Solid Pyrolysis Products Research Articles

Biochars from chlorine-rich feedstock are low in polychlorinated dioxins, furans and biphenyls

Chlorinated aromatic hydrocarbons like polychlorinated dibenzo-p-dioxins and -furans (PCDD/F) and polychlorinated biphenyls (PCB) are omnipresent in the environment due to historic production, use, and (unintended) release. Nowadays, their emission and maximum concentration in environmental compartments is strictly regulated. During biochar production, PCDD/F and PCB may be formed and retained on the solid pyrolysis product. Industrial biochars certified, e.g., under the European Biochar Certificate (EBC), exhibit concentrations that were always well below threshold values for soil application and even animal feed. However, this has not been sufficiently tested for chlorine (Cl) rich organic material such as marine biomass or polyvinyl chloride (PVC) contaminated feedstock. Here, we analyzed PCDD/F and PCB contamination in biochars produced at different temperatures from different biomasses with comparatively high Cl contents in the range from 0.2 % to 3.8 % (w/w, seagrass, two types of saltwater macroalgae, tobacco stalks, and PVC contaminated wood). All of the biochars produced showed PCDD/F and PCB contents well below the applicable threshold values given by the EBC (< 20 ng TEQ kg−1 for PCDD/F and < 2×105 ng kg−1 for PCB). The EBC thresholds were undershot by a minimum of factor 1.5 for PCDD/F (mostly factor 20) and by a minimum of factor 90 for PCB. Between 1 and 27 ppb of feedstock Cl were transformed to Cl bound in PCDD/F and PCB in the biochars. No consistent correlation between biomass Cl contents and contents of PCDD/F and PCB were found but higher Cl contents in the feedstock led to a more diverse PCDD/F congener pattern in the biochars. Pyrolysis of PVC-amended wood resulted in consistently higher contamination of PCDD/F and PCB in the biochars compared to pyrolysis of the other biomasses, potentially due to differences in Cl speciation in the feedstocks i.e., Cl in PVC is already covalently bound to an organic carbon backbone. A high contamination in PCDD/F and PCB in biochar was intentionally triggered by separation of pyrogas and biochar in the reactor at < 300 °C to promote condensation of contaminants on the solid product. Between 20 % and 80 % of feedstock Cl was released via the pyrogas, i.e., neutralization of HCl in burnt pyrogas might be necessary when pyrolyzing Cl-rich feedstock in industrial biochar production. Our results indicate that biochars produced from Cl-rich feedstocks with proper biochar production process control are conform with European certification guidelines for PCDD/F and PCB contamination. The results open the opportunity to exploit and valorize so far non-used marine or otherwise Cl enriched biomasses for the production of biochar and carbon sinks.

The effect of biochar obtained from waste filter coffee grounds on plant germination

Nowadays, coffee consumption is quite high, and the consumption of filter coffee is steadily increasing. Consequently, there is a significant increase in waste filter coffee. This study aims to evaluate waste filter coffee grounds using a zero-waste approach. In this context, the solid product of pyrolyzed waste filter coffee grounds was added to the soil in specific ratios to improve soil quality and increase yield. The effects on the root and stem development of arugula (Eruca vesicaria) and garden cress (Lepidium sativum) plants were investigated. Waste filter coffee grounds was homogeneously mixed with soil at application rates of 1, 2, and 4 tons/ha. The results of the study observed that the pyrolysis solid product positively affected plant growth. Comparing the data, the highest yield in plants was observed in soil with added biochar, while lower yields were seen in soil with added raw waste filter coffee grounds, and the lowest yield was found in soil without biochar. Among the soils with added biochar, the most significant root and stem development was observed in plants with 2 tons/ha of added biochar.

