The study investigates the co-combustion of straw with waste rubber thermolysis charand the addition of 4% lime in a small-scale pellet-fired boiler. Char content in the fuel was set at 10, 15, 25, and 49%. During combustion tests, flame visual were inspected, gas and particulate emissions were measured, individual losses and boiler efficiency were determined, and the amount and chemical composition of particulate depositions on boiler surfaces were estimated. Results indicate that burning fuel with char requires burner design modification to increase primary air relative to secondary air. Blends with up to 25% char content can be combusted while maintaining high boiler efficiency of approximately 87%, comparable to straw-only combustion. Significant fly ash deposits on boiler walls were observed, with K, Zn, Ca, and Si being predominant in the composition. Although there are risks of slagging and corrosion during co-combustion, these risks decrease with a higher char proportion. SO2 was detected in the flue gases, with high levels of particulate emissions, while NOx emissions stayed within permissible limits for small boilers. A marked increase in unburned carbon in bottom ash suggests the need for grate modifications and an extended combustion zone when co-combusting biomass with waste rubber thermolysis char.

This study investigates the suitability of a pilot-scale batch rolling-bed dryer for drying pine wood chips intended for torrefaction. The batch rolling bed dryer emerges as an ideal solution for further processes like torrefaction, offering a compact design and a wide range of operational parameters. Compared to rotary dryers, it occupies less volume, providing greater efficiency. Additionally, its adjustable drying airflow and compatibility with various biomass forms and particle sizes enhance its versatility. The volumetric evaporation rate was found 13.9 kg/m3 per hour for the total dryer volume and 78.8 kg/m3 for the bed volume. Mechanical tests demonstrate satisfactory operation, with potential for further optimization through impeller blade design improvements. The study also presents a simple model using the CDC modeling approach, successfully describing drying curves in most experiments, albeit with some limitations in temperature curve simulations. Overall, the rolling bed dryer proves to be a convenient solution for drying wood chips as a pretreatment for steam torrefaction, offering ease of operation and promising potential for application in continuous torrefaction lines.

The co-combustion of wheat straw (WS) and waste rubber thermolysis char (WRTC) was examined with the perspective of utilizing WRTC as a high-calorific value fuel addition to agricultural biomass. The study investigated the effect of different proportions of WS-WRTC blends (10/15/25/49 wt% WRTC) and a maximum of 4 wt% binders, including potato starch and calcium oxide, on the reactivity of co-combustion and the distribution of products during the process. Thermogravimetric analysis with Fourier Transform Infrared Spectroscopy (TGA-FTIR) analyses was employed at a temperature range of 25-1000 degrees C with a heating rate of 10 degrees C/min. The kinetics of co-combustion were analyzed using the Fraser-Suzuki (FS) deconvolution method and a model-based kinetic modeling. The results indicate that a 10% addition of WRTC char reduces the intensity and rate of combustion and prolongs the combustion time. It was observed that the optimal addition to the blend is 25% WRCT, and it resulting in a reduction in activation energy and combustion indexes. However, it remains with no significant impact on process stability and efficiency. Kinetics of the decomposition of the WRTC25 mixture modeled by the deconvolution method indicates a 5-step reaction course, which is a combination of the characteristic combustion stages of both fuels. The main denoted functional group observed in the FTIR absorption spectra were C=O, C-O, O-H, and C-H related to the release of CO2, CO, H2O, CH4, aromatic compounds, and hydrocarbons.

N-Heterocyclic carbenes (NHCs) represent a pivotal class of ligands in coordination chemistry owing to their unique electronic properties. In particular, hemilabile N-heterocyclic carbenes have garnered significant attention over the past decade due to their capacity to transiently coordinate to metals and open coordination sites. However, hemilabile NHC ligands have been predominantly limited to N, O and P donors, while NHC ligands bearing versatile S-donors have been severely underdeveloped. Herein, we report wingtip-flexible, sterically hindered NHC ligands that feature N,C/S,C-chelating thiazole donors in combination with the powerful IPr* (IPr* = (2,6-bis(diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene) scaffold. These ligands are prepared using a highly modular SNAr arylation of thiazole derivatives. Full structural and electronic characterization is reported. The ligands feature a high barrier to rotation around the N-thiazole axis (10 kcal mol-1). The ligands are evaluated for their steric, electron-donating and pi-accepting properties as well as coordination chemistry to Ag(i), Pd(ii), Rh(i) and Se. Preliminary studies on Ag, Pd and Rh catalysis are presented. The efficiency of the approach is highlighted by preparing a library of unsymmetrical imidazolium precursors. The mono-IPr* wingtip provides a highly hindered yet sterically flexible environment adjusting to metal centers, while the N-thiazolyl wingtip displays a fluxional behavior that interchanges from the hard/soft N,C to soft/soft S,C coordination. Considering the importance of hemilabile N-heterocyclic carbene ligands in metal stabilization in inorganic and organometallic chemistry, we expect that this class of ligands will be of broad interest.

