Solid Products Research Articles

Comprehensive assessment of cow manure hydrothermal treatment products for land application and energy recovery

In this study, cow manure was hydrothermally treated in a 2-litre reactor for 1 h at temperatures between 100 °C and 260 °C. Both the raw manure and the solid and liquid products of the hydrothermal treatment were characterized to understand the fate of the inorganic elements and to assess the suitability of the products for land applications and energy recovery. Satisfactory elemental balances were obtained for the organic and most inorganic elements and indicated that most inorganic elements were incorporated into the solids with lower solubility, with the exception of potassium and sodium, which were mostly solubilized in the process water; calcium and chlorine were also solubilized to a lesser extent in the process water. Elemental composition and surface functional groups showed that hydrochar produced within the hydrothermal carbonization range (180–260 °C) seemed better suited for utilization as a soil amendment than raw cow manure. The potential for energy recovery lies in the anaerobic digestion of the process water, from which higher methane yields can be obtained than from raw cow manure. Lower temperatures in hydrothermal carbonization are considered a compromise for the safe land applications of cow manure, energy recovery from the process water, and enhanced dewaterability. These findings can help to eliminate bottlenecks in the upscaling of cow manure hydrothermal treatment and promote the circular bio-economy.

Thermal conductivity of U-Mo alloy fuel

The thermal conductivity of U-Mo alloys for research reactor fuel was studied. Thermal conductivity is one of the most important properties concerning design, performance analysis, and safety evaluation of these alloys as research reactor fuel. Thermal conductivity data of unirradiated U-Mo alloy collected from literature were examined, analyzed, and used to develop a correlation as a function of Mo content and temperature. For irradiated U-10Mo alloy, a thermal conductivity correlation was developed as a function of fission density and temperature. This model considers the effects of porosity growth by fission gas bubbles, solid fission product accumulation, and buildup of grain boundaries due to recrystallization during irradiation.

A Rechargeable “Rocking Chair” Type Zn−CO2 Battery

AbstractRising global temperatures and critical energy shortages have spurred researches into CO2 fixation and conversion within the realm of energy storage such as Zn−CO2 batteries. However, traditional Zn−CO2 batteries employ double‐compartment electrolytic cells with separate carriers for catholytes and anolytes, diverging from the “rocking chair” battery mechanism. The specific energy of these conventional batteries is constrained by the solubility of discharge reactants/products in the electrolyte. Additionally, H2O molecules tend to trigger parasitic reactions at the electrolyte/electrode interfaces, undermining the long‐term stability of Zn anodes. In this report, we introduce an innovative “rocking chair” type Zn−CO2 battery that utilizes a weak‐acidic zinc trifluoromethanesulfonate aqueous electrolyte compatible with both cathode and anode. This design minimizes side reactions on the Zn surface and leverages the high catalytic activity of the cathode material, allowing the battery to achieve a substantial discharge capacity of 6734 mAh g−1 and maintain performance over 65 cycles. Moreover, the successful production of pouch cells demonstrates the practical applicability of Zn−CO2 batteries. Electrode characterizations confirm superior electrochemical reversibility, facilitated by solid discharge products of ZnCO3 and C. This work advances a “rocking chair” Zn−CO2 battery with an enhanced specific energy and a reversible pathway, providing a foundation for developing high‐performance metal‐CO2 batteries.

A Rechargeable "Rocking Chair" Type Zn-CO2 Battery.

Rising global temperatures and critical energy shortages have spurred researches into CO2 fixation and conversion within the realm of energy storage such as Zn-CO2 batteries. However, traditional Zn-CO2 batteries employ double-compartment electrolytic cells with separate carriers for catholytes and anolytes, diverging from the "rocking chair" battery mechanism. The specific energy of these conventional batteries is constrained by the solubility of discharge reactants/products in the electrolyte. Additionally, H2O molecules tend to trigger parasitic reactions at the electrolyte/electrode interfaces, undermining the long-term stability of Zn anodes. In this report, we introduce an innovative "rocking chair" type Zn-CO2 battery that utilizes a weak-acidic zinc trifluoromethanesulfonate aqueous electrolyte compatible with both cathode and anode. This design minimizes side reactions on the Zn surface and leverages the high catalytic activity of the cathode material, allowing the battery to achieve a substantial discharge capacity of 6734 mAh g-1 and maintain performance over 65 cycles. Moreover, the successful production of pouch cells demonstrates the practical applicability of Zn-CO2 batteries. Electrode characterizations confirm superior electrochemical reversibility, facilitated by solid discharge products of ZnCO3 and C. This work advances a "rocking chair" Zn-CO2 battery with an enhanced specific energy and a reversible pathway, providing a foundation for developing high-performance metal-CO2 batteries.

