ABSTRACT
Composites containing natural fibers are considered environmentally friendly materials which is related to the reduced use of fossil fuels and the emission of carbon dioxide compared to petroleum-based polymers. Nevertheless, a complete evaluation of their environmental impact requires a broader view. This paper presents a carbon, ecological, and water footprints assessment of polypropylene-based composites filled with cotton, jute, and kenaf fibers based on a standardized European pallet (EUR-pallet) case study. Obtained results were compared with unmodified polypropylene and composite with glass fibers. Incorporation of 30 wt% of cotton, jute, and kenaf fibers into a polypropylene matrix reduced its carbon footprint by 3%, 18%, and 18%, respectively. Regarding the ecological footprint, an 8.2% and 9.4% reduction for jute and kenaf fibers were noted, while for cotton fibers, its value increased by 52%. For these footprints, the use of jute and kenaf fibers was more beneficial than glass fibers. Nevertheless, the application of natural fibers caused a 286%, 758%, and 891% drastic increase of water footprint of the final product, which was mainly affected by cultivation and irrigation of crops. Therefore, in a holistic view, the incorporation of natural fibers into the polypropylene matrix definitely cannot be impartially considered as an environmentally friendly solution.
ABSTRACT
This article presents a model of the environmental assessment of the system of wastewater collection, transport and treatment. The model was developed based on an original environmental assessment method of a system consisting of four elements: septic tanks, household wastewater treatment plants, a sewerage system and a central wastewater treatment plant. To conduct the environmental assessment, the Life Cycle Assessment technique was applied. The Intergovernmental Panel on Climate Change (IPCC) method was also applied, which enabled the determination of the carbon footprint of the analysed wastewater management system. This article presents the outline of an original method applied to create a model and an inventory of the data necessary for environmental assessment and the application of the model for the environmental assessment of a system of wastewater collection, transport and treatment in a city with over 50.000 inhabitants. Three feasible variants (from a functional, technical, organizational and financial point of view) of the system's development were analysed. The variants were subjected to comparative analysis using the solution. The obtained results, together with the assessment method can be used as a practical tool to assess whether the European Commission's guidelines are met, as well as the challenges facing wastewater management in the circular economy are overcome.
ABSTRACT
This paper presents a water footprint assessment of polymers, polymer blends, composites, and biocomposites based on a standardized EUR-pallet case study. The water footprint analysis is based on life cycle assessment (LCA). The study investigates six variants of EUR-pallet production depending on the materials used. The system boundary included the production of each material and the injection molding to obtain a standardized EUR-pallet of complex properties. This paper shows the results of a water footprint of six composition variants of analyzed EUR-pallet, produced from biocomposites and composites based on polypropylene, poly(lactic acid), cotton fibers, jute fibers, kenaf fibers, and glass fibers. Additionally, a water footprint of applied raw materials was evaluated. The highest water footprint was observed for cotton fibers as a reinforcement of the analyzed biocomposites and composites. The water footprint of cotton fibers is caused by the irrigation of cotton crops. The results demonstrate that the standard EUR-pallet produced from polypropylene with glass fibers as reinforcement can contribute to the lowest water footprint.
ABSTRACT
This paper presents a life cycle assessment (LCA) of greenhouse gas emissions generated through methanol and electricity co-production system based on coal gasification technology. The analysis focuses on polygeneration technologies from which two products are produced, and thus, issues related to an allocation procedure for LCA are addressed in this paper. In the LCA, two methods were used: a 'system expansion' method based on two approaches, the 'avoided burdens approach' and 'direct system enlargement' methods and an 'allocation' method involving proportional partitioning based on physical relationships in a technological process. Cause-effect relationships in the analysed production process were identified, allowing for the identification of allocation factors. The 'system expansion' method involved expanding the analysis to include five additional variants of electricity production technologies in Poland (alternative technologies). This method revealed environmental consequences of implementation for the analysed technologies. It was found that the LCA of polygeneration technologies based on the 'system expansion' method generated a more complete source of information on environmental consequences than the 'allocation' method. The analysis shows that alternative technologies chosen for generating LCA results are crucial. Life cycle assessment was performed for the analysed, reference and variant alternative technologies. Comparative analysis was performed between the analysed technologies of methanol and electricity co-production from coal gasification as well as a reference technology of methanol production from the natural gas reforming process.
ABSTRACT
This paper presents a novel approach to environmental assessment of coal mining operations, which enables assessment of the factors that are both directly and indirectly affecting the environment and are associated with the production of raw materials and energy used in processes. The primary novelty of the paper is the development of a computational environmental life cycle assessment (LCA) model for coal mining operations and the application of the model for coal mining operations in Poland. The LCA model enables the assessment of environmental indicators for all identified unit processes in hard coal mines with the life cycle approach. The proposed model enables the assessment of greenhouse gas emissions (GHGs) based on the IPCC method and the assessment of damage categories, such as human health, ecosystems and resources based on the ReCiPe method. The model enables the assessment of GHGs for hard coal mining operations in three time frames: 20, 100 and 500years. The model was used to evaluate the coal mines in Poland. It was demonstrated that the largest environmental impacts in damage categories were associated with the use of fossil fuels, methane emissions and the use of electricity, processing of wastes, heat, and steel supports. It was concluded that an environmental assessment of coal mining operations, apart from direct influence from processing waste, methane emissions and drainage water, should include the use of electricity, heat and steel, particularly for steel supports. Because the model allows the comparison of environmental impact assessment for various unit processes, it can be used for all hard coal mines, not only in Poland but also in the world. This development is an important step forward in the study of the impacts of fossil fuels on the environment with the potential to mitigate the impact of the coal industry on the environment.