The paper presents an emergy analysis of the poultry farm regarding shifting energy sources from fossil fuels to biomass generated onsite in broilers and hen eggs rearing systems. It has been found that the manure produced on the farm has sufficient energy potential to replace the currently used energy carriers, both for heating and electricity supply. Replacing the currently used conventional energy resources with chicken manure will increase the emission charges. However, implementation of low -emission combustion techniques can help with reducing the emissions. Emergy analysis showed that for the conventional energy mix used in the farm, the Renewability Index (REN) is 0.5797, the Environmental Loading Ratio (ELR) is 171.49 and the Emergy Yield Ratio (EYR) has a value of about 1. If energy carriers are replaced by chicken manure, the REN may increase by 6.19% and the ELR may decrease by 6.11%. These relatively small changes should be considered in the context of the large scale of chicken production in Poland.

In this paper, the co-pyrolysis of blends of animal manure (AM) and high-density polyethylene (HDPE) waste was investigated using micro-thermal analysis techniques. Thermogravimetry coupled with Fourier-transform infrared spectroscopy was used to study the process kinetics and potential synergistic effects during co-pyrolysis. Dynamic co-pyrolysis experiments of animal manure (AM) and polyethylene (PE) blends in proportions of (90:10%) and (80:20%) were conducted at heating rates of 5, 10, 15, and 20°C/min under an N2 atmosphere. The process was analyzed and compared to the results obtained in the pyrolysis of pure components. AM and PE co-pyrolysis exhibited a synergic effect on the pyrolysis process, leading to a favorable change in the CPI pyrolysis initiation index. This was observed in the FTIR, shifting maximum devolatilization peaks by 14 °C towards lower temperatures and a lower activation energy of the main pyrolysis stage, with a decrease from 341.49±4.65kJ/mol to 273.04±6.93kJ/mol after the addition of 20wt.% PE to the blend. During co-pyrolysis, the main compounds observed in the FTIR absorption spectra were CO2, CO, CH4, NH3, and aromatic hydrocarbons from AM pyrolysis. Additionally, there was an increase in CH4 and short-chain hydrocarbons due to the PE pyrolysis.

This article examines the effects of different storage conditions on selected physicochemical properties of three types of agro-biomass pellets: sunflower husks, wheat straw and hemp hurds, and wood pellets. The tests were carried out in a climatic chamber, which allows simulation of real storage conditions, i.e. conditions with high air humidity and variable (±) ambient air temperatures. The results showed higher degradability of agro-biomass pellets compared to woody biomass. The pellets degraded to a less extent at varying ± temperatures than at high humidity (90% RH). After complete moisture saturation, durability decreases for agro-pellets by an average of 9%, while after freezing and defreezing for sunflower husk pellets and woody pellets durability decreases by 2%, and for hemp hurd pellets by 11%. In contrast, strength-by-dropping index for agro-pellets decreased by 20% after being in the environment (30 °C and 90%RH) and 15% under varying temperature conditions. No change in the energy parameters of all pellets in the dry matter was noted. On the other hand, an increase in the moisture content of pellets when they are stored under different environmental conditions results in a decrease in calorific value.

The study aimed to explore the potential use of coal-fired power plant bottom ashes in Pleurotus ostreatus cultivation using spent coffee grounds. The study analyzed five compositions of growth substrate for mushrooms: pure coffee grounds (I) as a control sample; coffee grounds substrate with the addition of 1% (II); 5% (III); 10% (IV) bottom ash; and bottom ash alone (V). The study revealed that compared to the control sample (I), the addition of 1% bottom ash (II) did not affect the time of mycelium growth but slowed fruiting body growth by 4 days. With 5% addition (III), mycelium growth slowed by 6 days, and fruiting body growth by 7 days. At 10% (IV), growth was completely inhibited. Compared to sample (I), fruiting bodies grown on sample (II) had higher phosphorus, copper, and zinc accumulation, while chromium, nickel, and lead levels were lower in fruiting bodies grown on samples (II) and (III). Additionally, fruiting bodies grown on samples (II) and (III) contained less iron, silicon, selenium, aluminum, calcium, and magnesium. The results presented in the article regarding the levels of contamination in the cultivated mushrooms and in the substrate after cultivation, indicate the potential for their further management.