Biomimetic Calcium Phosphate Nanoparticles: Biomineralization Models and Precursors for Composite Materials.

The formation of calcium phosphate under the control of water-soluble polymers is important for understanding bone growth in living organisms. These experiments also have spin-offs in the creation of composite materials, including for regenerative medicine applications. The formation of calcium phosphate (hydroxyapatite) from calcium chloride and diammonium phosphate was studied in the presence of polymers containing carboxyl, amine, and imidazole groups. Depending on the polymer composition, solid products and stable dispersions of positively or negatively charged nanoparticles were obtained. Oppositely charged nanoparticles can interact with each other to form a macroporous composite material, which holds promise as a filler for bone defects. The formation of a calcium phosphate layer around a living cell (dinoflagellate Gymnodinium corollarium A. M. Sundström, Kremp et Daugbjerg) using positive composite nanoparticles is a one-step approach to cell mineralization.

Ca2+-controlled Mn(II) removal process in Aurantimonas sp. HBX-1: Microbially-induced carbonate precipitation (MICP) versus Mn(II) oxidation

The application of manganese-oxidizing bacteria (MnOB) to produce manganese oxides (MnOx) has been widely studied, but often overlooking the concurrent formation of MnCO3. In this study, we found Ca2+ plays a crucial role in controlling Mn(II) removal in the bacterium Aurantimonas sp. HBX-1. Under conditions with 6.8 mM Ca2+ and without adding Ca2+, 100 μM Mn(II) was removed by 96.96 % and 38.28 % within 8 days, respectively. X-ray photoelectron spectroscopy (XPS) showed that adding Ca2+ increased the average oxidation state (AOS) of the solid products from 2.05 to 2.37. X-ray absorption fine structure (XAFS) analysis revealed the product proportions as follows: under Ca2+-supplemented condition, the ratio of MnOx (1 < x ≤ 2) to MnCO₃ was 52 % to 28.1 %, while under Ca2+-free condition, the ratio shifted to 4.6 % for MnOx (1 < x ≤ 2) and 55.2 % for MnCO₃. Urease activity assay and proteomic analysis confirmed the expression of urease and carbonic anhydrase, leading to the formation of MnCO3. Additionally, animal heme peroxidase (AHP) in strain HBX-1 was found to be responsible for Mn(II) oxidation through superoxide production, with Ca2+ addition promoting its expression level. Given the widespread presence of Ca2+ in wastewater, its potential impact on the biogeochemical Mn(II) cycle driven by bacteria should be reconsidered.

Transformation of phosphorus speciation during hydrothermal treatment of digestate of rural animal manure

Digestate of rural animal manures (DM) contain valuable P resource, but when they are directly used on land, they can cause soil and water pollution. Hydrothermal treatment (HT) has been widely applied as an effective method of waste treatment and P recycling. This study aims to realize the P recovery in DM by illustrating the migration and transformation of phosphorus (P) species during HT process of DM. Two acids (e.g., hydrochloric acid and oxalic acid) were compared in terms of their abilities to extract P from solid products after HT process. The results revealed that organic phosphorus (OP) was converted into inorganic phosphorus (IP), whereas non-apatite phosphorus (NAIP, mainly AlPO4) was transformed to apatite phosphorus (AP, Ca3(PO4)2) during HT at different temperatures. Specifically, the percentage of IP increased from 30.4% in DDM to 90.6% after HT process at 220 °C (HT220). The P leaching efficiency of HT220 reached 94.8% during HCl extraction. The study indicated that P bioavailability and solubility could be improved by HT process. This study would provide deeper insights into the application of HT technology for recovery of P in DM, as well as provide guidance for P recovery and recycling from P containing wastes.

