Rounds Of Recycling Research Articles

Van der Waals interactions enhanced multiple-times all-waste-recycled triboelectric nanogenerator for ultra-high lifetime stability

To mitigate the ever-increasing waste problem, utilization of recycled waste to fabricate energy harvesting devices has emerged as a propitious alternative. Despite several efforts, it is still a daunting challenge to sustain the properties of recycled-plastic-waste after multiple rounds of recycling. We address the above challenges by developing an industry-viable universal framework to recycle plastic-waste multiple-times without significant degradation in its properties. A multiple-times all-recycled triboelectric nanogenerator (MR-TENG) was demonstrated with high performance and record-high overall operational lifetime stability for 5 million cycles of mechanical impact. To the best of our knowledge, this is the first report of a nanogenerator made completely from recycled mixed-plastic-waste, which can sustain its energy-harvesting performance even after ten rounds of recycling. The multiple-times recyclability can be attributed to the improved van der Waals interactions between the polymeric blends at the macromolecular level facilitated by incorporating a mixed-plastic waste-derived compatibilizing agent, which is validated by molecular dynamics simulation. The adopted industry-viable reactive extrusion to fabricate the materials facilitates easy adaptability and commercialization. The practical application was demonstrated by utilizing it for deep learning-enabled MR-TENG-based advanced cognitive waste sorting and segregation, facilitating digitalized-waste-management, thus facilitating a major step towards upcycling of plastic-waste for circular economy.

Enhanced degradation of atrazine from soil with recyclable magnetic carbon-based bacterial pellets: Performance and mechanism

Herein, magnetic biochar coupled with Acinetobacter lwoffii DNS32 immobilized pellets (DMBC-P) were synthesized through sodium alginate embedding and fixation, which could fast and completely eliminate atrazine from contaminated farmland soil. Characterization results revealed that DMBC-P exhibited a significant abundance of three-dimensional network porous structures, thereby enhancing the stability and specific surface area of DMBC-P. The application of 0.5 % DMBC-P could completely remove 22 mg/kg atrazine from soil within 4 d under the condition of moisture content of 60 % and soil pH of 7.4. After 5 d of remediation, DMBC-P could be easily extracted from the soil by magnetic separation and still had 100 % removal efficiency for atrazine after 3 rounds of recycling. Moreover, DMBC-P effectively alleviated the oxidative damage of atrazine to soybean seedlings through significantly decreasing the activities of various plants antioxidant enzymes by 27 % to 79 %. Meanwhile, analysis of 16S rRNA revealed a significant increase in the relative abundance of functional microflora such as Acidobacteriota and Chloroflexi at the phylum level, which promoted the growth of soybean seedlings. Additionally, pore filling, hydrogen bonding, and π-π stacking were identified as the primary mechanisms responsible for atrazine adsorption onto DMBC-P. Subsequently, the degrading bacteria DNS32 immobilized on DMBC-P was employed to catalyze the decomposition of atrazine into non-toxic cyanuric acid based on LC-MS. Overall, this study provided a reasonable design of magnetic carbon-based bacterial pellet for atrazine-contaminated soil remediation, which could efficiently remove atrazine and be effectively recycled after remediation.

Tek Proseste Kompaund Elde Edebilen Tandem Bir Sistemle Yapılan Termoplastik Geri Dönüşümünün Çevreye ve Dünyaya Faydaları

The manufacture of polymers has experienced significant growth since the 1900s due to their favorable attributes such as ease of manufacturing, cost-effectiveness, desirable chemical and physical qualities, as well as their lightweight nature. The escalating utilization of plastic has begun to inflict damage upon the environment, organisms, and human well-being, hence giving rise to challenges pertaining to recycling and waste management. In the process of recycling, it is necessary to subject thermoplastics to two cycles of melting in order to get the correct material characteristics. As a result of the restricted number of mechanical recycling cycles for plastics, thermoplastics have an accelerated rate of expiration, double the usual timeframe. In the proposed tandem recycling process, a single melting operation can subject the trash that has already undergone recycling to a second round of recycling. By using this approach, the potential for enhancing the reusability of thermoplastic waste is heightened. The absence of an additional heating process results in energy savings, leading to a notable reduction in expenses.

Mechanical Recycling and Its Effects on the Physical and Mechanical Properties of Polyamides.

