MOHAMAD ANAS NAHIL - Academia.edu (original) (raw)

Papers by MOHAMAD ANAS NAHIL

Proceedings of the Institution of Civil Engineers, Feb 1, 2016

Activated carbons were produced from waste and investigated for their efficiency for the removal ... more Activated carbons were produced from waste and investigated for their efficiency for the removal of mono-nitrogen oxides (NO x) in simulated flue gases at a low temperature. The wastes used were waste biomass (date seeds), processed municipal solid waste in the form of refuse-derived fuel and waste tyres. The morphology, porous texture and surface chemistry of the prepared activated carbons were evaluated by scanning electron microscopy, energydispersive X-ray spectrometry, nitrogen adsorption and Boehm titration, and were compared with several commercial activated carbons. The carbons were then investigated in terms of their use in adsorbing NO x at a low temperature. The waste-derived activated carbons had NO x adsorption efficiencies at 50°C which were between 50 and 70% of those achieved for the commercial activated carbons. Increasing the adsorption temperature from 25 to 100°C significantly reduced nitrogen oxide (NO) adsorption. It was also shown that the NO adsorption efficiency depends on the porous structure, particularly the presence of micropores in the activated carbon, but to a lesser extent on the surface area of the carbons and acid-base surface groups on the carbon surface.

Energy & Fuels, Apr 12, 2023

Catalysis Today, Aug 1, 2023

Fuel Processing Technology, Nov 1, 2017

In this study, plasma-catalytic steam reforming of toluene as a biomass tar model compound was ca... more In this study, plasma-catalytic steam reforming of toluene as a biomass tar model compound was carried out in a coaxial dielectric barrier discharge (DBD) reactor. The effect of Ni/Al2O3 catalysts with different nickel loadings (5-20 wt. %) on the performance of the plasma-catalytic gas cleaning process was evaluated in terms of toluene conversion, yield of gas products, byproducts formation and energy efficiency of the plasma-catalytic process. Compared to the plasma reaction without a catalyst, the combination of DBD with the Ni catalysts significantly enhanced the toluene conversion, hydrogen yield and energy efficiency of the plasma process, whilst significantly reduced the formation of organic by-products. Increasing the Ni loading of the catalyst improved the performance of the plasma-catalytic processing of toluene, with the highest toluene conversion of 52 % and energy efficiency of 2.6 g/kWh when placing the 20 wt.% Ni/Al2O3 catalyst in the plasma. The possible reaction pathways in the plasma-catalytic process were proposed through the combined analysis of both gas and liquid products.

Fuel, Nov 1, 2016

Catalytic steam reforming of phenol over Ni/Al2O3 catalyst with 10 wt% of Ni loading was carried ... more Catalytic steam reforming of phenol over Ni/Al2O3 catalyst with 10 wt% of Ni loading was carried out in a fixed bed reactor. The effect of temperature (650-800 ºC), reaction time (20-80 min) and catalyst amount (0-2 g corresponding to 0-4.5gcat h gphenol-1) on carbon conversion, H2 potential and catalyst deactivation was studied. High efficiency of Ni/Al2O3 catalyst in steam reforming of phenol is observed at 750 ºC for a reaction time of 60 min when 1.5 g of catalyst (3.4 gcat h gphenol-1) is used, with carbon conversion and H2 potential being 81 and 59 %, respectively. An increase in temperature enhances phenol reforming reaction as well as coke gasification, minimizing its deposition over the catalyst. However, at high temperatures (800 ºC) an increase in Ni crystal size is observed indicating catalyst irreversible deactivation by sintering. As catalyst time on stream is increased the coke amount deposited over the catalyst increases, but no differences in Ni crystal size are observed. An increase in catalyst amount from 0 to 1.5 g increases H2 potential, but no further improvement is observed above 1.5 g. It is not observed significant catalyst deactivation by coke deposition, with the coke amount deposited over the catalyst being lower than 5 % in all the runs.

