Hydrocarbon Selectivity Research Articles

Novel catalyst configuration to boost the yield of longer hydrocarbons from methanol-mediated CO2 hydrogenation

Various C1 feedstocks and lower hydrocarbons (C2-C4) can be produced from CO2 hydrogenation, which is an important way to utilize excess CO2 and provide alternative fuel options for dwindling fossil fuels. Herein, a novel two-bed catalytic system was developed to increase the yield of liquid range hydrocarbons, where the first catalytic bed was composed of In2O3-ZrO2 (13 wt. In %)/HZSM-5 and the second bed was a desilicated HZSM-5 placed downstream from the first bed. A maximum hydrocarbon selectivity was found to be about 86% with 7.2% CO2 conversion at 533 K, while conversion increased up to 19.3% with 71.2% hydrocarbon selectivity at 623 K while keeping the pressure at 4.0 MPa. The selectivity of longer liquid range hydrocarbons (C8-C12) was increased from 29.2% to 42.4% using the oligomerization process in which the produced lower olefins from the first bed were oligomerized to enhance the liquid range hydrocarbon over desilicated HZSM-5. Additionally, a comparative study was carried out to examine the effect of desilication over HZSM-5 having different silica-to-alumina ratios of 24 and 59. Moreover, detailed characterizations were carried out before and after the desilication of the HZSM-5 to correlate catalytic activities with physical and chemical properties of the catalysts. The results suggest that a two-bed catalytic system is a promising option to increase the yield of liquid range hydrocarbons from methanol-mediated CO2 hydrogenation while there was a negligible effect on CO2 conversion due to the second bed.

Hydrodeoxygenation of stearic acid over zeolite–MOF composite-supported Pt catalysts

Herein, we report the synthesis of a series of zeolite-porous metal–organic framework (MOF) (ZM) composites with different Pt loadings via a two-step approach, in which –COOH functionalized ZSM-5 particles were added during the formation of MIL-100(Fe) (Materials Institute Lavoisier) by a microwave-assisted solvothermal method. The acidity of the ZM composites was significantly improved compared to that of the parent materials, and the highest acidity was observed for the ZM2-based catalyst. This ZM composite-supported Pt (Pt/ZM) catalyst was investigated as a promising candidate for the selective hydrodeoxygenation (HDO) of stearic acid as a fatty acid model compound. The effect of zeolite/MOF ratio and Pt content on the catalytic behavior was also evaluated. As a result, the 3% Pt/ZM2 catalyst showed a conversion efficiency of 92% for the stearic acid HDO with a hydrocarbon selectivity of 10–11 times higher than that of the original Pt/MIL-100 (Fe). In addition, 3% Pt/ZM2 catalyst exhibited stable catalytic performance for stearic acid HDO during the recycle runs. The optimized Pt/ZM catalyst showed high thermal and catalytic stability, as well as high product yield.

Enhanced conversion of syngas to high-quality diesel fuel over ZrO2 and acidized carbon nanotube bifunctional catalyst

Direct syngas conversion for diesel fuel becomes an attractive route for its possibility of utilizing non-petroleum carbon resources. However, there is a limited selectivity of around 36% for diesel hydrocarbons (C9-C22) via the conventional Fischer-Tropsch process due to the Anderson-Schulz-Flory (ASF) constraint. Herein, bifunctional catalysts composed of zirconium dioxide (ZrO2) dispersed on multi-walled carbon nanotubes (CNT) (ZrO2/CNT) were successfully designed and applied for direct conversion of syngas into diesel with selectivity far beyond the ASF limitation. At 350 °C with the pressure of 3 MPa, H2/CO of 2 and gas hourly space velocity of 2400 mL·h−1·gcat−1, ZrO2/CNT gave an unexceptionable C9-C22 selectivity of 50.74% at a single pass CO conversion of 43.86% compared with those (9.11% and 20.55%, respectively) of ZnO/CNT and those (14.07% and 25.76%, respectively) of ZnO-ZrO2/CNT. The iso/n-paraffin ratio in the C9-C22 reached up to 16. Moreover, after 100 h of operation, the catalyst still showed remarkable catalytic activity with CO conversion remaining at 40.61%, diesel hydrocarbon selectivity, and methane selectivity at 42.27% and 7.67%, respectively, while the by-product CO2 selectivity was also stable at about 3.77%.

