Environmental evaluation of european ammonia production considering various hydrogen supply chains

Room-temperature chemical looping hydrogen production mediated by electrochemically induced heterogeneous Cu(I)/Cu(II) redox

Negative net global warming potential hydrogen production through biomass gasification combined with chemical looping: Environmental and economic assessments

Reducing red meat consumption is an effective tactic for decreasing environmental impact of diets while maintaining nutritional adequacy, healthiness, and overall consumer acceptability. Still, dietary change in favor of plant foods is a controversial climate mitigation measure, especially in the Nordic region where agri-food heritage is linked to ruminant husbandry. In this study we aimed to explore sustainable diets for the Norwegian context by (1) investigating the environmental impacts of nutritionally optimized diets following the Nordic Nutrition Recommendations 2023 (NNR2023), (2) estimating potential for environmental impact reduction across scenarios of meat and legume consumption, and (3) identifying nutritional challenges. Quadratic optimization was employed to minimize departure from the average observed Norwegian diet while meeting nutrient, health, and carbon footprint constraints. The diet of Norwegian adults was estimated based on results from the national dietary survey Norkost 3. Global warming potential (GWP), freshwater and marine eutrophication, terrestrial acidification, water use, and transformation and use of land were calculated using data from the Norwegian Life Cycle Assessment Food Database version 01. Diets were optimized to meet NNR2023 nutrition and health recommendations for nutrients and food groups. Optimizations were first run without constraints on GWP, for three diet scenarios: (1) nutrients and health-based targets for food amounts (NNR2023), (2) nutrients and health-based targets for food amounts with ruminant meat ≥ observed intake (62 g/day) (Ruminant), and (3) nutrients and health-based targets for food amounts with legumes content ≥40 g/day (Legumes). Then, GWP constraints were applied in 5% increments until no solution was found. The optimal diet for each scenario was defined as the diet with the largest feasible reduction in GWP (NNR2023+/Ruminant+/Legumes+). Optimizing the diet to meet nutrient and health constraints alone resulted in a modest decrease in GWP (NNR2023); retaining ruminant meat consumption (Ruminant) impeded the reduction (-9% vs. 0%). Diets following NNR2023 nutrient and health constraints alone were feasible up until a 30% reduction in GWP (NNR2023+). A 35% reduction in GWP was achieved when legumes were added to the diet (Legumes+), while diets retaining 62 g of ruminant meat were not identified beyond a 15% reduction in GWP (Ruminant+). Sodium and selenium were the strongest limiting constraints in all scenarios. Diets with a 40% reduction in GWP were identified when nutrient constraints were lowered from the Recommended Intake to the Average Requirement (NNR2023+/Legumes+). Reductions in GWP coincided with reductions in all measured environmental indicators except marine eutrophication. The NNR2023 guidelines outline diets that have generally lower environmental impacts than the average Norwegian diet, though outcomes depend on distribution of meat and legume consumption in the diet. Regardless of degree of environmental impact reduction, diets following NNR2023 guidelines will require significant dietary changes compared to observed intake, including an increase in consumption of fruits, vegetables, and grains, and a strong decrease in consumption of red meat, total meat, and discretionary foods. Preventing the model from removing any ruminant meat from the diet limited GWP reduction to 15% and induced considerable changes in intake of other food groups, especially a decrease in other types of meat.

Any technology needs to be environmentally sustainable to be successful. The biomass gasification technology is often perceived to be carbon neutral. However, these perceptions need to be confirmed using a rigorous life-cycle assessment (LCA). This chapter presents a sustainability assessment of the biomass gasification technology for the production of ammonia. Conventional ammonia production that is based on hydrocarbon feedstock is known to be energy-intensive and tends to make a substantial contribution to the global greenhouse gas emissions. Therefore, an environmentally benign feedstock in the form of biomass is proposed as an alternative. Biomass, when used as a feedstock for ammonia production, is expected to yield a considerable reduction in environmental impacts. This chapter undertakes a cradle-to-gate life-cycle assessment (LCA) for ammonia production from biomass through the gasification route. Three different biomass feedstocks, namely wood, straw, and bagasse, are compared for their environmental sustainability by using different environmental indicators. Furthermore, these feedstocks are modeled for cultivation in three different geographical regions. The results suggest that different biomass feedstocks and geographical regions have their own niche environmental advantages. The global warming potential (GWP) for the straw-based ammonia production was found to be close to natural gas-based ammonia production. Contrariwise, 78% reduction in GWP compared to natural gas-based ammonia production is noticed when bagasse is used as a feedstock for ammonia production.

