Plastic waste accumulation poses significant environmental challenges, underscoring the importance of closing the plastic life cycle by converting waste into valuable products. Pyrolytic char, a promising byproduct, offers diverse industrial applications. However, little attention has been given to converting hydrocarbon-based plastics into solid carbon due to their low fixed carbon content. This study compares sulfonation and thermal oxidation stabilization techniques for carbonizing waste polyethylene and polyvinyl chloride. Results indicate sulfonation yields higher pyrolytic char formation and improves surface properties, surpassing Al2O3 in catalyst support characteristics. Thermal oxidation increases fixed carbon content but adversely affects char yield and surface properties. Both methods effectively enhance fixed carbon content, but sulfonation emerges as more advantageous, suggesting potential use of plastic-derived char as a catalyst support material, contributing to circular economy development.

Floods are the most frequent and devastating disasters in Bangladesh. The riverine islands, known as char-lands, are particularly vulnerable to flooding. As flooding poses a significant threat to the lives and livelihoods of residents, especially farmers, it is crucial to understand how they perceive flood risk and assess their adaptation strategies in this geographically susceptible context. However, the existing literature has not adequately addressed these issues. Therefore, this study aims to analyze the factors influencing farmers' perceived flood risk and their assessments of flood adaptation. In a survey of 359 farmers in Bangladesh's char-land region, located in the Chowhali sub-district of Sirajganj district, we used the protection motivation theory (PMT) to measure farmers' perceived flood risk and adaptation assessments. Multiple regression analysis was employed to identify factors influencing them. Farmers prioritized the risk to livelihoods (production and income) over psychological aspects (health and diseases). Larger farms, more flood experience, and greater risk awareness are associated with higher overall flood risk perception; and better flood adaptation, indicating higher self-efficacy, response efficacy, and response cost among farmers. Farmers perceived lower flood risk in exchange for greater house distance from the river and more trust in government actions. Hence, strengthening campaigns and programs is crucial to understanding flood risk in char-lands for improved adaptation to floods. The study highlights the application of PMT to assess farmers' perceptions of flood risk and their attitudes towards adaptation, suggesting further research opportunities.

This work aimed to study the thermal and crystalline properties of poly (1,4-phenylene sulfide)@carbon char nanocomposites. Coagulation-processed nanocomposites of polyphenylene sulfide were prepared using synthesized mesoporous nanocarbon of coconut shell as reinforcement. The mesoporous reinforcement was synthesized using a facile carbonization method. The investigation of the properties of nanocarbon was done by SAP, XRD, and FESEM analysis. The research was further propagated via the synthesis of nanocomposite by the addition of characterized nanofiller into poly (1,4-phenylene sulfide) at five different combinations. The coagulation method was utilized for the nanocomposite formation. The obtained nanocomposite was analyzed using FTIR, TGA, DSC, and FESEM analysis. The BET surface area and average pore volume of bio-carbon prepared from coconut shell residue were calculated to be 1517 m2/g and 2.51 nm respectively. The addition of nanocarbon to poly (1,4-phenylene sulfide) has led to an increase in thermal stability and crystallinity up to 6% loading of filler. The minimum achievable glass transition temperature is for 6 % doping of filler into the polymer matrix. It was established that the thermal, morphological, and crystalline properties have been tailored by synthesizing their nanocomposites with mesoporous bio-nanocarbon obtained from coconut shells. So, the loading of filler into poly (1,4-phenylene sulfide) can be optimized to enhance its thermoplastic properties for surface applications.

Bio-char is a charcoal-like substance made through the pyrolysis of organic biomass. It has the potential to address issues related to agriculture and the environment. This thorough analysis examines the potentials of bio-char in Ethiopia to enhance crop productivity, reduce climate change, and improve soil fertility. Drawing from academic databases and peer-reviewed literatures, the review explores the production and characterization of bio-char, its impact on soil fertility and crop productivity, and its role in carbon sequestration and greenhouse gas mitigation. The review emphasizes on how bio-char may improve plant nutrition and soil fertility, which raises agricultural yields and quality while improving drought resistance. The review also emphasizes the potential of bio-char for greenhouse gas mitigation and carbon sequestration, enhancing Ethiopia's efforts to mitigate climate change. Yet the study also points out several challenges and opportunities that need to be addressed to allow Ethiopians to use bio-char technology on a large scale. These include the need for appropriate policy and regulatory frameworks, the availability and accessibility of bio-char feedstocks, and the importance of continued research and development to optimize production methods and application strategies. The review concludes by highlighting the groundbreaking potential of bio-char in promoting environmentally friendly agricultural practices and sustainable agriculture in Ethiopia. It necessitates a coordinated effort to solve the problems and grasp the opportunities by making sound decisions in policy integration, research, and development. Ethiopia can advance its sustainable development goals by using bio-char to create a road towards increased food security, healthy soil, and environmental resilience.

