Solid Char Research Articles

Facile Synthesis of MgO Nanoparticle-Embedded Fe/N/S Codoped Carbon Materials from Oily Sludge for Efficient CO2 Capture

Oily sludge generated from the modern petrochemical industry is a large-scale hazardous solid waste. Pyrolysis with efficient catalysts is considered as a promising technology to convert the oily sludge into value-added chemicals or fuels without significant impact on the environment, but the solid char with spent catalysts does not find an application. In this study, the solid char obtained from catalytic pyrolysis of the oily sludge is applied as an adsorbent for CO2 capture. The char can be regarded as MgO nanoparticle-embedded Fe/N/S codoped carbon (MgO·FeOx@NSC) based on its structure and composition. MgO·FeOx@NSC presents a favorable performance toward CO2 capture. The maximum CO2 adsorption capacity is 4.57 mol/kg, and this value remains unchanged for more than 10 cycles of reuse. The mechanism for CO2 capture is analyzed with Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Physical adsorption and chemical interaction are identified as the primary contributors to the CO2 adsorption with MgO·FeOx@NSC, in which MgO, nitride-N, and sulfide-S are the main species contributing to the chemical interactions between CO2 and MgO·FeOx@NSC. This study will open up a new way for the sustainable management of hazardous organic solid wastes.

Producing eco-methane with raw syngas containing miscellaneous gases and tar by using a municipal solid waste char-based catalyst

Municipal solid waste pyrolysis char (MSWC) can be used as a catalyst carrier to support the synthesis of eco-methane from the syngas. In this paper, to understand the impacts of impurities in the raw syngas, the impacts of the H2/COx ratio, the H2O concentration, and the toluene concentration on methanation were investigated over a MSWC-supported Ni-based catalyst (Ni-MSWC). The varying H2/COx ratio in syngas affected CH4 and H2 concentrations in the final product. A lower H2/COx ratio corresponded to a higher CH4 concentration and a lower H2 concentration. The H2O concentration of less than 12% (vol.) in the syngas did not inhibit methanation, whereas excessive H2O was not favorable to the COx conversion; meanwhile, it destroyed the catalyst matrix by gasification. The Ni-MSWC catalyst showed a good tolerance to toluene (<100 g/Nm3), a representative of the tar. However, an excessively high concentration of toluene such as 200 g/Nm3 caused serious carbon deposition, significantly reducing CH4 yield. The introduction of H2O in 18% (vol.) in the syngas containing toluene (200 g/Nm3) alleviated carbon deposition by steam reforming of toluene; however, methanation was still inhibited. The results of this study provide guidance for the synthesis of eco-methane from the waste-derived syngas.

Effect of Fe impregnation on CO2-assisted pyrolysis of hazelnut shell

To find an economical and efficient way for mitigating CO2 emission, this study utilized CO2 as a reaction medium and investigated its influence on biomass pyrolysis. To this end, CO2-assisted pyrolysis of hazelnut shell (HS) and Fe-loaded HS (HSFe) was conducted using a thermogravimetric analysis (TGA) unit and a fixed-bed reactor. The temperature-programmed TGA tests demonstrated that there was no occurrence of the heterogeneous reaction between the solid char and CO2 at temperatures below 700 °C. However, the gaseous effluents evolved from the temperature-programmed pyrolysis of HS and HSFe in a fixed-bed reactor proved that CO2 played a mechanistic role in enhancing CO generation via the gas phase reactions (GPRs) between CO2 and volatile organic compounds (VOCs). Through the quantitative analysis of gas evolution rates, the CO production and the CO2 consumption in the GPRs always followed a stoichiometric relationship of about 2:1. A possible mechanism of the GPRs between CO2 and VOCs was proposed. Besides, Fe addition reduced the reaction temperatures of the GPRs between CO2 and VOCs by 120–160 °C, and significantly enhanced the reaction rate of these GPRs. As a result, the enhanced CO generation and the net CO2 consumption of HS loaded with 5 wt% Fe (HS5%Fe) in CO2 atmosphere were more than twice those of raw HS at temperatures above 500 °C. The XRD results revealed that Fe3O4 was the major chemical form of Fe species in HS5%Fe chars generated at temperatures ≥ 500 °C in CO2 atmosphere, which played a catalytic role in the GPRs between CO2 and VOCs.

