Medium-sized Plants Research Articles

Antioxidant and Anti-Inflammatory Activity of Star Anise (Illicium Verum) in Murine Model

Star anise (Illicium verum) is a medium-sized plant that is native to Asia as well as one of the most important medicinal plants used in Chinese herbal medicine. Star anise has bioactive compounds having antioxidant and anti-inflammatory properties. The antioxidant activity of Star anise (Illicium verum) methanolic extract was studied by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′azinobis-(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) assay. The current study aims to investigate the effect of Star anise (Illicium verum) methanolic extract as ant-inflammatory by reducing the concentration of pro-inflammatory cytokines TNF-α and IL 1beta and reducing the oxidative stress by acting as a scavenger because inflammation and oxidative stress can induce each other. The highest free radical scavenging activities were exerted by the APTS method (95.1±0.33 Trolox/g) whereas, the free radical scavenging activities were exerted by ABTS was 77.7±0.30 Trolox/g. The anti-inflammatory activity of the Star anise (Illicium verum) methanolic extract was studied by its ability to inhibit pro-inflammatory cytokines productions (Tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β)) and reduce oxidative stress at different concentrations. Star anise (Illicium verum) methanolic extract significantly reduce the pro-inflammatory TNF-α and IL-1β production (p<0.05) compared with negative control which is treated with lipopolysaccharide (LPS) and has a similar effect in reducing pro-inflammatory cytokines production similar to the positive control which treated with ascorbic acid. Star anise (Illicium verum) methanolic extract significantly reduces oxidative stress (p<0.05) by reducing antioxidant enzyme activity catalase and glutathione-peroxidase compared with the LPS treated group. In conclusion Star anise (Illicium verum) methanolic extract act as strong antioxidant and anti-inflammatory medicinal plant.

Tax Regulation of the Brewing Industry in Russia in the First Half of the 19th Century

Introduction. In article influence of the excise taxation on development of the brewing industry and business during early industrial changes of Russia in the first half of the 19th century is investigated. Direct dependence of brewing production on the size of excises duties: low profitability and an inefficiency of plants were caused both high rates of an excise, and ways of its collection. Results and Discussion. The abolition of farming and the transition to state-owned sales since 1819 had a positive impact on the brewing industry. This was the period of the rise of brewing, the formation of the national brewing industry in the form of a manufactory. The return in 1827 to farming again led to the restriction of the beer trade and, ultimately, to a reduction in the volume of the brewing industry. In order to further increase income in 1847, excise-farm commission was introduced, combining the methods of state-owned and farmed-out sale of vodka and beer. After the introduction of the excise commission, private brewing began to decline significantly. The characteristic features of the regional brewing industry were the widespread use of manual labor, low productivity and the predominance of small enterprises. Conclusion. In the first half of the 19th century in Russia brewing, in terms of the volume of production and consumption of beer, and state revenues, was by no means as important as the distillery industry. The low profitability and inefficiency of small and medium-sized plants were due to both high excise rates and the methods of its collection.

Assessing the impact of micropollutant mitigation measures using vertical flow constructed wetlands for municipal wastewater catchments in the greater region: a reference case for rural areas.

The present research aims at giving an approach to the issue of surface water contamination due to micropollutants in rural areas. The catchment of the Sûre river was selected as a reference case for the Greater Region, characterized mainly by settlements with low population density, small water bodies and small- to medium-sized wastewater treatment plants (WWTPs). For these WWTPs, conventional technical solutions for micropollutant elimination are not suitable; therefore, an adapted mitigation strategy is needed to prevent the impact of micropollutants, especially during the dry season. As a suitable alternative to more intensive technologies, Constructed Wetlands (CW) in Vertical Flow (VF) configuration have been successfully tested over a 1-year period and the elimination rate of 27 micropollutants was quantified. Emission reduction by VF was then considered in a static mass balance model that calculates the longitudinal concentration profile for the entire river catchment. The EmiSûre approach, which focuses on river quality (concentrations of pollutants) instead of emitted loads, effectively allowed simulation of adopted measures a priori and resulted in efficient support for decision-makers with WWTP upgrade scenarios.

