Quality Of Pyrolysis Oil Research Articles

Synergistic effects and comprehensive analysis of interaction during infrared co-pyrolysis of furfural residues and PVC

Infrared co-pyrolysis was employed to convert waste into valuable resource due to the increasing production of plastic waste. In this study, support vector machine (SVM) accurately predicted PVC and furfural residues thermal behavior. The results showed high accuracy (R2 > 0.95) after the SVM model was trained and validated. Furthermore, this research performed an in-depth characterized of the co-pyrolysis process using various analytical techniques, indicting TG-FTIR-GC/MS, XPS, simulated distillation, and GC/MS. As the temperatures and heating rates increased, the pyrolysis oil yield increased at first and then declined, reaching a maximum of 37.7 % at 600 °C and 10 °C/s. Notably, aromatic content was relatively high, comparing with other components, whereas the chlorinated content remained relatively low, all below 6.5 %, indicating the pyrolysis oil quality had effectively improved. According to the results of XPS, there was a significant 64.11 % increase in inorganic chlorination, which suggested the effective reduction in gaseous chlorine emission and achieving chlorine immobilization.

Production and characterization of two-step condensation bio-oil from pyrolysis

The goal of this project is to investigate the potential of fuel production directly from slow pyrolysis of straw pellets without further refining. A two-step condensation was used to separate liquids from the volatiles. The thermal process chosen is slow pyrolysis at 500°C to couple the fuel production with carbon capture by maximizing the char production alongside bio-oils collection. Condensation parameters were tuned to improve the pyrolysis oil quality. To assess the oil quality some requirements on marine fuels, bio-oils and boiler fuels were taken as reference. Three condensation conditions were inspected: the best pyrolysis overall process was repeated three times for a total of five pyrolysis processes (lately referred to as runs). As expected, the bio-oil characteristic changed with the condensation temperature. As a result of lowering the bio-oil condensation temperature, the bio-oil results less viscous, less dense, with lower heating value and with higher water content. The final bio-oil produced was almost compliant to ISO 8217:2017 for residual marine fuels K 380, apart from water content and acid number, while it was almost compliant for the standard EN 16900:2017 for industrial boilers fuels, apart for the kinematic viscosity. It was assessed that the char is produced with an average yield of 27 w% on dry basis, while bio-oil has a yield between 5 and 10 w%. It is possible to recover an average of 72 % of the total energy contained in the straw in the valuable products, gas, char and bio-oil. The carbon captured with charcoal was around 49 w% of the total present in straw. The pyrolysis experiments were performed using an innovative semi-batch, packed-bed reactor with gas re-circulation and a new two-fraction condensation appliance that is DTU patented. The innovation is both in the reactor, where the gas is directly heated and flushed back into the pyrolyser, and in the condensation section, where the bio-oil is separated from the water fraction during the pyrolysis. The company Stiesdal SkyClean A/S showed interest in further development and scale up of this pyrolysis and condensation system.

Stepwise dechlorination and co-pyrolysis of poplar wood with dechlorinated polyvinyl chloride: Synergistic effect and products distribution

With the combination of stepwise dechlorination and co-pyrolysis techniques, this study conducted polyvinyl chloride (PVC) dechlorination experiments and co-pyrolysis experiments of poplar wood (PW) with dechlorinated polyvinyl chloride (DPVC) by thermogravimetric analysis and a fixed bed reactor. Stepwise pyrolysis effectively removed Cl from PVC with a dechlorination efficiency of 99.84 % at 360 °C for 30 min. Thermogravimetric tests and thermokinetic variables were employed to describe the co-pyrolysis process's thermodynamic behavior, where co-pyrolysis significantly diminished the activation energy of the initial pyrolysis stage (9.65–21.62 kJ/mol) and increased the reaction rate (0.02–0.09 %/°C). The synergistic effect of co-pyrolysis enhanced the yield and quality of liquid oil and reduced the solid residue rate, with the maximum change in solid residue rate (−2.36 wt%) occurring at PW:DPVC = 3:7. The optimal conditions for the synergistic effect are a raw material ratio of 3:7 at 500 °C. Co-pyrolysis efficiently reduced the content of oxygen-containing compounds of phenols, ketones, and acids in oil, and elevated the selectivity of aromatics. The research methods avoid the drawbacks of bio-oil and plastic oil and improve the quality of pyrolysis oil in a concise and efficient manner, which provides some new ideas for the resource and clean utilization of municipal waste.

