411 research outputs found

    LCA to Estimate the Environmental Impact of Dairy Farms: A Case Study

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    Intensive farming is responsible for extreme environmental impacts under different aspects, among which global warming represents a major reason of concern. This is a quantitative problem linked to the farm size and a qualitative one, depending on farming methods and land management. The dairy sector is particularly relevant in terms of environmental impact, and new approaches to meeting sustainability goals at a global scale while meeting society's needs are necessary. The present study was carried out to assess the environmental impact of dairy cattle farms based on a life cycle assessment (LCA) model applied to a case study. These preliminary results show the possibility of identifying the most relevant impacts in terms of supplied products, such as animal feed and plastic packaging, accounting for 19% and 15% of impacts, respectively, and processes, in terms of energy and fuel consumption, accounting for 53% of impacts overall. In particular, the local consumption of fossil fuels for operations within the farm represents the most relevant item of impact, with a small margin for improvement. On the other hand, remarkable opportunities to reduce the impact can be outlined from the perspective of stronger partnerships with suppliers to promote the circularity of packaging and the sourcing of animal feed. Future studies may include the impact of drug administration and the analysis of social aspects of LCA

    Ammonia as a Carbon-Free Energy Carrier: NH3 Cracking to H2

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    In the energy transition from fossil fuels to renewables,hydrogenis a realistic alternative to achieving the decarbonization target.However, its chemical and physical properties make its storage andtransport expensive. To ensure the cost-effective H-2 usageas an energy vector, other chemicals are getting attention as H-2 carriers. Among them, ammonia is the most promising candidate.The value chain of NH3 as a H-2 carrier, consideringthe long-distance ship transport, includes NH3 synthesisand storage at the loading terminal, NH3 storage at theunloading terminal, and its cracking to release H-2. NH3 synthesis and cracking are the cost drivers of the valuechain. Also, the NH3 cracking at large scale is not a maturetechnology, and a significant effort has to be made in intensifyingthe process as much as possible. In this respect, this work reviewsthe available technologies for NH3 cracking, criticallyanalyzing them in view of the scale up to the industrial level

    Assessing opportunities and weaknesses of green hydrogen transport via LOHC through a detailed techno-economic analysis

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    In the transition towards a more sustainable energy system, hydrogen is seen as the key low-emission energy source. However, the limited H2 volumetric density hinders its transportation. To overcome this issue, liquid organic hydrogen carriers (LOHCs), molecules that can be hydrogenated and, upon arrival, dehydrogenated for H2 release, have been proposed as hydrogen transport media. Considering toluene and dibenzyltoluene as representative carriers, this work offers a systematic methodology for the analysis and the comparison of LOHCs, in view of identifying cost-drivers of the overall value-chain. A detailed Aspen Plus process simulation is provided for hydrogenation and dehydrogenation sections. Simulation results are used as input data for the economic assessment. The process economics reveals that dehydrogenation is the most impactful cost-item, together with the carrier initial loading, the latter related to the LOHC transport distance. The choice of the most suitable molecule as H2 carrier, ultimately, is a trade-off between its hydrogenation enthalpy and cost.(c) 2023 The Author(s). Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/)
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