Utilization of spent bleaching earth as green filler and plasticizer in the manufacture of rubber compounds for solid tire production

This study utilized spent bleaching earth (SBE) as a single form of filler and plasticizer in the manufacture of rubber components for solid tire vulcanizate. SBE, an underutilized byproduct of vegetable oil purification, is abundantly available globally and can be used as a filler and plasticizer in rubber compounds. This aligns with environmental sustainability principles, reduces disposal costs, and lowers raw material expenses in rubber manufacturing. In this research, the SBE was applied for each formula from SBE-02 to SBE-05 at ratios of 15–30 per hundred rubber (phr). As a comparison, carbon black (CB) filler (65 phr), CaCO3 (35 phr), and plasticizer derived from petroleum in the form of paraffinic oil (PO) (6 phr) were used. Rubber components were produced by masticating natural and synthetic rubber in an open mill, followed by the addition of filler, plasticizer, accelerator, co-activator, anti-degradant, and vulcanization agent. The resulting compounds were vulcanized at 150 °C and 10 MPa for 17 minutes. The test results demonstrated that incorporating SBE at a ratio of 15 phr (SBE-02) significantly reduced the cure time (t90) to 8 minutes and 20 seconds, the shortest among all tested formulations. The mechanical properties of the SBE-02 vulcanizate rubber met the requirements for solid wheelchair tire applications, with a hardness of 70 Shore A. However, its abrasion resistance test result of 189.1 g/cm³ was the lowest among the formulations tested. Furthermore, the scorch time (ts2) of the SBE-02 was determined to be 2 minutes and 35 seconds. Results from a 1000x magnification scanning electron microscope (SEM) reveal air gaps on all sample surfaces of different sizes. The elements C, O, Zn, Si, Ca, and Pb dominate the SEM-EDX results for all rubber vulcanizate samples from all three spectra, in varying weight percentages. The identification of functional groups with FTIR on all rubber vulcanizate samples shows Si–O–Si bending at 2, 4, and 5 and Si–O–Al stretching at 3, 5 on the wave number spectrum of 680–413 cm−1 Si–O–Si on the wave number spectrum 1100–1050 cm−1 from the infrared spectrum.

An Enhanced Extend Interface via the π–π Interaction to Achieve the Soluble Light‐Assisted Lithium–Oxygen Batteries

AbstractThe light‐assisted strategy is considered as an effective way to reduce the overpotential of lithium‐oxygen (Li─O2) batteries, however, the generated solid discharge products are prone to cover active sites of the solid‐state photocatalyst, causing the premature death of the cell. Herein, for the first time, the feasibility of soluble photocatalysts in Li─O2 battery system using Iron (II) Phthalocyanine (FePc) is verified. A micro reaction channel is constructed between the sp2‐carbon cathode and the soluble photocatalyst‐phthalein iron through π–π interaction, which can effectively increase the three‐phase reaction interface, facilitating the rapid separation and the transportation of photogenerated electrons and holes, thus improving the photocatalytic efficiency and the reaction kinetics of Li─O2 battery. Moreover, the FePc soluble photocatalysts induced the dual growth modes of surface growth and solution‐mediated growth pathways for the discharge products lead to an additional discharge capacity in the Li─O2 battery. Accordingly, the battery exhibits a lower overpotential of 0.33 V between discharge and charge plateaus at a current density of 0.01 mA cm−2, displaying the excellent cyclic stability (remaining a round‐trip efficiency of 81.1% after 130 cycles). The novel strategy provides new approaches for the construction of the light‐assisted Li─O2 batteries with reduced overpotential and boosted energy efficiency.

Models for estimating solid waste production in hospitality establishments in João Pessoa, Brazil

Municipalities are responsible for solid waste management in urban areas, from collection to final treatment, in case the waste produced by economic agents is not dangerous. In the scope of economic activities, tourism has been growing strongly, especially in Brazilian coastal urban areas. In this sense, a larger production of urban solid waste is one of the main effects of the development of the hospitality sector. This study aims to design models to estimate the production of solid waste in hospitality establishments. This research object refers to a sample of 7 hotels in the city of João Pessoa, Brazil. Solid waste generated by the hotel sector in the city of João Pessoa was estimated by developing linear regression models. The models showed that 71% of the waste refers to the number of guests, number of employees, and services offered in the hotel. Results indicate an estimated solid waste generated by hotel establishments in the city of João Pessoa of 4,148 kg.day-¹, out of which 59.2% are organic waste, 21.8% are recyclable, and 18.9% are non-recyclable.

