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Porous ZnO/SnS2 nanocomposites with adjustable SnS2 contents were prepared via microwave-assisted heating of different aqueous solutions of SnS2 precursors in the presence of fixed amount of ZnCO3 nanoparticles at pH 7. The structures, compositions, BET specific surface areas, and optical properties of the as-prepared products were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, N2 adsorption, and UV-Vis absorption spectra. Photocatalytic activities of the samples were tested by the removal of aqueous ciprofloxacin, CrVI, and methylene blue under visible-light (λ>420 nm) irradiation. The experimental results reveal that the as-prepared heterogeneous nanostructures exhibit much higher visible-light-driven photocatalytic activity for the degradation of the pollutants than pure SnS2 nanocrystals. The photocatalytic degradation rates Ct/C0 of the pollutants for the most active heterogeneous nanostructure are about 10, 49, and 9 times higher than that of pure SnS2. The enhanced photocatalytic activities exhibited by the heterojunctions could be ascribed to the synergetic effect of enhanced absorption in the visible region and the reduced rate of charge carrier recombination because of efficient separation and electron transfer from the SnS2 to ZnO nanoparticles. [ABSTRACT FROM AUTHOR]

The process of etching is the most crucial part of the work of manufacturing printed circuit boards (PCB). In the etching process by nitric acid, a spent etching waste solution of composition 250 g/L HN03, 30-40 g/L Cu, 30-40 g/L Sn, 30-40 g/L Pb and 20-25 g/L Fe is produced. High metal concentrations in the spent etching waste solution make it a viable candidate for the recovery of metals. Recovery of metals from spent etching waste solution is a significant concern as the recent growth in production of printed circuit boards has generated a drastic increase of spent etching waste solution each year. This study concerns itself with the recovery of metals from spent etching waste. In this study a dilution was made in order to increase the pH of the solution as spent etching waste solution has high acidity, and the electrowinning method was performed to recover metals from the spent etching waste solution. Glassy carbon and platinum were used as cathode and anode in order to investigate the electrodeposition of metals and cyclic voltammetry investigation suggests that the deposition of metals on glassy carbon electrodes occurs at four different overpotentials mainly at -0.15 V, -0.35 V, -0.45 V and -0.75 V. Microscopy observation demonstrates that there is a deposition of metals by applying the potentials in a set of current-time transient study for a duration of 60 seconds and the metals recovered formed as aggregates. [ABSTRACT FROM AUTHOR]

Oil palm is widely grown in Malaysia. There has been interest in the utilization of oil palm biomass for production of environmental friendly biofuels. The gasification of empty fruit bunches (EFB), a waste of the palm oil industry, was investigated in this study to effectively and economically convert low value and highly distribution solid biomass to a uniform gaseous mixture mainly hydrogen (H2). The effects of temperature, equivalence ratio (ER) and catalyst adding on the yields and distribution of hydrogen rich gas products were also investigated. The main gas species generated, as identified by GC, were H2, CO, CO2, CH4 and trace amounts of C2H4 and C2H6. With temperature increasing from 700 to 1000°C, the total gas yield was enhanced greatly and reached the maximum value (~90 wt. % ) at 1000°C with a big portion of H2 (38.02 vol. %) and CO (36.36 vol. %). Equivalence ratio (ER) showed a significant influence on the upgrading of hydrogen production and product distribution. The optimum ER (0.25) was found to attain a higher H2 yield (27.42 vol. %) at 850°C. The effect of adding catalysts (Malaysian dolomitel, P1), Malaysian dolomite2 (GML), NaOH, NaCl, CaO, ZnO, NiO) as a primary catalyst on gas product yield was investigated, and it was found that adding dolomite showed the greatest effect with the maximum H2 yield achieved (28.18 vol.% ) at 850°C. [ABSTRACT FROM AUTHOR]

Abstract: Waste plastics contain a substantial number of valuable chemicals. The wastes from post-consumer as well as from industrial production can be recycled to valuable chemical feedstock, which can be used in refineries and/or petrochemical industries. This chemical recycling process is an ideal approach in recycling the waste for a better environment. Polymer cracking using a laboratory fluidised bed reactor concentrated on the used highly contaminated catalyst, E-Cat 2. Even though E-Cat 2 had low activity due to fewer acid sites, the products yielded were similar with amorphous ASA and were far better than thermal cracking. The high levels of heavy metals, namely nickel and vanadium, deposited during their lifetime as an FCC catalyst, did not greatly affect on the catalyst activity. It was also shown that E-Cat 2 could be used with and without regeneration. Although there was more deactivation when there was no regeneration step, the yield of gases (C2–C7) remained fairly constant. For the first time, these results indicate that “waste” FCC catalyst (E-Cat) is a good candidate for future feedstock recycling of polymer waste. The major benefits of using E-Cat are a low market price, the ability to tolerate reuse and regeneration capacity. [Copyright &y& Elsevier]