Biomethane Community: A Research Agenda towards Sustainability

The bioeconomy is an effective solution to align with the sustainability agenda and to meet the pressing calls for action from Cop26 on a global scale. The topic of the circular bioeconomy has gained a key role in the literature, while the theme of energy community is a basic form of social aggregation among stakeholders. This work focuses on biomethane and proposes a framework based on several criteria that are evaluated using a hybrid Analytic Hierarchy Process (AHP) and 10-point scale methodology. The results show that regulation and energy community are considered the two most relevant categories. The overall ranking of criteria sees the stakeholders’ engagement as the most important, followed by more significant subsidies for small- and medium-sized plants and the principle of self-sufficiency applied at the inter-regional level. Subsequently, the Italian Adriatic corridor composed of four MMAP (Marche, Molise, Abruzzo, and Puglia) regions is considered as a case study in order to evaluate the possible environmental (854 thousand tons CO2eqyear) and economic (from 49 million EUR to 405 million EUR in function of plant size) benefits associated with potential biomethane production of 681.6 million m3. It is found that the biomethane community is an enabler of sustainability and this strategy can be used for sharing different natural resources.

New Stage in Russia’s Nuclear Energy Strategy

This article discusses a technological platform of nuclear energy for implementing the proposed Atomic Project 2.0 which is focused on the country’s objectives in sustainable development, including the development of advanced innovative technologies and materials, and producing examples of new equipment. The basis of modern nuclear power in Russia and the world is water-cooled pressurized reactors with capacity 1000 MW or more, and there are no objective prerequisites for changing this paradigm in the foreseeable future. In this connection, VVER technology remains the most important tool for achieving the strategic goals of our country in the field of nuclear energy. The existing strategic plans relegate extensive adoption of fast reactors and NFC closure based on them to the 2030s, which can be viewed as the customary maximalism in the face of the current moderate notions concerning growing demand for nuclear generation. The prospects for the introduction of small and medium-sized nuclear power plants, taking into account the forecasted demand for electricity and the territorial distribution of generation in Russia, as well as the opportunities for foreign business, promise a new quality of nuclear energy production and a fundamentally different niche in the energy basket. Perhaps the strongest indication of the current stage of progress in nuclear energy is a resurgence of expansion into new areas of energy consumption. It must be assumed that a version of the nuclear energy strategy worthy of presentation in Atomic Project 2.0 will incorporate development of directions of heat supply, hydrogen production, and seawater desalination by means of nuclear technologies for the home and international markets, as well as promising areas such as molten-salt nuclear technologies or hybrid systems.

Hydrokinetic Power Resource Assessment in a Combined Estuarine and River Region

The worldwide river and tidal hydrokinetic power potential is considerable. Harnessing such potential could allow the generation of a significant amount of sustainable electricity for local uses. To the present, most studies on hydrokinetic power have focused on large-scale commercial technology development, large tidal farms planning, and high-intensity resources assessment. Reduced attention was oriented towards investigating possibilities for small to medium-size hydrokinetic plants. However, given the characteristics of rivers and estuaries, in most cases, relevant hydrokinetic power exploitation possibilities exist regardless of the dimensions of the region considered. The planning of small to medium-size hydrokinetic plants for various aspects differs from larger developments. In the present work, a method for assessing the hydrokinetic resource is proposed and applied to the case study of the Douro waterway, which is characterized by moderate flow speeds and limited water depths. A high-resolution shallow-water numerical model is set up using ocean and river inflow boundary conditions. The flow velocities are estimated for the neap-spring period for different freshwater discharges. The spots presenting the highest annual hydrokinetic power average were identified, maximum flow speeds of about 1 m/s were found, and an annual mean power of 0.4 kW/m2 was estimated, indicating that prospects for hydrokinetic energy harvesting exist.

