Biogas is produced from biomass by means of digestion. Treated to so-called ‘green gas’, it can replace natural gas. Alternatively, biogas can be used to produce electrical power and heat in a combined heat power (CHP) installation. In 2014 global biogas production was only 1% of natural gas production. In the future, biogas is expected to play a role in specific applications, e.g. to provide flexibility in electricity supply
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The production of biogas through anaerobic digestion is one of the technological solutions to convert biomass into a readily usable fuel. Biogas can replace natural gas, if the biogas is upgraded to green gas. To contribute to the EU-target to reduce Green House Gases emissions, the installed biogas production capacity and the amount of farm-based biomass, as a feedstock, has to be increased. A model was developed to describe a green gas production chain that consists of several digesters connected by a biogas grid to anupgrading and injection facility. The model calculates costs and energy use for 1 m3 of green gas. The number of digesters in the chain can be varied to find results for different configurations. Results are presented for a chain with decentralized production of biogas, i.e. a configuration with several digesters, and a centralized green gas production chain using a single digester. The model showed that no energy advantage per produced m3 green gas can be created using a biogas grid and decentralized digesters instead of one large-scale digester. Production costs using a centralized digester are lower, in the range of5 Vct to 13 Vct per m3, than in a configuration of decentralized digesters. The model calculations also showed the financial benefit for an operator of a small-scale digester wishing to produce green gas in the cooperation with nearby other producers. E.g. subsidies and legislation based on environmental arguments could encourage the use of decentralized digesters in a biogas grid.
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A model to describe biogas transport costs in a regional grid is presented. In the model biogas is collected to a central location by transport through dedicated pipelines. Costs have been calculated for two different lay-outs of the grid i.e. star and fishbone lay-out. The costs depend on the covered area and the size of the digesters. Model results show that in a star layout transport costs for small scale digesters are much higher than costs for large scale digesters and costs in a fishbone lay-out are lower than costs in a star lay-out.
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Global society is confronted with various challenges: climate change should be mitigated, and society should adapt to the impacts of climate change, resources will become scarcer and hence resources should be used more efficiently and recovered after use, the growing world population and its growing wealth create unprecedented emissions of pollutants, threatening public health, wildlife and biodiversity. This paper provides an overview of the challenges and risks for sewage systems, next to some opportunities and chances that these developments pose. Some of the challenges are emerging from climate change and resource scarcity, others come from the challenges emerging from stricter regulation of emissions. It also presents risks and threats from within the system, next to external influences which may affect the surroundings of the sewage systems. It finally reflects on barriers to respond to these challenges. http://dx.doi.org/10.13044/j.sdewes.d6.0231 LinkedIn: https://www.linkedin.com/in/sabineeijlander/ https://www.linkedin.com/in/karel-mulder-163aa96/
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The ‘Grand Challenges’ of our times, like climate change, resource depletion, global inequity, and the destruction of wildlife and biodiversity can only be addressed by innovating cities. Despite the options of tele-working, tele-trading and tele-amusing, that allow people to participate in ever more activities, wherever they are, people are resettling in cities at an unprecedented speed. The forecasted ‘rurification’ of society did not occur. Technological development has drained rural society from its main source of income, agriculture, as only a marginal fraction of the labour force is employed in agriculture in the rich parts of the world. Moreover, technological innovation created new jobs in the IT and service sectors in cities. Cities are potentially far more resource efficient than rural areas. In a city transport distances are shorter, infrastructures can be applied to provide for essential services in a more efficient way and symbiosis might be developed between various infrastructures. However, in practice, urban infrastructures are not more efficient than rural infrastructures. This paper explores the reasons why. It digs into the reasons why the symbiotic options that are available in cities are not (sufficiently) utilised. The main reason for this is not of an economic nature: Infrastructure organisations are run by experts who are part of a strong paradigmatic community. Dependence on other organisations is regarded as limiting the infrastructure organisation’s freedom of action to achieve its own goals. Expert cultures are transferred in education, professional associations, and institutional arrangements. By 3 concrete examples of urban systems, the paper will analyse how various paradigms of experts co-evolved with evolving systems. The paper reflects on recent studies that identified professional education as the initiation into such expert paradigms. It will thereby relate lack of urban innovation to the monodisciplinary education of experts and the strong institutionalised character of expertise. https://doi.org/10.1007/978-3-319-63007-6_43 LinkedIn: https://www.linkedin.com/in/karelmulder/
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Energy policies are vital tools used by countries to regulate economic and social development as well as guarantee national security. To address the problems of fragmented policy objectives, conflicting tools, and overlapping initiatives, the internal logic and evolutionary trends of energy policies must be explored using the policy content. This study uses 38,277 energy policies as a database and summarizes the four energy policy objectives: clean, low-carbon, safe, and efficient. Using the TextCNN model to classify and deconstruct policies, the LDA + Word2vec theme conceptualization and similarity calculations were compared with the EISMD evolution framework to determine the energy policy theme evolution path. Results indicate that the density of energy policies has increased. Policies have become more comprehensive, barriers between objectives have gradually been broken, and low-carbon objectives have been strengthened. The evolution types are more diversified, evolution paths are more complicated, and the evolution types are often related to technology, industry, and market maturity. Traditional energy themes evolve through inheritance and merger; emerging technology and industry themes evolve through innovation, inheritance, and splitting. Moreover, this study provides a replicable analytical framework for the study of policy evolution in other sectors and evidence for optimizing energy policy design
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At gas stations, tetrahydrothiophene (THT) is added to odorless biogas (and natural gas) for quick leak detection through its distinctive smell. However, for low bio and natural gas velocities, evaporation is not complete and the odorization process is compromised, causing odor fluctuations and undesired liquid accumulation on the pipeline. Inefficient odorization not only endangers the safety and well-being of gas users, but also increases gas distribution companies OPEX. To enhance THT evaporation during low bio and natural gas flow, an alternative approach involves improve the currently used atomization process. Electrohydrodynamic Atomization (EHDA), also known as Electrospray (ES), is a technology that uses strong electric fields to create nano and micro droplets with a narrow size distribution. This relatively new atomization technology can improve the odorization process as it can manipulate droplet sizes according to the natural and bio gas flow. BiomEHD aims to develop, manufacture, and test an EHDA odorization system for applying THT in biogas odorization.
