Combustion of Biomass Fuel and Residues: Emissions Production Perspective

This article provides possibilities for minimising the emissions from eight types of biomass combustion boilers given by virtue of continuous emission measurement. The measurements were carried out on various types of one‐ or two‐stage combustion devices. In all investigated modes of combustor operation, the concentration of nitrogen oxides in the whole cycle of fuel combustion was without marked deviations and far lower than the emission limit of 650 mg/mn3. Concentrations of carbon monoxide (CO) and total organic carbon (TOC) are extremely variable at some operating schedules of combustion boilers. The variability of these concentrations indicates that there are unstable aerodynamic conditions in the combustion device. The causes of this aerodynamic instability have been studied. The mode with stable aerodynamic conditions, for which emission concentrations of CO and TOC are relatively stable, has been determined

Regional Labelling as a Tool for Supporting Rural Development: A Slovak Case Study

Regional product labelling has become a trend in recent years, with the goal of being able to stimulate and support local economies; increase the sales of quality local products and services; preserve and maintain traditions, local cultural values, and the character of rural landscapes; and promote the use of local resources, potential, and raw materials. The existing Slovak studies deal primarily with the perception of consumers and tourism. In this article, we analysed forms of rural development in connection with regional product labelling and the Slovak regions of Kopanice and Záhorie. This theme is a relatively new phenomenon in Slovakia, and that is the author's main contribution. The research was conducted using an online questionnaire administered between May and July 2022 in each district of the region, with a total of 283 respondents participating. The results obtained from the questionnaire survey were statistically processed using Pearson's correlation coefficient. We used STATISTIC 109 software (Tibco software, Palo Alto, California). The questionnaire method is the most suitable method for determining the perceptions of the respondents. The goal was to analyse rural development in connection with regional product labelling and to identify areas of the application of regional product labels. The term regional product was associated with production in a specific region (50.5%) and with the customs and traditions of the region (43.8%). Supporting employment and entrepreneurship in the region were considered by 43.1% of the respondents as the most important in the region. From the perspective of the application of regional labelling in connection with rural development, we confirmed gender and education dependence. Women with first- and second-level higher education saw regional labels as the main element in the development of the region and the local economy.O

An Assessment of Regional Sustainability through Quality Labels for Small Farmers’ Products: A Slovak Case Study

Regional product labelling can help develop regional business activities, especially with traditional regional products. Their general popularity is a significant source of income for less-developed regions. The Gemer-Malohont region is an economically underdeveloped area with a high unemployment rate. The subject of the survey was focused on regional food products that are made by small farmers. The analysis was carried out using data from a questionnaire survey on the period April–July 2017 in each of the region’s districts. The results obtained by the questionnaire survey were processed with the use of statistical methods (two-step cluster analysis, radar chart, box-plots, regression analysis) using Microsoft Excel and the IBM SPSS Statistics 23 software. We divided consumers into two groups—knowledgeable regional food purchasers and priced-oriented consumers—based on their preference for regional food and through cluster analysis. We show that the more developed regions (Rimavská Sobota and Rožňava) show a higher rate of purchase of regional foods. Less-developed regions (Poltár, Revúca) are represented by lower-income consumers for whom the food price is the decisive criterion. Local residents of backward regions should pay attention to domestic food and local small farmers who are tools for the creation of local capital and local development

Extensive Operating Experiments on the Conversion of Fuel-Bound Nitrogen into Nitrogen Oxides in the Combustion of Wood Fuel

This paper presents a wide, targeted, operational experiment on the conversion of fuel-bound nitrogen to nitrogen oxides. The experiment was implemented by studying the production of energy in 16-grate boilers. The conversion factor was determined based on the nitrogen content in individual types of dendromass and on nitrogen oxide emissions in flue gases. In measuring emissions, 103 average values for the concentration of nitrous oxide were found. Every average value was set using three consecutive half-hour emission measurements. The specific thermal output of the boilers was 300 to 2500 kW. The nitrogen content in the deliberately selected dendromass was within a wide interval of Ndaf values between 0.04% and 1.26%. The dependence of the conversion factor, XNOx, upon the content of fuel-bound nitrogen is very accurately expressed by the power function

The contamination of bottom sediments in water reservoirs in the vicinity of Banska Stiavnica (Slovakia) by potentially toxic elements