Abstract: Oil palm is one of the major economic crops in many countries. Malaysia alone produces about 47% of the world''s palm oil supply and can be considered as the world''s largest producer and exporter of palm oil. Malaysia also generates huge quantity of oil palm biomass including oil palm trunks, oil palm fronds, empty fruit bunches (EFB), shells and fibers as waste from palm oil fruit harvest and oil extraction processing. At present there is a continuously increasing interest in the utilization of oil palm biomass as a source of clean energy. One of the major interests is hydrogen from oil palm biomass. Hydrogen from biomass is a clean and efficient energy source and is expected to take a significant role in future energy demand due to the raw material availability. This paper presents a review which focuses on different types of thermo-chemical processes for conversion of oil palm biomass to hydrogen rich gas. This paper offers a concise and up-to-date scenario of the present status of oil palm industry in contributing towards sustainable and renewable energy. [Copyright &y& Elsevier]

Abstract: A study on gasification of empty fruit bunch (EFB), a waste of the palm oil industry, was investigated. The composition and particle size distribution of feedstock were determined and the thermal degradation behaviour was analysed by a thermogravimetric analysis (TGA). Then fluidized bed bench scale gasification unit was used to investigate the effect of the operating parameters on EFB air gasification namely reactor temperature in the range of 700–1000°C, feedstock particle size in the range of 0.3–1.0mm and equivalence ratio (ER) in the range of 0.15–0.35. The main gas species generated, as identified by a gas chromatography (GC), were H2, CO, CO2 and CH4. With temperature increasing from 700°C to 1000°C, the total gas yield was enhanced greatly and reached the maximum value (∼92wt.%, on the raw biomass sample basis) at 1000°C with big portions of H2 (38.02vol.%) and CO (36.36vol.%). Feedstock particle size showed an influence on the upgrading of H2, CO and CH4 yields. The feedstock particle size of 0.3–0.5mm, was found to obtain a higher H2 yield (33.93vol.%), and higher LHV of gas product (15.26MJ/m3). Equivalence ratio (ER) showed a significant influence on the upgrading of hydrogen production and product distribution. The optimum ER (0.25) was found to attain a higher H2 yield (27.31vol.%) at 850°C. Due to the low efficiency of bench scale gasification unit the system needs to be scaling-up. The cost analysis for scale-up EFB gasification unit showed that the hydrogen supply cost is RM 6.70/kg EFB ($2.11/kg=$0.18/Nm3). [ABSTRACT FROM AUTHOR]

Catalytic cracking of high-density polyethylene (HDPE) over fluid catalytic cracking (FCC) catalysts (1:6 ratio) was carried out using a laboratory fluidized bed reactor operating at 450°C. Two fresh and two steam deactivated commercial FCC catalysts with different levels of rare earth oxide (REO) were compared as well as two used FCC catalysts (E-Cats) with different levels of metal poisoning. Also, inert microspheres (MS3) were used as a fluidizing agent to compare with thermal cracking process at BP pilot plant at Grangemouth, Scotland, which used sand as its fluidizing agent. The results of HDPE degradation in terms of yield of volatile hydrocarbon product are fresh FCC catalysts≫steamed FCC catalysts≈used FCC catalysts. The thermal cracking process using MS3 showed that at 450°C, the product distribution gave 46wt% wax, 14% hydrocarbon gases, 8% gasoline, 0.1% coke and 32% nonvolatile product. In general, the product yields from HDPE cracking showed that the level of metal contamination (nickel and vanadium) did not affect the product stream generated from polymer cracking. This study gives promising results as an alternative technique for the cracking and recycling of polymer waste. [Copyright &y& Elsevier]