By enhancing the bitumen properties with the additives produced from wastes not only can be improved the performance of flexible pavements but also can be contributed to the environment. This research aims to produce a novel pyrolytic char from different wastes and to investigate the usability of this char as an additive in bitumen. In this study, firstly, the pyrolytic char was produced from co-pyrolysis of three different wastes including waste paper cups, polypropylene (PP) and polyethylene terephthalate (PET) wastes. Properties of the char were determined by using CHN (carbon, hydrogen, nitrogen) and Fourier transform infrared spectroscopy (FTIR) analyses. The high temperature rheological properties of binders were evaluated by using DSR (dynamic shear rheometer), RV (rotational viscometer), softening point and penetration tests. Additionally, specific gravity, storage stability, high temperature performance grades (PG) and temperature susceptibilities of binders were determined. Test results showed that this pyrolytic char enhanced the high temperature properties of neat bitumen by increasing softening point, viscosity, rutting resistance and high temperature PG. And, it can be said that the bituminous binder modified with this pyrolytic char had a good storage stability when it was used at 8% ratio in neat bitumen.

Coal gasification with carbon dioxide is a process for generating clean gaseous fuels and relieving greenhouse effect. Zhundong coal has high alkali and alkali earth metals (AAEMs) content, medium volatile and low ash in nature. Isothermal CO₂ gasification of char derived from Zhundong coal (R-char) and char from acid washing R-char (AR-char) are performed in thermo-gravimetric analyzer (TGA). The effect of AAEMs is investigated on the gasification behavior in the range of temperatures 1073 K to 1273 K. The carbon conversion increases rapidly with increasing reaction temperature and CO₂ concentration. R-char has high gasification rate and carbon conversion compared with AR-char. The accuracy of the free-model approach for calculating activation energy at different conversions is validated by compared with different kinetic models (volume reaction model, distributed activation energy model). Moreover, R-char gasification with CO₂ shows a compensation effect as the Arrhenius parameters (EA and k0) increase or decrease simultaneously.

Pulverized coal pyrolysis based on solid heat carrier has a huge advantage in high tar yield. In this study, pyrolysis experiments of pulverized coal were conducted in a lab-scale fluidized bed reactor at 650 ℃, utilizing char as the solid heat carrier. The influence of mass ratio of char to coal (RATIO) was investigated. Results show that the incorporation of solid heat carrier of char significantly enhanced the initial reaction in coal pyrolysis, resulting in increasing yields of tar and gas but reducing one of char. The yield of tar maximally reached 148.80-262.22% of the Gray-King analysis value at the RATIO of 14.52 g/g. As the RATIO increased, the tar contained more light component content, indicating that incorporating solid heat carriers improved the tar quality. These findings offer significant insights for the design of fluidized bed pyrolysis unit utilizing char as solid heat carrier.

The pyrolysis process has emerged as an attractive option for waste treatment. In this technology, inorganic compounds play catalytic effects in the pyrolytic reaction of organic materials, increa-sing the char's yield, porosity, and physicochemical properties. The present research investigates and compares the slow pyrolysis of spent coffee grounds (SCG) using potassium hydroxide (KOH) (weight ratio of 1:1) and landfill leachate membrane concentrate (LLMC) residue (weight ratio of 1:1) as pyrolitic additives. We hypothesized that the high content of alkali and alkaline earth metals in LLMC could enhance the yield or improve the quality of the carbon-based material produced in pyrolysis. This strategy could be a sustainable alternative for valorizing SCG and landfill wastes, replacing catalyzing agents such as steam, CO2, and chemical additives used on an industrial scale. The char yields in slow pyrolysis ranged from 18 to 24%. The SCG had a low specific surface area (4.5 m2 g-1), contrasting with the notable surface areas observed in both ac-tivated chars. In particular, the KOH-activated char displayed a higher surface area than the LLMC-activated char (1960 vs. 1130 m2 g-1). On the other hand, the combustion enthalpy of the LLMC-activated material was estimated at 22 MJ kg-1. This value was 22% higher than the energy enthalpy of SCG and KOH-activated char used for comparison. Our findings confirm that pyrolysis of SCG with KOH produces a microporous material with a high specific surface area. In contrast, the resulting LLMC-activated char demonstrates a higher calorific value. Our findings could contribute to establishing potential industrial applications for SCG and LLMC residues to produce energy and high-value materials.