Recovering high-quality glass fibers from end-of-life wind turbine blades through swelling-assisted low-temperature pyrolysis

The recycling of end-of-life wind turbine blades has become a global environmental challenge driven by the rapid growth of wind power. Pyrolysis is a promising method for recovering glass fibers from these discarded blades, but traditional pyrolysis is often operated at high temperatures, which degrades the mechanical properties of recovered fibers. To address this issue, a swelling-assisted pyrolysis method was proposed to recover high-quality glass fibers from end-of-life wind turbine blades at low temperatures. The results confirmed that the decomposition of the resin matrix within the blade was significantly promoted at low temperatures in the swelling-assisted pyrolysis process, achieving a resin decomposition ratio of 76.8 % at 350 °C. This improvement was attributed to enhanced heat transfer and co-pyrolysis with acetic acid. Swelling could physically disrupt the cross-linked structure of the blade, creating a more porous and layered structure, thereby enhancing heat transfer during the pyrolysis process. Simultaneously, the co-pyrolysis with acetic acid could generate hydrogen radicals, which promoted the cracking of macromolecular oligomers into lighter products or gaseous alkanes. Consequently, the formation of pyrolysis char within the solid pyrolysis product was reduced, shortening the oxidation duration to 30 min. In comparison to traditional pyrolysis, the swelling-assisted pyrolysis process effectively suppressed the diffusion of surface defects over the recovered fibers, leading to promising improvements in their flexibility, elasticity, and mechanical properties, with tensile strength notably increased by 27.5 %. These findings provided valuable insights into recovering high-quality glass fibers from end-of-life wind turbine blades.

Glossary of terms used in biochar research (IUPAC Technical Report)

Abstract Biochar is the solid carbonaceous product of biomass pyrolysis. The properties of biochar depend on the biomass feedstock as well as the pyrolysis temperature and time. Therefore, biochars with different properties and functionalities can be produced. Biochar research has been intensive in the past 15 years, focusing mainly on soil applications, wastewater treatment, and contaminant remediation. However, a formal definition of biochar and related terms is missing, which hinders the standardization of scientific results worldwide and the scaling-up of research at the industrial level. Furthermore, an official terminology may promote the development of a harmonized legal framework for biochar production and applications, both at regional and national levels. This glossary of terms consists of 178 scientifically sound definitions of the most commonly used terms in biochar research. The definitions of this glossary are interconnected, allowing the reader to further explore the synergies between terms. The distribution of terms reflects the multidisciplinarity of biochar research: chemistry, material science and engineering, and soil science are the main disciplines represented here. The list of terms is by no means exhaustive and the strategic objective of this effort is to develop a dynamic document in which more terms will be added in the future, and the existing ones will be refined, as biochar research evolves.

Pyrolysis solid product as a sorbent for flue gases mercury capture — Part II: Sorbent utilization

This study explores using solid pyrolysis products from six materials as sorbents to capture mercury from flue gas in an experimental fluidized bed combustor. It investigates the effects of activation methods, adsorption temperature, and Hg0/Hg2+ ratios on mercury removal efficiency. Physical and chemical activations are conducted using steam and NaOH, respectively. Tests are run at 100–160 °C with 5 g of sorbent. Results show 120 °C as optimal, with sorbents losing 0.34 % and 0.39 % efficiency with increasing temperature for lignite and black coal. Specific surface area (up to 641 m2∙g–1) significantly influences cumulative removal efficiency (CRE), reaching 80.8 % for lignite and 73.85 % for black coal. Mercury gas recovery averages 35.5 % and 53.7 % after physical and chemical activations. Lignite sorbents exhibit higher CRE than black coal, indicating greater mercury oxidation in black coal flue gas. This study offers a promising method for char recovery from pyrolysis, suggesting competitive sorbents for industrial use.

Co-, Ni-, and Cu-Doped Fe-Based Catalysts for the Microwave-Assisted Catalytic Pyrolysis of Polyethylene.