Feedstock recycling of high-density polyethylene (HDPE) over fluid catalytic cracking (FCC) catalysts (1:6 ratio) was carried out using a laboratory fluidized bed reactor operating at 450°C. Fresh and steam deactivated commercial FCC catalysts with different levels of rare earth oxide (REO) were compared as well as used FCC catalysts (E-Cats) with different levels of metal poisoning. Fresh FCC catalysts gave the highest results of HDPE degradation in terms of yield of volatile hydrocarbon product. Meanwhile, steamed FCC catalysts and used FCC catalysts showed similar but lower yields. Overall, the product yields from HDPE cracking showed that the level of metal contamination (nickel and vanadium) did not affect the product stream generated from polymer cracking. This study gives promising results as an alternative technique for the cracking and recycling of polymer waste. [ABSTRACT FROM AUTHOR]

Abstract: Current common polymer waste recycling methods, mechanical recycling and energy recovery, have drawbacks such as labour intensive sorting and atmospheric pollution. Feedstock recycling has emerged as an environmentally successful alternative for polymer waste management. [Copyright &y& Elsevier]

In this study, Malaysian dolomites as secondary catalysts are placed at the downstream of the fluidized-bed gasifier. Three types of Malaysian dolomites with different elemental ratios of CaO-MgO content denoted as P1, P2, and P3 are investigated with EFB gasification reaction at different cracking temperatures (700–900 °C). The performance of the catalysts with a variation of catalyst to biomass weight ratio (C/B) (0.05 to 0.30 w/w) is evaluated. The findings showed that the total gas yield increased by 20%, hydrogen increased by 66%, along with an almost 99% reduction in tar content with P1 catalyst with the following reaction conditions: gasification temperature of 850 °C, equivalence ratio (ER) of 0.25, and cracking temperature of 900 °C. Malaysia dolomite could be a secondary catalyst to provide a better alternative, tar-free hydrogen-rich gas with the possibility of regeneration and re-use. [ABSTRACT FROM AUTHOR]

The amount of waste, associated waste disposal costs, and environmental contamination may be minimized by identifying effective recycling approaches. These promising approaches will also lead to the protection of natural resources and economic gains. One example of waste disposal maybe by using it as a filling material or as a pozzolanic material for the production of concrete. In this regard, this study proposes to partially replace cement with aluminum dross and fly ash, and partially replace natural sand with quarry dust. Aluminum dross, cement, sand, and quarry dust were used in a variety of proportions with a constant percentage of fly ash for the design of nine concrete mixtures. Aluminum dross was replaced by 5, 10, 15, and 20% of the cement mass. At first, the optimum replacement of aluminum dross without using quarry dust was determined at a constant percentage of fly ash-15% based on the strength results. Later, by introducing the optimum substitution of aluminum dross with cement and fly ash, the quarry dust was partially replaced at 10, 20, 30, and 40% of river sand to determine the overall optimum mix. The mechanical and durability characteristics of the concrete using the three mixtures were analyzed. It has been observed that the mechanical and durability characteristics of a concrete mixture incorporating a fly ash-15%, aluminum dross-10%, and quarry dust-20% are better than that of standard concrete. Production of concrete using industrial waste can minimize infrastructure construction costs and reduce environmental impacts. [ABSTRACT FROM AUTHOR]