The operation of fuel-burning heating equipment results in soot build-up in the flues. Its ignition poses a significant fire risk to the building, as the flue temperature can reach 1000°C. Wooden structural elements located near the chimney (ceilings and roof penetrations) are particularly vulnerable. To date, research has focused on the fire safety of wooden ceiling elements. This is where, due to heat radiation from the chimney, wooden elements significantly increase their temperature and become the location of fire initiation in the buildings. The task of chimney designers is to limit the temperatures of heated wooden building components near these structures. The present work analysed a ceramic and concrete chimney with air space with an innovative perlite concrete casing with a dual-function (load-bearing and thermal insulation). Computational Fluid Dynamics (CFD) analyses verified by a full-scale experiment were conducted to evaluate the fire safety of wooden building ceilings. The tests showed that a high level of safety characterised the chimney under study. The maximum temperature of the casing when testing the soot fire reached 38°C, and the wooden elements simulating the ceiling reached 28°C - this result is almost four times better than the chimney standard requirement. Furthermore, a developed CFD model exhibited high accuracy compared to the experimental results and can be used for designing this type of chimney and other research and expert work, such as that performed after fires in buildings originating from the chimney. Practical Application The article describes CFD analyses and tests of an innovative chimney in a perlite-concrete casing. The described research showed the high safety of such a chimney during soot fires. The results obtained can be used to develop changes in standards to improve the safety of chimneys and design safer and more efficient ones. The author’s chimney model and CFD analysis make it possible to determine the temperatures in the chimney during a soot fire. This CFD model allows you to assess the fire safety of the chimney and the building elements located in its vicinity.

The substrate mixtures were created in the study, using spent coffee grounds for Pleurotus ostreatus cultivation with the addition of straw and fluidized bed ash at 5 and 10 percent by weight relative to the total weight of coffee grounds. In order to determine the ability to accumulate heavy metals and the possibility of further waste management, analyses of micro- and macronutrients, biogenic elements, as well as the metal content of fungal fruiting bodies, mycelium and post-cultivation substrate were performed. The addition of 5 percent resulted in slower growth of mycelium and fruiting bodies, and with the addition of 10 percent, the growth of fruiting bodies was completely inhibited. The accumulation of elements such as (Cr), (Cu), (Ni), (Pb) and (Zn) was reduced in the fruiting bodies grown on the substrate with the addition of 5 percent fly ash, compared to spent coffee grounds without additives.

Lignosulfonate is one of the main by-products of the pulping process, with enormous potential for application as an alternative source of aromatic and bioactive compounds, especially in a closed-loop Circular Economy Concept. The lignin-derived bioactive compounds have attracted enormous interest in the scientific community due to their positive effects on human health. In the present paper, hydrothermal treatment technologies of the 10 wt% and 20 wt% lignosulfonate solutions i.e., slow HTL in batch reactor and fast HTL in continuous-flow (CF) reactor, are compared, and discussed, to assess their potential for obtaining bioactive and aromatic compounds. The hydrothermal liquefaction (HTL) in the two reactors was carried out at 275 degrees C at a pressure of 21.4 MPa, a 1:3 feed-to-water ratio. GC-MS and LC-MS-QTOF analyses were used to determine the chemical composition of the liquid products. According to the chromatogram integrated peak areas (PA), the fast HTL of the lignosulfonate produced the most isoeugenol (35.8-49.2%), eugenol (10.4-16.9%), and homovanillyl alcohol (13.8-18.4%). Slow HTL product, on the other hand, was rich in guiacol (62%) and apocynin (19.7%). LC-MS analysis of the product showed a similar composition to the liquid product in terms of heaviest compounds. Observed m/z values in the chromatograms indicated a presence of the compounds with masses between 121.159 and 934.021 u, possible configurations of the polycyclic phenolic compounds are presented.

There is a gap for research dedicated to co-gasification of laying hens manure (LHM) with commonly used litter such as wheat straw. The lack of comprehensive studies for such blends with broad range of air–fuel equivalent ratios (AFER) is also a challenge. The study was performed on a laboratory scale fixed bed updraft reactor supplied with straw and LHM blends of different mixing ratios (25, 50, 75%) and at low (0.12–0.28) and high (0.30–0.45) AFER ranges. The main objective of the research was to recognize the impact of the LHM addition on the quality of the producer gas and process efficiency. For higher ranges of the AFER, the LHV of the producer gas remains in a range of 3.3–3.4 MJ/m3 depending of the fuel blend ratio, yielding the cold gas efficiency about 60% and the carbon conversion efficiency in range of 82–94%.

