Summary
The recent pandemic caused by COVID‐19 has globally affected air transport mobility as well as the airline industry in general. Numerous restrictions have been implemented in airline ...transport, which is potentially leading toward severe long‐term impacts on the global airline industry. In this paper, air transport mobility was analyzed regarding Europe (EU) based on the available data from the relevant sources associated with the airline industry. Data were analyzed in specific periods from January to April of 2020, which corresponded with the initialization of the pandemic in the EU and later in its full development. Specifically, two airports were selected in Croatia as case studies to analyze the impact of COVID‐19 more thoroughly on mobility together with the estimation of carbon footprint during the pandemic and the year before the pandemic state. The results revealed that COVID‐19 gradually affected air transport mobility in the EU where a peak was reached in April with a reduction in the number of flights in the EU region reaching more than 89%. Cargo traffic was not significantly affected by the pandemic, and was even increased in some cases due to the supply of medical equipment in the fight against the disease. The analyzed case study revealed the reduction in air transport mobility for selected airports to be more than 96%, which directly affected the reduction of CO2 emissions to factor 1.81 for the commercial airport of Zagreb and 3.49 for the seasonal airport of Split. A normalization of air transport mobility is expected to be reached through a 1‐year period with a continued reduction in the number of flights ranging from 15% to 25%, based on the projections and expectations from relevant EU associations.
Impact of COVID‐19 on airline mobility investigated. Two EU based airports analyzed from mobility, energy and environmental aspect.
Currently, the considerable decline in fossil fuel resources and the high rise in vehicle emissions have prompted researchers and governments to formulate strategies for sustainable energy ...development. In addition to imposing strict laws, promoting sustainable energy sources such as the development of new types of non-fossil fuels has been considered a suitable direction for the roadmap to healing the Earth’s environment. Biomass sources have affirmed huge potentials in the production of biofuels. In the pathway of searching renewable biofuels, it is found that that 2,5-dimethylfuran (DMF) can become a promising fuel because it is synthesized from lignocellulose biomass, which is an available feedstock for the production of prospective fuels. Indeed, recent review studies have focused in great detail on engine performance evaluation using DMF but seemed to have gaps in emission characteristics. In this work, the controversial issues of emissions from spark and compression ignition engines during the DMF combustion were completely assessed. Indeed, the mechanism of formation and oxidation of DMF compounds during combustion was clearly described to serve as the basis for analyzing and comparing the pollution emission behavior of different fuels. More importantly, gaseous emissions, PM characteristics, and soot tendency from spark and compression ignition engines were thoroughly evaluated on the basis of the experimental and numerical data. In general, DMF has shown outstanding advantages upon emissions compared to fossil fuels; however, the impacts of DMF on the engine durability and fuel system should be further investigated to have a comprehensive analysis of this biofuel class.
The primary source of the power for marine industry comes from large two-stroke low-speed marine diesel engines. The more severe emission regulations are forcing the ship owners to use more efficient ...engines. The electronically controlled engines were introduced which comply with the needs. The electronically controlled engine requires more calibration effort and is mostly based on calibration from the testbed with some environmental condition corrections. In this paper, the physical engine model was introduced including AVL multi-zone combustion model and self-developed models for turbocharger, charge air cooler, injector and rail model. Typical engine failures were simulated. The demonstrated engine model was based on six-cylinder large two-stroke low-speed marine diesel engine and verified with the measurements from the engine testbed. The model calibration was done for the pressure traces and available mean value measurement for 40%, 60% and 100% of engine load. The results show 2–7% of relative deviation of the BMEP, 1–2% relative deviation for in-cylinder peak pressure and almost no deviation in scavenged air pressure. The model showed representative engine behavior and was used for studies on engine failure simulation. The presented engine model can be used for optimization and diagnostic purposes.
•Using the optimized proposed system leads to a payback period (PBP) of 5.66 years.•The levelized cost of electricity is 0.2568 $.(kWh)-1.•Primary energy consumption and CO2 emission are improved by ...30.03 and 17.65%.•Electrical load is the most effective factor on energy and environmental indicators.•Inflation has a stronger impact than discount rate on the optimal results.