Removal of ciprofloxacin (CIP) pollutant from wastewater using conventional process is particularly challenging due to poor removal efficiency. In this work, CIP was photocatalytically degraded using a porous ZnO/SnS 2 photocatalyst prepared via microwaves. The influence of process parameters (e.g., pH, catalyst mass and initial CIP concentration) and radical scavengers on visible-light induced degradation of CIP on the catalyst was investigated. From the study, it was found that visible-light induced degradation of CIP on ZnO/SnS 2 is a surface-mediated process and the reaction kinetics followed the Langmuir-Hinshelwood first-order kinetics. It was found that the optimum condition for CIP degradation was at pH of 6.1 and catalyst dosage of 500 mg L−1. Higher catalyst dosage however led to a decline in reaction rate due to light scattering effect and reduction in light penetration. • Ciprofloxacin (CIP) was photocatalytically degraded using a porous ZnO/SnS 2 photocatalyst prepared under microwaves. • The roles and effects of radical scavengers on CIP degradation were investigated. • Five primary transformation products of CIP degradation were identified with empirical and structural formulae were proposed. • CIP degradation was mainly initiated by the direct hole attack with predominant reaction site was the piperazine moiety. • The optimum condition for CIP degradation was at pH of 6.1 and catalyst dosage of 500 mg L−1. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the capability of horizontal subsurface flow constructed wetlands (HSFCWs) in treating contaminated wastewater with a high concentration of polycyclic aromatic hydrocarbons (PAHs) (Phenanthrene, Pyrene, and Benzo[a]Pyrene), using two plants, namely Phragmites and Vetiver. The investigated parameters were (1) PAHs uptake by the plants, (2) PAHs removal efficiencies, (3) accumulated PAHs in the soil of CWs, (4) shoot/root concentration factor, (5) translocation factor, and (6) PAHs correlation to lipid contains in the plants. During the treatment period, the results showed that the highest concentration of Phenanthrene in the shoot and the root systems of Phragmites, was 229.3 and 192 μg/g; Pyrene was 69.1 and 59.2 µg/g; and Benzo[a]Pyrene 25.1 and 20.2 µg/g, respectively. Meanwhile, in the Vetiver shoot and root systems were Phenanthrene 87.5 and 64.1 µg/g; Pyrene 63.2 and 42.1 µg/g; and Benzo[a]Pyrene 21.3 and 27.3 µg/g, respectively. The removal rates of Phenanthrene, Pyrene, and Benzo[a]Pyrene (PAHs compounds) by the CW planted with Phragmites were found to be 83%, 71%, and 81%, respectively, while the removal rates by CW planted with Vetiver were found to be 67%, 66%, and 73%, respectively. Moreover, the removal rates by unplanted CW were found to be 62%, 58%, and 55%, respectively. The results indicated that the HSFCW planted with Phragmites has an effective pathway to remove high concentrations of PAHs. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) have the potential to act as a catalyst support in many sciences and engineering fields due to their outstanding properties. The CNT-coated monolith was synthesized over a highly active Ni catalyst using direct liquid injection chemical vapor deposition (CVD). The aim was to study the optimum condition for synthesizing CNT-coated monoliths. The Taguchi method with L9 (34) orthogonal array design was employed to optimize the experimental conditions of CNT-coated monoliths. The design response was the percentage of carbon yield expressed by the signal-to-noise (S/N) value. The parameters including the mass ratio of Ni to citric acid (Ni:CA) (A), the injection rate of carbon source (B), time of reaction (C), and operating temperature (D) were selected at three levels. The results showed that the optimum conditions for CNT-coated monolith were established at A1B2C1D2 and the most influential parameter was D followed by B, C, and A. The ANOVA analysis showed the design was significant with R-squared and standard deviation of the factorial model equal to 0.9982 and 0.22, respectively. A confirmation test was conducted to confirm the optimum condition with the actual values of the average percentage of carbon yield deviated 1.4% from the predicted ones. The CNT-coated monoliths were characterized by various techniques such as field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Raman spectroscopy. [ABSTRACT FROM AUTHOR]

In this study, the dehydrogenation of cyclohexanol to cyclohexanone over nitrogen-doped reduced graphene oxide (N-rGO) Cu catalyst has been reported. The N-rGO support was synthesized by chemical reduction of graphite oxide (GO). The synthesized N-rGO was used as a support to prepare the Cu/NrGO catalyst via an incipient wet impregnation method. The as-prepared support and the Cu/N-rGO catalyst were characterized by FESEM, EDX, XRD, TEM, TGA, and Raman spectroscopy. The various characterization analysis revealed the suitability of the Cu/N-rGO as a heterogeneous catalyst that can be employed for the dehydrogenation of cyclohexanol to cyclohexanone. The catalytic activity of the Cu/N-rGO catalyst was tested in non-oxidative dehydrogenation of cyclohexanol to cyclohexanone using a stainless-steel fixed bed reactor. The effects of temperature, reactant flow rate, and time-onstream on the activity of the Cu/N-rGO catalyst were examined. The Cu/N-rGO nanosheets show excellent catalytic activity and selectivity to cyclohexanone. The formation of stable Cu nanoparticles on NrGO support interaction and segregation of Cu were crucial factors for the catalytic activity. The highest cyclohexanol conversion and selectivity of 93.3% and 82.7%, respectively, were obtained at a reaction temperature of 270 °C and cyclohexanol feed rate of 0.1 ml/min. [ABSTRACT FROM AUTHOR]