Environmental issues caused by waste polyethylene are becoming increasingly severe. Among potential treatment processes, microwave-assisted catalytic pyrolysis is promising for converting waste plastics into valuable products owing to its energy efficiency and environmental sustainability. Herein, a modified citric acid combustion method was used to prepare a series of metal oxide catalysts with loose porous structures. The prepared Fe-based catalysts doped with Co, Ni, or Cu were employed in the microwave-assisted catalytic pyrolysis of polyethylene. The bimetallic Co1Fe1Ox catalyst exhibited the best performance, yielding hydrogen at a rate of 60.7 mmol/gplastic. Further variation in the Co : Fe ratio revealed that the Co1Fe9Ox catalyst achieved the highest hydrogen production efficiency (63.64 mmol/gplastic). Similar oil-phase products were obtained over the various catalysts, as revealed by infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. Furthermore, scanning electron microscopy (SEM) identified carbon nanotubes as the major solid product of pyrolysis, which were attached to the catalyst surface. Finally, a combination of thermogravimetric analysis, SEM, and energy-dispersive X-ray spectroscopy indicated that the reduction in catalytic activity following recycling was caused by the accumulation of carbonaceous products on the catalyst surface. Overall, Co1Fe9Ox catalysts were favorable for obtaining H2 and carbon nanotubes by the microwave-assisted pyrolysis of polyethylene.

Synthesis of porous carbon structures by thermal treatment of solid products of plasmochemical pyrolysis of hydrocarbons and heavy petroleum products

Synthesis of porous carbon structures by thermal treatment of solid products of plasmochemical pyrolysis of hydrocarbons and heavy petroleum products

Effects of circulating ash and dolomite on mercury transition during coal step conversion of pyrolysis and combustion

In aim to study the influence of circulating ash used as heat carrier and dolomite used as catalyst on mercury transition during the step conversion of coal pyrolysis and combustion, five experiments with different operating conditions were conducted in this study, including four pyrolysis experiments of raw coal, coal/ash, coal/dolomite, coal and ash/dolomite, and combustion experiment of pyrolysis solid product. By changing the experimental conditions including final pyrolysis temperature, heating rate, coal-ash ratio and dolomite type, the transition path and final mercury distribution in the step conversion process were comprehensively analyzed. Experiments results indicated that mercury completely released out from coal when the final pyrolysis temperature was 600 °C. The individual addition of ash could promote the mercury release from coal at lower temperature. Dolomite could catalyze the oxidation of Hg0 in gas phase, and the modified dolomite had better catalytic capacity for Hg0 oxidation than natural dolomite. The addition of circulating ash and natural dolomite both had a certain catalytic effect on Hg0 emission peaks during the coal pyrolysis. Increasing the coal-ash ratio was conducive to the oxidation of Hg0 in pyrolysis gas. During the direct combustion of coal, the content of Hg0 released into the gas phase could reach to 69.97%. By adding ash, ash/natural dolomite and ash/modified dolomite to the coal pyrolysis process, the content of Hg0 in pyrolysis gas decreased to 58.99%, 34.77% and 31.30%, respectively. The research is able to offer the theoretical foundation for mercury contaminants’ removal and process optimization of the step conversion technology.

Evaluation of EPDM waste in environmentally friendly epoxy hybrid composites

This study aims to reduce the production cost of composite materials, obtain composite materials with improved properties, and expand the applications of waste rubber composites using two different industrial wastes, ethylene-propylene-diene monomer rubber (EPDM) and tire waste pyrolysis solid product carbon black (CB). Composites were formed by adding EPDM waste or EPDM-CB mixture at 1:1, 1:3, and 3:1 ratios to bisphenol-A type epoxy resin in different weight ratios. Mechanical, water sorption, electrical conductivity, and flammability tests were applied to the composites. The effect of the EPDM:CB ratio and some environmental conditions on the mechanical properties of the hybrid composites were investigated. Composites with 3:1 weight ratio of EPDM:CB had the highest tensile strength, which varied between 115.5–158.6 MPa. Increasing the EPDM ratio in an epoxy matrix and hybrid filler decreased the composites’ density and tensile strength. EPDM-CB hybrid filler increased the thermal strength of epoxy. Mechanical properties are affected by water sorption, low temperature, and UV irradiation. Increasing the CB ratio in the hybrid filler decreased the flammability of the hybrid composites. ANOVA is applied to find the significant effect of different weight percentages of hybrid fillers and different varieties of fillers on the mechanical properties of composites.