The paper presents new approach in reducing of the CO emission in exhaust gases from small-scale wood pellet boilers. The results are obtained by control of the airflow to the boiler using a model-based nonlinear predictive controller. The complex-structure nonlinear model designed, and simplified to the nonlinear block-oriented Hammerstein system. Finally, the Hammerstein system is used to design the nonlinear predictive controller of the combustion process. The effectiveness analysis of the designed control algorithm under operating conditions at nominal heat power shows that 1) the airflow changes to the boiler is crucial for the CO concentration in the flue gasses and 2) accurate control of the airflow may lead to a significant reduction of the CO emission without any changes of the boiler design. The paper shows that reducing CO emissions from small-scale wood pellet boilers decreased by 35–50% of the original value with low implementation cost to fit industrial scale.

In contrast to the available studies, which concern mainly gasification and co-gasification of poultry litter, the work presented in the paper deals with co-gasification of laying hens manure (LHM), consisting no bedding material at all. The aim of the presented work was to investigate the potential for using chicken manure in co-gasification process with wheat straw pellets under air atmosphere. A laboratory scale fixed bed updraft reactor of capacity 5 kg/h was used in the research. The main objective of the study was to see the effect of the addition of LHM pellets to the straw pellet feedstock on the physicochemical properties of the producer gas, such as composition and lower heating value. The co-gasification was carried out for different air-fuel equivalence ratios AFER. It was shown that increasing AFER rises the AFER raised the gasification temperature and improved the producer gas quality. Moreover, at higher AFER the LHV of the producer gas remains in a range of 3.20-3.44 MJ/Nm 3 depending of the fuel used, yielding the cold gas efficiency CGE about 60% and the carbon conversion efficiency CCE in the range of 78-95%.

This paper presents the possibility of valorization of animal manure (camel and cow) by mixing it with agro-industrial biomass (cotton stalk and rapeseed oil cake) to produce pellets for use in power generation processes. Feedstocks were mixed in specific proportions based on certain assumptions concerning the energy and mechanical parameters of pellets. The assessment concerned both the combustion behavior as well as mechanical properties of four types of pellets derived from blends of animal manure and agro-industrial biomass. Thermogravimetry (TGA) and Differential Scanning Calorimetry (DSC) techniques are applied to analyze the reaction areas, characteristic temperatures as well as heat flow rates of raw materials and their blends. Results showed that addition of agro-industrial biomass (even 10%) to animal manure changed the specific combustion parameters: initiation and burn-out temperature and combustion time. For blends of cow manure (COM) and rapeseed oil cake (ROC), a reduction in the initiation temperature was achieved compared to the combustion of raw cow manure, and the combustion time increased by 1/3. In the case of camel manure (CAM) with the addition of cotton stalk (CS) the burn-out temperature and combustion time decreased. The addition of agro-biomass also causes a change in the heat release profiles, for the blends no pronounced DSC peaks are obtained in the area of devolatilization as it happens animal manure alone and in the area of fixed carbon combustion as for cotton stalk and rapeseed oil cake. The heat released from camel manure blends was 9.2-9.3 kJ/kg and from cow manure blends 10.2-10.4 kJ/kg. An evaluation of the physical and mechanical properties showed that all types of pellets at a moisture content of 10-15% have a similar drop strength in the range of 80-85%, while this strength decreases to 40-60% after the pellets have absorbed water.

In this study, the combustion of olive byproducts was investigated using the TG-FTIR technique. Different types of olive biomass were considered: twigs, leaves, olive-mill waste from the two-phase decanting method, and wastewater from the three-phase system. The reaction regions, ignition, and burnout temperatures at different heating rates were determined using TG/DTG analysis and the thermogravimetry results. Comprehensive combustion, ignition, burnout, and flammability indexes were also calculated. The highest combustion index values were obtained for waste from the three-phase system, followed by the two-phase decanting method, then with leaves and small twigs. The order of the index values indicated that the sample from the three-phase process ignited more quickly and yielded faster. The changes in activation energy calculated using different model-free isoconversional methods—Friedman, Ozawa–Flynn–Wall, and Kissinger–Akahira–Sunose—fell within the range of 130–140 kJ/kmol. FTIR analyses presented differences in the exhaust gas composition for specific combustion temperature ranges.