Can Biogas Plants Become a Significant Part of the New Polish Energy Deal? Business Opportunities for Poland’s Biogas Industry

The agricultural biogas sector is now facing the opportunity to become a significant actor in the new energy deal as a low-carbon source of electricity. Given the current prospects for rapid growth in the industry, the authors developed an economic model of a medium-sized agricultural biogas plant to assess the rate of return on such an investment. The analysis comprises energy prices, substrates, and other costs reported by the plants already in operation, as well as the electricity sales support system, the actual biogas and electricity yield from the substrates, and the digestate utilisation. It shows that a biogas plant capable of delivering ca. 2000 MWe generates a profit in a much shorter timeframe than 20 years, even under quite uncertain economic conditions. In the model scenario, the breakeven point is reached at slightly below 5000 MWh of power output or at ca. 5800 MWh including financing costs, with a planned annual output of approx. 8000 MWh. The profitability of the model biogas plant was also demonstrated by calculations made for other scenarios which differ in substrate composition and financing structure. The parameters of the econometric model are based on the data collected from a group of 41 units that use only organic plant matter for biogas production.

Особенности каталитической трансформации метанола в углеводороды в условиях микроструктурированных потоков

The methanol into hydrocarbons transformation is a complex catalytic reaction accompanied by the formation of a wide range of hydrocarbons and proceeding on the surface of acid sites of various zeolites. Zeolite H-ZSM-5 considered to be most often used catalyst for this process. H-ZSM-5 is a highly dispersed material with a crystal diameter of 1–20 microns, which complicates its direct use in reactors with a fixed catalyst bed due to the high hydraulic pressure drop of the catalytic bed. Traditionally in industry, this issue is solved by using complex reactor systems with a fluidized bed, which is justified for large-scale production. In small and medium-size plants, the use of fluidized bed systems is not economically feasible. One of the possible solutions to this problem is the use of a monolithic catalyst with a supported layer of H-ZSM-5 zeolite. This article presents a study of the catalytic activity of a zeolite-containing microstructured monolith in methanol into hydrocarbons transformation. The monolith was synthesized by pressing a zeolite-containing mass followed by drying, calcining, and secondary growth of the zeolite on the monolith surface. A sample of a monolith with an average channel diameter of 0.5, 1.0, 1.5, 2.0 mm were synthesized this way. Samples of the microstructured catalyst were tested at varying temperatures from 250 to 450 °C and at varying the specific methanol feed rate from 0.65 to 2.3 kg (MeOH)/(kg (Cat) h). For this purpose, the monolithic catalyst was placed in a reactor for testing microstructured catalysts, which consisted of a pump, a temperature controller, a catalytic reactor, a condenser, a separating funnel, and a chromatograph. Varying the conditions showed that for the preferential production of gaseous C1–C4 hydrocarbons, it is advisable to carry out the reaction under the following conditions: the average diameter of the catalyst channels is 2 mm, the reaction temperature is 350 °C, the methanol feed rate is 1.65 kg (MeOH)/(kg (Cat) h). For the predominant formation of liquid hydrocarbons of the C5–C8 fraction, it is advisable to carry out the transformation of methanol into hydrocarbons under the following conditions: the average diameter of the catalyst channels is 1 mm, the reaction temperature is 350 °C, the methanol feed rate is 0.65 kg (MeOH) / (kg (Cat) h). For the predominant formation of liquid hydrocarbons of the C9–C12 fraction, it is advisable to carry out the transformation of methanol into hydrocarbons under the following conditions: the average diameter of the catalyst channels is 0.5 mm, the reaction temperature is 350 °C, and the methanol feed rate is 0.65 kg (MeOH) / (kg (Cat) h).