Effect of CuSO4 on the behavior of nitrogen during supercritical water gasification of microalgal biomass

This study investigated the effect of added CuSO4 on the behavior of nitrogen during the supercritical water gasification (SCWG) of microalgal biomass. The results showed that CuSO4 inhibited the entry of N into the biocrude product and promoted the transfer of N into the solid and aqueous products during SCWG. Upon increasing the amount of CuSO4, the biocrude-N content decreased continuously, while the solid-N and aqueous-N contents increased continuously. When 10 wt% CuSO4 was added, the proportion of biocrude-N reached 5.56 %, and the proportions of solid-N and aqueous-N were 18.28 % and 58.78 %, respectively. In an aqueous solution, CuSO4 dissociates into Cu2+, which possesses strong oxidative properties that facilitate the removal of amino groups (-NH2) from amino acids. Therefore, CuSO4 increased the NH4+-N content in the aqueous product by promoting amino acid deamidation. Due to competition between amino acid deamidation and the Maillard reaction, CuSO4 inhibited the Maillard reaction, which reduced the proportion of nitrogen-containing heterocycles in the biocrude product. It also slightly promoted the conversion of pyridine-N to quaternary-N, allowing N to exist in more stable forms in the solid product. CuSO4 also inhibited the generation of heavy biocrude. These findings provide a valuable reference for regulating nitrogen during the SCWG of nitrogenous biomass.

Dynamics of Cu isotope fractionation during the reactions of pyrite with Cu(I)-bearing hydrothermal fluids

Experimental investigation of the fractionation behavior of Cu isotopes during the replacement of pyrite by Cu-bearing sulfides (chalcopyrite, bornite, and chalcocite) was conducted under hydrothermal conditions. At the initial stages of the replacement reaction, small mounds of product formed on the pyrite surface; these mounds then grew and coalesced, progressively covering the pyrite grains as the reaction proceeded. Chalcopyrite, bornite, and chalcocite formed sequential monomineralic zones from the pyrite reaction front towards the solution. During the early stage of the reaction, Cu isotope fractionation between the solids and the aqueous solution (Δ65Cusolid-aqueous, Δ65Cusolid-aqueous = δ65Cusolid – δ65Cuaqueous) was approximately –0.6 ‰, similar to the calculated equilibrium Cu isotope fractionation factors between Cu-bearing sulfides (chalcopyrite, bornite, and chalcocite) and CuCl2–. However, the Δ65Cusolid-aqueous moved progressively further from equilibrium with prolonged reaction time, with fractionation factors ranging from approximately –0.6 ‰ to –1.2 ‰. We found that significant fractionation of Cu isotopes between the solid products and aqueous solution was mainly controlled by the amount of chalcopyrite that formed in the product layers. We interpret that the Δ65Cusolid-aqueous was controlled by the diffusion of aqueous Cu(I) species among the product layers and the changes in Cu redox state during the precipitation of chalcopyrite. These results imply that the δ65Cu values measured in sulfides from low-temperature hydrothermal deposits may be controlled by the local chemistry of the fluids in product layers that precipitate sulfides. This study highlights the importance of local fluid characteristics, such as redox conditions, metal speciation, and diffusion, in controlling isotope fractionation pathways during non-equilibrium mineral replacement.

Comparative advantages of gas-pressurized torrefaction for corn stalk conversion to achieve solid biofuel production

Torrefaction is a feasible approach to produce biochar. Several new torrefaction methods have been conducted for biochar production. Among them, gas-pressurized torrefaction is considered a new technology to produce solid biofuel with better fuel performance, without carrier gas, and higher deoxygenation. This study conducts a comparative analysis between conventional torrefaction and gas-pressurized torrefaction to identify the potential applications of the latter. The results indicate that increasing reaction pressure can achieve biochar volume reduction and HHV improvement, thus leading to a higher energy density. The conventional torrefied biochar yield is in the range of 54.13–90.11%, and it is 48.59–80.13% for gas-pressurized one. Moreover, a more extensive surface area, higher carbonization degree, and more stable pyrolysis characteristics are obtained compared to conventional torrefaction. The carbonization index values of conventional and gas-pressurized conditions are 1.04–1.42 and 1.06–1.48. The correlation analysis results suggest that biochar grindability is highly correlated to carbonaceous properties, regardless of torrefaction methods. The expense and environmental impact analysis indicates that gas-pressurized torrefaction possesses lower cost and environmental pollution potential for biochar production.

