Pelleting Process Research Articles

Evaluation of different techniques for wet granulation and pelletization processes using milk as innovative pharmaceutical excipient for pediatric use

The present study focused on the use of milk as a novel excipient for the manufacture of pharmaceutical dosage forms specifically designed for the pediatric population. Dairy milks with different fat contents were studied to deliver paracetamol orally. The World Health Organization included milk in the list of GRAS (generally recognized as safe) substances, which together with its taste-masking ability and solubility solving properties, makes it a good candidate as an excipient in formulations containing paracetamol for pediatrics. The influence of the fat content in the milk, the fraction of paracetamol, the type of diluent and drying temperature (considered independent variables) were systematically investigated using a Design of Experiments (DoE) approach for the preparation of granules for oral administration, by wet agglomeration using different processing techniques, enabled the construction of mathematical models reflecting the correlation between the variables. Four different techniques were evaluated: wet granulation by low shear mixer, wet granulation by high shear mixer, wet granulation by fluidized bed, and extrusion and spheronization. The granules and pellets obtained were characterized for size, and size distribution of agglomerates, and complete release of the drug (dependent variables), according to the European Pharmacopoeia. The fraction of fat content in the milk promoted an increase on the dissolution rate of paracetamol. The key finding of the first two process techniques was a migration of paracetamol from powdered agglomerates towards the larger particles, probably due to friction and attrition events, which created a fraction of smaller size granules due to the fragmentation and loss of powder from the larger granules. The study has confirmed the potential of milk to be a novel and efficient excipient that can be used as a liquid binder in various agglomeration techniques to deliver drugs orally.

A Numerical Study of the Thermochemical and Aerodynamic States of H2‐intensive Direct Reduction Shaft Furnace

In the urgent pursuit of deep decarbonization, the steel industry has paid significant attention to the hydrogen‐intensive direct reduction process, where the H2‐to‐CO (volume) ratio of feed gas for the shaft furnace (SF) is increased compared to the current level. In this work, the reduction process of iron oxide pellets in the SF is investigated numerically to clarify how the in‐furnace thermochemical and aerodynamic states are affected by increasing hydrogen content, with the goal to provide guidelines for more efficient operations of the unit. Multiscale modeling is conducted to investigate the complicated gas–solid countercurrent reactive flows in the SF where the reduction behavior of an individual iron oxide pellet is described using a three‐interface unreacted shrinking core model. The results show that an increase in the hydrogen content leads to a lower temperature level and hence a deteriorated thermochemical state. It also induces a lower gas pressure drop over the in‐furnace packed bed.

The Effect of the Ratio of Fly Ash to Alkaline Activator and the Molarity of NaOH on the Mechanical Properties of Fly Ash-Based Aggregates

The global demand for aggregates has escalated, leading to a decline in the availability of quality natural aggregates. In response, the cold bond pelletization (CBP) process emerged in the early 2000s as a novel approach to artificial aggregate production, utilizing dry powdered fly ash. This method involves agglomerating fly ash particles at room temperature in an inclined rotating pan to form pellets. However, the abstract lacks clarity in elucidating the significance of this approach. Our study investigates the mechanical properties of aggregates produced through the CBP method via experimental laboratory methods, focusing on variations in the ratio of fly ash to alkaline activator (FA/AA) and the molarity of Sodium Hydroxide (NaOH). Notably, we found that an effective molarity of 15 resulted in the lowest Aggregate Impact Value (AIV) percentage, indicating improved mechanical properties. Furthermore, we observed fluctuations in AIV values across different FA/AA ratios and NaOH molarities, suggesting nuanced effects on aggregate quality. Our findings underscore the importance of optimizing parameters in the CBP process for enhanced aggregate performance.