Coprostanol as a Population Biomarker for SARS-CoV-2 Wastewater Surveillance Studies

Wastewater surveillance is a cost-effective tool for monitoring SARS-CoV-2 transmission in a community. However, challenges remain with regard to interpretating such studies, not least in how to compare SARS-CoV-2 levels between different-sized wastewater treatment plants. Viral faecal indicators, including crAssphage and pepper mild mottle virus, have been proposed as population biomarkers to normalise SARS-CoV-2 levels in wastewater. However, as these indicators exhibit variability between individuals and may not be excreted by everyone, their utility as population biomarkers may be limited. Coprostanol, meanwhile, is a bacterial metabolite of cholesterol which is excreted by all individuals. In this study, composite influent samples were collected from a large- and medium-sized wastewater treatment plant in Dublin, Ireland and SARS-CoV-2 N1, crAssphage, pepper mild mottle virus, HF183 and coprostanol levels were determined. SARS-CoV-2 N1 RNA was detected and quantified in all samples from both treatment plants. Regardless of treatment plant size, coprostanol levels exhibited the lowest variation in composite influent samples, while crAssphage exhibited the greatest variation. Moreover, the strongest correlations were observed between SARS-CoV-2 levels and national and Dublin COVID-19 cases when levels were normalised to coprostanol. This work demonstrates the usefulness of coprostanol as a population biomarker for wastewater surveillance studies.

A Straightforward High-Throughput Aboveground Phenotyping Platform for Small- to Medium-Sized Plants.

High-throughput phenotyping platforms for growth chamber and greenhouse-grown plants enable nondestructive, automated measurements of plant traits including shape, aboveground architecture, length, and biomass over time. However, to establish these platforms, many of these methods require expensive equipment or phenotyping expertise. Here we present a relatively inexpensive and simple phenotyping method for imaging hundreds of small- to medium-sized growth chamber or greenhouse-grown plants with a digital camera. Using this method, we image hundreds of tomato plants in 1day.

Design and techno-economic analysis of a hybrid system for energy supply in a wastewater treatment plant: A decentralized energy strategy

The crescent urbanization generates large volumes of solid residues and wastewater, more and more geographically concentrated. This worldwide trend has also created new challenges regarding energy generation and consumption. Renewable energy sources can be strategic to keep up with the increasing energy demand, especially for under developing countries whose population is large. This study focuses on designing a hybrid system based on photovoltaic energy, biomass gasifier, and electricity grid to optimize the energy supply and the costs of a wastewater treatment plant (based on activated sludge system with extended aeration, high energy-demanding process). The optimal combination of energy technologies, with and without electric energy generation from biogas combustion derived from anaerobic digestion of sewage sludge, was assessed to define the better cost-effective arrangement. The cost of energy for an off-grid biomass gasifier standing alone is USD 0.0426/kWh. However, in a grid-connected system including photovoltaic energy and biomass gasifier, the cost was reduced to USD 0.0298/kWh with an energy surplus available to supply the whole facility requirement and enough to supply 788,000 residential power consumers. The hybrid combination with biogas combustion can be an alternative for medium-sized wastewater treatment plants, promoting economic and environmental benefits. Moreover, the results of this case study could be applied to other similar facilities towards cleaner and optimized sewage sludge recycling.

Characterisation of the Vertical Wind Profile According to the Stability Classes of the Atmosphere in Conakry, Guinea

