Search

The potential improvement in methane recovery and reaction kinetics from different mixes of potato peel (PP) and pig manure (PM) in a single stage anaerobic co-digestion/mono-digestion process was investigated in a laboratory study. The highest methane yield of 231 mL/g [TCOD.sub.added] was observed in the 50:50 mix of potato peel and pig manure. Compared to the mono-digested substrates, co-digestion of PP and PM at 75:25, 50:50, and 25:75 synergistically improved methane yield by 17%, 25%, and 11%, respectively. The co-digested mixes also produced methane at a faster rate, with the fastest methane production rate occurring at the 50:50 mix. Thus, co-digestion of potato peel and pig manure enhanced the methane yield and reaction kinetics. Hence, co-digestion rather than mono-digestion should be actively considered when a carbon rich waste (such as potato peel) and nutrient rich waste (such as pig manure) are available within reasonable proximity. Key words: anaerobic digestion, mono-digestion, co-digestion, methane yield, reaction kinetics. L'amelioration potentielle de la recuperation du methane et de la cinetique de reaction a partir de differents melanges de pelures de pomme de terre (PP) et de fumier de porc (FP) dans un processus de co-digestion anaerobie/mono- digestion en une seule etape a ete etudiee dans le cadre d'une etude en laboratoire. Le rendement de la production de methane le plus eleve, soit 231 mL/g de demande chimique totale en oxygene ajoutee, [TCOD.sub.added], a ete observe dans le melange 50:50 de PP et de FP. Par rapport aux substrats mono-digeres, la co-digestion de PP et de FP a 75:25, 50:50 et 25:75 a ameliore de maniere synergique le rendement en methane de 17, 25 et 11 %, respectivement. Les melanges co-digeres ont egalement produit du methane a un rythme plus rapide, le taux de production de methane le plus rapide se produisant au melange 50:50. Ainsi, la co-digestion des PP et du FP a ameliore le rendement en methane et la cinetique de reaction. Par consequent, la co-digestion plutot que la mono-digestion devrait etre activement envisagee lorsqu'un dechet riche en carbone (comme la PP) et un dechet riche en nutriments (comme le FP) sont disponibles a proximite raisonnable. [Traduit par la Redaction] Mots-cles : digestion anaerobie, mono-digestion, co-digestion, rendement de la production de methane, cinetique de reaction., Introduction The increase in world population and economic growth has led to a corresponding increase in energy consumption and organic waste generation. Energy demand is projected to further increase by [...]

Life Cycle Assessment (LCA) is a widely used tool to measure the environmental sustainability of products or processes. Integrating LCA into the assessment of waste diversion strategies recognizes that current waste diversion strategies are insufficient to stem the global impacts of waste effectively. The increased pressure to divert organic and inorganic materials to reduce landfills impacts and promotes the circular economy. Historically, waste diversion efforts in municipalities and industries focused on higher-profile inorganic wastes, such as plastics and other recyclables. However, organic waste is increasingly identified as a key waste fraction that must be effectively managed and regulated. This research surveys published LCAs from 2019 to 2023 focusing on the anaerobic digestion (AD) of organic waste. Notable conclusions include the lack of studies comparing AD with the latest treatment options such as co-gasification; the insufficient attention to the LCAs on biogas upgrading methods; and the monetization of LCA results using carbon credits. In addition, more than 50% of reviewed LCA studies concluded the results with a sensitivity analysis, which was not a common practice before 2019 in LCA studies on anaerobic digestion. This signifies the increasing need to understand uncertainty in the circumstances governing applying AD to wastes. Finally, neglecting the combined effect of several parameters in the sensitivity analysis might have reduced the accuracy of the sensitivity analyses in the reviewed LCAs. Overall, LCAs conducted on AD-related applications vary widely in terms of scope and consistency, implying that the outcomes may not be as applicable as intended. The identified challenges, issues, and other findings related to this research are expected to help standardize LCA procedures as applied to AD to promote greater comparability. [ABSTRACT FROM AUTHOR]

The foundation industries in the UK were responsible for emitting 42 Mt CO2eq in 2020, which is approximately 10% of the yearly territorial greenhouse gas emissions. The UK government decarbonisation roadmap issued in 2015 predicted that high-tech strategies such as carbon capture and utilisation, hydrogen and biofuels, as well as electrification of processes are key for achieving the climate mitigating targets by 2050. In this study, a critical assessment was performed on the limitations to achieve these high-tech strategies such as biomass availability, capital investment, and technology readiness. The study is the first to use the UK carbon budget values as the resource limit for the high-tech decarbonisation strategies. The findings show that the significant uncertainty associated with the high-tech scenarios limits their decarbonisation potential by 2050. More importantly, to stay within the mid-century carbon budget for the foundation industries, 20–40% reduction in production, through circular economic strategies such as material efficiency and/or changes in product specifications, is required in order to achieve the decarbonisation targets. [ABSTRACT FROM AUTHOR]

Compressed earth blocks (CEBs) are a low-cost, low-carbon construction product, which are well-suited for masonry infill in the Global South. A knowledge gap remains around the technical and socio-economic barriers to CEB adoption. A combined survey and interview study was carried out among architects, CEB manufacturers, and academics within Egypt: firstly, to explore technical and socio-economic barriers to greater adoption of CEBs for masonry infill, and secondly, to identify potential enablers. Many technical challenges still exist, despite the fact that building codes for CEB in Egypt were introduced in 2019. The majority of respondents agreed that socio-economic barriers are more significant than technical barriers. These included CEBs being unfamiliar to most architects and builders, and that most clients perceive CEBs as 'low-quality' or 'inaesthetic'. Most respondents believed that CEBs can achieve ≥25% market share for masonry in Egypt. However, CEB press supply is likely to be a major barrier to scale-up. Suggested enablers included tailored marketing suggestions for low-/middle-income and high-income clients, and deciding at the earliest possible design stage whether to manufacture CEBs on-site or off-site. Mapping the enablers across stakeholders showed that more research is needed to understand the views of CEB press manufacturers and government officials. [ABSTRACT FROM AUTHOR]