This paper presents an analysis that aimed to quantify the consequences of modelling choices in the life cycle assessment of composting by investigating the influence of composting management practices and the influence of the selected marginal product for substitution. In order to investigate the different influencing factors, a set of 11 scenarios were defined. The scenario results revealed that increasing the turning frequency of the input material leads to a Global warming potential (GWP) reduction of approx. 50%. However, there is a trade-off between GWP reduction and increases in other environmental impacts, including acidification potential (AP), ozone formation potential (OFP), and stratospheric ozone depletion potential (ODP). GWP and AP can also be reduced by optimal exhaust gas filter maintenance, although this causes OFP and ODP to increase. The most relevant factor for GWP is the choice of substituted products. When peat for horticulture can be replaced, GWP can be substantially lowered while hardly affecting other environmental impacts.

Hydrogen (H 2 ) has been widely considered the clean energy carrier of choice for emerging renewable energy generation technologies. However, H 2 is a secondary fuel mainly derived from natural gas. Over the past decades, research on developing H 2 production technology that reduces carbon emissions has gained momentum due to increasing atmospheric levels of carbon dioxide (CO 2 ). This study proposed a new sorption‐enhanced (SE) and biochar‐direct (BD) integrated chemical looping system for hydrogen production from biomass gasification, using iron oxide as an oxygen carrier, calcium oxide (CaO) as a CO 2 adsorbent, and biochar as a reducing agent. In this study, a thermodynamic model with the proposed sorbent‐enhanced biochar‐direct (SE‐BD) chemical looping hydrogen production (CLHP) process has been developed using an Aspen Plus simulator. The effect of important process parameters, including the reactor temperature, the syngas composition, and the molar feeding ratios of iron oxide/syngas, biochar/syngas, and CaO/syngas on the performance in terms of product gas composition, iron oxide conversion, H 2 yield, H 2 purity, and reactor heat demand has been evaluated. The simulation results show that the addition of biochar significantly enhances the overall hydrogen yield compared to the conventional CLHP process; whereas the addition of CaO‐sorbent was found to significantly improve the H 2 purity. Moreover, the exothermic lime carbonation further reduced the thermal requirements of the process. In addition, this thermodynamic simulation demonstrates that the sorbent‐enhanced biochar‐direct chemical looping hydrogen production (SE‐BD‐CLHP) process can achieve a wide operating window for complete iron oxide (Fe 3 O 4 ) reduction by adjusting the CaO and biochar feeding ratio.

Life Cycle Assessment of Natural Gas-based Chemical Looping for Hydrogen Production

Life cycle assessment of hydrogen production via iron-based chemical-looping process using non-aqueous phase bio-oil as fuel

Techno-economic assessment of hydrogen production processes based on various natural gas chemical looping systems with carbon capture

Hydrogen and ammonia production from low-grade agricultural waste adopting chemical looping process

Life Cycle Assessment of Hydrogen Production from Imported Green Ammonia: A Korea Case Study

Advanced anaerobic co-digestion of hydrothermally pretreated wheat straw: Process performance, techno-economic and life cycle assessment.

Environmental evaluation of hydrogen production employing innovative chemical looping technologies – A Romanian case study

SummaryIn the last decade, numerous life cycle assessments (LCAs) on environmental impacts of electricity generation with carbon capture and storage (CCS) have been conducted. This meta‐analysis comprises 15 LCAs of the three CCS technologies (postcombustion, oxyfuel, precombustion) with a focus on greenhouse gas reduction for different regions (Europe, United States, Japan, global), different fuels (hard coal, lignite, natural gas), and different time horizons (between the present and 2050). It presents a condensed overview of methodological variations, findings, and conclusions gathered from these LCAs.All LCAs show the expected reduction in global warming potential but an increase in many other impact categories, regardless of capture technology, time horizon, or fuel considered. Three parameter sets have been identified that have a significant impact on the results: (1) power plant efficiency and energy penalty of the capture process, (2) carbon dioxide capture efficiency and purity, and (3) fuel origin and composition.This meta‐analysis proves that LCA is a helpful tool to investigate the variety of environmental consequences associated with CCS. However, there are differences in the underlying assumptions of the LCAs as well as methodological shortcomings that yield heterogeneity of results. Without a better understanding of the technology, it is not possible to give a comprehensive picture. There also remains a wide field of subjects and technologies that have not yet been covered.

Sustainable retrofitting for shipping: Assessing LNG dual fuel impact on global warming potential through life cycle assessment