The characteristics of the vertical wind profile and the wind potential study on the Conakry site for each atmospheric stability class were investigated in this study. Wind speed and air temperature data recorded over the period from January 2001 to December 2019 at 10 m and 50 m above the ground at daily (50 m) and hourly (10 m) scales were used. The wind shear parameters were determined from the logarithmic and power law. Based on the Newman and Klein wind shear model, a new formulation of this parameter was proposed as a function of the Obukhov length at order 2 and calibrated from the measurements using the simplex algorithm of Nelder and Mead. From the Weibull parameters obtained for the stable and unstable period of the atmosphere, the available wind potential at Conakry was estimated from 10 m to 80 m. The results indicate that the annual average of the ground roughness length is 1.7 x 10-2 m. The annual average of the ground friction velocity is 0.19 m.s-1. The atmosphere remains stable at the Conakry site from 09 p.m. to 10 a.m. and unstable from 10 a.m. to 09 p.m. The proposed wind shear formulation gives a better estimation of the wind speed in function of altitude with the lowest values of RMSE and MAE (4.5x10-4 ; 3.8x10-4) m.s-1 in stable and unstable periods (0.09 ; 0.07) m.s-1 compared to some models found in the literature. The mean annual wind shear coefficient in stable period is 0.26 and in unstable period 0.28. The annual mean shape parameter from 10 m to 80 m above ground in stable period is between 1.25 and 1.64, and during unstable period, it varies from 1.55 to 2.07. The annual mean scale parameter at 10 m and 80 m above ground is (3.9; 7.10) m.s-1 (unstable atmosphere) and (2.45; 4.41) m.s-1 when the atmosphere is stable. The annual average of the energy production under a convective atmosphere at 10 m and 80 m is estimated at 72 W.m-2 and 301 W.m-2 respectively. During the night cycle, this annual production varies from 28 W.m-2 (10 m) to 93 W.m-2 (80 m). Based on these results, the Conakry site is suitable to host medium-sized wind power plants for electricity and water production.

Allelopathic Activity and Characterization of Allelopathic Substances from Elaeocarpus floribundus Blume Leaves for the Development of Bioherbicides

To help protect the environment as well as increase agricultural production, the use of synthetic herbicides must be reduced and replaced with plant-based bioherbicides. Elaeocarpus floribundus is a perennial, evergreen, and medium-sized plant grown in different areas of the world. The pharmaceutical properties and various uses of Elaeocarpus floribundus have been reported, but its allelopathic potential has not yet been explored. Thus, we carried out the present study to identify allelopathic compounds from Elaeocarpus floribundus. Aqueous MeOH extracts of Elaeocarpus floribundus significantly suppressed the growth of the tested species (cress and barnyard grass) in a dose- and species-dependent way. The three most active allelopathic substances were isolated via chromatographic steps and characterized as (3R)-3-hydroxy-β-ionone, cis-3-hydroxy-α-ionone, and loliolide. All three substances significantly limited the seedling growth of cress, and the compound (3R)-3-hydroxy-β-ionone had stronger allelopathic effects than cis-3-hydroxy-α-ionone and loliolide. The concentrations of the compounds required for 50% growth inhibition (I50 value) of the cress seedlings were in the range of 0.0001–0.0005 M. The findings of this study indicate that all three phytotoxic substances contribute to the phytotoxicity of Elaeocarpus floribundus.

Changes in Risk in Medium Business Plating and Paint Manufacturing Plants following the Revision of the Korean Chemical Accident Prevention System.

Chemical accidents can occur anywhere. The need for chemical management in Korea was realized following the 2012 Gumi hydrofluoric acid accident in 2012. The Chemicals Control Act was enacted in 2015. This system evaluates the risks (high, medium, low) and consequent safety management at all plants that handle hazardous chemical substances. However, the system was criticized as excessive when most plants were designated high-risk without considering their size. Thus, laboratories and hospitals handling very small quantities were subject to regulation. Accordingly, in 2021 Korea revised the system to include off-site consequence analyses and a Korean-style risk analysis. Plants handling very small quantities, such as laboratories and hospitals, were exempt from regulation. In this study, changes in risk were examined for four medium-sized plating and paint manufacturing plants. Under the previous system, all four factories were judged as high-risk groups. In particular, the paint manufacturing plant A, which has an underground storage tank, received a medium risk like the plating plant C, although the possibility of a chemical accident was lower than that of other plants. However, in the changed system, all plants were changed to the low-risk group. In the Korean-style risk analysis, it is possible to see at a glance what is lacking in the plants, such as cooperation between local residents and local governments and the construction of safety facilities according to the type of accident scenario. The revised system is a reasonable regulation for medium business plants.