A hybrid photovoltaic-wind turbine driven system with H2 storage unit is proposed for a residential building complex in which an emerging technology, called desiccant enhanced evaporative (DEVAP) cooling system, is utilized to enhance the performance by heat recovery during the cooling season. The best design is found using dynamic multi-objective optimization (MUOBOP), as an advanced method, while the results are compared with the conventional optimization approach without heat recovery in the cooling season as the base case. Energy, environmental, and economic aspects are considered as the objective functions. Impact of changing electrical load, as well as discount and inflation rates on the optimization results is also determined through a detailed sensitivity analysis. According to the results, primary energy reduction percent (PERP) is improved by 30.03%, while it has the most sensitivity to the electrical load variation. Payback period (PBP) and levelized cost of electricity (LCOE) have also 21.93 and 32.40% enhancement. In addition, with 20.4 and 17.8% increase, changing the inflation rate from 0.80 to 1.20 of the initial case has the strongest impact on PBP and LCOE, respectively. Moreover, carbon dioxide reduction percent (CDRP) exhibits the highest variation when the electrical load changes from 80.0% to 120.0% of the initial case. Employing dynamic MUOBOP leads to 17.65% improvement for that performance indicator, as well.
The novel potential of hybrid phase change materials (PCM) as a mix of animal fat, specifically pork fat (lard), with edible and waste oil from the food processing industry was investigated in this ...paper. Lard is a relatively accessible phase change material of organic origin, with a significantly lower unit price when compared to conventional PCM materials (wholesale price of lard can be less than 0.50 €/kg). On an annual basis, a large amount of lard is thrown away because it has become inedible from a nutritional point of view. Experimental results directed that the addition of oils can improve the thermal constants of lard such as thermal conductivity, volumetric heat capacity, with the thermal diffusivity being reduced. The best result was achieved for a hybrid PCM as a combination of pork fat and waste burnt oil as the thermal conductivity was improved by 1.4% and the volumetric heat capacity by 11% with respect to the base PCM, i.e., pork fat (lard). The novel proposed hybrid PCMs are more economically viable, enabling the utilization of waste resources, and securing less environmental impact when compared to conventional PCMs as organic materials. The possible application of lard should be further investigated for specific engineering applications, such as thermal energy storage.
Graphic abstract
The role of smart technologies can become very important and useful to solve the main population issues nowadays and provide foundations for a sustainable future. A smart approach is an opportunity ...for knowledge integration, necessary to solve crucial problems of contemporary societies. Today, the main challenge is to reduce the effects of global warming and ensure a balanced economic development of society. The close collaboration of all involved engineering professions is mandatory to achieve interdisciplinary synergies and can bridge challenging engineering tasks. Intense research efforts should be directed towards balanced resource utilization, efficient energy conversion technologies, integration of renewable energy systems, effective approaches to enable circular economy framework, effective process integration as well as other issues important to the population. This review editorial is primarily focused on the contributions presented at the 3rd International Conference on Smart and Sustainable Technologies held in Split, Croatia, in 2018 (SpliTech2018). The SpliTech2018 conference was a multidisciplinary event with research topics related to the main conference tracks, i.e. Smart City/Environment, Energy, Engineering Modelling and e-Health. The strategic focus of the conference was to help solve crucial issues of our times, mainly related to the sustainability and smart utilisation of limited and valuable resources. This contribution brings new ideas and discusses present issues as well as challenges that should lead towards a sustainable future based on the application of the smart technologies. The herein addressed papers bring together latest research progress into four main topic areas: (i) Green Buildings, Energy Use and Consumption, (ii) Solar Energy Utilisation, (iii) Efficiency and Waste Elimination, (iv) Smart Cities and Internet of Things. The main results of this introduction review article include a discussion of different concepts and technologies that bring further development on a broad range of topics focused on efficiency improvement, smart and sustainable resource management, cleaner production concepts and on the discussion of the various actions which would lead towards a sustainable future.