Conversion of low-density polyethylene into monocyclic aromatic hydrocarbons through continuous microwave pyrolysis with ex-situ dual-catalyst beds

The single-use of polyolefins-based individual protective equipment has led to the rapid generation of substantial plastic waste. This study aimed at cleaner disposal of the polyolefin waste, and carried out the continuous microwave pyrolysis (CMP) of low-density polyethylene (LDPE) over dual-catalyst beds of MCM-41 and HY. The dual-catalyzed trial was able to produce more condensate fractions with higher selectivity of monocyclic aromatic hydrocarbons (MAHs), compared with using only MCM-41 or HY zeolite. It was because the larger pore size of the MCM-41 catalyst (4.00 nm) could crack long-chain polyolefin intermediates into shorter chains. This alleviates steric and diffusional resistance while entering and exiting the micropores of the HY zeolite (0.74 × 0.74 nm). The maximum liquid yield (63.75 wt%) and MAHs selectivity (78.21%) were achieved at a catalysis temperature of 450 °C, feedstock to catalyst ratio of 8:3, and HY to MCM-41 ratio of 2:1. In addition, the performance of the CMP reactor was also compared favorably with the batch microwave pyrolysis (BMP) reactor under the same conditions. It has been found that the CMP reactor generated more MAHs products, whereas the BMP reactor was more selective for the generation of polycyclic aromatic hydrocarbons (PAHs) and gas products. The combination of CMP and the co-catalysis process offers new insight into sustainable management and value-added recovery of medical plastic waste.

A Core-Shell Structured Na/Fe@Co Bimetallic Catalyst for Light-Hydrocarbon Synthesis from CO2 Hydrogenation

The direct CO2 Fischer–Tropsch synthesis (CO2-FTS) process has been proven as one of the indispensable and effective routes in CO2 utilization and transformation. Herein, we present a core-shell structured Na/Fe@Co bimetallic catalyst to boost CO2 conversion and light hydrocarbon (C2 to C4) selectivity, as well as inhibit the selectivity of CO. Compared to the Na/Fe catalyst, our Na/Fe@CoCo-3 catalyst enabled 50.3% CO2 conversion, 40.1% selectivity of light hydrocarbons (C2-C4) in all hydrocarbon products and a high olefin-to-paraffin ratio (O/P) of 7.5 at 330 °C and 3.0 MPa. Through the characterization analyses, the introduction of CoCo Prussian Blue Analog (CoCo PBA) not only increased the reducibility of iron oxide (Fe2O3 to Fe3O4), accelerated the formation of iron carbide (FexCy), but also adjusted the surface basic properties of catalysts. Moreover, the trace Co atoms acted as a second active center in the CO2-FTS process for heightening light hydrocarbon synthesis from CO hydrogenation. This work provides a novel core-shell structured bimetallistic catalyst system for light hydrocarbons, especially light olefin production from CO2 hydrogenation.

Evaluation of MgO as a promoter for the hydrogenation of CO2 to long-chain hydrocarbons over Fe-based catalysts

Thermocatalytic conversion of CO2 into liquid fuels and chemicals is a promising approach to mitigate global warming. Although, the CO2 conversion and long-chain hydrocarbon selectivity are highly dependent on the choice of metal-oxide promoter, but role of the promoter remains unclear. Herein, the role of MgO as a promoter for an Fe-based catalyst was investigated. Bimetallic Na-FeMgOx catalyst exhibited a high C5+ yield of 25.1% with a CO2 conversion of 49.1% at the early stage of the reaction. The presence of MgO facilitates the reduction of Fe oxides and formation of oxygen vacancies by transferring electrons to Fe-based phases. In addition, at the early stage of reaction, the decoration of the Mg oxide surface with nanosized χ-Fe5C2 enhances the C5+ yield. However, the progressive transformation of MgO to MgCO3 during CO2 conversion deactivates the Na-FeMgOx catalyst. A detailed deactivation mechanism is also discussed.

