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AbstractThe effect of heat distribution or inter-heating on the total energy requirement for CO2 stripping is investigated. Here we look at retrofit design of an existing column. It means the height and diameter of the stripper is given. The results show that inter-heating can have both negative and positive effects on the total energy requirement. If only one heat source at constant temperature exist, the inter-heating will increase the total energy requirement. If there are other heat sources at different temperatures, inter-heating can be beneficial. It depends on the energy price of the different heat sources and the temperature profile of the column. If there are some hot streams available to utilize the heat in the inter-heater, the total energy requirement will decrease. As a case study utilizing heat from lean amine in the inter-heater is investigated. The simulation results show a saving up to 6.4 and 11.3 percent by one and two inter–heater respectively

An important issue for optimal operation and plantwide control is to find the degrees of freedom available for optimal operation. A previously published systematic approach to determine the steady state degrees of freedom is expanded to take into account the active charge as a possible degree of freedom in cyclic processes. Additional degrees of freedom related to the composition of the circulating refrigerant are also discussed. Two liquified natural gas (LNG) processes of current interest, the C3MR process from Air Products and the mixed fluid cascade (MFC) process developed by Statoil-Linde LNG Technology Alliance, are studied with respect to operational degrees of freedom.

The primary goal of this paper is to investigate the most cost-effective decommissioning and refurbishment investment decision for existing gas networks. An optimization model is developed and tested on a real test bed in an Austrian federal state. The analysis is performed from the network operator’s perspective and depicts different network decommissioning or refurbishment options under the decision of supplying or not supplying available gas demands. Whether or not there is ensured supply, we find that smaller gas networks (in terms of pipeline capacity and network length) are needed in the future. Analyzed shadow prices indicate that a balance/trade-off between the cost-optimal gas network design with and without ensured supply could lead to a robust and economically competitive future for downsized gas networks. The results demonstrate that it is necessary to socialize network operators’ costs among the remaining consumers connected to the network in the future. This adds a cost component to consumers, which needs to be considered when determining the profitability of sustainable alternatives to natural gas.

In accordance with current sustainable development objectives, it is intended to implement innovative and sustainable solutions at economic, environmental, and functional levels, boosting the construction sector to increasingly contribute to society. Expanded cork is an alternative to sand aggregate in improving the thermal insulating properties of renders. In addition, other materials can be incorporated as aggregates in an attempt to contribute to both the improvement of the physical characteristics that the render must fulfil as well as the improvement of thermal behaviour (if possible). In this sense, bio-based materials generated by the aquaculture sector, such as oyster shells, can contribute as a bio-based insulation material for thermal renders. In this study, thermal natural hydraulic lime mortars were produced from a mixture of expanded cork (EC) insulating aggregate and oyster shells (OSs). The percentages of replacing EC by OSs were 20, 30, 40, and 50%. The tests were carried out in fresh and hardened states. The studied mortars presented a thermal conductivity and compressive strength of 0.151 W/(m·K) and 0.63 MPa, respectively. The most interesting performance between thermal conductivity and compressive strength was for the composite with 50% of each bio-based material. The potential of incorporating oyster shells as a bio-based insulation material could contribute to a sustainable blue circular economy.

ABSTRACT Three graduate-level short courses on ecological agriculture and food systems were held in 1995–1997 in Norway to introduce systems thinking, creative research methods, and innovative learning approaches. In 1999, a three-day evaluation and planning workshop was held to assess course impacts, to determine relative importance of content areas, to compare learning methods with special attention to case studies, and to vision and develop action plans for future education in the region. Students and faculty agreed that soft systems research methods and varied learning processes in the course were more valuable than specific technical content that can be learned in other venues. Nine priority education areas were identified for ecological agriculture: (1) systems thinking, (2) research methods, (3) farmer/stakeholder participation, (4) improving production methods, (5) relating agriculture to food systems, (6) learning about learning, (7) values and ethics, (8) faculty development and institutional ch...

Spatial planning has to deal with trade-offs between various stakeholders’ wishes and needs as part of planning and management of landscapes, natural resources and/or biodiversity. To make ecosystem services (ES) trade-off research more relevant for spatial planning, we propose an analytical framework,which puts stakeholders, their land-use/management choices, their impact on ES and responses at the centre. Based on 24 cases from around the world, we used this framing to analyse the appearance and diversity of real-world ES trade-offs. They cover a wide range of trade-offs related to ecosystem use, including: land-use change, management regimes, technical versus nature-based solutions, natural resource use, and management of species. The ES trade-offs studied featured a complexity that was far greater than what is often described in the ES literature. Influential users and context setters are at the core of the trade-off decision-making, but most of the impact is felt by non-influential users. Provisioning and cultural ES were the most targeted in the studied trade-offs, but regulating ES were the most impacted. Stakeholders’ characteristics, such as influence, impact faced, and concerns can partially explain their position and response in relation to trade-offs. Based on the research findings, we formulate recommendations for spatial planning.