The aim of this study is to investigate the impact of mechanical recycling on the physical and mechanical properties of recycled polyamide 6 (PA6) and polyamide 66 (PA66) in relation to their microstructures. Both PA6 and PA66 raw materials were reprocessed six times, and the changes in their properties were investigated as a function of recycling number. Until the sixth round of recycling, slight changes in the mechanical properties were detected, except for the percentage of elongation. For the physical properties, the change in both flexural strength and Young's modulus followed a decreasing trend, while the trend in terms of elongation showed an increase. Microscopic analysis was performed on virgin and recycled specimens, showing that imperfections in the crystalline regions of polyamide 6 increased as the number of cycles increased.

Universal approach for developing reprocessable and reprintable plant oil-based resins for digital light processing 3D printing

Recently, researchers have shown great interest in the development of biobased and reprintable 3D printing materials for sustainable 3D printing. Herein, a method for developing plant oil (PO)-based digital light processing (DLP) printing resins that are both reprocessable and reprintable is proposed. Biobased UV-curable monomers (POPITs) containing dynamic hindered urea bonds (HUBs) from POs were synthesized via the thiol-ene click reaction. A range of DLP printing resins (POPIT-I) with high biobased content (52.6%–58.1%) were prepared by blending POPITs with the biobased dilute monomer isobornyl acrylate. These resins demonstrated good mechanical and thermal properties (e.g., tensile strength: 45.1–49.5 MPa and Tg: 74–92 °C), as well as high DLP printing quality. Reprocessable DLP printing was employed to fabricate large-volume parts through the dissociation and reorganization of HUBs, thereby reducing printing difficulty and printing time. Additionally, a powder blending and modification method was used to recycle and reprint printed materials. The printing materials, including printed green parts and discarded supporting materials, were milled into micron-sized powders and then blended with POPIT-I to prepare the powder blending resins. The milled powders in the powder blending resins were further modified by 2-(tert-butylamino) ethyl methacrylate to prepare reprinting resins. This process resulted in the grafting of C = C onto the powder surface, which eliminated heterogeneity between the powders and POPIT-I. The mechanical and thermal properties of the reprinting resins were comparable with those of POPIT-I even after three rounds of recycling. Furthermore, the reprinting method reported here is applicable to other dynamic covalent bond-based 3D printing systems.

Sustainable route to prepare functional lignin-containing cellulose nanofibrils

With nano-dimension, high aspect ratio, and high mechanical properties, cellulose nanofibrils (CNFs) are emerging sustainable nanomaterials with potential applications in films and composites. However, their preparation often involves a series of chemical treatments such as delignification, bleaching and harsh chemical pretreatments, and treats lignin as waste. Herein, we report a sustainable method to prepare high-quality lignin-containing cellulose nanofibrils (LCNFs) from bamboo chips, using a one-step maleic anhydride esterification treatment without any toxic organic solvent or catalyst. The resultant LCNFs have high lignin content (24%), high surface charge (2.25 mmol/g), fine diameter (∼2.5 nm), and high aspect ratio (>400). These superior properties can be translated into the corresponding nanopaper films with high optical transmittance (85% at 600 nm), UV shielding (<10% transmittance at 200–350 nm), hydrophobicity (water contact angle 75°), thermal stability (maximal weight loss temperature at 338 °C), and mechanical properties. Importantly, such films show the best reported tensile strength (290 MPa) among all the LCNF films, and it still outperforms conventional CNF films after 5 rounds of recycling. Furthermore, as sustainable nanofillers, such LCNFs can be directly incorporated into a hydrophobic polyester matrix, and significantly enhances the UV shielding and mechanical properties of the final nanocomposites. Altogether, with eco-friendly production and multiple functions, these LCNFs are a new class of nanocelluloses with high industrial relevance.