Fe- and Cu–Zn-Containing Catalysts Based on Natural Aluminosilicate Nanotubes and Zeolite H-ZSM-5 in the Hydrogenation of Carbon Dioxide

Iron- and Cu–Zn-containing carbon dioxide hydrogenation catalysts based on natural aluminosilicate nanotubes and zeolite H-ZSM-5 are synthesized. Their textural and acidic properties are studied via low-temperature nitrogen adsorption–desorption, temperature-programmed desorption of ammonia, temperature-programmed reduction of hydrogen, and elemental analysis. The effect the temperatures of the reaction have on the conversion of CO2 and distribution of its product is studied. Catalysts based on aluminosilicate halloysite nanotubes exhibit methanol and С2–С4 hydrocarbon selectivities of 88 and 16%, respectively.

Effect of K-promoter use in iron-based plasma-catalytic conversion of CO2 and CH4 into higher value products

In the new field of plasma-catalytic synthesis, iron-based catalysts have been intensively studied but no study was reported on the use of potassium promoter although it is widely used in thermo-catalytic synthesis. In this frame, we study the effect of K-promoter on iron-based plasma-catalytic conversion of CO2 and CH4 into higher value products, through a series of experiments with and without potassium. As expected, K-promoter increases the selectivity of unsaturated hydrocarbons but also that of long-chain oxygenates (C3 + acids and alcohols), by changing the H-adsorption property of the catalyst. Based on this selectivity tuning way, this paper proposes a first process optimization attempt for maximizing at the same time the production of liquid products and the share of unsaturated hydrocarbons. Coproduction of high quality syngas (H2/CO∼2.0), C2 + hydrocarbons and C1 + oxygenates with 5.10% CO2 and 12.65% CH4 conversions, 21.76% liquid selectivity and unsaturated over saturated hydrocarbons ratio close to 1.

Efficient solvent- and hydrogen-free upcycling of high-density polyethylene into separable cyclic hydrocarbons.

Plastic pollution is a planetary threat that has been exacerbated by the COVID-19 pandemic due to the surge in medical waste, personal protective equipment and takeaway packaging. A socially sustainable and economically viable method for plastic recycling should not use consumable materials such as co-reactants or solvents. Here we report that Ru nanoparticles on zeolitic HZSM-5 catalyse the solvent- and hydrogen-free upcycling of high-density polyethylene into a separable distribution of linear (C1 to C6) and cyclic (C7 to C15) hydrocarbons. The valuable monocyclic hydrocarbons accounted for 60.3 mol% of the total yield. Based on mechanistic studies, the dehydrogenation of polymer chains to form C=C bonds occurs on both Ru sites and acid sites in HZSM-5, whereas carbenium ions are generated on the acid sites via the protonation of the C=C bonds. Accordingly, optimizing the Ru and acid sites promoted the cyclization process, which requires the simultaneous existence of a C=C bond and a carbenium ion on a molecular chain at an appropriate distance, providing high activity and cyclic hydrocarbon selectivity.

Hydrocarbon selectivity enhancement through catalytic fast co-pyrolysis of almond shell and plastic blends