Mechanism of sulfur migration and conversion in pyrolysis/combustion staged conversion process of high sulfur coal

To investigate the effects of circulating ash heat carriers and dolomite catalysts on sulfur migration in the coal pyrolysis/circulating fluidized bed combustion staged conversion process, five experiments of coal pyrolysis, ash/coal co-pyrolysis, coal pyrolysis catalyzed by dolomite, ash/coal co-pyrolysis catalyzed by dolomite and combustion of pyrolysis solid products were designed and carried out. By examining the effects of pyrolysis temperature, heating rate, coal-ash ratio and dolomite species on sulfur migration, the final distribution of sulfur-containing pollutants throughout the staged conversion process was systematically analyzed. The results showed that the separate mixing of ash heat carrier at final pyrolysis temperature of 600 °C increased the residual sulfur in solid phase from 79.29 % of raw coal pyrolysis to 90.00 %. When dolomite catalyst was added individually, the sulfur released into gas phase and tar was reduced from 18.28 % and 2.43 % of the raw coal to 13.14 % and 1.94 %, respectively. And Fe additive significantly improved sulfur resistance of the dolomite catalyst. The regeneration process has little effect on the sulfur fixation capacity of natural dolomite. When ash heat carrier and dolomite catalyst were simultaneously added to the system, the sulfur fixed in ash increased from 79.29 % of the raw coal to 91.27 %, and the sulfur fixed in natural dolomite and modified dolomite accounted for 4.32 % and 4.46 % of the total sulfur, respectively. In the combustion experiments of pyrolysis solid phase products, 43.57 %, 65.57 % and 61.44 % of sulfur was retained in the solid phase residue after combustion with circulating ash, circulating ash/natural dolomite and circulating ash/modified dolomite were added, respectively. Compared with direct combustion of coal, the staged conversion process resulted in a 55 % reduction of sulfur in the boiler flue gas. This study provides a theoretical basis for the purification of sulfur-containing pollutants in the staged conversion process.

Ignition and Emission Characteristics of Waste Tires Pyrolysis Char Co-Combustion with Peat and Sawdust

The pyrolysis processing of waste tires is a promising technology for obtaining products with high marginality. One of the possible methods of solid pyrolysis product utilization is its combustion for energy production, but this is complicated by poor reactivity and sulfur emissions. The combustion of char together with more reactive fuels could solve this problem. The current study is devoted to the combustion characteristics of waste tires pyrolysis carbon residue mixed with biomass: pine sawdust and peat. The oxidation characteristics in thermal analyzer conditions were found to change insignificantly. In contrast, 15 wt% of peat and sawdust additives was found to decrease ignition delay times in realistic conditions of combustion at 800 °C by 42 and 78%, respectively, while the SO2 emissions also dropped by 73 and 52%, respectively. The extra sulfur was found to be contained in ash residue in the form of CaS and CaSO4. While increasing peat concentration from 5 to 15 wt% was found to have almost no effect, the same increase for sawdust resulted into an almost proportional decrease in ignition delay times. The results obtained could be used for the integration of waste tires pyrolysis char mixtures with peat or sawdust into the energy sector.

