Numerical Analysis of Harmful Environmental Impact of Accidental Explosion at a Hydrogen Filling Station Environmental Impact of an Accident Hydrogen Explosion at a Gas Station

The purpose of this study is to evaluate numerically the consequences of a hydrogen-air mixture explosion at a vehicle hydrogen filling station. The physical process of the explosion, which takes place after the hydrogen gas release into the air due to the accidental destruction of a number of high-pressure storage cylinders, is considered. The blast pressure wave moves in all directions from the epicenter of the accident, gradually losing its intensity and having a negative shock impact on the service personnel of the filling station and the structures of the surrounding buildings. The scale of the accident depends on the number of destroyed cylinders, which determines the size of the hydrogen-air cloud and the power of the explosion. The degree of negative consequences for the environment depends on the maximum overpressure in the blast wave front. Numerical obtaining of spatial pressure distributions in the area of the accident based on a hydrogen explosion mathematical modeling makes it possible to separate zones that are dangerous to human health and building structures strength. The direct problem of gas dynamics of combustion products of a hemispherical cloud of a stoichiometric hydrogen-air mixture in the surface layer of the atmosphere is considered. The mathematical model of an instantaneous hydrogen explosion takes into account the three-dimensional and non-stationary nature of the propagation of the explosion wave, the compressibility of the gas flow, the complex terrain, the shape and initial concentration of the cloud of hydrogen combustion products, and their thermodynamic parameters. The model makes it possible to obtain three-dimensional fields of maximum overpressure, which are the basis for deterministic assessment of the consequences of an accident for human health and the integrity of structures in the area of the explosion. The presented computer technology allows security experts to identify potential dangerous zones by means of mathematical modeling, recommend effective protective measures to mitigate or even eliminate the negative consequences of the blast wave environmental impact

Recycling Possibilities of Wood-Cement Particle Board Manufacturing Waste

Wood-cement particle boards are gaining popularity within construction materials as they combine natural fiber architectural value with Portland cement durability. The production of the material is associated with processing the produced fiberboards, which includes cutting, grinding, and polishing. The remaining wood-cement dust residues are classified as production waste, which is now deposited in the dump and gives extra expenditure for the enterprise. The utilization of wood-cement dust would also benefit the circular economy and reduce the environmental impact of the production process. Two scenarios are analyzed in this research, and the life cycle assessment (LCA) tool with SimaPro software is compared. The first scenario is associated with the partial replacement of Portland cement with wood-cement dust powder. The second scenario offers re-activation of the wood-cement dust at 450 °C to obtain binder properties. Both materials' mechanical strength is comparable, reaching 10 MPa after 28d curing. To maintain target strength, 70 % of Portland cement can be replaced. To produce 1 t of binder by heating at 450 °C, 1.2 t of wood-cement dust is needed as natural moisture evaporates, and wood dust particles go through pyrolysis, giving extra heat and CO2 emissions as well. LCA results indicate the 70% replacement of Portland cement reduces CO2 emissions from 597 kg of CO2/ton of CEM II/A-LL 42,5 to 179 kg of CO2/ton, while the second scenario is associated with high energy consumption during burning of the binder and increased CO2 value due to fossil fuel consumption and CO2 release from burning organic compounds in the material

Factors Affecting Waste Recycling Habits in Latvia - Results From an Online Survey

While waste sorting is compulsory within the European Union, not all households in Latvia have the access to the waste sorting bins nor wish to recycle their household waste even if the bins are available. Despite the fact that several surveys have been conducted concluding that the recycling rates in Latvia are improving with every year, it is still not clear what are the factors that determine waste sorting and sustainable consumption habits in Latvia. Therefore, the goal of this study was to identify factors that could be seen as predeterminants for waste sorting and sustainable consumption habits among the citizens of Latvia. Prior to the survey, an extensive literature search was made to identify and understand what are the most prominent socio-demographic and other factors that could affect waste sorting, plastic consumption, or sustainable behaviour habits. Literature findings revealed a heterogeneity of factors that could not be fully attributed nor classified based on the region of the country, some cultural aspects, the customs, or specific socio-demographic factors, indicating that the sustainable behaviour was mostly country -specific, and, therefore, could not be generalised to all the countries. Based on these findings an online survey was made. It was conducted for a one month period between the end of January and the end of February 2024. The data from different age groups of citizens of Latvia were collected. The results of the survey should shed a light on the factors that could be seen as determinants for waste sorting and sustainable consumption habits (or lack of them) among the inhabitants of Latvia. These results could help to develop better communication strategies based on the survey results to help to improve recycling indicators in Latvia