Assessment and Perspectives of Heat Transfer Fluids for CSP Applications

Different fluid compositions have been considered as heat transfer fluids (HTF) for concentrating solar power (CSP) applications. In linear focusing CSP systems synthetic oils are prevalently employed; more recently, the use of molten salt mixtures in linear focusing CSP systems has been proposed too. This paper presents a comparative assessment of thermal oils and five four nitrate/nitrite mixtures, among the ones mostly employed or proposed so far for CSP applications. The typical medium-size CSP plant (50 MWe) operating with synthetic oil as HTF and the “solar salt” as TES was considered as a benchmark. In the first part of the paper, physical properties and operation ranges of different HTFs are reviewed; corrosion and environmental issues are highlighted too. Besides an extensive review of HTFs based on data available from the open literature, the authors report their own obtained experimental data needed to thoroughly compare different solutions. In the second part of the paper, the impact of the different HTF options on the design and operation of CSP plants are analyzed from techno-economic perspectives.

Ethanol from residual biomass of banana harvest and commercialization: A three-waste simultaneous fermentation approach and a logistic-economic assessment of the process scaling-up towards a sustainable biorefinery in Brazil

This work performs the ethanol production by a fermentation approach based on three banana residues simultaneously (banana pulp and peels, and banana pseudostem) in the realistic proportion (1:2:10) as generated at harvest and commercialization. A process model was developed using a commercial simulator to assess the energy consumption, inputs, and ethanol production, aiming to carry out a preliminary economic analysis for large-scale production in Brazil. Five scenarios for large and medium-sized plants installed in the state of Santa Catarina were created, seeking the lowest logistic cost. Two types of inoculums were chosen in the fermentations: with a monoculture of Saccharomyces cerevisiae, and with a coculture of Saccharomyces cerevisiae and Pachysolen tannophilus (ATCC32691). The highest ethanol yield (0.4 g/g), volumetric productivity (1.1 g/L h), and annual production (32.713 m3) with lower energy expenditure (138.4 GJ/m3) were obtained with fermentation by co-culture with wet pseudostem in the composed broth. Massaranduba is considered the most appropriate municipality of Santa Catarina state for the installation of a biorefinery. In an optimistic scenario, where the energy cogeneration would meet the plant's energy demand, the proposed process is economically viable, with the lowest payback time of 12.4 yr.

Characterization and expression of a novel thaumatin-like protein (CcTLP1) from papaveraceous plant Corydalis cava

Thaumatin-like proteins (TLPs, osmotins) form a protein family which shares a significant sequence homology to the sweet-tasting thaumatin from the plant Thaumatococcus daniellii. TLPs are not sweet-tasting and are involved in response to biotic stresses and developmental processes. Recently it has been shown using a proteomic approach that the tuber extract from Corydalis cava (Papaveraceae) contains a TLP protein. The aim of this work was to characterize the structure and expression of TLP from C. cava tubers. The results obtained using a PCR approach with degenerate primers demonstrated a coding sequence of a novel protein, named CcTLP1. It consists of 225 aa, has a predicted molecular weight of 24.2 kDa (NCBI GenBank accession no. KJ513303) and has 16 strictly conserved cysteine residues, which form 8 disulfide bridges and stabilize the 3D structure. CcTLP1 may be classified into class IX of plant TLPs. The highest CcTLP1 expression levels were shown by qPCR in the stem of the plant compared to other organs and in the medium-size plants compared to other growth phases. The results confirm that CcTLP1 is expressed during plant growth and development until flowering, with a possible defensive function against different stress conditions.