The rapid development and implementation of smart and IoT (Internet of Things) based technologies have allowed for various possibilities in technological advancements for different aspects of life. ...The main goal of IoT technologies is to simplify processes in different fields, to ensure a better efficiency of systems (technologies or specific processes) and finally to improve life quality. Sustainability has become a key issue for population where the dynamic development of IoT technologies is bringing different useful benefits, but this fast development must be carefully monitored and evaluated from an environmental point of view to limit the presence of harmful impacts and ensure the smart utilization of limited global resources. Significant research efforts are needed in the previous sense to carefully investigate the pros and cons of IoT technologies. This review editorial is partially directed on the research contributions presented at the 4th International Conference on Smart and Sustainable Technologies held in Split and Bol, Croatia, in 2019 (SpliTech 2019) as well as on recent findings from literature. The SpliTech2019 conference was a valuable event that successfully linked different engineering professions, industrial experts and finally researchers from academia. The focus of the conference was directed towards key conference tracks such as Smart City, Energy/Environment, e-Health and Engineering Modelling. The research presented and discussed at the SpliTech2019 conference helped to understand the complex and intertwined effects of IoT technologies on societies and their potential effects on sustainability in general. Various application areas of IoT technologies were discussed as well as the progress made. Four main topical areas were discussed in the herein editorial, i.e. latest advancements in the further fields: (i) IoT technologies in Sustainable Energy and Environment, (ii) IoT enabled Smart City, (iii) E-health – Ambient assisted living systems (iv) IoT technologies in Transportation and Low Carbon Products. The main outcomes of the review introductory article contributed to the better understanding of current technological progress in IoT application areas as well as the environmental implications linked with the increased application of IoT products.
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Being declared a global emergency, the COVID-19 pandemic has taken many lives, threatened livelihoods and businesses around the world. The energy industry, in particular, has experienced tremendous ...pressure resulting from the pandemic. In response to such a challenge, the development of sustainable resources and renewable energy infrastructure has demonstrated its potential as a promising and effective strategy. To sufficiently address the effect of COVID-19 on renewable energy development strategies, short-term policy priorities should be identified, while mid-term and long-term action plans should be formulated in achieving the well-defined renewable energy targets and progress towards a more sustainable energy future. In this review, opportunities, challenges, and significant impacts of the COVID-19 pandemic on current and future sustainable energy strategies were analyzed in detail; while drawing from experiences in identifying reasonable behaviors, orientating appropriate actions, and policy implications on the sustainable energy trajectory were also mentioned. Indeed, the question is that whether the COVID-19 pandemic will kill us or provide us with a precious lesson on future sustainable energy development.
•Two-faced impacts of COVID-19 pandemic on global energy system were evaluated.•Opportunities and challenges of the shift progress to clean energy were analyzed.•Drawn lessons, strategies for the future, and policy implications were mentioned.
The idea of using convective vortices as heat engines as the source of useful mechanical work for carbon free electricity production is really intriguing one. On the other side technical realisation ...of assumed alternative energy concepts represents an exceptional engineering challenge, but with huge potential benefits to society. Foundations and motivation for proposal of the herein elaborated alternative energy concepts lies in the existence of the natural vortex phenomena's, such as tornadoes, waterspouts and dust devils. Namely, they are clear and obvious proof that it is possible to obtain and maintain vortex in specific surrounding circumstances. The main energy source for the herein assumed energy concept is heat input that can be ensured in the form of waste industrial heat, for example from convectional power plants, or even solar energy as a renewable energy source. Therefore in the recent decades alternative energy concepts have been proposed, where the main feature is a specific fluid flow (vortex) that is assumed to be produced and maintained artificially from available heat input. By proposed alternative energy concepts it is possible to obtain significant increase in the energy efficiency of the existing convectional power plants or even to produce carbon free electricity. Thus, this paper provides insight in the main research outcomes from recent decades (a state of the art), where all important issues have been addressed together with the discussed perspective for future research activities in this challenging and demanding research topic.
•Alternative renewable based energy concepts were analysed.•Utilization of the convective vortices as heat engines was considered.•Obtained review of the vortex based alternative energy concepts.•Present state and future perspective was addressed.
Smart energy technologies Nižetić, Sandro
International journal of energy research,
January 2021, 2021-01-00, 20210101, Letnik:
45, Številka:
1
Journal Article
PDF