Development of Green Alkali-Activated Mortar Based on Biomass Wood Ash

Portland cement (PC) is the most commonly used binder material for producing concrete. Nonetheless, increasing concerns have been attached to its manufacture which is highly energy-intensive and generates a large quantity of greenhouse gases. Developing cement-free alkali-activated materials as eco-binders is a sustainable replacement for PC, especially the possibility to utilize industrial by-products as precursors significantly reduces the environmental burden due to waste disposal. Many investigations have been reported successfully using coal fly ash, slag, and metakaolin as precursors. However, owing to the low reactivity, studies regarding biomass wood ashes (BWA) in the field of alkali-activated materials are still limited. To produce a green cementless alkali-activated mortar material, in this study, biomass fuel by-products -biomass wood bottom ash (BWBA) at 0, 25, 50, 75, and 100% as well as biomass wood fly ash (BWFA) at 100, 75, 50, 25 and 0%- were binarily used as precursors. Sodium hydroxide (NaOH) at 10 mol/L and calcium hydroxide (Ca(OH)2)at 0 and 20% by binder mass were applied together as alkali activators. Recycled sand, substituting natural sand, was adopted as fine aggregate at an aggregate/binder ratio of 2 to reduce the consumption of non-renewable natural resources. The objective is to investigate the influence of various mix ratios of BWFA and BWBA on the produced alkali-activated mortar, and identify the effects of Ca(OH)2. Compressive and flexural strength were tested to evaluate the evolution of mechanical performance. A cradle-to-gate lifecycle assessment was conducted to analyze the environmental impacts. The results reveal that the alkali-activated mortar has less environmental impact compared to the traditional PC mortar. NaOH solution is the primary source of environmental influence and BWA only contributes to very limited impacts. When 50% BWFA and 50% BWBA are binarily used, the greatest mechanical properties are achieved. The usage of Ca(OH)2 effectively improves the mechanical strength by a maximal 350% (flexural strength) and 320% (compressive strength), but meanwhile increases environmental burdens

Assistance in Model Driven Development: Toward an Automated Transformation Design Process

Model driven engineering aims to shorten the development cycle by focusing on abstractions and partially automating code generation. We long lived in the myth of automatic Model Driven Development (MDD) with promising approaches, techniques, and tools. Describing models should be a main concern in software development as well as model verification and model transformation to get running applications from high level models. We revisit the subject of MDD through the prism of experimentation and open mindness. In this article, we explore assistance for the stepwise transition from the model to the code to reduce the time between the analysis model and implementation. The current state of practice requires methods and tools. We provide a general process and detailed transformation specifications where reverse-engineering may play its part. We advocate a model transformation approach in which transformations remain simple, the complexity lies in the process of transformation that is adaptable and configurable. We demonstrate the usefulness, and scalability of our proposed MDD process by conducting experiments. We conduct experiments within a simple case study in software automation systems. It is both representative and scalable. The models are written in UML; the transformations are implemented mainly using ATL, and the programs are deployed on Android and Lego EV3. Last we report the lessons learned from experimentation for future community work

Understanding Municipal Green Initiatives and Citizen Habits in Four Baltic Sea Region Countries: Survey Results

The need to reach climate neutrality is addressed in this study by highlighting activities including boosting renewable energy sources, improving energy efficiency, and putting laws and incentives in place for the adoption of low-emission technology. Importantly, it is recognized that there is another important key factor in determining the success of sustainability projects which is an individual's willingness to change their behavior and accept new guidelines. This cross-cultural research examines the everyday routines of people from Sweden, Estonia, Latvia, and Poland and how these residents evaluate their municipalities. The research investigates the connections between citizens' behaviors in waste management, energy conservation, and transportation by considering the inhabitants' age, location of residence, and personal views. This study aims to collect the necessary data for creating focused, culturally appropriate sustainability projects. The study promotes international cooperation on environmental issues, supports sustainable practices adapted to various cultural settings, and gives policymakers useful information. Using a survey, this study takes a thorough approach to comprehending and resolving sustainability issues. The findings demonstrate that interventions need to be tailored to specific characteristics and cultural contexts to effectively encourage durable behaviors. All things considered, this study adds to the current conversation on sustainability by providing information and suggestions for encouraging environmentally friendly behavior in a variety of cultural contexts