Investigation of pyrolysis productions (pyrolysis oil, pyrolysis gas and carbon nanotubes) distribution in co-pyrolysis of torrefied oiltea camellia shells and polypropylene

The co-pyrolysis of torrefied oiltea camellia shells (OCS) and reused polypropylene (PP) was investigated for pyrolysis oil, pyrolysis gas and carbon nanotubes (CNTs) distribution characters in a two-stage pyrolysis system. Compared with raw OCS/PP, the quality of pyrolysis oil from torrefied OCS and PP was upgraded while yield decreased gradually. In particular, torrefaction pretreatment was beneficial to the formation of aromatic hydrocarbons and the higher selectivity of phenols in pyrolysis oil. And serious N2 torrefaction (260 N) and slight CO2 torrefaction (200C) is more conducive to the synthesis of C6–C11 (gasoline component). In addition, torrefaction could contribute to lower volatiles, which resulted in a lower yield of CNTs. For comparison, higher graphitized CNTs was prepared from the co-pyrolysis of torrefied OCS and PP. Appropriate torrefaction temperature and atmosphere have a potential for high value conversion of pyrolysis oil, pyrolysis gas and CNTs from co-pyrolysis of biomass and plastics.

Pyrolysis char from waste tyres its characteristics, upgrading and application

The pyrolysis of waste tyres can recycle energy and produce reusable products (oil, char and gas). Although there are many reviews in the literature in regard to the pyrolysis characteristics of waste tyres, but this paper critically looked as pyrolysis char as one of the useful product. Its physical characteristics include pore diameter, pore volume, specific surface area, and composition. The common detection techniques of the physical characteristics include elemental analysis, proximate analysis, SEM, EDS, TGA, XRF, BET, and Raman spectroscopy. The chemical characteristics of tyre char mainly include calorific value, the surface functional groups (i.e phenols, alcohols, carboxylic acid and C-O/C-O-C chemical structures) which can be determined by FT-IR, XRD. The higher sulfur retention on the surface of tyre char is obtained at low temperature compared with that obtained at high temperature. Tyre char could also be directly used as a catalyst material to decrease the operational cost, and improve the quality of pyrolysis oil and gas. The modified tyre char with high specific surface area and lower ash content could be used as an activated carbon adsorbent material, catalyst and catalyst support, capacitor electrode to create higher commercial value, as an adsorbent, in batteries and so on. It is suggested that the recycling applications of tyre char should be developed, which can create a high level of potential economic prospects for the waste tyre pyrolysis industry.

Hydrothermal dechlorination strategy for high-quality oil recovery from polyvinyl chloride

The global production of PVC is around 3.5 million tons each year. Unfortunately, the disposal of PVC waste releases toxic substances such as hydrochloric acid, polychlorinated dioxins, and furans, which can harm the environment. Therefore, there is an urgent need for a safe and environmentally friendly thermochemical treatment method that reduces the damage caused by HCl gas produced during PVC pyrolysis and improves the quality of pyrolysis oil. Hydrothermal treatment technology is one of the potential dechlorination strategies for PVC. However, its efficiency is reduced in the supercritical region, while the additives used result in secondary pollution and increased operating costs. This study is pioneering in its approach, aiming to produce high-quality oil with reduced chlorine through low-temperature hydrothermal treatment of PVC, all without additives. The results are promising, indicating that by administering steam at 250 °C with a 2.0–3.0 g-steam/g-feed ratio, we can significantly reduce chlorine content to 0.13 % while achieving an oil yield of up to 14.9 % from PVC. The hydrothermal process can reduce CO2 emissions by 15–43 % compared to pyrolysis methods, providing a simultaneous opportunity for carbon neutrality and resource recovery.