Effect of phosphorylated lignin on flame retardancy of polypropylene‐based composites

AbstractPolypropylene (PP) is a synthetic polymer with excellent physical properties useful for various industries. However, its flammability in air limits its applications. In the present work, lignin filler was modified by phosphorylation, and characterized through chemical, structural, thermal, and morphological analyses. The resultant products were incorporated into PP to increase the flame retardancy of PP‐based composites. Although, the mechanical properties of the PP composites containing 30 wt% filler deteriorated, the tensile strength was maintained. An addition of phosphorylated lignin (pL) into PP decreased the heat release rate from 1136.5 to 777.2 kW/m2 and the total smoke release from 25.1 to 9.6 m2/m2. Furthermore, scanning electron microscopy images of the pL incorporated composites after the combustion test revealed that the solid char formed on the composites acted as a protective layer for PP. Thus, incorporating pL into PP is a feasible approach for improving its flame retardancy.

Solid Fuel Char Production via Pyrolysis Process of Oily Sludge Produced as a Resulted in Storage Tanks at North Refineries Company Baiji

The oily sludge contains a toxics material. It has an impact effect to the environment and worker’s health. Therefore, treatment the residue oily sludge in the refineries storage tanks and convert it to useful product, is an important task. Oily sludge (OS) sample was obtained from North Refineries Company (NRC) Baiji which produced about 3000-3500 m3/ year. In this study, different range of pyrolysis temperatures have been applied (300, 500, 700, and 900 °C). The parameters have been investigated the efficiency of char produced from OS. The operation conditions of (20 g, 700 °C, and 1.5 h, under N2 pressure) are investigated. The calorific value was enhanced from 9.125 to 17.247 MJ.kg-1 with an increased rate ~ 89.0 %. The fuel ratio was increased from 0.78 of OS to 0.97 around 24.35 % increased percentage of char at 700 °C. Finally, the energy recovery was enhanced at maximum value 1.909 % of char at 700 °C. The results show the fuel properties were upgraded to burn with a small amount of CO2.

Halogen‐Free Coatings Combined with the Synergistic Effect of Phytic Acid and Montmorillonite for Fire Safety Flexible Polyurethane Foam

AbstractTo overcome defects of some synthetic flame retardants, water‐based coatings using ammonium phytate (AP) and montmorillonite (MMT) as low‐cost renewable materials are fabricated to improve the flame retardancy of flexible polyurethane foam (FPUF). The flame‐retardant FPUF with uniform coatings can avoid melt‐dripping during the vertical flame test (UL‐94), and AP5MMT5/FPUF (flame‐retardant FPUF with the 5:5 weight ratio of AP:MMT in the solutions) reaches a UL‐94 V‐0 rating. A remarkable conclusion can be found that AP and MMT present a synergistic effect under the appropriate proportions. The thermal stabilities of flame retardant FPUF at higher temperature zones are enhanced. Furthermore, flame‐retardant samples prevent the flame from spreading on the surface of FPUF. Cone calorimetry results reveal 67% (AP5MMT5/FPUF) reduction of peak heat release rate relative to pure FPUF, and the release of toxic smoke significantly decreases. AP can catalyze the carbonation of FPUF, and MMT is heated and dehydrated to form a silicon‐containing barrier layer. AP/MMT coatings can form stable and solid physical char layers, which act as a barrier to heat and oxygen exchange, and the release of volatiles is delayed and inhibited. This work introduces a green plan for improving the fire safety of FPUF.