Utilization of Plastic Waste and Waste Rubber Tyres to Modify Bitumen Binder in Road Construction

In line with the recent environmental concerns due to waste, researchers focus has been shifted to finding ways of recycling the waste in a most sustainable way. Accumulation of plastic waste, and rubber tyres in the environment is a concern and a threat to the environment. The current waste management has raised public awareness to look for new technologies for handling waste and an alternative to the current disposal technique. Some of the challenges encountered with the current waste management such as recycling, includes contamination of recycling streams, inability to meet recycling demand and the quality of the recycled plastics. One of the disadvantages of recycling is that it produces wastewater and air pollutants. Since recycling degrades the plastic integrity, most recyclable plastic waste is only suitable after one round of recycling, which ultimately leaves most recyclable plastic in the landfills, environment, and oceans. In addition to landfilling (waste management) and waste disposal, waste tires are also a worldwide problem. The current waste management method for waste tires is through incineration, whereby waste tires disposed and piled up in landfills, are treated through incineration. However, this process was found to be releasing enormous emissions, such as hydrocarbons and halogen-chlorinated compounds (chlorinated methanes, dioxins, and polychlorinated biphenyl (PCBs)). This also produces the pyrolytic oils that contains heavy metals and toxic chemicals, which have a potential of causing severe health effects. Moreover, exhausts from incineration of waste tires are far more mutagenic compared to coal-fires plants emissions . The study investigated the potential of modifying the bitumen binder with plastic (Polyethylene Terephthalate) and tyre wastes. In bitumen-rubber tyre modified binder, increasing the rubber tyre percentage above 5% in the binder, resulted in low ductility, due to the elasticity property of rubber, for both 5.5% and 6% bitumen. For the Bitumen-plastic modified binder, the softening point and ductility had a direct proportionality relationship. As the plastic percentage in the total weight of the binder increased, so did the ductility and the softening point, due to the plasticity property of the plastic that enabled the mixture to be homogenous.

Sulfur-containing adsorbent made by inverse vulcanization of sulfur/oleylamine/potato starch for efficient removal of Hg(II) ions

Mercury contamination is considered the most harmful pollutant considering its high toxicity and persistence in the environment. This study aims to design an efficient and inexpensive adsorbent to capture Hg(II) ions. Herein, a polysulfide complex material was prepared through sulfur, oleylamine, and potato starch. Initially, the potato starch was functionalized by using dimethyl sulfoxide and (3-aminopropyl) triethoxysilane. The polysulfide adsorbent was then created by copolymerizing sulfur with oleylamine and sulfhydrylation starch using the inverse vulcanization process. The composition, structure, and morphology of polysulfide adsorbent were characterized by SEM/EDS, FT-IR, TGA, and XRD. The results indicated that the adsorption capacity and removal of adsorbent reached 248.2 mg/g and 99.28%. The adsorption data were fitted with adsorption kinetics, isothermal adsorption model and adsorption thermodynamics, followed by an analysis of the possible adsorption mechanism of the adsorbent. Meanwhile, it exhibited high selectivity for Hg(II) ions and other co-existing ions, with favorable recyclability after 5 rounds of recycling. In general, a promising polysulfide for the treatment of Hg(II)-containing wastewater is reported in this study, moreover, opening a novel avenue for elemental sulfur applications.

One-pot encapsulation of lactate dehydrogenase and Fe3O4 nanoparticles into a metal-organic framework: A novel magnetic recyclable biocatalyst for the synthesis of D-phenyllactic acid.

The main challenges in bio-catalysis of d-phenyllactic acid (D-PLA) are poor tolerance of lactate dehydrogenase (LDH) to harsh environmental conditions and inability to recycle the catalyst. A novel magnetic framework composite was prepared as solid support for the immobilization of enzymes via one-pot encapsulation in this study. LDH/MNPs@MAF-7 was synthesized by the one-pot encapsulation of both LDH and magnetic nanoparticles (MNPs) in MAF-7. The LDH/MNPs@MAF-7 showed stable biological activity for the efficient biosynthesis of D-PLA. The structure and morphology of LDH/MNPs@MAF-7 were systematically characterized by SEM, FT-IR, XRD, VSM, XPS, TGA and N2 sorption. These indicated that LDH/MNPs@MAF-7 was successfully synthesized, exhibiting enhanced resistance to acid and alkali, temperature and organic solvents. Furthermore, the bio-catalyst could be separated easily using a magnet, and the reusability was once considerably expanded with 80% of enzyme activity last after eight rounds of recycling. Therefore, LDH/MNPs@MAF-7 could be used as a potential biocatalyst for the biosynthesis of D-PLA due to its good stability and recovery properties.