BackgroundThe aim of this article is to explore possible pathways for the synergistic optimization of bio-oil by the catalytic fast co-pyrolysis of almond shell (AS) and plastic residues (polyethylene, PE, and polystyrene, PS). Pyrolysis was carried out at 650 °C at a heating rate of 20 °C/ms at a residence time of 20 s. Hydrogen from the plastic promoted the decarboxylation of acids and decarbonylation of carbonyls and sugars from biomass waste.ResultsCo-pyrolysis results showed a fall in oxygen in the AS/plastics blends, whereas carbon yields increased as did the calorific value of the oil. As expected, AS/PE blends enhanced production of hydrocarbon fractions, especially olefins, with yields reaching 81.1%, whereas AS/PS blends enhanced formation of aromatic compounds. HZSM-5 assisted the increase of monocyclic aromatics content in AS/PE blends. AS/PS blends favoured the increased of aromatics (45% of total hydrocarbons for 1:2 AS/PE-HZ). For AS/PS-HZ blends toluene was enhanced as was the production of 1,3,5-cycloheptatriene.ConclusionsThese findings helped to gain a great insight into how catalytic co-fast pyrolysis of feedstocks can enhance the formation of value-added products, promoting their economic potential for agricultural exploitations.Graphical

Hollow ZSM-5 encapsulated with single Ga-atoms for the catalytic fast pyrolysis of biomass waste

The development of efficient metal-zeolite bifunctional catalysts for catalytic fast pyrolysis (CFP) of biomass waste is highly desirable for bioenergy and renewable biofuel production. However, conventional metal-loaded zeolites often suffer from metal sintering during pyrolysis and are thus inactivated. In this study, single-site Ga-functionalized hollow ZSM-5 (GaOx@HS-Z5) was synthesized via an impregnation-dissolution-recrystallization strategy without H2 reduction. The Ga atom was coordinated to four oxygen atoms in HS-Z5 frameworks. Benefitting from the highly dispersed single-Ga atoms and hollow zeolite framework, 3GaOx@HS-Z5 performed the best in producing hydrocarbon-rich bio-oil compared to impregnated 3GaOx/HS-Z5 and H2-reduced 3Ga@HS-Z5 in the maize straw CFP. In particular, 3GaOx@HS-Z5 delivered the highest bio-oil yield (23.6 wt%) and hydrocarbon selectivity (49.4 area%). 3GaOx@HS-Z5 also retained its structural integrity and catalytic activity after five pyrolysis-regeneration cycles, demonstrating its advantage in practical biomass CFP. The elimination of H2 reduction during the synthesis of catalyst provides an additional advantage for simplifying the CFP process and reducing operating costs. The retained Ga micro-environment and anti-sintering properties were unique for 3GaOx@HS-Z5, as severe metal sintering occurred during pyrolysis for other metals (e.g., NiOx, ZnOx, FeOx, and CoOx) that encapsulated HS-Z5.

Co-hydropyrolysis of pine and HDPE over bimetallic catalysts: Efficient BTEX production and process mechanism analysis

Co-pyrolysis of plastics and biomass is expected to replace traditional petroleum processing to produce BTEX (benzene, toluene, ethylbenzene, and xylenes) on a large scale, which are important chemical raw materials. The introduction of bimetallic catalysts and hydrogen in co-pyrolysis systems is an effective strategy to increase the content of aromatic hydrocarbons in pyrolysis oils, which has not been studied so far. The present study investigated the efficacy of bimetallic catalysts in enhancing aromatization and Diels-Alder reactions in comparison to Mo/ZSM-5. The synergistic interaction between bimetals contributed to the improved selectivity of aromatic hydrocarbons, particularly BTEX. Results revealed that NiMo/ZSM-5 catalysts led to higher aromatics selectivity in liquid oil, whereas FeMo/ZSM-5 resulted in higher BTEX selectivity in aromatic hydrocarbons. Moreover, metal oxide-supported bimetallic catalysts exhibited lower selectivity for aromatic hydrocarbons in liquid oil, despite facilitating higher liquid-oil yield. Among the metal oxide-supported bimetallic catalysts, FeMo/TiO2 demonstrated the highest selectivity (56%) for aromatic hydrocarbons in liquid oils. The introduction of hydrogen resulted in 100% selectivity of BTEX in aromatic hydrocarbons, thus highlighting the significance of hydrogenation in enhancing the selectivity of BTEX. Combined with the experimental results and literature, a possible reaction mechanism was also proposed.