Effect of solvent and feedstock selection on primary and secondary chars produced via hydrothermal carbonization of food wastes

Hydrothermal carbonization is a thermochemical process that converts wet waste biomass into hydrochar, a renewable solid fuel that comprises a coal-like primary phase and an oily secondary phase. The varying oxidation rates of these phases may result in an inefficient energy recovery when combusting the hydrochar, as secondary char is more reactive. Brewer’s spent grain, dairy cheese whey and food waste were hydrothermally carbonized at 250 °C. The hydrochars were extracted using six solvents to evaluate the hydrochar partitioning between primary and secondary char phases. Feedstock nature and solvent selection impact the amount and composition of these phases detected. For lipid-rich feedstocks, ethanol extracts up to 50 wt% secondary char enriched in liquid fuel precursors from a solid primary char with enhanced coal-like characteristics. For substrates rich in carbohydrates, proteins, and lignocellulose, less secondary char is produced. Acetone and dichloromethane remove the oily secondary char and maximize primary char yield.

Steam reforming of biomass tar model compound over two waste char-based Ni catalysts for syngas production

The removal of biomass tar is the key technology in the pyrolysis and gasification technology, and the advantages of solid waste pyrolysis char in tar removal gradually become prominent. In this paper, the tar model compound (benzene) was catalytic reformed by a novel hybrid carrier catalysts using a laboratory dual-stage reactor. The hybrid carrier catalyst was prepared by wet impregnation method with nickel active substance, and the carrier was a two-material mixture of peat char and sludge char. In the reaction of steam reforming benzene, the effects of temperature (600–800 °C) and nickel load (5%–20%) on benzene conversion were investigated, showing that the catalyst have good benzene removal ability (91.8%) and the gas product with high syngas content (93.6%) was obtained. The surface properties of the catalyst was detected by SEM, EDS, BET and XRD detection, in order to prove that the catalytic performance was related to surface nanoparticles and abundant active sites. The novel hybrid carrier catalyst can effectively remove the aromatic tar and produce syngas with high performance.

The influence of char particle morphology on char burnout behavior by atomistic simulation

Bituminous coal char particles will differ in morphology, porosity, reactivity, and behavior within the zone II regime (where most practical system operates) due to the influence of maceral, rank, and time–temperature-histories. Effective boiler design requires simulations that appropriately capture char behavior. Most simulations, however, assume solid spherical particles that have homogeneous physical and chemical properties. Unfortunately, coal and time–temperature-history variations make it impossible to make a direct comparison of morphologies alone using traditional experimental approaches. Thus, here the influences of coal char morphologies on its reaction behavior and physical structure were explored via small-scale atomistic simulations. Three (ash-free) chars of solid, thick-, and thin-walled morphologies were examined. The atomistic representations had ∼ 143000 carbon atoms, comprised of similar polycyclic aromatic hydrocarbons (PAH) sizes and stacking distributions. While these structures are far below the actual particle size, the approach permits a direct comparison with a level of control not possible via physical experimentation. The densities of the thick- and thin-walled char models were similar to literature observations (apparent and helium densities). The specific surface area for the solid, thick-, and thin-walled char models were 110, 368, and 509 m2/g, with the latter two being closer to experimental data. A simplified combustion simulation (diffusion and oxygen proximity calculations) demonstrated that the char morphology had a significant impact upon their relative reactivities. The thin-walled structure had the highest overall reactivity due to greater reactive surface access, while the solid and thick-walled structure was respectively 27 and 23% lower. The reaction rate profiles with char conversion for these three structures are close to the experimental observations for pulverized bituminous coal chars, where the rate peak occurs at ∼ 20% conversion. The changes in char size, density, and specific surface area (with char conversion) indicated the thick-walled structure was more similar to the literature data. These atomistic approaches have the potential to aid in exploring the reaction behavior of char particles with various morphologies and complicated structures. With scale-up additional behaviors such as particle fragmentation and ash behavior could be incorporated.