The Influence of Alkali Cations on the Performance of Pt Electrodes in Kolbe Electrolysis of Acetic Acid

AbstractElectrochemical decarboxylation of carboxylic acids is considered a sustainable method to improve the quality of pyrolysis oil. In this study, we assess the effect of monovalent alkali cations (of the acetates) on the performance of Pt electrodes in acid decarboxylation and the competing OER, using various electrochemical methods. We reveal a strong cation dependence generally following the trend Li+<Na+<K+~Cs+ within a large pH range. Using rotating ring disc electrode measurements, we highlight the strong contribution of the oxygen evolution reaction particularly for electrolytes containing Li+ and Na+ which decreases the selectivity for Kolbe oxidation. In addition, the faradaic efficiency (FE) towards methanol ranges between 16 % (for Li+) and 29 % (for Cs+) at high solution pH (9 or 12). The observed trends are generally explained by a cation‐dependent interfacial pH and surface coverage of acetate, both lowest for Li. This is evident from differences in charge transfer resistance determined by impedance measurements and local pH measurements. Additionally, enhanced dissolution of Pt by Li+ is also proposed. This work highlights that K+ and Cs+ cations favor FE for electrochemical Kolbe oxidation, at relatively low current densities.

Insight into dechlorination of pyrolysis oil during fast co-pyrolysis of high-alkali coal and polyvinyl chloride (PVC)

Thermal treatment can utilize polyvinyl chloride (PVC) in a high-value, eco-friendly method, but HCl generation and high oil chlorine content are key pyrolysis issues. Therefore, this research extensively characterized fast co-pyrolysis of PVC and high-alkali coal (HAC) using XPS, TG-FTIR-GC/MS, and GC-MS. This explored alkali metal catalysis and volatile reforming effects on Cl transfer and utilizing PVC as a hydrogen donor to improve the quality of pyrolysis oil. According to the GC-MS results, increasing the PVC ratio to 40 % raised monocyclic (MAHs) and polycyclic aromatic hydrocarbons (PAHs) to 59.1 % and 33.4 % respectively. However, co-pyrolysis of PVC and HAC inhibited the polyene reconstruction of the carbon skeleton, leading to a decrease of oxygenates, such as phenolic, acid, and ester. The XPS results showed that the inorganic chlorine in the solid product increased from 1 % to 66 % after co-pyrolysis at 600 °C, indicating the high fixed chlorine effect of HAC. Fast heating almost merges the PVC dechlorination stage with the conjugated polyene reconstruction stage, creating a liquid–gas synergy. Abundant coal α-carbon selectively binds with H+, dechlorinated PVC, and polyene fragments, rather than binding with Cl-. This study provides valuable insights into coal-PVC interactions and the dechlorination of pyrolysis oil during fast co-pyrolysis processes and advances the sustainable management of PVC waste.

Enhancement of aromatics and syngas production by co-pyrolysis of biomass and plastic waste using biochar-based catalysts in microwave field

In this study, O-rich biomass (bamboo) was co pyrolyzed with H-rich plastic waste (PE) based on the biochar-based catalysts to investigate the yield and quality of pyrolysis oil and syngas. Focusing on the variations of aromatics and phenolics, to reveal the synergetic mechanism between biomass and PE in microwave field. Biomass is “rich in O and lack of H″, and waste plastics are “rich in C and rich in O″ which can provide a lot of H radicals for catalytic pyrolysis of biomass, improve the quality of bio-oil. And the active factors of biomass effectively activated PE. The biochar-based catalysts further promoted deoxygenation and arylation reactions, intensifying the generation of aromatics and reducing oxygen-containing compounds (phenols, etc.). Bamboo: PE = 1: 3 catalyzed by Zr-modified biochar-based catalysts resulted in aromatics yielded as high as 74.13%, while phenols yields was only 9.39%. Incorporation of the externally H-donor PE promoted the growth of carbon chains, and the microwave field activated free radicals which facilitated the cyclization and arylation of carbon. The biochar-based catalysts also promoted the generation of high-value monocyclic aromatics by utilizing the selective ability in the microwave field. Finally, the coupled synergistic mechanism of co-pyrolysis in microwave field was proposed.

