Life cycle of an ideal green solvent from cradle to grave for sustainability studies of green solvents.

This critical review provides an overview of the sustainability outcomes associated with flow chemistry, as a new concept in process chemistry, and its related technology and engineering field, microreaction technology. This study is broad in scope and covers cost and life cycle assessment methodologies applied to flow chemistry. The present review differs from past studies by providing a mechanistic viewpoint, i.e., starting by listing key levers (e.g. mass transfer), and then unravelling their impact on costs and life cycle, using reported flow chemistry studies as examples to underline the sustainability capability. This way, this review transitions from informing on how flow chemistry and microreactors can improve fundamental principles in chemical engineering and chemistry to their translation to improved sustainability. Gaps and opportunities in the reporting of microreactor/flow chemistry are identified. To put the reported achievements into perspective, a life cycle assessment (LCA) study is conducted that reports on the effects of the key levers, as identified in this study, for a flow chemistry reaction at the pilot scale, conducted at an industrial site (technology readiness level 4). This way, this study provides a quantitative forecast of what principally can be achieved when maximising the key levers, in terms of the individual LCA impact categories and their total average outcome.

Cold plasma is formed by the nonthermal ionization of gas into free electrons, ions, reactive atomic and molecular species, and ultraviolet (UV) radiation. This cold plasma can be used to alter the surface of solid and liquid foods, and it offers multiple advantages over traditional thermal treatments, such as no thermal damage and increased output variation (due to the various input parameters gas, power, plasma type, etc.). Cold plasma appears to have limited impact on the sensory and color properties, at lower power and treatment times, but there has been a statistically significant reduction in pH for most of the cold plasma treatments reviewed ( p < 0.05). Carbohydrates (cross linking and glycosylation), lipids (oxidation), and proteins (secondary structure) are more significantly impacted due to cold plasma at higher intensities and longer treatment times. Although cold plasma treatments and food matrices can vary considerably, this review has identified the literary evidence of some of the influences and impacts of the vast array of cold plasma treatment parameters on the biomolecular and organoleptic properties of these foods. Due to the rapidly evolving nature of the field, we have also identified that authors prioritize the presentation of different information when publishing from different research areas. Therefore, we have proposed a number of key physical and chemical cold plasma parameters that should be considered for inclusion in all future publications in the field.