Modeling and optimization of an algal-based sewage treatment and resource recovery (STaRR) system

This paper presents modeling and optimization of an algal-based sewage treatment and resource recovery (STaRR) system composed of the following subprocesses: S,1) mixotrophic algal sewage treatment; S,2) hydrothermal liquefaction (HTL) of the resulting algal biomass; S,3) phosphorus recovery from the solid HTL char via leaching and precipitation; and S,4) nitrogen recovery from the HTL aqueous phase via a gas-permeable membrane (GPM). Specific models for the above subprocesses have been developed and validated in previous studies. Here, those models are integrated to optimize the STaRR system based on operating cost and profit to reduce wastewater treatment costs. The following operational conditions were identified as optimal for the STaRR system: 1) fed-batch cycle time of 3 d for S,1; 2) temperature of 350 °C, process time of 1 h, and biomass content of 20 wt% for S,2; 3) temperature of 60 °C, process time of 72 h, alkali concentration of 0.5 M NaOH, alkali eluent-to-char (L:S) ratio of 20 with mixing at 20 rpm to recover calcium phosphate in S,3; and 4) process time of 70 h and a membrane area:feed volume ratio of 2.32 m2/m3 for S,4. Under these optimal conditions, the STaRR system incurred 20% lower operating costs than the pre-optimization version with a different P recovery process and without N-recovery via GPM. The optimized STaRR system recovered 69.1 ± 2.4% of P in the primary effluent as calcium phosphate and 42.9 ± 1.9% of N as ammonium sulfate at an operating cost of $0.20/m3 of primary effluent.

Ultra-highly porous carbon from Wasted soybean residue with tailored porosity and doped structure as renewable multi-purpose absorbent for efficient CO2, toluene and water vapor capture

Renewable and cost-efficient absorbent is of continuous interest to address the challenges induced by greenhouse gas and volatile organic chemicals (VOCs). Inspired by the needs for pyrolysis valorization of organic solid wastes, this work reported the synthesis of series of super-developed porous carbons with specific surface area and total pore volume up to 4293 m2/g and 2.52 cm3/g, respectively, via easily scalable KOH activation of pyrolysis char from waste soybean residue. By finely regulating the synthesis parameters, the resultants offered tunable porosity and surface chemistry for exceptionally high CO2/N2 selectivity (308 by Henry's Law at 298 K) and ultrahigh absorption capacity toward toluene (1587 mg/g under P/P0 of 0.99 and 25 °C) and water vapor (2187 mg/g under P/P0 of 0.9–1 and 25 °C). These features made them competitive candidates as physical absorbents for CO2 capture, VOCs removal and dehumidification. Furthermore, the CO2 molecules generally experienced adsorption at ultramicropores and doped sites, in addition to stacking in larger pore space under higher pressure. By contrast, the hierarchical porosity offered extensive surface and space for vapor adsorption, whilst those aromatic and oxygenic structures at surface may further interact with non-polar toluene and polar H2O, respectively. The current products can be envisioned with a broader application in gas separation given the findings here. Besides, conversion of solid char instead of directly the raw biomass waste is worthy of both academic and industrial focuses toward optimal valorization of biomass waste.

Recovery, separation and production of fuel, plastic and aluminum from the Tetra PAK waste to hydrothermal and pyrolysis processes.

The establishment of a method of separation of materials from Tetra Pak waste to obtain products for use as raw material, fuel or other purposes was investigated in this study. First, the feasibility of hydrothermal treatment for the production of a solid fuel (hydrochar) and solid fraction formed by polyethylene and aluminum, called composite was analyzed. The results indicated that hydrothermal treatment performed at 240°C yield the formation of hydrochar with good properties for its use as fuel and a composite of polyethylene and aluminum. The best conversion and separation of the cardboard and polyethylene/aluminum were obtained using 120min as operating time. Then, the recovery of the aluminum fraction from the composite by using spent olive oil waste was studied. A partial separation of the composite layers (polyethylene and aluminum) was accomplished with improved aluminum purity for higher operating temperatures. Finally, the operating conditions of the pyrolysis process for the production of a solid (char) and high purity composite (aluminum) were optimized. The characterization results indicated that both char and aluminum resulting from the pyrolysis of the Tetra Pak at 400°C still have a significant amount of polyethylene while higher purity levels of aluminum can be obtained at temperatures equal of higher than 500°C.