The thermal stability of the as-synthesized Nitrogen-doped reduced graphite oxide supported copper catalyst was investigated by a thermogravimetric analyzer (TGA) at a temperature range 273-1173 K under purified N2 atmosphere using three different heating rates (15, 20 and 25 K min−1). Firstly, to obtained nitrogen-doped reduced graphite oxide (N-rGO), the functionalized graphite oxide was synthesized using Staudenmaier’s method reduced by continuously stirring in an ammonia solution subsequently. The rGO was doped with nitrogen and impregnated with Cu-precursor to obtain Cu/N-rGO. The as-synthesized GO; N-rGO and Cu/N-rGO were characterized by FESEM, EDX, TEM, XRD and XPS. All these analyses were resulted in successfully samples synthesized. The TGA kinetic data were fitted into Kissinger and Flynn-Wall-Ozawa model free expressions to obtain apparent activation energies of 83.34 and 102.59 J mol−1 and pre-exponential factors of 2.40 × 107 and 5.01 × 1011 s−1. The high R2 values of 0.9999 and 0.9666 obtained from fitting TGA kinetic data using the Kissinger and Flynn-Wall-Ozawa model free expressions show that the data were well fitted to the expressions. This implies that the thermal behavior of nitrogen doped reduced graphite oxide supported Cu catalyst can be investigated using Kissinger and Flynn-Wall-Ozawa model free expressions. [ABSTRACT FROM AUTHOR]

Empty fruit bunches (EFBs) from the palm plantation sector are abundant agricultural waste products in Malaysia. Supercritical water gasification (SCWG) is a prominent way to convert high-moisture-content biomass such as EFBs into valuable end products. This investigation is focused on EFB conversion into hydrogen-rich products using SCWG (temperature = 380 °C and pressure ≈ 240 bar). Lignocellulosic model compounds (xylan, cellulose, and lignin) were used to study the degradation patterns and gas compositions under similar reaction conditions. The effect of the EFB/water ratio and the SCWG reaction time on the composition of the product gas was examined. Carbon gasification does not improve with increasing EFB/water ratio as well as with increasing reaction time caused by the thermally stable tar formation during reaction. The hydrogen concentration was found to be increased with reaction time along with raising the EFB/water ratio to 0.3 g (3.75 wt%). In addition, the possibility of using palm oil mill effluent as a reaction medium in comparison to deionized water was analyzed. [ABSTRACT FROM AUTHOR]

Abstract: The increase of fossil fuel burning to meet massive energy demands has resulted in major environmental problems. Extensive green house gas emissions and the depletion of non-renewable resources have promoted the use of hydrogen as an alternative energy source. Empty palm fruit bunches (EFB) are a type of agricultural waste that have a high potential for use as a sustainable biomass feedstock for hydrogen production. This study is focused on generation of biomass-derived hydrogen through catalytic biomass gasification using a modified CaO-based catalyst. The catalyst was prepared by adding 5% Ni as a primary dopant, followed by the addition of secondary dopants (La, K, Co, Fe) through a wet impregnation method, and characterised by X-ray diffractometer (XRD), N2 adsorption (BET) and Thermogravimetric Analysis (TGA). The synthesised catalysts were used as the primary catalysts in the reaction and were tested in temperature programmed gasification (TPG). The reaction was carried out in a partial oxygen environment by incorporating the biomass with the catalyst in a ratio of 1:2 from 50 to 900 °C and the product gases were detected by an online mass spectrometer. Interestingly, the addition of secondary dopants significantly increased the hydrogen production with notable changes in the CO2 absorption capacity of the catalyst. Moreover, K, Co and Fe dopants showed tar reforming properties and the highest hydrogen yield was observed with K as the added catalyst. [Copyright &y& Elsevier]

• NiO-CMD catalyst has shown potential bi-functional deoxygenation catalyst due to high capacity in removing oxygen compound to produce high quality of green fuel. • Synergistic effects of bi-functional NiO-CaO/MgO (acid-base) properties favored deoxyegnation pathways. • NiO doped Malaysian Dolomite restricted coke formation and improved product selectivity. • NiO-CMD catalyst had catalyzed simultaneous cracking- deoxygenation reaction. This study investigates the multi-objective optimization of reaction parameters with response surface methodology (RSM) with central composite design (CCD) for the deoxygenation of waste cooking oil (WCO) over low cost-modified local carbonate mineral catalyst (NiO-Malaysian dolomite) into green fuel in the range of gasoline, kerosene and diesel. RSM was performed to study the effect of four operating parameters: temperature (390–430 °C), time (30–120 min), catalyst loading (1–10 wt%) and nitrogen flow rate (50–300 cm3/min). The results indicate that for maximum WCO conversion, deoxygenated oil and product yield, the optimum parameters of the deoxygenation reaction were at 410 °C, 60 min, 5.50 wt% of catalyst loading, and 175 cm3/min of N 2. The green fuel properties testing (density, kinematic viscosity, flash point, cloud point, pour point, sulfur, carbon residue, cetane index, oxidation stability, acid value, iodine value and calorific value) and GC–MS analysis show that the product oil meets almost all the requirements of green diesel fuel and hydrocarbon biofuel standards for fuel application while the quadratic model proposed agreed with the experimental data (95% confidence) which indicates that the RSM can adequately predict the reaction products. [ABSTRACT FROM AUTHOR]