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.

Physical and mechanical properties of fused deposition modelling PLA/carbon dot nanocomposites

This study explores the incorporation of carbon dots (CDs) into polylactic acid (PLA) filaments to improve their mechanical properties for fused deposition modelling (FDM). Known for their adjustable photoluminescence, high quantum yield, low toxicity, and biocompatibility, CDs are integrated into PLA at various concentrations (0.1, 0.3, 0.5, 0.7, 1.0, 3.0, and 5.0 wt%). Samples reinforced with 0.1–0.7 wt% CDs exhibit a tensile modulus ranging from 3.55 to 4.0 GPa and a tensile strength from 30 to 35 MPa. Meanwhile, those with 3.0 wt% achieve a higher tensile modulus (4.3 GPa) and strength (55 MPa), albeit with noted manufacturing challenges. The inclusion of 5.0 wt% CDs compromises the filament manufacturing process, resulting in a reduced tensile stress of 27 MPa, lower than pristine PLA, and exhibiting micro defects after 3D printing. Fluorescence analysis during tensile testing indicates that lower CD concentrations reduce fluorescence, while higher concentrations increase it, suggesting a correlation with the mechanical response. PLA reinforced with 0.5 wt% CDs not only offers improved mechanical properties but also facilitates easy manufacturing, showing promise for creating both solid and lattice 3D-printed products.

Design and development of pilot plant applied to wind and light abandonment power conversion: Electromagnetic heating of solid particles and steam generator

With the rising capacity of renewable energy electricity but incomplete supporting dissipation equipment, this work develops a new charging and discharging device for electromagnetic heating of solid particles to convert electricity from renewable sources into superheated steam, which achieves battery storage efficiency with sufficient safety, terrain-independent and scalable through paralleling. The study reveals that the electro-thermal conversion efficiency of electromagnetically heated iron ore particles increases with particle mass flow rate at different wall temperatures, reaching a maximum of 93.8% at 500 °C. In contrast, the efficiency trend for quartz sand particles is inconsistent, peaking at 68% due to poor thermal conductivity causing inefficiencies at higher mass flow rates. A dimensionless mathematical model (Re-Nu, Re < 10) for both particles is derived from experimental data, offering theoretical guidance for industrialization. Experiments with a shell-and-tube solid particle-packed bed yield continuous production of 35 kg/h, 300 °C superheated steam for 12 min with an 86.4% discharge efficiency and achieve an 81% cycle efficiency, which surpasses compressed air storage(60%), approaches battery and flywheel efficiency(85%). Economic feasibility analysis for a 5MW/5MWH system under two business models demonstrates a short payback period of 2.62 years when providing industrial steam and 6.4 years when used in thermal power plant flexibility transformation. Technological innovations to improve equipment efficiency are critical to the first business mode (selling steam), while grid-determined peak prices are critical to the latter (thermal flexibility retrofits). The study underscores the technical and economic superiority of the proposed devices for utilizing abandoned wind and light, providing a novel solution for carbon reduction and peak shaving in the context of new energy.

BIOCHAR-SUPPORTED IN VITRO CULTURES OF Lavandula officinalis L.

Plants are the sources of valuable biomass that are being currently used in many areas. It is important to produce high biomass for efficient commercial production. Amongst the many factors that affect in vitro propagation of plants, changing or enriching the media composition is one of the commonly used techniques in micropropagation of plants. Biochar is a solid product obtained from organic wastes and because of its rich composition, it has many beneficial effects on plants. In our study, Lavandula officinalis plantlets were subjected to two types of biochars (Geocharged biochar and Biorfe biochar) at 0.5 and 2 g/L concentrations and their effects were investigated by means of plant growth, biomass accumulation and biochemical composition. The results showed that 0.5 g/L concentration of biochar had better effects than 2 g/L concentration and except for biochemical composition, biochar type had no significant effect on plant growth and biomass accumulation. Mean root dry weights and multiple shoot formations/explant enhanced up to 3.7 and 4.17 times higher than the control at 0.5 g/L concentration. Explant browning was also detected lower in biochar-applied media. The differences between biochemical accumulations of different media were also found statistically significant. The total concentrations of phenolics and flavonoids and radical scavenging activities were detected lower when biochars were applied. The total antioxidant concentration was higher in the control group. These findings showed that biochars lowered the negative effects of the culture conditions for L. officinalis plantlets.