In this work, the effect of reaction time and biomass-to-H2O ratio on the structural evolution of hydro-char and kinetic of by hydrothermal processing of corn Stover with hot compressed H2O, have been systematically investigated. The experiments were carried out at 250 °C, heating rate of 2.0 °C/min, biomass-to-H2O ratio of 1:10, and reaction times of 60, 120, and 240 minutes, and at 250 °C, 240 minutes, heating rate of 2.0 °C/min, and biomass-to-H2O water ratio of 1:10, 1:15, and 1:20, using a pilot scale stirred tank reactor of 5 gallon. The characterization of solid phase products performed by thermo-gravimetric analysis, scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction, and elemental analysis (C, N, H, S). The physical-chemistry properties of solid phase analyzed in terms of dry matter (DM), total organic content (TOC), and ash. The yields of solid and gas phases decrease linearly with decreasing biomass-to-H2O ratio, while that of liquid phases increases linearly. For constant biomass-to-H2O ratio, the yields of solid, liquid, and gaseous reaction products varied between 52.97 and 35.82% (wt.), 44.84 and 54.59% (wt.), and 2.19 and 9.58% (wt.), respectively. The yield of solids decreases exponentially by decreasing the reaction time, while the yields of liquid and gas phases increase exponentially. For constant biomass-to-H2O ratio, TG/DTG curves shows that reaction time of 60 minutes was not enough to carbonize corn Stover. For constant reaction time, TG/DTG curves shows that increasing the H2O-to-biomass ratio worse the carbonization of corn Stover. For constant biomass-to-H2O ratio, the SEM images show the main morphological structure of the corn Stover remains practically unchanged, while for constant reaction time, SEM images show that plant microstructure retains part of its original morphology, demonstrating that a decrease on biomass-to-H2O ratio worse the carbonization of corn Stover. For constant biomass-to-H2O ratio, the EDX analysis shows that the carbon content in hydro-char increases with reaction time, while for constant reaction time, the carbon content decreases with increasing biomass-to-H2O ratio. The kinetic of corn Stover degradation was correlated with a pseudo-first order exponential model, exhibiting a root-mean-square error (r2) of 1.000, demonstrating that degradation kinetics of corn Stover with hot compressed H2O, expressed as hydro-char formation, is well described by an exponential decay kinetics.

This work aims to investigate the effect of process temperature and catalyst content by pyrolysis and thermal catalytic cracking of (organic matter + paper) fraction from municipal household solid waste (MHSW) on the yields of reaction products (bio-oil, bio-char, H2O, and gas), acid value and chemical composition of bio-oils, and characterization of bio-chars, in laboratory scale. The collecting sectors of MHSW in the municipality of Belém-Pará-Brazil were chosen based on geographic and socio-economic database. The MHSW collected and transported to the segregation area. The gravimetric analysis of MHSW carried out and the fractions (Paper, Cardboard, Tetra Pack, Hard Plastic, Soft Plastic, Metal, Glass, Organic Matter, and Inert) separated. The selected organic matter and paper submitted to pre-treatment of crushing, drying, and sieving. The experiments carried out at 400, 450, and 475 °C and 1.0 atmosphere, and at 475 °C and 1.0 atmosphere, using 5.0, 10.0, and 15.0% (wt.) Ca(OH)2, in batch mode. The bio-oil characterized for acid value. The chemical functions present in bio-oil identified by FT-IR and the composition by GC-MS. The bio-char characterized by SEM, FT-IR and XRD. The variance in mass (wt.%) for organic fraction of municipal household solid waste, between 56.21 and 67.45% (wt.), lies with the interval of 56% (wt.) and 64% (wt.) of OFMHSW for middle and low income countries. The pyrolysis of MHSW fraction (organic matter + paper) show bio-oil yields between 2.63 and 9.41% (wt.), aqueous phase yields between 28.58 and 35.08% (wt.), solid phase yields between 35.29 and 45.75% (wt.), and gas yields between 16.54 and 26.72% (wt.). The bio-oil yield increases with pyrolysis temperature. For the catalytic cracking, the bio-oil and gas yields increase slightly with CaO content, while that of bio-char decreases, and the H2O phase remains constant. The GC-MS of liquid reaction products identified the presence of hydrocarbons (alkanes, alkenes, alkynes, cycloalkanes, and aromatics) and oxygenates (carboxylic acids, ketones, esters, alcohols, phenols, and aldehydes), as well as compounds containing nitrogen, including amides and amines. The acidity of bio-oil decreases with increasing process temperature and with aid Ca(OH)2 as catalyst. The concentration of hydrocarbons in bio-oil increases with increasing Ca(OH)2-to-MHSW fraction ratio due to the catalytic deoxygenation of fatty acids molecules, by means of de-carboxylation/de-carbonylation, producing aliphatic and aromatic hydrocarbons.