Chemical Engineering Journal, Jul 1, 2023

Journal of The Energy Institute, Jun 1, 2022

This is a repository copy of Pyrolysis-catalytic steam/dry reforming of processed municipal solid... more This is a repository copy of Pyrolysis-catalytic steam/dry reforming of processed municipal solid waste for control of syngas H :CO ratio ₂ .

Energy & Fuels, Mar 9, 2022

A two-stage pyrolysis−nonthermal plasma/catalytic steam reforming reactor system was used to prod... more A two-stage pyrolysis−nonthermal plasma/catalytic steam reforming reactor system was used to produce hydrogen from waste high-density polyethylene in relation to different catalyst support materials. The catalyst support materials investigated were MCM-41, Y-zeolite, ZSM-5, Al 2 O 3 , TiO 2 , dolomite, BaTiO 3 , CaTiO 3 , and Mo 2 C. Some of the materials suppressed the generation of plasma, while others enhanced it by improving the generation of microdischarges and surface discharges. Among the tested materials, MCM-41 gave the highest gas yield of 29.2 wt % and a hydrogen yield of 11 mmol g −1 plastic. The coupling of the catalyst with the plasma environment resulted in synergy in terms of enhanced total gas yield and hydrogen production, which were higher than those in the absence of plasma (catalyst alone) or plasma alone (no catalyst). Other parameters investigated using the MCM-41 support material showed that the particle size and the catalyst bed depth affected the plasma discharge and the total gas yield. Impregnating nickel (10 wt %) on the MCM-41 support further enhanced the total gas yield to 33.3 wt % and the hydrogen yield to 18 mmol g −1 plastic due to increased surface reactions. The 10 wt % Ni/MCM-41 was stable when subjected to a 3 h stability test showing no significant change in the yield of the gases.

Energy & Fuels, Jul 16, 2019

The production of methane through the optimization of various operating parameters and the use of... more The production of methane through the optimization of various operating parameters and the use of different catalysts has been investigated using a two-stage, pyrolysiscatalytic hydrogenation reactor. Pyrolysis of the biomass in the 1 st stage produces a suite of gases, including CO2 and CO, which undergo catalytic hydrogenation in the presence of added H2 in the 2 nd stage. The influence of the biomass pyrolysis temperature, catalyst temperature and H2 gas space velocity have been investigated for the optimization and enhancement of the methane yield. In addition, different metal catalysts (Co/Al2O3, Mo/Al2O3, Ni/Al2O3, Fe/Al2O3), the influence of different metal loadings, catalyst calcination temperature and different support materials (Al2O3, SiO2 and MCM-41) were investigated. The yield of methane was linked to the properties of the catalysts including the preparation calcination temperature and support material which influenced the catalyst surface area and metal crystallite particle size by sintering. The highest methane yield of 7.4 mmol g-1 biomass was obtained at a final pyrolysis temperature of 800 °C, catalyst temperature of 500 °C and H2 gas hourly space velocity of 3600 ml h-1 g-1 catayst. This optimization process resulted in 75.5 vol.% of methane in the output gaseous mixture.

Energy technology, Sep 18, 2019

This is a repository copy of Parametric Study of CO Methanation for Synthetic Natural ₂ Gas Produ... more This is a repository copy of Parametric Study of CO Methanation for Synthetic Natural ₂ Gas Production.

Energy Conversion and Management, Sep 1, 2017

To explore the mechanism of the influence of Ni-Fe bimetallic catalyst for the producing high-val... more To explore the mechanism of the influence of Ni-Fe bimetallic catalyst for the producing high-value carbon nanotubes (CNTs) with clean hydrogen from waste plastic pyrolysis, the pyrolysis-catalysis of plastics were performed using a two stage fixed bed reaction system with Ni and Fe loading at variant molar ratios. The catalysts and produced carbon were analyzed with various characterization method, including temperature-programed reduction/oxidation, X-ray diffraction, scanning electron microscopy or/and Raman spectroscopy. Both the H2 concentration and H2 yield reached maximum values of 73.93 vol.% and 84.72 mg g-1 plastic, respectively, as the ratio of Ni Fe at 1:3. The amount and quality of CNTs were greatly influenced by the catalyst composition, and Ni and Fe display different roles to the overall reactivity of Ni-Fe catalyst for the pyrolysis-catalysis of waste plastics. Catalyst with more Fe *

Catalysis Today, Oct 1, 2019

This is a repository copy of Enhanced hydrogen-rich gas production from waste biomass using pyrol... more This is a repository copy of Enhanced hydrogen-rich gas production from waste biomass using pyrolysis with non-thermal plasma-catalysis.