Electric field-enhanced immobilization of Cd and Pb in contaminated river sediments

The immobilization of heavy metal pollutants in river and lake sediments is critical for environmental health and safety. In this study, combined electrokinetic and chemical immobilization were used to remediate Cd and Pb polluted river sediments. The effect of the concentrations of the immobilization reagents and the applied voltage were investigated. Immobilization ratios for Cd and Pb of 98.6% and 84.3%, respectively, was achieved at 7.5 V cm−1 using seven successive rounds of recycling of the immobilization solution of mixed 1.0 g L−1 CO32− and 3.0 g L−1 H2PO4− at the volume ratio of 1:9 with 100 mL immobilization solution to 100 g sediment. The enhancement effect of the electric field is mainly attributed to the increased contact between the immobilization reagents and the heavy metals due to electroosmosis. This study provides a new method for the treatment of heavy metal-polluted sediments.

Surface display of (R)-carbonyl reductase on Escherichia coli as biocatalyst for recycling biotransformation of 2-hydroxyacetophenone

The purified (R)-Carbonyl reductase (RCR) is widely applied in the synthesis of chiral compounds, but often involves tedious procedures and high production costs of protein separation and purification. A surface immobilization of biocatalyst on cell surface for biotransformation is an option for ease enzyme separation and recycling. In this study, the RCR from Candida parapsilosis was immobilized on the surface of E. coli using the Lpp–OmpA and EhaA anchors, showing that the Lpp–OmpA is better for displaying the target molecules in terms of enzyme activities, product formation, and display efficiency. By deleting the NAD+ degrading enzyme UshA, the whole-cell biocatalytic activity was two-fold higher than that of the original strain. The created biocatalyst can retain about 80% of its catalytic activity after four rounds of recycling, reached the conversion rate of 83.5% within 30 mins with the substrate (R)-PED concentration of 1 mM. This study provides a novel strategy for 2-hydroxy acetophenone synthesis using the surface display of the enzyme on the cell while avoiding enzyme purification and side reactions from the host.

Towards closed-loop material flow in additive manufacturing: Recyclability analysis of thermoplastic waste

Thermoplastic is one of the most popular materials used in additive manufacturing (AM). As the adoption of AM technologies has been rapidly increasing, the feasibility of recycling AM waste and the quality of recycled materials need to be investigated to facilitate closed-loop material flow and cleaner production. In current literature, studies have been performed to compare material property changes before and after recycling, and a certain level of mechanical degradation has been observed. Some material properties such as molecular weight distribution have not yet been investigated in AM recycling. In addition, the recyclability of waste materials under multiple rounds of recycling has not yet been well studied. These knowledge gaps indicate a research need for AM material recyclability evaluation and improvement. In this research, an assessment framework is proposed and implemented to evaluate the recyclability of acrylonitrile butadiene styrene in extrusion-based AM, providing guidelines for quantifying variations of molecular weight distribution, material density, fabrication quality, and mechanical properties under multiple rounds of recycling. Different process parameters and their impact on material recyclability in each round are also studied. Experimental results indicate that the ultimate tensile strength degradation after each recycling round varies from 27% to over 50%; surface roughness increases 29.54% after three rounds of recycling; molecular weight distribution of recycled materials demonstrates obvious shifts, and the polydispersity is decreased by 13.16% after three rounds of recycling. The results of this research will help AM users better understand and implement waste recycling, which will positively impact the AM community by contributing towards achieving cleaner production and enhancing the material efficiency and environmental sustainability of AM.

COVID-19-inspired “artificial virus” to combat drug-resistant bacteria by membrane-intercalation- photothermal-photodynamic multistage effects

COVID-19 threatens human life because of the super destructiveness produced from its coronal morphology and strong transmembrane infection based on spike glycoprotein. Inspired by the coronal morphology of COVID-19 and its means of infecting, we designed an “artificial virus” with coronal morphology based on the concept of “defeating superbacteria with superviruses” by self-assembling a transacting activator of transduction peptide with triple-shell porous graphitic carbon nitride (g-C3N4) embedded with cobalt nanoparticles to forcefully infect methicillin-resistant Staphylococcus aureus (MRSA). The results confirmed that this “artificial virus” had unique properties of crossing the bacterial cell membrane barrier, heating the internal bacterial microenvironment and triggering ROS outbreak, based on its coronal morphology, membrane penetration, temperature-rising and heat insulation, oxidase-like activity and excellent visible-light harvesting properties. It had a high sterilization efficiency of 99.99% at 20 min, which was 18.6 times that of g-C3N4, and the efficiency remained at 99.99% after 3 rounds of recycling and reuse. Additionally, it can rapidly inactivate bacteria in river water and accelerate wound healing.