Activated carbons can be produced from biomass in a thermal process either in a direct carbonization-activation process or by first carbonizing the biomass and later on activating the biochars into activated carbons. The properties of the ACs are dependent on the type of process used for production. In this study, the properties of activated carbons produced in a one-stage and a two-stage process are considered. Activated carbons were produced by physical activation of two types of starting materials, bio chars produced from spruce and birch chips in a commercial carbonization plant and from the corresponding raw chips. The activated carbons produced were characterized regarding specific surfaces, pore volumes and pore size distributions. The un-activated bio chars had some degree of surface area 190 and 140 m²g^-1 for spruce and birch and pore volumes of 0.067 and 0.092 cm³g^-1. According to the results obtained, two slightly different types of activated carbons are produced depending if a one-stage or a two-stage carbonization and activation process is used. The ACs produced in the one-stage process had higher specific surface areas compared to the ones produced in a two-stage process (761-940 m²g^-1 vs. 540-650 m²g^-1) . In addition, total pore volumes were higher in one-stage process but development of micropores is greater compared to two-stage process. There was no significant difference in total carbon content between one-stage and two-stage process.

Disrupted nutrient recycling is a significant problem for Europe, while phosphorus and nitrogen are wasted instead of being used for plant nutrition. Mineral phosphate is critical raw material, which contains environmentally hazardous elements such as cadmium and uranium. Therefore, phosphorus recovery from agricultural by-product streams is critically important key priority. Phosphorus recovery from food grade animal bone by-products have been applied researched since 2002 with objective driven evolution progress towards specialized pyrolysis processing technology and animal bone char product (ABC) developments in economical industrial scale. Different animal bone by-products tested under different conditions at 400 kg/h throughput capacity in the continuously operated 3R zero emission autothermal carbonization system. The different material core treatment temperatures (between >300°C and <850°C) were combined with different residence times under industrial productive processing conditions. It has been industrial demonstrated that material core treatment temperature <850°C with 20 minutes residence time is necessary to achieve high quality ABC with useful agronomic value. The output ABC product having concentrated >30% phosphorus pentoxide (P2O5) and specific quality innovative fertilizer for agronomical efficient organic and low input farming applications as functional organic fertilizer, soil improver, growing medium and/or fertilizing product blend with high mineral phosphate fertiliser replacement value.

This study examines the chemical recycling of polymethylmethacrylate (PMMA) dental waste via pyrolysis in a semi-batch fixed-bed reactor, aiming to convert it into the valuable monomer methyl methacrylate (MMA). Experiments were conducted in a 2L reactor at temperatures of 425 °C, 450 °C, and 475 °C to understand the effects of heating rate and temperature on product yield and composition. Results show that at 425 °C, MMA was the primary liquid component, with minimal by-products, suggesting that lower temperatures enhance monomer recovery. Higher temperatures, however, increased gas yields and reduced MMA yield due to intensified thermal cracking. The study also highlights that char formation and non-condensable gases increase with reactor scale, indicating that heat transfer limitations can influence MMA purity and yield. These findings emphasize that for effective MMA recovery, lower temperatures and controlled heating rates are optimal, especially in larger reactors where heat transfer issues are more prominent. This research contributes to scaling up PMMA recycling processes, supporting industrial applications to achieve efficient monomer recovery from waste.

Cashew nut shells (CNS) are the primary waste produced during the processing of cashew nuts; and needs constant attention to handle or valorize these wastes effectively. As a result, these CNS wastes are processed into solid briquettes citing their significant calorific content, thus making them as a promising renewable biofuel for combustion based applications. In most cases, these wastes are pre-treated either through de-oiling or carbonizing prior to compaction, thus removing the harmful hydrocarbons present in them in form of CNS liquids. Presently, this chapter focus on summarising various data related to these CNS wastes and their briquettes in terms of their availability, chemical characteristics, pre-treatment and processing technique, fuel and combustion properties as reported in various literatures. Here, availability depicts the current trend in global consumption of these snack nuts and the proportionate amount of waste shells produced; while, chemical characteristics focused on discussing their anatomy, proximate, lignocellulosic and elemental compositions. Following this, pre-treatment and processing techniques list out the various practises followed to remove CNSL, process de-oiled CNS cakes into bio-char through carbonization, and briquetting of pre-treated CNS wastes along with their compacting techniques prescribed by various researchers. Lastly, fuel and combustion properties brief out about the fuel traits of developed CNS briquettes along with their burning characteristics; and include parameters like proximate and elemental compositions, density and compressive strength, and results related to their combustion and water boiling tests. Moreover, all the reported results and data in this study were in accordance with the international testing standards; and ranged in between their permissible range.