Shape memory alloys are functional materials characterized by the effect of shape memory and superelasticity. Due to these properties, they are widely used, particularly, in bioengineering, aeronautics, robotics and civil engineering. The temperatures of phase transformations and the influence of external temperature and strain rate on the functional and mechanical characteristics of Ni55.75Ti44.15 shape memory alloy are investigated in this paper. The temperature of alloy phase transformations is obtained by differential scanning calorimetry (DSC) in the temperature range from -70°C to 70°C. Diagrams of differential scanning calorimeters at different heating and cooling rates of Ni55.75Ti44.15 alloy is constructed and analyzed. Samples for mechanical tests are made of round rod 8 mm in diameter. The samples working area is 12.5 mm in length and 4 mm in diameter. Mechanical tests are carried out at temperatures close to the maximum value of the completion temperature of martensitic-austenitic transformation Af = 14.7°C. Diagrams of deformation under uniaxial tension are constructed and stresses of phase transformations, Young's modulus and relative elongations of transformation areas at different loading speeds and exterior temperatures are determined. Using Clausius-Clapeyron formula, it is shown that with simultaneous changes in temperature and strain rate, the stresses of phase transformations are largely due to changes in temperature rather than load rates. The coefficients of Clausius-Clapeyron equation for superelastic Ni55.75Ti44.15 alloy with shape memory, which are consistent with those known in the literature, are determined.

The aim of research is to provide a comprehensive view of the combustion process of coal with a liquid fuel additive. The studies were carried out in laboratory conditions and on low and high power boilers which are usually used in households and local district heating plants. TGA/DSC analysis shows that the additive decreases the ignition temperature of coal as well as increases the maximal heat flow and its temperature. Application of the additive significantly decreases oxygen O2 concentration, while maintaining the same flue gas temperature. This affects the increase of efficiency of low power boiler by 2.49 p.p. (percentage point). Emission of hydrocarbons, formaldehyde, benzene and hydrogen cyanide was lowered, whereas there was no significant impact on SO2 and NOx emission. The studies carried on the industrial boiler with thermal output of 12 MW demonstrate that the flue gas heat loss and unburnt fuel heat loss decreased by ca. 2 p.p. As a result, the efficiency increased from ca. 86 to 88% which, in turn, influences the decrease of CO2 emission per unit of energy by 5%. The originality of the work is comprehensive research on the impact of additive on the coal combustion process, mainly concerning the efficiency.

The main goal of this paper is the evaluation of combustion and grindability of torrefied palm kernel shells (PKS) obtained in a pilot-scale installation. The torrefied samples were prepared in different time conditions and temperatures, ranged from 220 to 300 degrees C. The physico-chemical properties were identified. Thermogravimetric analyses (TG-DTA) were used for characterization of the combustion performance and evaluation of the activation energy E-alpha. The grindability of the pre-treated biofuel was investigated in a pilot-scale, coal bowl-roller milling unit. The results were compared to those of the raw PKS and bituminous coal. Torrefaction was found to increase carbon C content and HHV by 2-33 and 2-26%, respectively. Moreover, the combustion characteristics of the torrefied PKS samples are close to each other, but the ignition and burn-out temperatures differ significantly. The torrefaction changes the activation energy E-alpha and it approaches the E-alpha values to those of coal. Both the torrefaction temperature and residence time significantly affect the grindability. The grinding effect of PKS torrefied at 220 degrees C reached the value of 10%, whereas after torrefaction at 300 degrees C it doubled. The torrefaction considerably improves the properties and combustion behaviour of biomass, which is a good predictor for burning and co-burning in industrial units. (C) 2019 Elsevier Ltd. All rights reserved.

The purpose of the work is to determine the impact of a commercial coal additive on the efficiency and the pollutants emissions of an industrial boiler. The tests were carried out in a 41.1 MW thermal output moving grate boiler in common operating conditions for a period of two months. At that time, coal was alternately dosed with and without the additive. The amount of the additive to coal ratio was fixed at 1 L/Mg during the tests. The additive applied was a 20% aqueous solution of four compounds, i.e. isopropanol, manganese (II) acetate tetrahydrate, acetic acid glacial... % and N,N-Dimethylethanolamine. The samples of coal, bottom and fly ash were collected from the installation twice a day during the tests in order to check their properties. The boiler's main energy parameters and the emission levels of CO, NOx, SO2 and dust were measured and registered. The additive influence on the boiler operation was evaluated based on the efficiency and three indicators which highlighted this impact. The additive influence was mainly demonstrated in boiler efficiency increase, in the range of 0.5-1 p.p., as well as the oxygen concentration in the flue gas which indicates that there was a decreased amount of the combustion air. On the other hand, the studies do not show any evident influence on the NOx, SO2 and CO emissions with the applied catalyst to fuel ratio. The research showed that even a little improvement of efficiency gives a measurable economic effect. (C) 2018 Energy Institute. Published by Elsevier Ltd. All rights reserved.