Green production of ammonia from nitrogen-rich biomass pyrolysis: Evolution of fuel-N under H2-rich atmosphere

Ammonia (NH3) is an emerging carbon-free energy carrier. A sustainable route for NH3 production is proposed in this work via pyrolysis process of nitrogen-rich renewable resources. Microalgae, the carbon-neutral and renewable resource with a high content of nitrogen, were selected in this work. H2 was used as a reinforcing agent to enhance NH3 production. The influence of H2 on the fuel‑nitrogen transfer during the microalgae pyrolysis was experimentally investigated. The formation and conversion pathways of the N-containing species in bio-char, bio-oil and gaseous products were evaluated. Results indicate that H2 promotes the nitrogen transformation into gaseous products, while reduces the contents of the nitrogen in solid char and bio-oil. Meanwhile, H2 greatly promotes the conversion of protein-N to pyridinic-N, pyrrolic-N and quaternary-N in biochar, but also facilities the formation of N-heterocyclic compounds in bio-oil. Pyrolysis temperature is an important factor affecting the distribution and conversion of N-containing species. NH3 and HCN yields increase gradually with temperature. H2 is beneficial for the thermal cracking of stable proteins, the deamination of amides, and the ring-opening of N-heterocyclic species, thereby facilitating the formation of NH3. The highest NH3 yield of 37.34 wt% is obtained at 800 °C under 15%H2 + 85%Ar atmosphere.

Reaction kinetics, mechanism, and product analysis of the iron catalytic graphitization of cellulose

Biomass based porous graphitic carbon are valuable materials in terms of renewable energy and environmental remediation; however, the catalytic graphitization mechanism of biomass and the solid char evolution process have not been comprehensively studied. Therefore, iron catalytic graphitization process of cellulose was investigated and the reaction kinetics, thermodynamics, pyrolytic behavior, and product properties analyzed in detail. It was found that iron addition lowered cellulose decomposition temperature, but higher average activation energy (230 kJ/mol), and higher entropy (100 J/mol). In-situ-produced Fe3C and Fe promoted secondary reactions and activated C–H bonds, which led to an increase in the production of hydrogen and solid char from 2.9 mmol/g to 8.1 mmol/g and 6.3 wt% to 19.9 wt%, respectively, at the expense of the liquid oil yield. Furthermore, the iron addition promoted the degree of graphitization and etched porosity. The intrinsic reaction kinetics, thermodynamics, and technical analysis reported herein may guide the application of bioenergy for the preparation of porous graphite and hydrogen.

Energy conversion performance in co-hydrothermal carbonization of sewage sludge and pinewood sawdust coupling with anaerobic digestion of the produced wastewater

Energy conversion and utilization of sewage sludge (SS) and lignocellulosic biomass are an important measure to deal with environmental pollution and resource utilization. Addressing the waste by-product in a clean way is essential. In this study, solid char fuel (hydrochar) was obtained through co-hydrothermal carbonization of SS with pinewood sawdust (PS), and methane gas was obtained through anaerobic digestion (AD) of hydrothermal carbonization wastewater (HTCWW). The energy conversion performance of the feedstock organics under different HTC conditions (temperature of 160 °C, 220 °C, and 280 °C; reaction time of 0, 2, and 4 h; feedstock liquid–solid mass ratio of 4:1, 10:1, and 16:1), and the mass and energy yields of hydrochar and methane and their influencing factors were emphasized. More than 60% of the energy in SS and PS can be recovered by coupling the HTC-AD process. With the increase in hydrothermal reaction temperature and reaction time, the mass yield of hydrochar decreased, but the higher heating value increased. The maximum energy yield of hydrochar was 86.47% under the HTC temperature of 160 °C, liquid–solid ratio of 10:1, and reaction time of 2 h. The HTCWW obtained at a lower temperature (160 °C) showed the highest cumulative methane yield of 304.16 mL-CH4/g-COD.