Numerical investigation on hydrogen reduction of iron oxide pellets in a shaft furnace: Unveiling the impact of particle size

The reduction process of iron oxide pellets in the hydrogen shaft furnace is investigated numerically with the main purpose of clarifying the extent to which the pellet diameter can be reduced under the particle fluidization constraint, further exploring feasible options for preventing fluidization. A standalone numerical routine is developed to estimate the fluidization factor of the in-furnace burden. The results show that an increase in the gas feed rate yields a higher solid reduction degree, but also causes a larger fluidization factor due to the increase in the pressure drop. Under the conditions where the specific gas feed rate and pellet diameter are 1600 Nm3/t-pellet and 13 mm, respectively, the fluidization factor is smaller than unity, which is the threshold representing the occurrence of particle fluidization. A decrease in the pellet diameter is kinetically beneficial for the reduction reactions but also results in a clear rise of the pressure drop and hence an increase in the fluidization factor, which surpasses unity when the pellet diameter becomes smaller than 11 mm. The fluidization factor can be effectively lowered by adopting a higher top gas pressure, indicating that increasing the operating pressure is a feasible option for preventing fluidization of small particles.

Decoupling study of municipal solid waste gasification: Effect of pelletization on pyrolysis and gasification of pyrolytic char

To explore the influence of pelletization on the thermal conversion of municipal solid waste (MSW), pyrolysis characteristics and gasification reactivity of MSW pellet and powder were investigated in this study. Besides, the physicochemical properties of internal char and external char within the char pellet were separately characterized. Moreover, the relationship between the physicochemical properties of char pellet and its gasification reactivity was clarified. Results showed that the pyrolytic gas yields of MSW pellets were increased by 15.47 % and 11.55 % at 700 °C and 800 °C, respectively, compared to powder MSW. It was mainly attributed that the conversion of monocyclic aromatic hydrocarbons to polycyclic aromatic hydrocarbons was promoted by the longer residence time within the pellets. Meanwhile, the physicochemical properties of pyrolytic char pellets exhibited a significant heterogeneity. Specifically, the number of ordered aromatic rings of char pellet was reduced, while the order degree of carbon structure was enhanced, particularly the internal char. However, the difference magnitude between internal and external char was diminished with temperature. This was due to the higher temperature resulting in a larger surface specific area and pore volume of the char pellet, especially the internal char, thereby enhancing the pyrolysis process. Furthermore, an increase in pore volume within the char pellet improved gasification reactivity when the conversion rate > 0.4. These findings provide a reference for the pyrolysis and gasification process of MSW pellets.

Testing Pellets Fuel Production from Sewage Sludge of Palm Oil Industry

The wastes from the palm oil production process were used in this study, such as wastewater sludge and cake decenter or decanter waste. That moisture was less than 40% and increased density by the cold pelletizing process. The aim is to use pellet fuel for heating. Analysis of pellet fuel consists of physical properties, proximate (moisture, ash, volatile matter and fixed carbon) and heating value. The results showed that cake decenter and wastewater sludge had similar high volatile matter. The decenter cake had a higher heating value than the wastewater sludge at 26.649 and 14.965 MJ/kg, respectively. The ash of decenter cake was lower than wastewater at 11.71% and 22.34%, respectively. Blending both raw materials for pelletization increased the volatile matter that did not mix with another material. Therefore, both materials can be used to produce pellet fuel that has an optimal shape and size. That was hard to break. The results of chemical property testing show that it is within acceptable limits and can be used as pellet fuel.

Enhancing Concrete Properties through Fly Ash Pelletized Aggregates and Fibre Reinforcement - A Review

This literature review examines recent studies in Lightweight Aggregate Concrete (LWAC), specifically focusing on utilizing fly ash pelletization and fibre reinforcement to enhance concrete properties. Fly ash, a by-product of coal combustion, has gathered attention because of its potential to be put forward as a critical component in creating lightweight aggregates. The process of pelletization, which involves forming fly ash into small, spherical pellets, has been shown to improve the mechanical properties of the resulting concrete. The process mainly includes the cold-bonded pelletization method, which consumes energy and is easy to use. The review gives fusion findings from various studies examining fly ash's role in producing lightweight aggregates and the impact of different additives and processes on the resulting material properties. Key insights reveal that incorporating silica fume, fly ash, and steel fibres remarkably improves concrete's compressive and bonding strengths. Additionally, the cold-bonded pelletization of fly ash and cement, especially when combined with Polypropylene (PP) and steel fibres, leads to enhanced aggregate properties, including strength, density, and water absorption. The review also highlights the importance of optimizing pelletization parameters and binder usage to improve the quality of lightweight aggregates and enhance the properties of concrete. Moreover, integrating hybrid fibres, such as carbon and polypropylene, enhances concrete's postpeak performance and flexibility. The findings suggest that these innovations in fly ash pelletization and fibre reinforcement improve mechanical performance and contribute to more sustainable and cost-effective concrete production. This review provides a comprehensive overview of the current state of research, offering insights into the future direction of LWAC development.

