6,160 research outputs found

    Retrofit of water network with regeneration using water pinch analysis

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    This paper presents the development of a new systematic technique for the retrofit of water network with regeneration based on water pinch analysis. The procedure consists of two parts: retrofit targeting and design for a water network with regeneration unit(s). In the targeting stage, retrofit targets (utility savings and capital investment) were determined for a range of process parameters (total flowrate and/or outlet concentration of the regeneration unit) to obtain a savings versus investment curve. Next, the existing water network was re-designed to meet the chosen targets. A case study on paper making process was used to demonstrate the new methodology

    Industrial water management by multiobjective optimization: from individual to collective solution through eco-industrial parks.

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    Industrial water networks are designed in the first part by a multiobjective optimization strategy, where fresh water, regenerated water flow rates as well as the number of network connections (integer variables) are minimized. The problem is formulated as a Mixed-Integer Linear Programming problem (MILP) and solved by the ε-constraint method. The linearization of the problem is based on the necessary conditions of optimality defined by Savelski and Bagajewicz (2000). The approach is validated on a published example involving only one contaminant. In the second part the MILP strategy is implemented for designing an Eco-Industrial Park (EIP) involving three companies. Three scenarios are considered: EIP without regeneration unit, EIP where each company owns its regeneration unit and EIP where the three companies share regeneration unit(s). Three possible regeneration units can be chosen, and the MILP is solved under two kinds of conditions: limited or unlimited number of connections, same or different gains for each company. All these cases are compared according to the global equivalent cost expressed in fresh water and taking also into account the network complexity through the number of connections. The best EIP solution for the three companies can be determined

    On the flexibility of an eco-industrial park (EIP) for managing industrial water

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    In a recent paper, a generic model, based on a multiobjective optimization procedure, for water supply system for a single company and for an eco-industrial park was proposed and illustrated by a park involving three companies A, B and C. The best configuration was identified by simultaneously minimizing the fresh water flow rate, the regenerated water flow rate and the number of connections in the eco-industrial park. The question is now to know what the maximal increase/decrease in pollutant flow rates is, so that the eco-industrial park remains feasible, economically profitable and environmentally friendly. A preliminary study shows that the park can accept an increase of pollutant flow rates of 29% in company A, 12% in company B and only 1% in company C; beyond these limits the industrial symbiosis becomes not feasible. The proposed configuration is not flexible with a very limited number of connections. Indeed, the solution implemented for conferring some flexibility to this network is to increase the number of connections within the park. However, connections have a cost, so the increase of their number needs to remain moderate. The number of connections is augmented until the symbiosis becomes unfeasible, or until the gain for each company to participate to the park becomes lower than a given threshold. Several cases are studied by increasing the pollutant flow rates under two different scenarios: 1) in only one company, 2) in two or three companies simultaneously

    Minimizing water and energy consumptions in water and heat exchange networks.

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    This study presents a mathematical programming formulation for the design of water and heat exchangers networks based on a two-step methodology. First, an MILP (mixed integer linear programming) procedure is used to solve the water and energy allocation problem regarding several objectives. The first step of the design method involves four criteria to be taken into account., ie, fresh water consumption (F1), energy consumption (F2), interconnection number (F3) and number of heat exchangers (F4). The multiobjective optimization Min [F1, F2] is solved by the so-called ɛ-constraint method and leads to several Pareto fronts for fixed numbers of connections and heat exchangers. The second step consists in improving the best results of the first phase with energy integration into the water network. This stage is solved by an MINLP procedure in order to minimize an objective cost function. Two examples reported in the dedicated literature serve as test bench cases to apply the proposed two-step approach. The results show that the simultaneous consideration of the abovementioned objectives is more realistic than the only minimization of fresh water consumption. Indeed, the optimal network does not necessarily correspond to the structure that reaches the fresh water target. For a real paper mill plant, energy consumption decreases of almost 20% as compared with previous studies

    Co-producing commons-based resilience: lessons from R-Urban

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    The co-production of resilience in European urban neighbourhoods is explored based on the experiences from a case study. Within the current ‘resilience imperative’, co-production processes involving multiple stakeholders can be a key factor for increasing cities’ resilience. Co-produced resilience processes are more successful when embedded in collaborative forms of governance such as those associated with urban commons and when fulfilling needed roles with a community. Through the application of the R-Urban approach in a neighbourhood of Colombes (near Paris), the co-production of a commons-based resilience strategy is described. This involved a group of designers as initiators and a number of citizen as stakeholders of a network of civic hubs. The specific strategies involving a participatory setting, collective governance aspects and circular economies are analysed in the light of co-production theories and practices. Internal and external challenges are identified within the implementation process. The nature of conflicts and negotiations in this co-production approach are discussed, and the role of the architects/designers as agents within the process is investigated. Reflections from this example are provided on the limits and promises of this approach and the lessons learned from R-Urban for collaborative civic resilience

    Четверта міжнародна наукова-практична конференція «Комп’ютерне моделювання в хімії і технологіях та системах сталого розвитку»

