that the work presented in this collection sends a very optimistic message. Readers will find out not only that there is high-quality research on the utilization of fuels like lignite and heavy fuel oil but also that the engineering and scientific community has responded in an inventive manner to the research needs of sustainability. Miniature combustors are being developed to probe in detail the physical chemistry of fossil-fuel oxidation, and high-fidelity optical diagnostics are being combined with powerful computer codes to give combustion engineers strong predictive capabilities. Innovative technologies are presented that show that renewable and fossil-fuel energy are not two separate worlds, such as combined coal/solar plants; the use of alkali carbonates to reduce chlorine emissions, which may open new avenues in terms of incineration of biomass and plastics; as well as additive manufacturing of burners. In parallel, results are presented that record the impressive progress that recent fuel and engine technologies have achieved toward sustainability. This includes dual-fuel and variable-geometry engines, exhaust gas recirculation, water injection, and novel oxygenated fuel mixtures that utilize second-generation bio-alcohols as well as liquid fuel derived from coal.

It is, of course, realized that the sample that we provide cannot be expected to exhaust the wide spectrum of research that relates to the sustainable use of fossil-fuel resources, but we believe that readers will get a representative view of the state of the art. Our hope is that the special issue will act as a reference for practitioners of related research and that it will demonstrate that combustion research and sustainability do not compete but actually go hand in hand.

We would like to thank all of the authors for their valuable contributions and the referees for conducting thorough and detailed reviews that have raised even further the level of the contributed papers. We express our gratitude to the editor-in-chief of the journal, Dr. Chung-Li Tseng, for this opportunity and for his excellent cooperation during the production of the collection.