Local carbonate mineral, Malaysian dolomite has the potential as a deoxygenation catalyst due to its high capacity of CaO–MgO which enhances oxygen compound removal and produces high-quality green fuel with desirable lighter hydrocarbon. In this work, the performance of Ni-doped-calcined Malaysian dolomite (Ni/CMD900) catalyst with different catalyst synthesis techniques (precipitation, impregnation, and co-precipitation) were compared on the deoxygenation of waste cooking oil (WCO) process for green fuel production. The physicochemical properties of the synthesized catalyst were investigated by X-ray diffraction, Brunauer-Emmette-Teller surface area, temperature-programmed desorption of carbon dioxide, X-ray fluorescence, scanning emission microscopy and transmission electron microscopy analysis while the liquid products were analyzed by gas chromatography-mass spectroscopy and Fourier-transform infrared spectroscopy. Evidently from the result of the observation, the preparation technique plays an important role in determining the physicochemical properties of the catalyst for deoxygenation reaction of WCO in which precipitation technique outperformed other methods. Synthesized Ni-Malaysian dolomite-based catalyst, PRE/Ni/CMD900 catalyst was found to be superior in deoxygenation reaction activity as compared to other catalysts with high conversion of WCO (68.0%), high yield of pyrolysis oil (36.4%), and less coke formation (32.0%). [Display omitted] • Bi-functional Ni/CMD900 catalyst synthesized by precipitation and impregnation method. • Significant structural changes of dolomite with dispersion of Ni using precipitation technique. • Synthesized Ni/CMD900 proven to be potential deoxygenation catalyst. • PRE/Ni/CMD900 gave the highest conversion (68%) and yielded 80% hydrocarbon. • Catalytic deoxygenation of WCO produces gasoline, kerosene and diesel-range biofuels. [ABSTRACT FROM AUTHOR]

This study evaluated and compared the bio-oil yield produced from the co-pyrolysis of empty fruit bunch (EFB) and high-density polyethylene (HDPE) feedstock using four calcium oxide (CaO)-based catalysts. Three catalysts were derived from waste sources, namely, clamshell (CS), eggshell (ES), and chicken bone (CB), whereas Malaysia dolomite (MD) was extracted from limestone. Pure CaO catalyst served as a control experiment for comparison purposes. Surface area (BET), particle size (PSA), X-ray diffraction (XRD), and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) examinations were used to compare all catalysts. BET and PSA demonstrated that waste-derived catalysts (CS, CB, ES) have the properties required for co-pyrolysis to produce good yield and quality of bio-oil, whilst XRD and SEM/EDX revealed the existence of CaO compound in each of the catalysts. The co-pyrolysis of EFB-HDPE was performed under controlled conditions in a fluidized-bed reactor. All co-pyrolysis parameters such as catalyst loading, feedstock loading, gas flow, and temperature were fixed for all reactions. The study explored the effect of each catalyst on the catalytic cracking of EFB-HDPE through the bio-oil yield and hydrocarbon composition from the reaction. The chemical composition of the bio-oil samples was analyzed by gas chromatography–mass spectrometry (GC-MS) analysis, whereas the bio-oil yield was calculated using mass-balance equation. The maximum oil yield was 26.07 wt% for ES, whereas pure CaO generated a 52.39% hydrocarbon composition, the highest among all catalysts, followed by ES. • Co-pyrolysis of EFB and HDPE blends utilising a variety of low-cost CaO catalysts. • Egg Shell catalyst produced the highest oil yield (26.07 wt%) among other catalyst. • The deoxygenation properties of Pure CaO give the highest hydrocarbon composition. [ABSTRACT FROM AUTHOR]