Promoting sustainable carbon sequestration of plants in urban greenspace by planting design: A case study in parks of Beijing

Urban greenspace has been highlighted as a means of offsetting carbon dioxide (CO2) emissions and mitigating climate change in cities. However, it is still challenging to design for sustainable carbon sequestration. This study developed a transdisciplinary framework to link carbon sequestration research with planting design practices. Taking 28 urban parks in Beijing as a case, we integrated field investigation and remote sensing images to analyze the relationship between planting design indicators and carbon sequestration efficiency, and the change of carbon sequestration efficiency with the growth of plant biomass. The results showed that carbon sequestration efficiency varied over the urban parks with a mean value of 8.72 gC m−2d-1, and varied with plant growth. The difference was associated with individual plant properties and biotope structure. Medium-sized plants and biotopes with partly open structure are proved cost-effective for sustainable carbon sequestration of urban greenspace. We summarized adaptive planting design strategies for different biotope types and emphasized the benefits of nurturing growing and partly open biotopes structured with different sizes of plants. The results will be possible to produce information for landscape architects for improving sustainable carbon sequestration not only in the study area but also in other cities with similar climatic characteristic.

Influence of Valorization of Sewage Sludge on Energy Consumption in the Drying Process

Valorization of digested sewage sludge generated in a medium-sized sewage treatment plant and the effect of valorization on energy consumption during sludge drying used for energy recovery are presented. Anaerobic digestion of sewage sludge reduces dry matter content compared to raw sludge. This lowers its calorific value leading to the lower interest of consumers in using it as fuel. The aim of the study was to valorize digested sewage sludge prior to drying with high-energy waste with low moisture content. The procedure led to the reduction in moisture content by about 50% in the substrate supplied for solidification and drying. The calorific value of digested sewage sludge increased by 50–80%, and the energy consumption of the drying process decreased by about 50%. Physical and chemical properties of sewage sludge and moisture content of substrates and mixtures after valorization were determined. The heat of combustion of valorized sewage sludge mixtures, their elemental composition, and ash content is investigated. Their calorific value in the analytical and working states of 10% H2O was calculated. The highest calorific value was obtained for the mixture of sewage sludge valorized with waste plastics or combined with wood dust, averaging 23 MJ/kg. A mathematical approximation of sewage sludge valorization is presented.

Co-Combustion of Tire Pyrolysis Products and Wood Pellets

Thermal power plants remain one of the main sources of environmental pollution. The deterioration of the quality of traditional carbon-containing energy resources leads to the need to develop technologies for co-combustion of biofuel and coal at small and large power plants. The paper proposes the concept of using solid waste from tire recycling by adding to the composition of the mixed fuel “coal – wood waste” as a substitute for coal slag, which is formed during the utilization of worn-out tires by pyrolysis. The aim of the work was to determine the possibility of increasing the calorific value of wood pellets by co-firing with pyrolysis slag instead of coal without increasing the burden on the environment. At the same time, the following tasks have been set: to determine the lowest combustion heat of mixed fuels and assess its change when replacing coal with slag; to determine moisture content, total sulfur content, volatile matter yield, ash content of mixed fuels according to standard methods; to assess the change in these parameters when replacing coal with slag at the same component ratios; to determine the optimal ratios of components in mixed fuels, which will not increase the burden on the environment when replacing coal with pyrolysis slag. It has been determined that replacing coal with slag results in an increase in calorific value by 37–45 %, a decrease in ash content by 37–42 %, and an increase in the yield of volatile substances. At the same time, the sulfur content increases by 5.6–18 %. The use of traditional cleaning equipment is recommended in order to reduce the emission of sulfur dioxide. The research results make it possible to substantiate the possibility of replacing coal with slag in mixed fuels at certain ratios of components. A new direction of using solid products from recycling of rubber products, i.e. worn-out tires, has been proposed by the pyrolysis method in mixed fuels “slag-wood pellets” for small and medium-sized power plants.