Steel mill solid waste transformation: Optimizing converter sludge recycling through RHF technology

Current methods for treating converter sludge include reintroducing it into the sintering or pelletizing process. However, this method leads to the enrichment of zinc in the blast furnace, which affects the stability of the production operation. To solve this problem, a direct reduction process utilizing multi-solid waste collaborative rotary hearth furnace (RHF) has been implemented in steel plants to recover and safely dispose of valuable components in waste. The laboratory results show that the dezincization rate of the metallized pellets is 99.12 % and the metallization rate is 80.51 % under the premise of reducing 50 °C by calcination at 1200 °C for 15 min in the nitrogen atmosphere. In the industrial test conducted in RHF production line of Shagang from March 2022 to August 2023, the temperature in the high temperature zone was reduced by 50 °C, and the time in the high temperature zone was controlled to 15 min. The industrial test results showed that the residual zinc content in the metallized pellets was 0.63 %, and the metallization rate was about 75.12 %. These particles can be used as feedstock or coolant in the steelmaking process. The average grade of by-product zinc oxide coarse powder can reach 65.88 %, which can be further processed into zinc products with remarkable economic benefit. Through RHF integrated management of converter sludge and other solid waste in steel mills, metallized pellets and high-value products can be produced, which can effectively reduce solid waste in steel enterprises and improve resource utilization.

Evaluation of Mechanical Properties of Composite Material with a Thermoplastic Matrix Reinforced with Cellulose Acetate Microfibers.

Low-density polyethylene (LDPE) has been widely used in various applications due to its flexibility, lightness, and low production cost. However, its massive use in disposable products has raised environmental concerns, prompting the search for more sustainable alternatives. This study aims to investigate the mechanical properties achievable in a composite material utilizing low-density polyethylene (LDPE), potato starch (PS), and cellulose microfibrils (MFCA) at loadings of 0.05%, 0.15%, and 0.30%. Initially, the cellulose acetate microfibrils (MFCA) were produced via an electrospinning process. Subsequently, a dispersive mixture of the aforementioned materials was created through the extrusion and pelletizing process to form pellets. These pellets were then molded by injection molding to produce test specimens in accordance with ASTM D 638, the standard for tensile strength testing. The evaluation of the properties was conducted through mechanical tensile tests (ASTM D638), hardness tests (ASTM D 2240), melt flow index (ASTM D1238), and scanning electron microscopy (SEM). This study determined the influence of cellulose acetate microfibril loadings below 0.3% as reinforcement within a thermoplastic LDPE matrix. It was demonstrated that these microfibrils, due to their length-to-diameter ratio, contribute to an enhancement in the mechanical properties.

Dietary supplementation with calcium peroxide improves methane mitigation potential of finishing beef cattle