Conversion of LDPE Plastic Oil to Gasoline by Supercritical Water Liquefaction

LDPE (Low Density Polyethylene) is one of the plastic waste that is often found in the surrounding environment. Based on data from the National Waste Management Information System (SIPSN) in 2022, waste in Indonesia reached 17.834.071 tons/year with 18.5% being plastic waste. Plastic waste management generally uses recycling. However, recycling plastic waste is not efficient enough in tackling plastic waste in Indonesia. Recently, a promising alternative recycling method for the future is pyrolysis, a process to convert plastic into fuel oil. However, the pyrolyzed oil still contains impurities that reduce the quality of the oil. As an effort to improve the quality of pyrolysis oil, the author proposes the addition of zeolite catalyst in the pyrolysis process followed by the Supercritical Water Liquefaction (SWL) method. The zeolite catalyst aids the degradation process thereby accelerating the reaction rate. The SWL method is able to convert plastic waste into low molecular weight chemicals. The results obtained will be analyzed by gas chromatography mass spectroscopy (GC-MS) to determine the length of the carbon chain in the sample. Based on the chromatography data, it is found that the number of peaks and retention times show carbon chains ranging from C8-C12, from these results it can be identified that the sample is included in kerosene or kerosene compounds. After the SWL process, the percentage of kerosene and diesel is reduced to 11% gasoline. So the Supercritical Water Liquefaction process is proven to break down long hydrocarbon chains into lighter ones.

Synergistic production of fuels from co-pyrolysis of lignite coal and waste plastic

In this study, the co-pyrolysis of Thar lignite coal and waste plastic was investigated, exploring the effects of different parameters such as the coal to waste plastic blending ratio and temperature. The oil obtained from pyrolysis was analyzed for GCV, viscosity, flash point and for chemical composition through GC-MS and FTIR techniques. The results revealed that a blend of 20 % coal and 80 % waste plastic yielded 67 % pyrolysis oil with a GCV of 42 MJ/kg. It was found that adding waste plastics to coal enhanced both the yield and quality of pyrolysis oil. Physical parameters including viscosity and GCV were found to be highly promising and comparable to regular Petro diesel. According to FTIR, presence of significant quantities of aliphatic and aromatic linkages along with carbonyl and hydroxyl functional groups were observed. Similarly, GCMS analysis showed the presence of C7 to C20 carbon fractions in pyro-oil of optimum sample. Char residue 21 % was also obtained from the results with carbon contents up to 68 % and less than 1 % sulfur at 80:20 blending ratio of WP and coal. This char residue could be especially useful for use in steam generation or cement industries as clean fuel.

Improving plastic pyrolysis oil quality via an electrochemical process for polymer recycling: a review

In this review we discuss the application of electrochemical hydrogenation for pyrolysis oil upgrading, thus facilitating a circular polymer economy and low-carbon fuel production.

Efektivitas Katalis Zeolit Alam Ende pada Pirolisis Polietilena dari Sampah Plastik

The high amount of plastic waste in landfills will pollute the environment. Direct combustion releases pollutants into the air, and recycling is only possible in small quantities. One method to overcome this problem is pyrolysis. However, pyrolysis requires a catalyst such as zeolite to accelerate the reaction rate, lower the activation energy, and improve the basic properties of the pyrolysis liquid. This study aims to characterize the activated natural zeolite Ende and determine the effect of the catalyst from the activated natural Ende zeolite on the activation energy, as well as the quality of the liquid resulting from the pyrolysis. Based on the research results, the activation process could change the degree of crystallinity became 36.63%, the surface area became 74.57 m2/g, the average radius became 20,21 Å, the pore volume became 72.34 cm3/g, and the number of acid sites became 4.342 NH3/g zeolite. Ende's active natural zeolite catalyst in the polyethylene pyrolysis process from plastic waste reduced the activation energy to 4,371.1 cal/mol in treating 0.10% catalyst composition from 1 kg of plastic. Increasing the temperature and catalyst improves the quality of pyrolysis oil, but the composition of the catalyst ratio is 0.10% of 1 kg of plastic.

Investigation of Pyrolysis of Walnut Shells and Pyrolysis Oil Quality

The energy demand is increasing in parallel with the technological developments and population in the world. Fossil fuels are the main source for this demand. As a result of energy production from fossil fuels, natural environment is adversely affected. Furthermore, many countries depend on the fossil fuels for their energy need. Researchers have been interested in alternative energy sources such as solar, biomass, and wind. There are many studies for investigating pyrolysis of lignocellulosic biomass. Studies mainly focused on the chemical structure of pyrolysis oil from different feedstocks. In this study, producing pyrolysis oil from walnut shells using pyrolysis reactor, investigating pyrolysis oil properties while comparing it with fossil fuels to determine if the oil can be used in internal combustion engines are investigated. The effect of pyrolysis reaction temperature on pyrolysis oil yield is studied. The results indicates that pyrolysis oil can be produced from walnut shells, the reaction temperature is an important factor on pyrolysis oil yield and pyrolysis oil has complex nature compare to fossil fuels.

