Gaseous streams in biorefineries have been undervalued and underutilized. In cellulosic biorefineries, coproduced biogas is assumed to be combusted alongside lignin to generate process heat and electricity. Biogas can instead be upgraded to compressed biomethane and used as a transportation fuel. Capturing CO 2 -rich streams generated in biorefineries can also contribute to greenhouse gas (GHG) mitigation goals. We explore the economic and life-cycle GHG impacts of biogas upgrading and CO 2 capture and storage (CCS) at ionic liquid-based cellulosic ethanol biorefineries using biomass sorghum. Without policy incentives, biorefineries with biogas upgrading systems can achieve a comparable minimum ethanol selling price (MESP) and reduced GHG footprint ($1.38/liter gasoline equivalent (LGE) and 12.9 gCO 2e /MJ) relative to facilities that combust biogas onsite ($1.34/LGE and 24.3 gCO 2e /MJ). Incorporating renewable identification number (RIN) values advantages facilities that upgrade biogas relative to other options (MESP of $0.72/LGE). Incorporating CCS increases the MESP but dramatically decreases the GHG footprint (−21.3 gCO 2e /MJ for partial, −110.7 gCO 2e /MJ for full CCS). The addition of CCS also decreases the cost of carbon mitigation to as low as $52−$78/t CO 2 , depending on the assumed fuel selling price, and is the lowest-cost option if both RIN and California's Low Carbon Fuel Standard credits are incorporated.

The MAPSYN project of the European Union (standing for Microwave, Acoustic and Plasma SYNtheses) aims at the utilization of plasma technology for nitrogen fixation reactions on an industrial scale and with industrial plasma reactor technology, developed and utilised commercially [1]. Key motif is enhanced energy efficiency to make an industrial plasma process viable for chemical industry. The corresponding enabling technologies – plasma catalysis, smart reactors (microreactors) and more – go beyond prior approaches. Continuing a first more project-based literature compilation, this overview focus on the two first enabling functions, plasma catalysis and smart reactor technology, which are reviewed for industrial and near-industrial plasma-based applications. It is thereby evident that notable promise is given for the nitrogen fixation as well and indeed this has been demonstrated also for nitrogen fixation; yet, initially and without the holistic system engineering dimension

Flow chemistry has changed chemical process designs toward process intensification and is generally considered as green methodology. In this connection, this perspective provides a more critical and holistic view about the sustainability of flow chemistry by introducing both simple and complex holistic tools for environmental quantitative assessment on sustainability and providing examples of how they were used for flow chemistry. The latter also shows a critical assessment of what flow chemistry can add to make chemical processes more sustainable. With the increasing complexity of assessment, green chemistry metrics, life cycle assessment methodology, and circular transition indicators are discussed. In this way, the sustainability of flow chemistry is assessed first on the level of a reaction only and then moving to a process level and beyond. Flow chemists are very aware of the principles of green chemistry and their simple metrics. Yet, they hardly use life cycle assessment, and quantitative circularity analysis has not been made. When those assessments are used, it is usually done by researchers with an ecology background. This perspective aims to make flow chemists aware of the opportunities that complex environmental assessment can provide and that protecting our planet requires a holistic sustainability consideration. The perspective critically states what each of the three types of assessments can do and what their limitations are.

The importance of ammonia in the fertilizer industry has been widely acknowledged over the past decades. In view of the upcoming increase of world population and, in turn, food demand, its production rate is likely to increase exponentially. However, considering the high dependence on natural resources and the intensive emission profile of the contemporary ammonia synthesis route, as well as the rigid environmental laws being enforced at a global level, the need to develop a sustainable alternative production route becomes quite imperative. A novel approach toward the synthesis of ammonia has been realized by means of non-thermal plasma technology under ambient operating conditions. Because the given technology is still under development, carrying out a life cycle assessment (LCA) is highly recommended as a means of identifying areas of the chemical process that could be potentially improved for an enhanced environmental performance. For that purpose, in the given research study, a process design for a small-scale plasma-assisted ammonia plant is being proposed and evaluated environmentally for specific design scenarios against the conventional ammonia synthesis employing steam reforming and water electrolysis for hydrogen generation. On the basis of the LCA results, the most contributory factor to the majority of the examined life cycle impact categories for the plasma-assisted process, considering an energy efficiency of 1.9 g NH 3 /kWh, is the impact of the power consumption of the plasma reactor with its share ranging from 15% to 73%. On a comparative basis, the plasma process powered by hydropower has demonstrated a better overall environmental profile over the two benchmark cases for the scenarios of a 5% and 15% NH 3 yield and an energy recovery of 5% applicable to all examined plasma power consumption values.

The importance of nitrogen fixation is evident in every aspect of a human being’s life, from the synthesis of vital for all organisms nutrients and, in turn, the ecosystem conservation to the production of fertilizers, plastics, and many other daily usage products. However, increasing concerns about the environmental sustainability of contemporary chemical industry seem to impose, nowadays, great challenges to the industrial nitrogen fixation which is linked to immense energy consumption and burdened emissions profile. Upon these considerations, it becomes imperative to adopt a holistic approach toward the development of novel “green” process technologies for the synthesis of fixed nitrogen. A considerable effort to that direction has been made by means of plasma technology mainly at the laboratory scale. Although research studies have shown promising results, little attention has been placed on conceptualizing plasma-assisted nitrogen fixation at an industrial scale and evaluating its environmental footprint. This issue is practically addressed in the present research work which focuses on the ex-ante process design of plasma-assisted nitric acid synthesis for a modular plant and the respective life cycle assessment (LCA) incorporating renewable energy sources. In order to facilitate the analysis of the LCA study, a sensitivity analysis has been considered on the reaction yield, the plasma power consumption, the recycle of unreacted gas stream, and the energy recovery in the plasma reactor. LCA results exhibit for the plasma-assisted nitric acid, incorporating the recycle of the tail gas and solar energy, an improvement in the global warming potential of 19% as compared to the conventional production pathway.