Improper disposal of industrial waste, particularly non-biodegradable solid waste like waste tires, has long been a significant environmental concern. Despite this, waste tires can be converted to fuel as alternative source through pyrolysis. However, waste tire pyrolysis oil (WTPO) has limitations, such as high sulfur content, making it unsuitable for direct use as a fuel. This research aims to improve the quality of waste tire pyrolysis oil (WTPO) by catalytic hydrogenation. Using modified metal catalysts, including nickel, cobalt, ammonium molybdenum, and alumina as supporting substances. The catalyst was synthesized using the impregnation method and subsequently subjected to calcination. The catalyst performance was evaluated by conducting the hydrogenation reaction. The catalytic hydrogenation reaction results indicate that the catalyst Mo/Al 2 O 3 exhibited the best performance in producing refined oil. The refined oil was desulfurized to a sulfur compound of 0.7 wt% at 320 °C under the flow rate of the gas of 100 ± 50 cm3/min, which corresponded to a sulfur reduction of 75% compared to the initial feedstock. Interestingly, while the non-catalytic reaction presented the highest performance towards sulfur removal of 80%, it was inferior towards the selectivity of benzene, D-limone and p-cymene. [Display omitted] • Catalytic hydrogenation reaction was catalysed by catalyst Ni/Al 2 O 3; Mo/Al 2 O 3 ; Co/Al 2 O 3. • The synthesized catalyst presents a significant performance in the hydrogenation reaction. • The hydrogenation reaction led to a significant reduction in the sulphur content. • The refined oil produced from the catalytic and non-catalytic reactions mostly in the range of C 4 -C 19. • Non-catalytic reactions showed a significant performance towards sulphur removal rates of up to 80%. [ABSTRACT FROM AUTHOR]

The utilisation of calcium oxide (CaO) from waste chicken eggshells, fishbone, and dolomite as a catalyst in the co-pyrolysis of empty fruit bunch (EFB) and high-density polyethene plastic (HDPE) was investigated and compared with existing commercial zeolite catalysts (HZSM-5, NaY, and FCC). In-situ catalytic co-pyrolysis of EFB-HDPE was performed for each CaO and zeolite-based catalyst. Gas Chromatography-Mass Spectrometry (GC-MS) was used to analyse the hydrocarbon content of the bio-oil produced by pyrolysis. The highest hydrocarbon content (61.62%) was obtained from the calcined eggshell (CES) catalyst and was comparable to that of the commercial zeolite catalyst, HZSM-5, with a hydrocarbon content of 53.53%. Brunauer–Emmett–Teller (BET) analysis, Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX) analysis, and Particle Size Analysis (PSA) have proven the viability of CaO-based catalysts in the co-pyrolysis process for bio-oil production via fast pyrolysis. The CES achieved the desired pore diameter (175.15 nm) which was exhibited in the morphology analysis (SEM) and exhibited a uniform arrangement of calcium oxide particles and a porous structure. This finding provides fundamental insight into CaO from organic waste as a suitable alternative to zeolite catalysts in the co-pyrolysis of organic and inorganic feedstocks. [Display omitted] • Co-pyrolysis of biomass/plastic into bio-oil is an important sustainable waste management. • Calcium oxide catalyst was evaluated and compared to zeolites catalyst. • Quality and characteristics of catalyst affects the production and hydrocarbon of bio-oil. • Eggshell can achieve 61.62% hydrocarbon and 31.16% bio-oil yield. [ABSTRACT FROM AUTHOR]

The experimental studies have shown that a pulsed loop reactor can be used to successfully reduce the reaction time for the transesterification of oils and fats. In the present study, the transesterification of palm methyl ester (PME) and trimethylolpropane (TMP) to produce palm oil based TMP ester was conducted using the vacuum operated pulsed loop reactor. The reaction was catalyzed with sodium methoxide solution in methanol. The influences of five operating variables such as vacuum pressure, catalyst loading, molar ratio of high oleic PME to TMP, reaction temperature and oscillatory speed on the yield of TMP esters and unwanted fatty soap formation were examined. The optimum conditions for the reaction were found at 120 °C, 20 mbar, 3.9:1 M ratio of PME:TMP, 1.0 wt% catalyst solution and 180 rpm oscillatory speed. The product containing 95 wt% TMP triester was successfully synthesized in 1 h with 167 mg/g of fatty soap. The physicochemical properties of the TMP esters obtained using pulse reactor were comparable to characteristics of high oleic TMP esters. [ABSTRACT FROM AUTHOR]