Calcium peroxide (CaO2) offers potential as an anti-methanogenic dietary feed material. The compound has been previously assessed in vitro, with methane (CH4) reductions of > 50% observed. The objective of this study was to assess dietary supplementation of CaO2 at different inclusion levels and physical formats in a finishing beef system on the effects of animal performance, gaseous emissions, rumen fermentation parameters and digestibility. Seventy-two dairy-beef bulls (465 kg; 16 months of age) were randomly allocated to one of four treatments supplemented with CaO2; in a coarse ration (1) CON (0% CaO2), (2) LO (1.35% CaO2), (3) HI (2.25% CaO2), and in a pellet (4) HP (2.25% CaO2) (n = 18). Animals received their respective treatments for a 77 d finishing period, during which DM intake (American Calan Inc., Northwood, NH), average daily gain (ADG), feed efficiency and enteric emissions (GreenFeed emissions monitoring system; C-Lock Inc., Rapid City, SD) were measured. The finishing diet was isonitrogenous and isoenergetic across the four treatment groups, composed of 60:40 grass silage:concentrate. Silage was offered each morning (0900 h), and concentrates were offered twice daily (0800 and 1500 h). Supplementation of CaO2 had no effect on final weight (P = 0.09), ADG (P = 0.22) or feed efficiency (P = 0.13). Regarding DM intake, the HI treatment group consumed in the order of 1 kg less than CON (P < 0.01), while HP did not affect DM intake compared to CON (P = 0.79). Across treatments, DM intake ranged from 8.43 to 9.57 kg/d, equating to 1.6–1.8% of BW. Daily CH4 values for the control were 240 g/d, while CaO2 supplemented diets ranged from 202 to 170 g/d, resulting in daily CH4 reductions of 16, 29 and 27% for LO, HI and HP, respectively, compared to CON (P < 0.0001). Additionally, hydrogen was reduced in CaO2 supplemented animals by 32–36% relative to CON (P < 0.0001), with a simultaneous reduction in volatile fatty acid production (P < 0.01) and an increase in propionate concentration (P < 0.0001). Across all universally accepted CH4 metrics (yield, intensity, production), the dietary inclusion of CaO2 whether at a low or high rate, or indeed, through a coarse ration or pelleted format reduced CH4 in the order of 16–32%. This study also concluded that CaO2 can successfully endure the pelleting process, therefore, improving ease of delivery if implemented at farm level.

Physical and Energy Properties of Fuel Pellets Produced from Sawdust with Potato Pulp Addition

This paper presents the findings of a study of the pelleting process of pine sawdust with the addition of waste in the form of potato pulp (as a natural binder), in the context of producing fuel pellets. The process of pelleting was carried out for sawdust and for a mixture of sawdust and potato pulp (10, 15, 20, and 25%). The highest moisture content was obtained in the case of pellets produced from a mixture of straw with a 25% potato pulp content, i.e., 26.54% (with a potato pulp moisture content of 85.08%). Increasing the potato pulp content in a mixture with sawdust from 10 to 25% reduced the power demand of the pelletizer by approx. 20% (from 7.35 to 5.92 kW). The obtained density values for pellets made from a mixture of sawdust and potato pulp (over 1000 kg∙m−3) with a potato pulp content of 10% make it possible to conclude that the obtained pellets meet the requirements of the ISO 17225-2:2021-11 standard. Increasing the potato pulp content from 0 to 25% caused a slight decrease in the heat of combustion, i.e., from 20.45 to 20.32 MJ∙kg−1, as well as in the calorific value, from 19.02 to 18.83 MJ∙kg−1 (both for dry sawdust matter and the mixture). The results of the laboratory tests were used to verify the densification process of mixtures of sawdust and potato pulp under industrial conditions at the PANBAH plant, using pelleting mixtures with a 5%, 10%, and 25% content of potato pulp. Industrial research also confirmed that the use of the addition of potato pulp in a mixture with sawdust significantly reduces the power demand of the pelletizer, and it also increases the kinetic strength of the obtained pellets.

Bacillus altitudinis 1.4 genome analysis-functional annotation of probiotic properties and immunomodulatory activity.

Probiotics are live microorganisms that, when administered in adequate quantities, provide health benefits to the host. In this study, phenotypic and genotypic methods were used to evaluate the probiotic properties of Bacillus altitudinis 1.4. The isolate was sensitive to all antimicrobials tested and presented a positive result in the hemolysis test. B. altitudinis 1.4 spores were more resistant than vegetative cells, when evaluated in simulation of cell viability in the gastrointestinal tract, as well as adhesion to the intestinal mucosa. The isolate was capable of self-aggregation and coaggregation with pathogens such as Escherichia coli ATCC 25922 and Salmonella Enteritidis ATCC 13076. Genomic analysis revealed the presence of genes with probiotic characteristics. From this study it was possible to evaluate the gene expression of pro-inflammatory and anti-inflammatory cytokines for different treatments. Viable vegetative cells of B. altitudinis 1.4 increased the transcription of pro-inflammatory factors, in addition to also increasing the transcription of IL-10, indicating a tendency to stimulate a pro-inflammatory profile. Given the results presented, B. altitudinis 1.4 showed potential to be applied in the incorporation of this microorganism into animal feed, since the spores could tolerate the feed handling and pelletization processes.