Fuel Processing Technology, Nov 1, 2020

Synthetic natural gas (methane) production was systematically investigated by optimising various ... more Synthetic natural gas (methane) production was systematically investigated by optimising various operating parameters using a three stage (i) biomass pyrolysis (ii) catalytic steam reforming (iii) catalytic hydrogenation reactor system. Several operating parameters were optimized including catalytic steam reforming temperature, steam weight hourly space velocity (WHSV), catalytic hydrogenation temperature and hydrogen gas space velocity. In addition, the influence of different metal catalysts (Ni/Al2O3, Fe/Al2O3, Co/Al2O3, and Mo/Al2O3), catalyst calcination temperature, catalyst metal loadings, and different catalyst support materials (Al2O3, SiO2, and MCM-41) was carried out specifically to optimize 15 catalytic hydrogenation in the third stage reactor. The highest methane yield of 13.73 mmoles 16 g-1 biomass (22.02 g CH4 100 g-1 biomass) was obtained with a second stage catalytic steam 17 reforming temperatureof 800 °C over a 10 wt.% Ni/Al2O3 catalyst and with a steam WHSV 18 of 5 mL h-1 g-1 catalyst together with a third stage catalytic hydrogenation temperature of 350 °C 19 over a 10 wt.% Ni/Al2O3 catalyst with added hydrogen gas space velocity of 2400 mL h-1 g-20 1 catalyst.

Journal of Material Cycles and Waste Management, Jan 4, 2022

Biomass and waste polystyrene plastic (ratio 1:1) were co-pyrolysed followed by catalysis in a tw... more Biomass and waste polystyrene plastic (ratio 1:1) were co-pyrolysed followed by catalysis in a two-stage fixed bed reactor system to produce upgraded bio-oils for production of liquid fuel and aromatic chemicals. The catalysts investigated were ZSM-5 impregnated with different metals, Ga, Co, Cu, Fe and Ni to determine their influence on bio-oil upgrading. The results showed that the different added metals had a different impact on the yield and composition of the product oils and gases. Deoxygenation of the bio-oils was mainly via formation of CO 2 and CO via decarboxylation and decarbonylation with the Ni-ZSM-5 and Co-ZSM-5 catalysts whereas higher water yield and lower CO 2 and CO was obtained with the ZSM-5, Ga-ZSM-5, Cu-ZSM-5 and Fe-ZSM-5 catalysts suggesting hydrodeoxygenation was dominant. Compared to the unmodified ZSM-5, the yield of single-ring aromatic compounds in the product oil was increased for the Co-ZSM-5, Cu-ZSM-5, Fe-ZSM-5 and Ni-ZSM-5 catalysts. However, for the Ga-ZSM-5 catalyst, single-ring aromatic compounds were reduced, but the highest yield of polycyclic aromatic hydrocarbons was produced. A higher biomass to polystyrene ratio (4:1) resulted in a markedly lower oil yield with a consequent increased yield of gas.

Journal of The Energy Institute, Aug 1, 2021

This is a repository copy of Catalytic co-pyrolysis of biomass and waste plastics as a route to u... more This is a repository copy of Catalytic co-pyrolysis of biomass and waste plastics as a route to upgraded bio-oil.