Low-temperature dechlorination of polyvinyl chloride (PVC) for production of H2 and carbon materials using liquid metal catalysts.

Polyvinyl chloride (PVC) is ubiquitous in everyday life; however, it is not recycled because it degrades uncontrollably into toxic products above 250°C. Therefore, it is of interest to controllably dechlorinate PVC at mild temperatures to generate narrowly distributed carbon materials. We present a catalytic route to dechlorinate PVC (~90% reduction of Cl content) at mild temperature (200°C) to produce gas H2 (with negligible coproduction of corrosive gas HCl) and carbon materials using Ga as a liquid metal (LM) catalyst. A LM was used to promote intimate contact between PVC and the catalytic sites. During dechlorination of PVC, Cl is sequestrated in the carbonaceous solid product. Later, chlorine is easily removed with an acetone wash at room temperature. The Ga LM catalyst is reusable, outperforms a traditional supported metal catalyst, and successfully converts (untreated) discarded PVC pipe.

Designation and characterization of cold-set whey protein isolate-low acyl gellan gum emulsion-filled gel for enhancing limonene flavor perception: A study on structure, breakdown characteristics, and sensory perception in the human mouth

Flavor perception depends on food structure and oral processing behavior. Emulsion-filled gel (EFG) is a category of soft to solid food products that utilizes the advantages of emulsions to deliver lipid-soluble ingredients, such as the limonene flavor. This paper aimed to design a cold-set EFG system as a carrier to improve limonene flavor perception using whey protein isolate and low-acyl gellan gum (LAGG) (0–0.7% w/w). With increasing LAGG levels, the EFGs shifted towards forming a true gel structure with a brittle and hard 3D network based on the steady shear, amplitude (increasing GLVE′ and decreasing tanδLVE), frequency sweep (increasing K′ and decreasing n′), and uniaxial compassion (increasing Young's modulus and decreasing fracture strain) tests. EFG with 0.7% LAGG needed a higher chewing process, and the fragmentation increased as EFG hardness increased. According to the time-intensity test, the highest and lowest limonene perception were found in the EFG-contained 0.3% (Imax: 5.14, area: 79.20) and 0.7% (Imax: 4.35, area: 57.40) LAGG. In conclusion, by manipulating the structure, custom architectures can be created in the oral cavity, resulting in specific performance and controlled release of their components.

STUDY OF THE EFFECT OF SUPERCRITICAL WATER ON SOLID PRODUCTS OBTAINED AFTER CRACKING

One of the possible applications of supercritical water is the conversion of heavy hydrocarbon feedstocks with a high content of resins and asphaltenes. The use of supercritical water makes it possible to reduce the yield of solid products and increase the yield of light fractions. In this work, a comparative analysis of the cracking processes of petroleum residue, asphaltenes and resins isolated from it was carried out in an environment of supercritical water and without water. The experiments were carried out in an autoclave at a temperature of 450 °С and a pressure of up to 47 MPa. Cracking duration – 60 min. Cracking of petroleum residue, as well as its individual components - resins and asphaltenes, in a supercritical water environment - showed a positive effect on conversion; in all experiments, the yield of solid products decreased and the yield of maltenes increased. Solid products were studied using X-ray diffraction and thermogravimetric analysis and scanning electron microscopy. Using X-ray diffraction analysis, the influence of supercritical water on the parameters of the macrostructure was studied. It was determined that cracking with water affects the increase in the distance between saturated fragments of molecules (dr) in the structure of solid cracking products in comparison with products obtained without water. Using scanning electron microscopy, the surface of particles of insoluble cracking products was characterized. Solid products obtained in a supercritical water environment have a porous surface. According to thermal analysis data, it is shown that solid products obtained by cracking in water are characterized by more intense dynamics of sample weight loss and a smaller residue at the final temperature. For citation: Nalgieva Kh.V., Kopytov M.A. Study of the effect of supercritical water on solid products obtained after cracking. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 8. P. 113-120. DOI: 10.6060/ivkkt.20246708.14t.