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    Робота присвячена дослідженню робастності комбінаторного підходу до проектування та модернізації схем промислового підприємства, розробці методів підтримки проектних рішень при проектуванні технологічних схем водного господарства. Запропоновано критерії оцінювання процедур структурної оптимізації схем водного господарства. У відповідності до вказаних критеріїв запропоновано математичне забезпечення для процедури проектування схем водного господарстваThe work is devoted to investigation of robustness of combinatorial approach to the grassroot and retrofit design of industrial water networks. The evaluation criteria of procedures for structural optimization of water networks were proposed. According to the criteria the mathematical model procedures of water networks design was proposed.Работа посвящена исследованию робастности комбинаторного подхода к проектированию и модернизации схем промышленного предприятия, разработке методов поддержки проектных решений при проектировании технологических схем водного хозяйства. Предложены критерии оценки процедур структурной оптимизации схем водного хозяйства. В соответствии с указанными критериями предложено математическое обеспечение для процедуры проектирования схем водного хозяйства

    Circular cities: planning for circular development in European cities

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    Circular development could produce more resource efficient, ecologically regenerative and resilient cities. This development pathway offers many ecological, social and economic benefits. However, there are also many challenges to implementation, not least a heavy reliance on the market to transform urban systems of provision. A regulatory and policy framework is essential for a circular transformation, until circular activities become competitive within existing markets. Spatial and land-use planning can offer this framework. This paper provides insight into the circular development process. It discusses the role of planning in delivering circular development, using examples from four European cities. It identifies the tools for delivery and discusses the inherent limitations of using planning tools to deliver a circular transformation

    Towards an\u2028 EU research and innovation policy agenda for nature-based solutions & re-naturing cities. Final report of the Horizon 2020 expert group on nature-based solutions and re-naturing cities.

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    1. Nature-based solutions harness the power and sophistication of nature to turn environmental, social and economic challenges into innovation opportunities. They can address a variety of societal challenges in sustainable ways, with the potential to contribute to green growth, 'future-proofing' society, fostering citizen well-being, providing business opportunities and positioning Europe as a leader in world markets. \u2028 2. Nature-based solutions are actions which are inspired by, supported by or copied from nature. They have tremendous potential to be energy and resource-efficient and resilient to change, but to be successful they must be adapted to local conditions. \u2028 3. Many nature-based solutions result in multiple co-benefits for health, the economy, society and the environment, and thus they can represent more efficient and cost-effective solutions than more traditional approaches. \u2028 4. An EU Research & Innovation (R&I) agenda on nature-based solutions will enable Europe to become a world leader both in R&I and in the growing market for nature-based solutions. For this, the evidence base for the effectiveness of nature-based solutions needs to be developed and then used to implement solutions. Both need to be done in conjunction with stakeholders. The potential for transferability and upscaling of solutions also requires further investigation. There is also a need to develop a systemic approach that combines technical, business, finance, governance, regulatory and social innovation. \u2028 5. Four principal goals have been identified that can be addressed by nature-based solutions: �� Enhancing sustainable urbanisation through nature-based solutions can stimulate economic growth as well as improving the environment, making cities more attractive, and enhancing human well-being. \u2028 �� Restoring degraded ecosystems using nature-based solutions can improve the resilience of ecosystems, enabling them to deliver vital ecosystem services and also to meet other societal challenges. \u2028 �� Developing climate change adaptation and mitigation using nature-based solutions can provide more resilient responses and enhance the storage of carbon. \u2028 �� Improving risk management and resilience using nature-based solutions can lead to greater benefits than conventional methods and offer synergies in reducing multiple risks. \u2028 6. Based on the four goals, seven nature-based solutions for R&I actions are recommended to be taken forward by the European Commission and Member States: �� Urban regeneration through nature-based solutions \u2028 �� Nature-based solutions for improving well-being in urban areas \u2028 �� Establishing nature-based solutions for coastal resilience \u2028 �� Multi-functional nature-based watershed management and ecosystem restoration \u2028 �� Nature-based solutions for increasing the sustainability of the use of matter and energy \u2028 �� Nature-based solutions for enhancing the insurance value of ecosystems \u2028 �� Increasing carbon sequestration through nature-based solutions \u2028This report was produced by the Horizon 2020 Expert Group on 'Nature-Based Solutions and Re- Naturing Cities', informed by the findings of an e-consultation and a stakeholder workshop. \u202

    Ecological Planning in Built Environment

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    The downgrade of natural environment in the last decades is obvious and the source of problem is located in urban centers. Respectively, the solution of the problem should be sought there. The ecological urban planning aims at the upgrade of urban space, redefining its relationship with residents. The present article methodizes the approach to the ecological urban planning and it is one of the there are too. Particularly, it essays an approach to the ecological urban planning through the management of those elements that compose the operation of a city and concerns the management and the control of green space, energy, water, transports, litter and society. In this way, a catholic consideration and management of the urban space, as well as a set of policies and actions for its upgrade, is achieved. Furthermore, specific references to examples in Greece – problems and perspectives – are made. Coinstantaneously, the study of international and European cities that have achieved a high level of quality of life is the proof that the ecological city does not constitute a utopia, but a challenge for the society, the planners, the local governments and the residents-users. Finally, the institutional frame and the policies, that support the ecological urban planning, are analyzed, as these are the base for its implementation.
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