Biochar for the Control of Plant Pathogens

Biochar, the solid product of pyrolysis of biomass at thermal degradation temperatures, is useful in agriculture as manure for enhancing plant growth through the supply of nutrients. It is used in protected cultivation practices of vegetables and flower crops in the pot culture and grow bags especially to improve soil physicochemical properties, and in hydroponics to remove pollutants like heavy metals in the water. The usage of biochar as a potential soil amendment for plant growth promotion, improving soil fertility and plant disease suppression are being explored in recent years. Biochar made from many of the agro waste materials was found to suppress the plant pathogens in the soil and also effective in controlling the pathogens affecting aerial parts of the plants. Although direct antifungal or antibacterial effects and metabolites of biochar are poorly understood, induced systemic resistance in plants through signal transduction and expression of defence chemicals and metabolites have been studied. In addition, microbiome analyses through metagenome sequencing revealed an increase in the population of beneficial microbes (antagonistic to plant pathogens) in the rhizosphere soils applied with biochar.

Investigation on co-combustion of semi-coke and bituminous coal in oxygen-enriched atmosphere: Combustion, thermal conversion, and kinetic analyses

Semi-coke is the solid pyrolysis product of low-rank coal, with high carbon content and difficult to ignite and burn out. The blending of semi-coke with bituminous coal can realize a large amount of utilization of semi-coke. In this paper, the combustion, thermal conversion, and kinetic analyses of semi-coke blending with bituminous coal are investigated under oxygen-enriched conditions (30% O2 atmosphere). Compared with 20% O2 atmosphere, the ignition and burnout temperatures are reduced by 10, 7, 8, 12, 7 °C and 129, 76, 85, 115, and 152 °C for the semi-coke blending ratios of 0, 30, 50, 70 and 100% under 30% O2 atmosphere. Oxygen-enriched combustion can effectively decrease the ignition temperature and improve the combustion performance of the mixture. In 30% O2 and 20% O2 atmospheres, the synergy effect of the co-combustion process is different. Under the 30% O2 atmosphere, semi-coke, and bituminous coal have a strong synergistic effect, which can reduce burnout temperature. However, under 20% O2 atmosphere, the burnout temperature of the mixture will increase. At a higher blending ratio of semi-coke, the effect of oxygen-enriched conditions on co-combustion is greater, and high oxygen concentration will make the interaction of the mixture combustion process more intense. Compared with bituminous coal, the activation energy of the mixture gradually increases with the increase of the blending ratio of semi-coke, and different combustion stages correspond to different mechanism functions, respectively. The research results can provide ideas for the utilization of semi-coke under oxygen-enriched conditions.

The pyrolysis of end-of-life wind turbine blades under different atmospheres and their effects on the recovered glass fibers

Pyrolysis is a promising technology to reclaim glass fibers from end-of-life wind turbine blades (WTBs), while the pyrolysis atmosphere has significant effects on the depolymerization of WTBs and the mechanical properties of recovered fibers. In this study, the pyrolysis performance of commercial end-of-life WTBs under different atmospheres was investigated as well as their effects on the mechanical properties of recovered fibers. The results showed that the pyrolysis gas in N2 atmosphere mainly consisted of CO2, CH4, and CO, and its calorific value was 22.53 MJ/Nm3. Various phenolic compounds were also recovered in the pyrolysis oil. After the post-oxidation of pyrolysis solid products, clean glass fibers could be reclaimed successfully. H2O was an effective gasifying agent in accelerating the decomposition of epoxy resins at 500 °C, which increased the yields of pyrolysis gas and phenolic products while inhibited the formation of char. Besides, the reactivity of residual char was improved, thereby promoting their oxidization in the post-oxidization process but causing the thermal-oxidative diffusion of surface flaws, which slightly degraded the tensile strength of recovered fibers by 5.97%. CO2 suppressed the cracking of epoxy resins and contributed to the simultaneous accumulation of uncracked resins and pyrolysis char, which then aggravated the diffusion of surface flaws by thermal oxidization and uneven heating in the post-oxidation, thereby degrading the tensile strengths of recovered fibers by 16.02%.