Aging characteristics of asphalt binders modified with waste tire and plastic pyrolytic chars.

Globally, the growing volume of waste tires and plastics has posed significant concerns about their sustainable and economical disposal. Pyrolysis provides a way for effective treatment and management of these wastes, enabling recovery of energy and produces solid pyrolytic char as a by-product. The use of pyrolytic chars in asphalt binder modification has recently gained significant interest among researchers. As asphalt binder aging influences the cracking, rutting, and moisture damage performance of asphalt binder and the mixtures, evaluation of aging characteristics of char modified asphalt binders is quite important. The main objective of this study is the investigation of the aging characteristics of asphalt binders modified with waste tire pyrolytic char (TPC) and waste plastic pyrolytic char (PPC) through rheological and spectroscopic evaluations. To imitate short-term and long-term aging conditions, the asphalt binders were first treated in a rolling thin film oven (RTFO) and then in a pressure aging vessel (PAV). The aging characteristics were determined using four rheological aging indices based on complex modulus (G*), phase angle (δ), zero shear viscosity (ZSV), and non-recoverable creep compliance (Jnr) from multiple stress creep and recovery (MSCR) test. The fatigue cracking potential was then measured through binder yield energy test (BYET). These parameters were measured through a dynamic shear rheometer. Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy analyses were then used to investigate changes in chemical composition due to aging in the char modified binders. Both TPC and PPC improved the high-temperature deformation resistance properties of asphalt binder. The TPC-modified binder showed better aging resistance than the control and PPC-modified binders, based on the different rheological and spectroscopic indices. The pyrolytic char modified binders also demonstrated good fatigue performance.

Experimental investigation on the influence of novel catalyst in co-pyrolysis of polymeric waste: Characterization of oil and preparation of char reinforced composites

A massive challenge in handling and disposing the polymeric waste, generated by the growing human population and continuous development, has been faced currently as a result of human negligence. Fortunately, among many methods to deal with the problem of increasing polymer debris in the environment, pyrolysis stands out due to its efficiency and accessibility. In the present study, automobile plastic scrap (APS) and tyre crumb rubber (TCR) materials as a combination were subjected to co-pyrolysis using a novel catalyst (NOVC-FZP) that was synthesized using ferrocene and zeolite as precursors. Thermogravimetric analysis (TGA) of the raw materials (APS and TCR) shows single-stage decomposition at 402 °C and 340 °C, respectively. Gas chromatography-mass spectroscopy (GC-MS) analysis confirms higher production of the hydrocarbon (HC) groups in the oil with NOVC-FZP as compared to the neat oil (without NOVC-FZP). The cetane index of the oil with NOVC-FZP was found to be 22 and the calorific value of the same was 9162 Cal/g. A very high proportion of gasoline (86.8% of oil) was found in the oil resulting from the catalyzed pyrolysis. Solid product char (SPC) obtained through pyrolysis was incorporated into linear low-density polyethylene (LLDPE) to form LLDPE/SPC composite (LCC) for use in several applications rather than disposing it off. Higher mechanical properties like tensile strength, hardness as well as enhanced dielectric constant were exhibited by the prepared LCC.

Investigation of the combustion behaviors and kinetic modelling of municipal solid waste char under isothermal conditions using a micro-fluidized bed