Synergistic optimization of bio–oil quality and heavy metal solidification during microwave co–pyrolysis of cow dung and red mud

To decrease the environmental risks caused by heavy metals (HMs) in red mud (RM) and improve the quality of pyrolysis oil from biomass, high–temperature pretreated RM and cow dung (CD) were microwave co–pyrolyzed. Then, the optimization potential of energy consumption was evaluated and the interaction mechanism between RM and CD was explored. The results showed that the increase in transition metal oxides and specific surface area improved the microwave–absorption and catalytic capacity of the pretreated RM. By optimizing the parameters, a pretreatment temperature of 650 °C resulted in a 21.65% reduction in acid content of bio–oil, higher HMs immobilization rates (>91%) and a 7.44% reduction in energy consumption. The synergistic optimization of bio–oil quality, HMs immobilization and energy consumption was achieved. After microwave co–pyrolysis with cow dung, the larger specific surface area (92.90 m2 g−1) and higher carbon crystallinity (ID/IG = 1.02) of pyrolysis residues enhanced the physical adsorption to HMs. The complexation of HMs with –OH could further enhance the solidification of HMs. This work will provide support to efficient resource utilization of solid waste, and demonstrate the great potential of microwave co–pyrolysis in HMs immobilization.

Products distribution and heavy metals migration during catalytic pyrolysis of refinery oily sludge

The reclamation disposal of oily sludge, which is a hazardous waste from the extraction, transportation, storage, and refining of crude oil, is a paramount challenge for environmental protection and resource recycle. Herein, a catalytic pyrolysis approach with the participation of CaO was adopted for oil resource recovery. The results show that the optimal pyrolysis temperature for recovering oil was 500 °C, in which the pyrolysis oil yield was 44.37%. CaO could act as a catalyst during the pyrolysis process, thus promoting the formation of light components in the pyrolysis oil. The light components in pyrolysis oil increased from 5.08% to 16.67% with the participation of CaO. Meanwhile, the addition of CaO immobilized As, Cr, Pb and Zn into the pyrolysis slag, thus decreasing their migration into pyrolysis oil and gas. The migration of Ni displayed a different trend, and part of Ni entered into the pyrolysis oil and gas. The BCR continuous extraction experiments display that the highly biological-activity heavy metals (i.e., F1, F2 and F3 form) was transformed to a more stable state (i.e., F4 form). These results demonstrate that the catalytic pyrolysis approach with the participation of CaO not only improve the yield and quality of pyrolysis oil, but also reduce the emission and mobility of heavy metals.

A Study of Copyrolysis Characteristics of Sewage Sludge and Waste Polypropylene

This study investigates the copyrolysis of sewage sludge (SS) and waste polypropylene (PP). SS exhibited low heating value and high ash content, whereas PP had a high heating value and volatile content. The properties of SS and PP were analyzed, and copyrolysis process, activation energy, synergistic effects, and gas yield were investigated using thermogravimetry combined with Fourier-transform infrared spectroscopy. The results showed the existence of a three-stage synergy, and 10 % PP + 90 % SS showed maximum aromatic yield. The activation energy value for the blended fuel exhibited positive synergy. The Taguchi method was used to determine the operating conditions in a high-temperature furnace for the maximum C5–12/C19+ ratio and optimal pyrolysis oil quality. The PP : SS ratio was the most influencing parameter, followed by the pyrolysis temperature. 30% PP and 10% PP had the best C5–12/C19+ ratio and pyrolysis oil quality, respectively. We obtained a maximum C5–12/C19+ ratio of 9.1 and the optimal ratio of petrochemical product components ( alkenes + monoaromatics ) to worthless products ( polyaromatics + cyclic compounds ) of 4.02. The optimal experimental parameters to achieve these two targets were operated with 10% HZSM-5 and activated alumina. HZSM-5 improved the heating value, oil yield, carbon-number ratio, and pyrolysis oil quality.