Pelletized Straw for Biogas Production—Substrate Characterization and Methane Formation Potential

The use of agricultural residues in biogas plants is becoming increasingly important, as they represent an efficient and sustainable substrate alternative. Pelletizing straw can have positive effects on transportation, handling, and biogas production. In this study, different grain straw pellets from mobile and stationary pelleting plants in Germany as well as the corresponding untreated straw were characterized and investigated for their suitability for anaerobic digestion (AD). Therefore, tests on the biochemical methane potential (BMP) and the chemical–physical characterization of unpelletized straw and straw pellets were carried out. The characterization of the pellets and the straw revealed a high average total solid content of 91.8% for the industrially produced straw pellets and of 90.8% for the straw. The particle size distribution within the tested pellet samples varied greatly depending on the pelleting process and the pre-treatment of the straw. In addition, a high C/N ratio of 91:1 on average was determined for the straw pellets, whereas the average higher heating value (HHV) content of the pellets was 17.58 MJ kg−1. In the BMP tests, the methane production yields ranged from 260–319 normal liter (NL) CH4 kg−1 volatile solids (VS) for the straw pellets and between 262 and 289 NL CH4 kg−1 VS for the unpelletized straw. Overall, pelleting increases the methane yield on average from 274 to 286 NL CH4 kg−1 VS, which corresponds to an increase in methane yield of 4.3%. Based on the results, the feasibility of using straw pellets for AD could be confirmed, which can facilitate the possibility of increased biogas production from agricultural residues such as straw pellets and thus make the substrate supply more sustainable.

Tribological Properties of PEEK and Its Composite Material under Oil Lubrication

PEEK (Poly Ether Ether Ketone) is a high-performance thermoplastic polymer with excellent mechanical, thermal and chemical stability. PEEK has good performance, and is widely used in hydraulic motors. However, there are few studies on the friction and wear properties of materials under the condition of oil lubrication with wide application. The modification of PEEK and the expansion of its application have become a hot research topic in the industry. This study focuses on the modification of the design of PEEK and explores the friction and wear characteristics of self-lubricating materials under different modification schemes. Friction and wear samples were prepared using PEEK-modification pelletizing and injection-molding processes, followed by fixed-condition friction and wear tests. The tribological mechanisms and wear properties of the materials under different modification schemes were analyzed, leading to the identification of several sets of improved reinforced materials. Experimental results demonstrate that modified materials can enhance surface tribological performance, with the best modification effect observed at an SCF filling rate of 15%. The modified PEEK material can better meet the requirements of specific applications, such as high-temperature environments, chemically aggressive environments, or applications requiring high strength and wear resistance.

Development and Characterization of Polyethylenimine-Infiltrated Mesoporous Silica Foam Pellets for CO2 Capture.

Polyethylenimine (PEI) has been shown to be promising for direct air capture (DAC) of carbon dioxide and has potential for commercial scale-up globally. Laboratory scale processes include multiple steps, such as mixing, solvent extraction, vacuum application, sonication, and various flushes and activation steps. It is critical to properly control these operating parameters to achieve higher capture capacity as a result of the optimized material configuration. This study adopts previously published pelletization processes for PEI-infiltrated mesoporous foam silica (mesoporous silica foam) to uncover the adsorption mechanisms and optimize the associated fabrication steps, such as sonication, to achieve higher sorbent productivity. A high capture capacity was achieved at 46 °C for 75 wt % PEI loading (2.27 mmol/g) followed by PEI_MSF 70 (1.81 mmol/g) and PEI_MSF 80 (1.44 mmol/g). As part of the optimization, sonication parameters of frequency, amplitude, and time were modified for PEI_MSF 75 sorbent, which resulted in the highest uptake capacity of 3.04 mmol/g (sonicated at 40 kHz and a wave amplitude of 50% for 30 s). These preliminary results would tend to prove that sonication energy affects carbon capture capacity, although there is still a lack of understanding regarding the exact underlying mechanism, suggesting the need for further investigation. It is important to note that the present work is focused on the adsorption mechanisms and not desorption or durability of the capture performance. Ongoing research addresses these factors. This paper is intended to establish baseline DAC behavior of a promising capture medium and begins probing the optimization spectrum by considering the effects of sonication energy on adsorption. Ongoing work intends to address potential abbreviations of the full range of process steps and furthers the understanding of kinetics by considering the desorption and resorption attributes.