Approaches to the accurate measurement of combustion kinetics are essential for the numerical simulation, reactor design and process optimization of MSW-fired systems. The micro-fluidized bed reaction analyzer (MFBRA), which consisted of a micro-fluidized bed reactor and electrical control devices, was applied in the investigation of the combustion behaviors and kinetic modelling of noodles char (NC) and bamboo chopsticks char (BC). And the kinetics obtained from the thermogravimetric analyzer (TGA) were compared. The results indicated that the TGA might not fully meet the requirement for kinetic study of MSW char combustion due to the temperature deviation and prolonged testing time. Besides, the lower activation energy suggested insufficient heat and mass transfer in TGA. The combustion rate was strongly temperature dependent in MFBRA and BC exhibited around two times higher reactivity than NC. The combustion behavior would transfer from chemically controlled regime into pore diffusion controlled regime at 973 K for NC, and 923 K for BC. Volumetric reaction model (VRM) would overestimate the combustion rate due to the active surface variation during combustion. In contrast, random pore model (RPM) could well predict the conversion process for both samples at high temperatures, which might correspond to the pore enlargement and coalescence. The obtained activation energies of NC and BC combustion in the chemically controlled regime were 56.12 and 48.73 kJ/mol, respectively. Therefore, elevating the oxygen partial pressure and increasing the feeding rate were feasible ways for acquiring fast combustion rate of MSW char as a result of good reactivity in industrial applications.

Inhibitory and synergistic effects on thermal behaviour and char characteristics during the co-pyrolysis of biomass and single-use plastics

The co-pyrolytic behaviour of single-use plastics (Polystyrene, Low-density polyethylene) and Eucalyptus biomass was investigated at variable temperatures (300, 400, 500, and 600 °C) and the effects of their interactions on the characteristics of solid chars were also studied. The variation in thermal profiles of ‘Δ Mass loss%’ showed the inhibitory and synergistic effects of plastics on the biomass degradation, resulting in higher and lower yields of char composite, respectively. The blend containing polystyrene exhibited the highest synergistic (Δ M ≈ 15.1) and inhibitory (Δ M ≈ - 4) effects. The thermal kinetics of blends also indicated the presence of both the effects through relatively higher and lower apparent activation energies compared to the calculated, before and during the degradation of plastics. Despite low fixed carbon contents and high volatile matter, polymer-coated char composites had higher fuel value indices (36–136%), energy yields (1–26%) and calorific values (15–21%), relative to biochar. After the complete degradation of plastics, char composites exhibited higher values of electrical conductivity (2–40%), surface area (15–64%), and cation exchange capacity (5–19%). These properties advocate the flexibility of char composites' applicability as solid fuel or soil amender depending on the optimized conditions of co-pyrolysis.

Pyrolysis of Solid Waste for Bio-Oil and Char Production in Refugees’ Camp: A Case Study

The current research focuses on assessing the potential of municipal solid waste (MSW) conversion into biofuel using pyrolysis process. The MSW samples were taken from Zaatari Syrian Refugee Camp. The physical and chemical characteristics of MSW were studied using proximate and elemental analysis. The results showed that moisture content of MSW is 32.3%, volatile matter (VM) is 67.99%, fixed carbon (FC) content is 5.46%, and ash content is 24.33%. The chemical analysis was conducted using CHNS analyzer and found that the percentage of elements contents: 46% Carbon (C) content, 12% Hydrogen (H2), 2% Nitrogen (N2), 44% Oxygen (O2), and higher heat value (HHV) is 26.14 MJ/kg. The MSW pyrolysis was conducted using tubular fluidized bed reactor (FBR) under inert gas (Nitrogen) at 500 °C with 20 °C/min heating rate and using average particles size 5–10 mm. The products of MSW pyrolysis reaction were: pyrolytic liquid, solid char, and gaseous mixture. The pyrolytic oil and residual char were analyzed using Elemental Analyzer and Fourier Transform Infrared Spectroscopy (FTIR). The results of FTIR showed that oil product has considerable amounts of alkenes, alkanes, and carbonyl groups due to high organic compounds contents in MSW. The elemental analysis results showed that oil product content consists of 55% C, 37% O2, and the HHV is 20.8 MJ/kg. The elemental analysis of biochar showed that biochar content consists of 47% C, 49% O2, and HHV is 11.5 MJ/kg. Further research is recommended to study the effects of parameters as reactor types and operating conditions to assess the feasibility of MSW pyrolysis, in addition to the environmental impact study which is necessary to identify and predict the relevant environmental effects of this process.