Assessing the effect of K2CO3 and aqueous phase recycling on hydrothermal liquefaction of corn stover

The effects of reaction temperature (300–340 °C) and reaction time (30–90 min), catalyst loading (0–10% K2CO3), and aqueous phase recycling (up to 3 recycling rounds) on the hydrothermal liquefaction (HTL) of corn stover were investigated. The oil yield ranged from 0.28 to 14.54%daf. A high reaction temperature and a long reaction time have a synergistic effect on the oil production under non-catalytic HTL. The effect of K2CO3 loading on oil yield is dependent on the reaction temperature. The FTIR analysis of the solid residue showed that the peak characteristics of lignin and cellulose are still intact without or with different K2CO3 loading suggesting low lignin and cellulose degradation. The effect of the aqueous phase with the presence of K2CO3 showed an increased oil yield, energy recovery, and abundance in silanes and siloxanes after the 3rd round of recycling.

Fast and sustainable recycling of epoxy and composites using mixed solvents

Chemical recycling of thermosets and composites can reclaim polymer matrix and high-value reinforcement to protect the environment and save resources. However, efficient and sustainable chemical recycling of epoxy thermosets is still a significant challenge, specifically, improving the decomposition rate, easily separating and reusing the decomposed components under mild condition. Herein, we report the fast and sustainable recycling of epoxy and composites by small-molecule assisted bond exchange reaction (BER) in a mixed solvent. The anhydride-cured epoxy resin with embedded catalyst was rapidly decomposed by the mixed solvent containing a high boiling point alcohol and inert good solvent via transesterification below 150°C at normal pressure. The epoxy decomposition rate was optimized by altering the good solvent types and solvents mixing ratios. We found the epoxy decomposition rate was the fastest in dimethylformamide/ethylene glycol (50/50) due to balanced solvent diffusion/swelling and reaction rate. After epoxy decomposition, the depolymerized epoxy oligomer (DEO) and residual solvents were readily separated by reduced pressure distillation below 80°C. The DEO as an additive (up to 20%) was repolymerizated with fresh epoxy resin to make epoxy materials, which showed similar mechanical properties to the original epoxy with slight deterioration even for several recycling cycles. The reclaimed solvent was used for the next round of recycling. With the optimized condition, carbon fiber reinforced epoxy composite was also recycled to reclaim the high-value carbon fiber with unchanged mechanical properties. This work presents a sustainable and fast recycling paradigm for industrial-grade epoxy and composite with potential for upscale engineering applications.

Bio-Crude Production through Recycling of Pretreated Aqueous Phase via Activated Carbon

The management and optimization of the aqueous phase are the major challenges that hinder the promotion of hydrothermal liquefaction (HTL) technology on a commercial scale. Recently, many studies reported about the accumulation of the N-content in the bio-crude with continuous recycling of the aqueous phase from high protein-containing biomass. In the present study, sewage sludge was processed at 350 °C in an autoclave. The produced aqueous phase was treated with activated carbon, and its subsequent recycling effect on the properties of the bio-crude and aqueous phase was investigated. By contacting the aqueous phase with activated carbon, 38–43% of the total nitrogen was removed from the aqueous phase. After applying the treated aqueous phase recycling, the energy recovery of the bio-crude increased from 50 to 61% after three rounds of recycling. From overall carbon/nitrogen recoveries, 50 to 56% of the carbon was transferred to the bio-crude phase and more than 50% of the nitrogen remained in the aqueous phase. The aqueous phase contained mostly of N&amp;O-heterocyclic compounds, small chain organic acids, and amides. ICP-AES analysis showed that more than 80% of the inorganic elements were concentrated into the solid phase.

Cationic cellulose nanocrystals for fast, efficient and selective heparin recovery