A study on molecular structural evolution of type II kerogen in a gold tube thermal system: Insights from solid-state 13C NMR

Lacustrine type II kerogen is widely distributed in China and has important hydrocarbon potential, but the study of its structural evolution is not comprehensive enough. In this study, a closed gold tube system was used to simulate the maturation of kerogen extracted from the Nengjiang Formation of the Songliao Basin to investigate a model of hydrocarbon generation and molecular structure change in lacustrine type II kerogen. The pyrolysis products at two heating rates were collected and quantitatively analyzed, and the Easy%Ro of 20 solid kerogen residue samples (solid pyrolysis products after extraction of methylene chloride and methanol) ranged from 0.69 to 2.49. From elemental analysis and 13C nuclear magnetic resonance (13C NMR), the molecular structure evolution of kerogen was clearly determined, and four average molecular models of kerogen were established. The results show that with increasing maturity, the aliphatic fractions of kerogen decreased, and the aromatic fractions increased. Before the main oil window (Easy%Ro < 0.89), the main products were nonhydrocarbon heteroatomic functional groups (NSOs: asphaltene and resin). The oil peak occurred at an Easy%Ro of approximately 1.1 when hydrocarbon C14+ production reached the maximum and kerogen residue was the lowest. After the oil peak, aromatic groups became dominant in the structure. C14+ began to decrease, and the kerogen residue proportion increased, which was related to the occurrence of secondary coking reactions after the main oil window. The hydrocarbon generation capacity of kerogen was exhausted after the oil peak, and the kerogen likely became the precursor of generated gaseous products. In the gas window (Easy%Ro > 1.53), the large quantity of C1-5 was mainly due to the secondary cracking of hydrocarbons. The number of aromatic structures caused by alkyl bond breaking and condensation was estimated. It was found that before the oil peak, the number of aromatic structures caused by alkyl bond breaking decreased and was higher than that of aromatic structures caused by condensation. After the oil peak, the latter structures were obviously dominant, which further indicates that polymerization is the main structural change mechanism of kerogen evolution.

Water sorption, thermal, and fire resistance properties of natural shell‐based epoxy composites

AbstractIn this study, walnut shell (WSh), hazelnut shell (HSh), and mussel shell (MSh) waste as inexpensive reinforcements were recycled for the preparation of epoxy composite materials. Subsequent used inexpensive fillers are chars (WShC and HShC), which are the pyrolysis solid products of the natural WSh and HSh wastes. Three types of epoxy resins: bisphenol‐A type (DGEBA), modified with polyurethane (MER with PU), and rubber modified (MER with rubber) epoxy resins were used as the matrix in MSh composites. Thermogravimetric analysis of the composites showed that the thermal strength of the epoxy matrix increased significantly with the MSh and chars. The best water sorption results were obtained with the MSh. The contact angle values of MSh composites prepared with DGEBA epoxy resin were quite high (111°–113.5°) and their water retention values ranged from 0.2% to 0.32%. The composites that were produced using 50 wt% chars and the same epoxy resin showed better flammability stability. The full extinction times were determined as 63 and 58 s for WShC and HShC composites, respectively.

Effects of Combined Application of Solid Pyrolysis Products and Digestate on Selected Soil Properties of Arenosol and Plant Growth and Composition in Laboratory Experiments

Biochars as soil amendments have been reported to improve soil properties and may have an important role in the mitigation of the consequences of climate change. As a novel approach, this study examines whether biochar and digestate co-application can be utilized as cost-effective, renewable plant nutrients. The effects of two types of biochar—wood chip biochar (WBC) and animal bone biochar (ABC), applied alone or in combination with an anaerobic digestate—on soil physicochemical properties, on the levels of selected elements, and on growth yields of ryegrass were studied in laboratory experiments. Most parameters were significantly affected by the treatments, and the investigated factors (biochar type, application rate, and the presence of digestate), as well as their interactions, were found to have significant effects on the characteristics investigated. The easily soluble phosphorus content (AL-P2O5) of the soil increased in all WBC and ABC biochar treatments, and the presence of digestate caused a further increase in AL-P2O5 in the case of anaerobic digestate-supplemented ABC treatment (ABCxAD). The pH increased in both ABC and WBC treatments, and also in the case of ABCxAD treatments. Similar increases in the salt content were detected in ABC-treated samples and in ABCxAD treatments at higher application rates. WBC increased the water holding capacity and carbon content of the soil. Phytotoxic effects of biochars were not detected, although higher doses resulted in slower germination. Combined biochar–digestate applications resulted in increased plant yields compared to sole biochar treatments. Thus, biochar–digestate combinations appear to be applicable as organo-mineral fertilizers.