Biomass Pellet Processing from Sugar Industry Byproducts: A Study on Pelletizing Behavior and Energy Usage

As global energy demand has increased, bioenergy has emerged as a viable option for reducing greenhouse gas emissions. This study focuses on using waste materials from the sugar industry, such as sugarcane straw, bagasse, and filter cake, to compress into pellets to investigate pelletizing behavior and energy usage. Raw material preparation was a critical phase influencing pelletizing efficiency. Biomass pellet quality depended on a uniform particle size distribution and adequate moisture content. A moisture content of 20% (wb) was found to be suitable for biomass pelletization from the sugar sector. Specific energy in the pelletizing process ranged from 144.28 to 197.85 Wh/kg. The suggested mixing ingredients (sugarcane leaves: bagasse: filter cake) of 0% sugarcane leaves, 90% bagasse, 10% filter cake, and 5% sugarcane leaves, 93.5% bagasse, and 1.5% filter cake resulted in pellets with a bulk density of over 600 kg/m3 and a durability of at least 97.5%. All aspects were assessed according to standardized criteria for developing biomass pellet processing technology from sugar industry byproducts. This method could improve efficiency, boost production volume, lower production costs, and promote the efficient and cost-effective use of renewable energy.

Preparation and evaluation of lipid-based sustained release pellets of chlorpheniramine maleate by the wet extrusion-spheronization method

Introduction: This study aimed to investigate the feasibility of preparation of sustained-release chlorpheniramine maleate (CPM) pellets based on Compritol® as a lipid matrix and evaluation of the affecting factors on pellet properties. Methods: Using the D-optimal experimental design, different pellet formulations containing various amounts of CPM, Compritol® and Avicel were prepared by the wet extrusion-spheronization method. Then the pellets were cured at 40, 65 and 90 ̊C for 4 and 8 h to study the effect of the thermal process. The physicomechanical properties of the pellets were investigated in terms of particle size distribution, pelletization yield, mechanical strength, aspect ratio and sphericity. To investigate the possible interaction of CPM and Compritol®, as well as to evaluate the morphology and surface characteristics of the pellets DSC and SEM were used, respectively. Also, to investigate the drug release rate from pellets the dissolution test was carried out and mean dissolution time (MDT) was calculated to compare different formulations. Results: The results showed that the curing process up to 65 °C improves the strength of the pellets. However, increasing the curing temperature from 65 to 90 °C and also increasing the curing time from 4 to 8 h did not have a significant effect on the strength of the pellets but increased the drug release rate of pellets. Increasing the amount of the drug or decreasing Compritol® in the matrix of pellets leads to a larger particle size with greater mechanical strength. All formulations of the pellets had an aspect ratio and sphericity of about 1.1 and 0.9 respectively, which indicates the spherical shape of the pellets as shown by SEM. DSC thermograms indicate the reduction of the crystallinity or the change of the crystalline form of the drug to amorphous during the pelletization process. Conclusion: The results revealed the feasibility of preparing lipid-based sustained-release matrix pellets using the wet extrusion-spheronization method. The optimal formulation in terms of physicomechanical properties and release rate was the formulation containing 8% CPM, 67% Compritol® and 25% Avicel, which were dried at 40 ° C for 4 h and released about 90% of the drug within 12 h.