Hydrodeoxygenation of safflower oil over cobalt-doped metal oxide catalysts for bio-aviation fuel production

The catalytic hydrodeoxygenation process provides an alternative route for the production of renewable jet fuel, which can directly replace petroleum-derived hydrocarbons. To this end, the catalytic performance of Co-based catalysts supported by different metal oxides, γ-Al2O3, TiO2, ZnO and ZrO2 was tested to evaluate their catalytic activity and product selectivity in hydrodeoxygenation of safflower oil. The results indicated that catalytic performance changed in response to acidity, morphologies and particle size of catalysts. Benefiting from these combined characteristics, Co/ZnO catalyst exhibited a highly catalytic activity, being capable of producing jet fuel-range hydrocarbon selectivity of 65.96% under reaction parameters of 350 °C of reaction temperature, 8 h of reaction time and 75 bar of H2 initial pressure. In addition to superior activity, the coke content of Co/ZnO was much lower compared to other employed catalysts thereby affecting the stability of the catalyst and resulting in less deactivation and coke formation.

Facet-Controlled Cu-doped and K-promoted Fe2O3 nanosheets for efficient CO2 hydrogenation to liquid hydrocarbons

Hydrogenation of CO2 into liquid hydrocarbons is an attractive route for chemical utilization of CO2, but suffers from limited product selectivity. By controlling the exposed surface atoms of metal catalyst, purposefully enhancing the reaction rate of bottleneck steps for CO2 activation and C-C coupling is expected to solve this problem. Here, we tuned the exposed surface atoms of catalysts separately and simultaneously by facet control, doping and promoter modification; a nanosheet-shaped Fe2O3 rich in oxygen vacancies was first constructed to enhance the adsorption and activation of CO2. Cu doping and K promoter were further used to promote the formation of active χ-Fe5C2 phase and facilitate the coupling of C-C bond to form long chain fuels. The optimized K-promoted and Cu-doped Fe2O3 nanosheets (3 K/6Cu-Fe-S) exhibited high CO2 conversion (46.5%) and C5+ hydrocarbons selectivity (53.6%), accompanied with low CO (5.3%) and CH4 selectivity (12.2%) at 300 °C, outperforming other reported Fe-based catalysts significantly. Meanwhile, a 205 h on stream test indicated the excellent stability of 3 K/6Cu-Fe-S. The effects of each tuning method on catalytic activity and product selectivity were further studied by combining the change of the phase and surface electronic structure of the catalyst before and after the reaction. Cu doping and K promoter were verified to have a synergistic enhancement effect on the hydrogenation performance of CO2, rather than just the sum of the two. These findings would be beneficial for the rational design of CO2 hydrogenation catalysts.

Pyrolysis of Rice husk, Coconut shell, and Cladophora glomerata algae and application of the produced biochars as support for cobalt catalyst in Fischer–Tropsch synthesis

The performance of bio chars prepared from Rice husk, Coconut shell, and Cladophora glomerata algae as Fischer–Tropsch synthesis (FTS) cobalt catalyst support is investigated. The biochars are synthesized through the pyrolysis process. The three substrates were activated precisely at a specific temperature and time. 15 wt% cobalt catalysts were prepared by impregnation method. The physicochemical properties of catalysts were assessed using different techniques. The activity and selectivity of catalysts were studied in a fixed bed micro reactor at 220 °C, H2/CO ratio of 2, feed flow rate of 60 mL/min, 2 MP pressure and 14–16 h reduction on 400 °C. The catalytic performance of biochars supported cobalt catalysts was evaluated and compared with a γ-Alumina supported industrial catalyst. The modified algae biochar supported cobalt catalyst showed the highest FTS rate of 0.345 g HC/(g cat. h) and 67% CO conversion. While, C5+ liquid hydrocarbons selectivity showed a slight decrease.

Co0 -Coδ+ Interface Double-Site-Mediated C-C Coupling for the Photothermal Conversion of CO2 into Light Olefins.