A new sustainable strategy for oil, CH4 and aluminum recovery from metallised food packaging plastics waste using catalytic pyrolysis over ZSM-5 zeolite catalyst

Paraffin wax and syngas are the major energy products synthesized by pyrolysis of metallised food packaging plastics waste (MFPW). These pyrolysis products contain a small amount of flammable compounds with negligible economic profit. Within this framework, this work aims to upgrade wax into oil and to increase the yield of flammable gases (e.g., CH4, C2H6, C3H8) in syngas generated during pyrolysis of MFPW using the catalytic pyrolysis process over ZSM-5 zeolite catalyst (10, 30, and 50 wt.%). The thermo-chemical experiments were performed in a semi-batch pyrolysis plant at 600°C. N2, O2, CO2, CO, CH4, and H2 gases generated during the entire process were observed with a digital gas analyser, while FTIR and GC measurements were employed to specify the chemical compounds of the obtained energy products (oil or wax and gases). Finally, aluminium (Al) fraction was separated from the obtained solid product of pyrolysis using leaching process. The results showed that addition of 10 and 30 wt.% of ZSM-5 to the reaction contributed to increase in wax yield from 12% to 19% without a significant effect on its structure. At 50 wt.% of ZSM-5, wax was converted into light hydrocarbon oil abundant in flammable compounds such as p-Xylene (18.2%), Benzene (14.6%), Toluene (7.3%), and o-Xylene (4.7%). Also, GC-MS results revealed that the gas obtained from 50 wt.% batch was rich in CH group (derived from CH4 compound) and Toluene (33%), p-Xylene (27%), Benzene (14.4%). Based on that the catalytic pyrolysis with 50 wt.% ZSM-5 zeolite catalyst is considered to be a promising thermo-chemical technology that can be applied at industrial scale to convert MFPW into oil (21%), gas (66%), Al (8.8%), and Al-free char particles (3.12%).

Changes in thermophysical and thermotechnical characteristics of flour-milling waste in the process of slow pyrolysis

In the process of biomass pyrolysis, its composition and structure changes significantly that results in changing the thermophysical characteristics of the carbon residue. Information about the elemental composition of raw materials and their characteristics in the process of thermal processing is necessary for optimizing technological parameters and understanding the flowing processes. The work purpose is to determine the thermophysical characteristics of flour-milling wastes during slow pyrolysis process. The thermophysical characteristics were determined by the flash laser method. In the course of the study, such methods as an experiment, differential thermal analysis and scanning electron microscopy were used. It has been established that carbon residues obtained at temperatures not exceeding 300 ⁰С have a higher heat capacity than the original bran. A further increase in temperature leads to a sharp decrease in heat capacity, which is due to the decomposition of some fundamental components (hemicellulose, cellulose, lignin). The thermal conductivity of carbon residues (0.146-0.173 W/(m·K)) enhances with an increase in their production temperature. The values of the thermophysical characteristics for the initial bran and solid pyrolysis products were established that can be used to assess their effective values in relation to any fraction of wheat bran after determining the bulk density.

Process Optimization for Two-Stage Leaching of Metals from Pretreated Asr Pyrolysis Solid Product and Derived Mathematical Kinetic Model Study in Leaching of Metals Through Solvometallurgy Route

Process Optimization for Two-Stage Leaching of Metals from Pretreated Asr Pyrolysis Solid Product and Derived Mathematical Kinetic Model Study in Leaching of Metals Through Solvometallurgy Route