Transforming olive-processed waste and almond shells into high-quality Biofuels: a comprehensive development and evaluation approach

ABSTRACT Amidst the energy crisis, biomass energy has emerged as a pivotal solution, given its abundant distribution, impressive storage capabilities, and carbon-neutral nature. The study aims to develop biofuels of good quality using various agroalimentary waste products, Examining the pelletization process of including wet olive pomace (wet olive pomace (2 phases)(OP)), de-oiled olive pomace (DOP), olive stones (OS), and almond shells (AS), this research assesses its effectiveness in enhancing both bulk and energy densities, highlighting it as the optimal method for such enhancement. The preparation of these biofuels without binder has yielded promising results in terms of bulk density, hardness, calorific value, and ash content. Tests comparing biofuels to commercial olive pomace pellets (COP) showed the following: Using biomass with moisture content below 15%, granulometry of 1 mm or smaller, and no binder produces high-quality pellets. These pellets had high density (889, 675, 643, and 621 kg/m3), high hardness (99.18%, 99.80%, 98.92%, and 99.14%), and high heating values (18.93, 20.29, 22.51, and 20.38 MJ/kg) at average temperatures and pressures. These results are comparable to those of commercial products. In general, biomass and solid biofuels offer credible alternatives to produce energy in the form of electricity, heat, or both, using various processes, such as combustion, pyrolysis, and gasification. The knowledge gained from this research is very helpful in developing and improving bioenergy systems and promoting sustainable methods of producing energy from agricultural wastes.

Waloryzacja pozostałości rolniczych na pelety w zrównoważonej biogospodarce o obiegu zamkniętym

It is a truism by now that the combustion of fossil fuels has execaerbated climate change, and its repercussions. Biomass in pelletised form, will emerge as substitutes, in the circular bioeconomies of the future. This brief review focuses on the utilisation of agricultural residues as raw materials for pellets, and explores the aspects of sustainability – socio-cultural, economic, environmental, and techno-functional – in the 20-plus peer-reviewed articles selected for that purpose using Scopus with a set of search-phrases. The articles are case studies dated between 2012 to 2023, tracing their provenance to different countries in the world – Brazil, Canada, China, Denmark, Greece, India, Italy, Mexico, Peru, Spain, Thailand, Türkiye, Zambia, etc. Among the many gleanings which are reported in this review, some deserve mention here in the abstract. The social aspect of sustainability has not been studied as much as the economic and environmental. The case studies emphasize the importance of adapting the pelleting process to the properties of the agricultural/horticultural residues and the prevalent local conditions. It is encouraging to note that there is a surfeit of agricultural residues (corn, coffee, quinoa, beans, oats, wheat, olives, tomatoes, pomegranates, grapes, etc. in the articles reviewed) which can be valorised to pellets, also in combination with the in-vogue forestry wastes. This is more advisable if the status quo is open burning of such residues in the fields. The journey towards the sustainable development goals (SDGs) will be aided by investments in such biorefinery-projects, SDG 17 is extremely vital for their success – collaboration and cooperation among several stakeholders around the world. This review, though based on only 20-plus articles from around the world, is an in-depth analysis which promises to be of interest to decision-makers and sustainability-specialists keen on contributing to the transition to a circular bioeconomy.

Predictive study of drying process for limonite pellets using MLP artificial neural network model

Due to the decline in high-grade iron ore production, the utilization of low-grade iron ore, such as limonite, has become necessary. Limonite contains a significant amount of bound water, which requires a drying process prior to use. Excessive heat stress caused by the evaporation of bound and free water during the drying of limonite pellets can lead to pellet disintegration and adversely affect gas-solid reactions. In recent years, artificial neural network (ANN) has been developing continuously in the fields of modeling and intelligent control, and has been widely used. Many predecessors used artificial neural network model to study the drying process of natural organic matter, and analyzed the factors affecting the drying rate of organic matter. In this study, we employed big data analysis, specifically Multilayer Perceptron (MLP) artificial neural networks, to analyze the drying process of limonite pellets and successfully established a predictive drying model applicable to limonite pellets. The MLP artificial neural network demonstrated excellent fitting between predicted and experimental values, with a maxi-mum R2 value of 0.999. The artificial neural network for drying developed in this study provides technical guidance for industrial material drying, reduces the workload of manual measurements, and minimizes energy consumption.