MSW Management in Mountainous Areas: Outcomes from a Comparison Between Two Italian Provinces

In the present paper, two case studies are reported regarding the municipal solid waste (MSW) management trend in the last decades in two Italian areas in order to propose some guidelines for replicating the approaches. The first case study has a very good selective collection (SC) rate that is expected to reach 80 % in a few years. SC is made mainly kerbside. There is no thermo-chemical plant in the territory (but a part of the residual MSW is burnt in an external combustion plant). A local plant combines anaerobic digestion with post-composting as a main destination for food waste and green waste. A sanitary landfill receives the main stream of locally pre-treated residual MSW. The adopted tariff helped increasing the SC rate: since 2013, the punctual tariff has been adopted. The second case study concerns an area where SC reached about 75 % in 2019, before the pandemic period that affected the performances of the sector. The punctual tariff has been recently introduced. In the territory, there are an incineration plant and a Solid Recovered Fuel (SRF) plant that sends the final product mainly to a cement factory. No plant for the biodegradable waste exists locally (export is adopted). Looking at the two case-studies, useful waste guidelines for similar areas could be set up starting from these experiences

Optimizing Biobutanol Production: Analysis of Feedstock Selection, Pre-treatment Methods, and Microorganism Strains for Biobutanol Production from Agricultural and Industrial By-products

This study presents an analysis of key elements of biobutanol production, including feedstock selection, pre-treatment methods, and microorganism strains. Using laboratory experiments, we evaluated the ability of different microorganisms to convert various agricultural and industrial by-products into biobutanol. We tested three microorganism strains: C. acetobutylicum DSM 792, C. beijerinckii DSM 6423, and C. saccharoperbutylacetonicum DSM 14923. The results showed that biodiesel production residues, various agricultural hydrolysates, yeast residues, and milk processing residues were the most suitable feedstocks for biobutanol production. In addition, the authors explored different pre-treatment methods, such as microbial and chemical hydrolysis, to enhance the efficiency of biobutanol production. Our findings provide valuable insights for optimizing biobutanol production processes in line with sustainable and cost-effective production principles

The Agricultural Sector towards Climate Neutrality

Agriculture is one of the leading sectors which significantly contribute to the increase of GHG emissions, thus contributing to the negative impact that climate change can cause on biodiversity and create extreme weather changes, raise the sea levels, revers ocean currents etc. One of the main objectives of the new Common Agricultural Policy (CAP) is to improve and promote the sustainability of rural regions by providing economic support and direct payments to ensure farmers’ incomes, which can be compared with the level of other sectors. Direct payments are not only a way to reward farmers but also an opportunity to generate income for farmers in an environmentally friendly operation, providing compensation for possible losses due to reduced production intensity or for costs incurred by farmers in applying climate and environmentally-friendly practices. However, the mechanisms used in the CAP – direct payments and subsidies – do not significantly increase agriculture’s sustainability and technological efficiency. Using a results-based scheme, it is possible to see more clearly the relationship between payment and biodiversity achievements; farmers are defined with specific results that must be achieved. Still, no specific actions are being taken taken to arrive at the results. In this article, the analysis based on a sustainability assessment of CAP measures is performed and blind spots are identified

Analysis of Textile Circularity Potential

Global annual textile consumption has doubled in the last two decades and is expected to keep increasing [1]. Since the textile system operates primarily in a linear way, it is highly polluting and creates a lot of waste. But nevertheless, it has a high potential for circularity since most textile products can be recycled or reused. Today most of the waste ends up in landfills, and less than 1% is recycled back into textiles [2]. This study aims to gather information and evaluate which textile product group has the highest potential for circular economy growth. It covers three main textile product streams: fashion, home, and technical textiles. The groups were compared using eleven criteria: environmental impact, washes, market demand, technology energy efficiency, social aspect, production, export/import, landfilled waste, recycled waste, synthetic materials, projected lifetime. Indicative values have been found for each sustainability indicator by using and mathematically transforming data from the scientific literature. The evaluation method used in this study was multi-criteria decision analysis. The results indicated that the fashion textile group has the most significant potential for circular economy development