Solar-driven CO2 hydrogenation into multi-carbon products is a highly desirable, but challenging reaction. The bottleneck of this reaction lies in the C-C coupling of C1 intermediates. Herein, we construct the C-C coupling centre for C1 intermediates via the in situ formation of Co0 -Coδ+ interface double sites on MgAl2 O4 (Co-CoOx /MAO). Our experimental and theoretical prediction results confirmed the effective adsorption and activation of CO2 by the Co0 site to produce C1 intermediates, while the introduction of the electron-deficient state of Coδ+ can effectively reduce the energy barrier of the key CHCH* intermediates. Consequently, Co-CoOx /MAO exhibited a high C2-4 hydrocarbons production rate of 1303 μmol g-1 h-1 ; the total organic carbon selectivity of C2-4 hydrocarbons is 62.5 % under light irradiation with a high ratio (≈11) of olefin to paraffin. This study provides a new approach toward the design of photocatalysts used for CO2 conversion into C2+ products.

Production of bio-oils from the catalytic pyrolysis of neem sawdust: Comparative study of versatile zeolite parameters

Catalytic fast pyrolysis (CFP) is promising in converting biomass into renewable bio-oils, wherein zeolites play a critical role in bio-oil upgrading. Although it is widely known that zeolite properties (e.g., morphology, acidity, metal modification) determine bio-oil quality, studies on their uniformly comparative effect are limited and hinders a precise design of efficient zeolite catalyst for biomass CFP. Herein, the CFP of neem sawdust was catalyzed by fourteen ZSM-5 zeolites with different structural parameters. The separate impacts of zeolite morphologies (0.2, 0.5, 1, 3 μm), acidity (Si/Al = 25, 50, 100, 200), loaded metal types (Ni, Zn, Co, Ce), and metal loadings (1, 2, 5, 8 wt%) on bio-oil production were initially studied in detail. Then, their relative contributions in regulating bio-oil yield and hydrocarbon selectivity were compared. Results showed that nanosized ZSM-5 with a higher Si/Al ratio improved bio-oil yield, while metal modification had a greater impact on hydrocarbon selectivity. The nanosized 2NiOx/ZSM-5 with a Si/Al ratio of 50 and a NiOx loading of 2 wt% was superior in producing a maximized bio-oil yield and a satisfactory hydrocarbon selectivity. To shed light on future zeolite catalyst design, a pyrolysis mechanism was proposed for neem sawdust over ZSM-5 with varied parameters.

Hydrocarbon-rich bio-oil production from the coupling formaldehyde-pretreatment and catalytic pyrolysis of poplar sawdust

The efficient preparation of hydrocarbon-rich bio-oil is a promising method for biomass utilization. However, the complicated bio-oil composition and low hydrocarbon yield reduced the utilization efficiency of biomass. To solve this problem, a novel technology of coupling formaldehyde-pretreatment (FA) and catalytic fast pyrolysis (CFP) was proposed and tested on poplar sawdust. This coupling technology (FACFP) was featured by introducing catalyst in the pretreatment process, which not only promoted the dissolution of lignin but also enhanced the conversion of lignin-deficient biomass residues into hydrocarbons. Effects of other pretreatment parameters (e.g., solvents, temperature, processing time) on bio-oil production were studied in detail. Compared to water, the utilization of FA as pretreatment solvent was advantageous in lignin removing and improving the accessibility of cellulose to catalyst during pyrolysis. The FACFP of poplar sawdust conducted at a moderate FA-pretreatment temperature (180 °C) and processing time (3 h) was superior in producing hydrocarbon-rich bio-oils, which led to a 1.7-fold hydrocarbon selectivity and a 1.3-fold bio-oil yield as compared to the two-staged FA + CFP mode. Finally, a reaction mechanism for the coupling FACFP of biomass was proposed by highlighting the crucial role of HZSM-5 and FA solvent.