Effect of Ni-Fe/CaO-Al2O3 catalysts on products distribution in in-situ and ex-situ catalytic pyrolysis of Chinese herb residue

It is necessary to investigate the differences between in-situ and ex-situ methods of bimetallic supported catalysts for biomass catalytic pyrolysis. In this paper, the Ni–Fe/CaO–Al2O3 catalysts with different Ni/Fe ratios have been synthesized by coprecipitation method, and it was explored that the effect of products distribution about Chinese herb residue(CHR) catalytic pyrolysis by in-situ and ex-situ methods. The results showed that in-situ NiFe-3 group had the highest content of aromatic compounds (59.68%) and the lowest content of aliphatic compounds (17.67%). This was beneficial to the utilization of chemical raw materials extracted from pyrolysis oil. Meanwhile, the CaO in the catalyst effectively reduces the acid content and corrosion of pyrolysis oil. The results showed that higher Ni and CaO content has the synergistic catalytic action in ex-situ catalytic experiments. It could promote water-gas shift reaction, which is conducive to the generation of H2. In-situ catalysis is mainly used for the upgrading of pyrolysis oil, while ex-situ catalysis is mainly used to promote secondary pyrolysis of pyrolysis products and improve the quality of pyrolysis oil. This work provides reference for the difference and high value utilization of biomass pyrolysis by different catalytic methods.

Self-circulation of oily spent hydrodesulphurization (HDS) catalyst by catalytic pyrolysis for high quality oil recovery

In this study, roasted spent HDS ash (sHDSc-A) was used for the first time to catalytically pyrolyze oily spent HDS catalysts (sHDSc) to improve the yield and quality of pyrolysis oil. The results showed that sHDSc-A promoted the decomposition of coke in oily sHDSc, resulting in the recovery of more oil and gas. Meanwhile, sHDSc-A significantly improved the quality of the pyrolysis oil. They inhibited the aromatization of alkanes to increase the saturation of the pyrolysis oil from 59.39% to 74.25% and the H/C radio from 1.62 to 1.72; promoted the decomposition of long-chain alkanes to increase the content of C11–C22 from 41.97% to 61.99%; enhanced the conversion of carboxylic acids to ketones led to the reduction of heteroatomic compounds such as N (56.10%–45.39%), S (66.95%–56.59%), and O (45.26%–26.70%) in the pyrolysis oil. The promotion of sHDSc-A in the pyrolysis process is attributed to the catalytic effect of the metal oxides in sHDSc-A. Among them, Al2O3 and Fe2O3 can promote decarboxylation of carboxylic acids and reduce O mobility, while MoO3 and Fe2O3 play a significant role in reducing coke and increasing pyrolysis oil. NiO can also promote methane vapor reforming, and thus increase the production of H2 in non-condensable gas. This study achieves self-circulation of oily sHDSc with a “waste-treatment-waste” strategy that presents the advantage of value-added energy recovery and waste reuse.

Co-pyrolysis of paper mill sludge and textile dyeing sludge with high calorific value solid waste: Pyrolysis kinetics, products distribution, and pollutants transformation

Paper mill sludge (PMS) and printing and textile dyeing sludge (TDS) are two typical industrial sludge with high calcium content, high ash content and low calorific value. To attain effective removal of industrial solid waste, in this study, PMS and TDS are first pyrolyzed independently to study their thermochemical behavior. Results show that 600 °C is the optimal pyrolysis temperature for both PMS and TDS from the perspective of organics degradation. However, the yield and quality of pyrolysis oil and gas are still at low level due to the characteristics of high ash content and low organic content, which is not suitable for fuel recovery. Two kinds of organic solid wastes with high calorific value, duckweed (DW) and waste tire (WT), are co-pyrolyzed with PMS and TDS, which can effectively reduce activation energy and increase the yield of liquid and gas products. The most prominent is P1D1 pyrolysis gas, the production of CH4 and C2-C3 increased from 10.80 L/kg and 3.89 L/kg to 20.16 L/kg and 15.58 L/kg respectively, and the high calorific value also increased to 230.93 kJ/kg. The quality of pyrolysis liquid has been improved significantly as the declined N and O-heteroatom content (especially for P1D1 and T1W1) due to the inhibition effect of co-pyrolysis on the N/O migration into pyrolytic liquid. The solid residue from the co-pyrolysis of PMS and DW contains rich N-functional groups and can promote the conversion of pyridinic-N and pyrrolic-N to quaternary-N. Compared with independent pyrolysis, co-pyrolysis can promote the degradation of harmful organic matter in sludge. The addition of DW and WT co-pyrolysis reduced the solid residue yield of PMS by 19.9 wt% and 14.9 wt% (13.4 wt% and 10.5 wt% for TDS). This work provides inspiration for further understanding the safe disposal of PMS and TDS by pyrolysis.