Co-pyrolysis is one of the best new technologies to utilise excess of plastic waste where the products are generated in the form of oil, gas and char. A selective catalyst is needed to improve the quality of the co-pyrolysis product, in which, oil with low of oxygenated compounds content and high yield of oil are favoured. In this work, Malaysian dolomite was modified by doping with transition metals (Ni/Fe/Ca) at 10 wt% loading using the precipitation method and then compared with a modified commercial catalyst named NiO/ZSM-5 zeolite. Co-pyrolysis was conducted using empty fruit bunch (EFB) and high-density polyethylene (HDPE) at 500 °C operating temperature, 10 cm3/min N 2 flow rate, 10 wt% catalyst loading, 1:3 HDPE:EFB ratio and 75 g of feedstock with 60 min of operating time in a stainless-steel fluidised bed reactor. The catalysts were characterised using different analysis methods such as XRD, BET and SEM. The highest gas yield of 68% was obtained by increasing the content of calcium oxide (CaO) in dolomite (in dolomite (CaO/CMD900). For the Fe-doped dolomite (Fe 3 O 4 /CMD900), the highest oil yield (10.34 wt%) and a high content oxygenated compounds were obtained. For the Ni-doped dolomite (NiO/CMD900), the oil with the highest hydrocarbon yield (85.32 %) and low oxygenated compound (14.68 %) was obtained. This study confirms that modified dolomite can increase the yield and quality of bio-oil. [Display omitted] • Dual catalytic bed Malaysian dolomite-based catalyst (MO-CaO/MgO) was synthesized with various transition metals. • Catalyst structure changes due to transition metal dispersion play a vital role in promoting efficient deoxygenation pathways. • Synergistic effect of HDPE(H) and EFB(E) during co-pyrolysis process has a beneficial effect on the bio-oil product increment. • Nickel doped dolomite (NiO-CMD900) demonstrated the best performance by producing 85.32% of hydrocarbon compound. [ABSTRACT FROM AUTHOR]

• Development of CoW/SA catalyst for effective deoxygenation-cracking of tung oil into jet fuel hydrocarbons. • Weak + medium acid sites, metal dispersivity and synergistic effect play important role in the progressive deoxygenation and cracking activity. • The tung oil-jet qualities are complied with standard Jet A-1 standard. • The tung oil-jet exhibited excellent cold properties and superior combustion characteristic. Bifunctional Co-W catalysts with variable Co-W dosages on silica-alumina (SA) were prepared and tested for the catalytic deoxygenation-cracking of tung oil (TO) for the production of jet fuel (n -(C 10 -C 16)) fractions. The CoW/SA catalyst appeared to be most active (hydrocarbon yield = 69%, jet fuel selectivity = 60%) and outperformed the monometallic Co and W analogues. Based on the effect of metal dosage, Co– and W-rich catalysts do not provide a workable approach in enhancing deoxygenation-cracking of the TO for jet fuel production, and overly cracking can be successfully controlled at lower metal dosages (5 wt% Co, 10 wt% W). The CoW/SA reusability study showed a consistent deoxygenation-cracking ability for four runs with hydrocarbon yields within the range of 77–84% and 64–77% jet fuel selectivity. GCMS analysis and physicochemical properties of TO oil fuel (TO-gasoline, TO-jet, TO diesel) confirmed that rich aromatic species in TO-diesel negatively affected the quality of the fuels. TO-fuels with a short chain had better combustion properties than those with a longer chain hydrocarbon. The TO-jet qualities are complied with standard Jet A-1 in accordance to ASTM D1655 and DEF STAN 91–91 specification standards. The TO-jet also exhibited excellent cold properties and superior combustion characteristic than Jet A-1. [ABSTRACT FROM AUTHOR]

Abstract: In recent years, the race for producing biodegradable products has increase tremendously. Different approaches have been attempted to use biomass as natural biopolymer for production of biodegradable plastics. In this work, cellulose was derived from oil palm empty fruit bunch fiber (EFBF) by standard ASTM D1104 method. The cellulose and EFB fibers were blended in different ratios up to 50-wt.% with polypropylene (PP) using Brabender twin-screw compounder. Effects of cellulose and EFB fibers on the mechanical properties of PP were investigated. Studies on the morphological properties and the influence of fiber loading on the properties of PP-cellulose and PP-EFBF composites were also conducted. The PP-cellulose composite gave better results in comparison with PP-EFBF composite. The changes in mechanical and morphological properties with different cellulose and fiber loading were discussed. [Copyright &y& Elsevier]