A stable microporous framework with multiple accessible adsorption sites for high capacity adsorption and efficient separation of light hydrocarbons

Metal-organic frameworks (MOFs), a type of designable porous materials, are effectively employed to realize light hydrocarbons storage and separation in favor of energy conservation and environmental protection, superior to traditional separation technology. Significantly, a novel MOF, Ni2(L)2(HCOO)2·4H2O (1) has been constructed from a bifunctional group ligand of 3-hydroxy-4-(4H-1,2,4-triazol-4-yl) benzoic acid ligand (HL). MOF 1 possesses stable porous structure with narrow channels functionalized with multiple accessible adsorption sites of hydroxy group, carboxyl oxygen atoms from the L− and HCOO−, exhibiting a well trade-off between good capacity and selectivity for light hydrocarbons. The single-component sorption isotherm results of Ni2+ based MOF not only shows good gas sorption capacity for light hydrocarbons of C2H2, C2H6, C2H4, C3H8, and greenhouse gas CO2, especially remarkable uptake for C2H2 (122.0 cm3 g−1 at ambient condition), but also favorable selectivity for binary mixtures of C2H2/CH4, C2H6/CH4, C3H8/CH4, C2H4/CH4, C2H2/C2H4 as well as C3H8/C2H6/CH4 ternary mixture, as confirmed by ideal adsorbed solution theory (IAST) calculations, and dynamic breakthrough experiment. Grand canonical Monte Carlo (GCMC) simulation reveals the multiple synergism of accessible adsorption sites including functional OH groups, carboxylate groups, HCOO− and π···π stacking interaction between guest molecules and host-pore are crucial to contribute selective gas adsorption of light hydrocarbons.

Study on pyrolysis behavior of polymeric coated aluminium scrap using TGA and Py-GC/MS

Polymeric-coated aluminium scrap obtained from a local recycling plant in Thailand was used as raw material. The thermal decomposition behavior and evolved gas from the pyrolysis of the polymeric fraction coated on the aluminium surface were investigated using thermogravimetric analysis (TGA) and pyrolysis-GC/MS (Py-GC/MS). Initially, thermogravimetric analysis (TGA) was used to study the thermal decomposition of all the coated aluminium scraps (white, black, and brown color). From the TGA results, a major thermal degradation at 300–480 °C associated with the decomposition of the polymeric fraction was found in all the powder-coated samples. The weight loss was 4.57 wt %, 3.56 wt %, and 1.64 wt % in the white-, black-, and brown-coated scraps, respectively. Then, the pyrolysis of the polymeric layer coated on the surface was investigated using a Py-GC/MS. The effect of pyrolysis temperature (400–600 °C) and the type of coated aluminium scrap on product selectivity was studied. In terms of pyrolysis, the polymeric materials used in the coating would decompose via scission reaction generating volatile compounds. At a temperature of 600 °C, the carboxylic end groups (40.46–45.62 %) and aliphatic HCs (19.69–25.34 %) were the major pyrolytic products with a small number of aromatic HCs (2.76–7.76 %). In addition, low fractions of N-containing compounds (3.05–8.08 %) produced from the decomposition of cross-link agents were found. The maximum temperature (600°C) promoted high selectivity of hydrocarbons (aromatic and aliphatic) from β-H scission, cracking, and deoxygenation reactions. Aliphatic hydrocarbons consisted of alkenes, alkynes, and cycloalkenes with carbon in the range of C5–C24, while aromatic hydrocarbons with carbon in the range of C6–C20 were composed of mainly toluene, biphenyl, styrene, etc. These organic products can be utilized as chemical raw materials as well as alternative fuel. Additionally, to identify the remaining components after heat treatment at 600 °C, the chemical analysis was performed using the EDX technique. The residue compositions after heat treatment at 600 °C were C, Ti, Ba, Pb, Si, Ca, Fe, and S, chiefly corresponding to TiO2, SiO2, CaO, Fe2O3 as pigments and BaSO4 as a filler. Thus, the removal of these inorganic components remaining after thermal de-coating process should be considered to maintain melting cleanliness.