Článek je přístupný po bezplatné registraci na webu vydavatele.The Štiavnické lakes located in the vicinity of Banská Štiavnica (Slovakia) represent unique, historical engineering works that are part of UNESCO’s World Heritage. From the scientific point of view, lake sediments from an area rich in silver, gold, lead, and other metals, which have been mined and processed here for over 1000 years, could become a valuable historical research material. Sediment sampling has been performed according to STN ISO 5667-12. Sediment samples were collected from water reservoirs Bakomi, Rozgrund, and Vindšachta. Potentially toxic elements in sediments were analyzed by AAS spectrometry. The Bakomi water reservoir sediments contained on average (in mg·kg-1): Cd 2, Cu 17, Mn 530, Pb 94 and Fe 27,601. Sediments taken from the Vindšachta area contained on average (in mg·kg-1): Cd 2, Cu 30, Mn 980, Pb 96 and Fe 26,884. The sediment in Rozgrund differed significantly from the sediments of other lakes. The sediments of the Rozgrund area, whose reservoir has not been drained in 270 years, contained on average (in mg·kg-1): Cd 6, Cu 39, Mn 1,471, Pb 205 and Fe 37,786. The concentration profile of sediments was examined to the depth of 42cm, while in one case (Mn in the reservoir sediment) the gradual increase of concentration with depth was observed. Concentration anomalies associated with depth were not detected in the examined metals. Concentration anomalies associated with mining or severe air pollution were not detected in the examined metals.Web of Science9220719

Identification of Significant Impact of Silicon Foundry Sands Mining on LCIA

This paper presents a case study based on a LCA (Life Cycle Assessment) research program of the silicon foundry sand (SFS) due to the large quantity of produced waste foundry sand (WFS). The foundry waste is a high priority sector within the growing European foundry industry. It is necessary to understand the full life cycle of the foundry waste in order to correctly identify magnitude and types of impacts it has on the environment. System boundary includes the processes: mining, modification, packing, storage and transport to foundry. Inventory analysis data were analyzed and finally converted to the functional unit, which has been defined as one ton of SFS. The resulting environmental impact of SFS production in endpoint is: consumption of natural resources 70.9%, ecosystem quality 18.2% and human health 10.9%. The following portions, with respective percentages, have the greatest overall effect on these results: diesel fuel consumption 32.4% and natural gas consumption 28.7%, electricity usage 17.2%, transport 12.2%, devastation caused by the SFS 5.35% and oil (engine, gear and hydraulic) consumption 4.14%. The highest contributor to the diesel fuel consumption is the SFS exploitation. The overall effect of desiccation was 35.8% and was caused by high consumption of resources and electricity

Quantification of Improvement in Environmental Quality for Old Residential Buildings Using Life Cycle Assessment

In Slovakia, 35% of buildings are older than 50 years but most newer buildings built before 1990 have greater energy consumption. Some other countries also have similar problems. The growing importance of energy saving in buildings can be, in the case of new and old residential buildings (RB), achieved by lowering thermal energy consumption most often by application of polystyrene insulation on the external walls and roof and the exchange of wood window frames for PVC (polyvinyl chloride) windows. The novelty of the article for Slovakia and some other central European countries consists in using the life cycle assessment (LCA) method for the objective assessment of the environmental benefits of the selected systems of wall insulation, as well as of energy savings in various time intervals of insulation functionality (up to 20 years). LCA software SimaPro (LE Amersfoort, The Netherlands) was used with ReCiPe and IMPACT 2002+ assessment methods to quantify the total environmental impact at selected endpoints and midpoints (IMPACT 2002+) of basic structural materials of an RB and its energy demand—heat consumption (hot water heating, central heating) before the application of insulation and thermal energy saving (TES) after application of insulation to its external walls, roof, and the exchange of windows. The data we obtained confirmed that the environmental impact of the polystyrene insulation of external walls, roof, and exchange of windows of one residential building (RB) in the first year after insulation is higher than the reduction caused by achieving a TES of 39%. When taking a lifespan of 20 years into consideration, the impact over the life cycle of the building materials is reduced by 25% (global warming: −4792 kg CO2 eq; production of carcinogens: −2479 kg C2H3Cl eq; acidification: −12,045 kg SO2 eq; and aquatic eutrophication: −257 kg PO4 P-lim). The verified LCA methodology will be used for comparative analysis of different variants of thermal insulation of buildings, and their functionality in the long term, while taking into account local specifics and the preparation of environmental product declarations

Analysis of Hygrothermal Microclimatic (HTM) Parameters in Specific Food Storage Environments in Slovakia

The quality of work environment, temperature changes and humidity must be controlled in every production process and in the locations where employees are present. The aim of this paper is to objectively assess the exposure of employees to microclimatic factors of the workplace environment: the warehouse, changing rooms, office and cold room refrigerator. Data were obtained in real working conditions. The heat stress due to cold and heat exposure in the individual locations was evaluated using the WBGT (wet bulb globe temperature) indicator. The parameters of the hygrothermal microclimate (HTM) were objectified by a QUES Temp 44/46 T spherical thermometer. The measurements were performed both in cold and hot periods of the year. The measurements confirmed standard temperatures for individual types of interiors in the winter period, but in the summer period there was a variability of results, leading to the thermal discomfort of employees. The assessment of the WBGT index revealed that nearly 80% of employees are susceptible to hypothermia as a result of thermal stress conditions. It was proven that the temperatures measured by a spherical thermometer in the hottest room were 8.62% higher than the calculated operating temperature, while the difference in the cold room refrigerator was only 1.28% higher