• Green and renewable cellulose nanocrystals were utilized for heparin recovery. • Polycationic side chains were grafted from cellulose nanocrystals. • Instantaneous heparin-capture in biological conditions reduced recovery efforts. • Selective heparin-recovery was achieved via salt concentration or pH adjustment. • Significantly higher heparin-recovery ability than Amberlite was achieved. Heparin is one of the most important anticoagulant agents used in clinical applications. Commercial heparin production includes an isolation from mucosa and an additional enrichment step by cationic resins. However, this process remains time-consuming while heparin is obtained in very low concentrations with the presence of macromolecular impurities, such as proteins. Therefore, an alternative with a fast, efficient and selective heparin-recovery performance is highly desirable. In this work, we utilized a biomass-derived cellulose nanocrystal colloid conjugated with cationic polyelectrolytes for heparin recovery. The high specific surface area and brush-like structure significantly increased the heparin-capture speed and efficiency under physiologically relevant conditions, which were demonstrated by the methylene blue binding assay and quartz crystal microbalance measurement. We also found that a selective heparin capture can be realized via adjusting salt concentration or pH. Finally, we showed that after several recycle rounds, the heparin-recovery ability of the cationic nanocrystals was largely retained and the majority of active heparin dose was recovered, showing a significantly higher heparin-recovery performance than the commercial Amberlite IRA-900 and demonstrating its applicability from an economic perspective. Therefore, the reported cellulose nanocrystal-polymer conjugate represents a promising candidate for a green and efficient heparin recovery.

Alkoxyl side‐chain effects of acidic ionic liquids catalysts for the esterification of n‐butyl butyrate

AbstractThree kinds of alkoxy group‐functionalized acidic ionic liquids (ILs) are reported in this work, namely, 1‐(methoxyethyl)‐3‐methylimidazolium hydrogen sulphate [MOE‐MIM]HSO4, 1‐(ethyoxyethyl)‐3‐methylimidazolium hydrogen sulphate [EOE‐MIM]HSO4, and 1‐(propyoxyethyl)‐3‐methylimidazolium hydrogen sulphate [POE‐MIM]HSO4. The short side chain on the cation of [MOE‐MIM]HSO4 decreases the solubility of the IL in butanol and butyric acid and facilitates the separation of the IL from a reaction medium. The yield of butyl butyrate is up to 99.5%. After 10 rounds of recycling, the catalytic performance of [MOE‐MIM]HSO4 shows no significant changes.

Sustainable Additive Manufacturing: Mechanical Response of Polyethylene Terephthalate Glycol over Multiple Recycling Processes.

The continuous demand for thermoplastic polymers in a great variety of applications, combined with an urgent need to minimize the quantity of waste for a balanced energy-from-waste strategy, has led to increasing scientific interest in developing new recycling processes for plastic products. Glycol-modified polyethylene terephthalate (PETG) is known to have some enhanced properties as compared to polyethylene terephthalate (PET) homopolymer; this has recently attracted the interest from the fused filament fabrication (FFF) three-dimensional (3D) printing community. PET has shown a reduced ability for repeated recycling through traditional processes. Herein, we demonstrate the potential for using recycled PETG in consecutive 3D printing manufacturing processes. Distributed recycling additive manufacturing (DRAM)-oriented equipment was chosen in order to test the mechanical and thermal response of PETG material in continuous recycling processes. Tensile, flexure, impact strength, and Vickers micro-hardness tests were carried out for six (6) cycles of recycling. Finally, Raman spectroscopy as well as thermal and morphological analyses via scanning electron microscopy (SEM) fractography were carried out. In general, the results revealed a minor knockdown effect on the mechanical properties as well as the thermal properties of PETG following the process proposed herein, even after six rounds of recycling.

Effect of Accumulative Recycling of Aqueous Phase on the Properties of Hydrothermal Degradation of Dry Biomass and Bio-Crude Oil Formation

For hydrothermal liquefaction of dry biomass to produce liquid fuels, water needs to be added or the aqueous phase products can be recycled. This paper focuses on understanding the relationship between hydrothermal degradation of the dry biomass and oil formation under the condition of accumulative recycling of the aqueous phase. Completely dried corn stalk and deionized water were used for the hydrothermal liquefaction (HTL) experiment. The aqueous products for subsequent recycling were not diluted. It was demonstrated that the recycling of the aqueous can promote the enrichment of organic acids and the conversion of ketones and phenols in the aqueous, improving the yield and quality of Bio-crude oil. After recycling, the yield of Bio-crude oil increased from 20.42% to 24.31% continuously, and the oxygen content decreased from 13.34% to 9.90%. Although the process was accompanied by solid deposition and had a negative impact on the hydrothermal degradation efficiency, the formation of carbon microspheres during the deposition enhanced the utilization of nondegradable solids, while the formation of metal salt particles had a positive impact on oil production. After three rounds of recycling, the solid deposition effect was weakened. At this time, oil production and solids degradation can be promoted simultaneously.