Journal of Analytical and Applied Pyrolysis, Mar 1, 2017

The two-stage pyrolysis-catalysis of high density polyethylene has been investigated with pyrolys... more The two-stage pyrolysis-catalysis of high density polyethylene has been investigated with pyrolysis of the plastic in the first stage followed by catalysis of the evolved hydrocarbon pyrolysis gases in the second stage using solid acid catalysts to produce gasoline range hydrocarbon oil (C 8-C 12). The catalytic process involved staged catalysis, where a mesoporous catalyst was layered on top of a microporous catalyst with the aim of maximising the conversion of the waste plastic to gasoline range hydrocarbons. The catalysts used were mesoporous MCM-41 followed by microporous ZSM-5, and different MCM-41:zeolite ZSM-5 catalyst ratios were investigated. The MCM-41 and zeolite ZSM-5 were also used alone for comparison. The results showed that using the staged catalysis a high yield of oil product (83.15 wt.%) was obtained from high density polyethylene at a MCM-41:ZSM-5 ratio of 1:1 in the staged pyrolysiscatalysis process. The main gases produced were C 2 (mainly ethene), C 3 (mainly propene), and C 4 (mainly butene and butadiene) gases. In addition, the oil product was highly aromatic (95.85 wt.% of oil) consisting of 97.72 wt.% of gasoline range hydrocarbons. In addition, pyrolysis-staged catalysis using a 1:1 ratio of MCM-41: zeolite ZSM-5 was investigated for the pyrolysis-catalysis of several real-world waste plastic samples from various industrial sectors. The real world samples were, agricultural waste plastics, building reconstruction plastics, mineral water container plastics and household food packaging waste plastics. The results showed that effective conversion of the real-world waste plastics could be achieved with significant concentrations of gasoline range hydrocarbons obtained.

Proceedings of the Institution of Civil Engineers - Waste and Resource Management, 2021

The production of hydrogen (H2) from the pyrolysis–catalytic steam reforming of polyethylene, pol... more The production of hydrogen (H2) from the pyrolysis–catalytic steam reforming of polyethylene, polystyrene (PS) and polyethylene terephthalate waste plastics was investigated using a two-stage reactor. The highest yield of hydrogen (125 mmol/gplastic) was obtained with PS at a catalyst temperature of 900°C and steam input weight hourly space velocity of 7.59 g/(h/gcatalyst) with a 10 wt% nickel/aluminium oxide (Ni/Al2O3) catalyst. Further investigation using PS showed that the process parameters of high catalyst temperature (900°C) and optimised steam input rate significantly increased the yield of hydrogen. Examination of several different catalysts (nickel/aluminium oxide, iron/aluminium oxide, copper/aluminium oxide, cobalt/aluminium oxide) showed that nickel/aluminium oxide had by far the highest catalytic activity and selectivity towards the yield of hydrogen.

Journal of Analytical and Applied Pyrolysis, 2021

Polypropylene and polystyrene were processed in a pyrolysis/catalytic reactor with a Ni-Fe/Al2O3 ... more Polypropylene and polystyrene were processed in a pyrolysis/catalytic reactor with a Ni-Fe/Al2O3 catalyst to produce carbon nanotubes (CNTs). A high yield of catalyst carbon deposits were produced; 33.5 g 100 g-1 polypropylene and 29.5 g 100g-1 polystyrene and consisted of multi-walled carbon nanotubes (MWCNTs). X-ray diffraction (XRD) of the Ni-Fe/Al2O3 catalyst suggested the active metal was a Ni-Fe alloy which was confirmed using X-ray absorption near edge structure (XANES); extended X-ray absorption fine structure (EXAFS) analysis showed that the alloy was primarily FeNi2. Electron microscopy showed that the MWCNTs were entangled, several μm in length and ~50 nm in diameter comprising ~30 graphene layers. Optical Raman spectroscopy confirmed the carbons to be of high purity and crystallinity with polypropylene showing a higher degree of graphitisation and fewer defects compared to those produced from polystyrene. X-ray Raman scattering spectroscopy of the MWCNTS confirmed their graphitic carbon composition, but demonstrated poor alignment. Commercially produced MWCNTs showed a high degree of graphitisation, with less metal impurities and were of long length (several μm), straighter, smaller diameter (~10 nm) and with fewer number of graphene layers (~12) in the CNT wall compared with the plastic derived MWCNTs.

Energy & Fuels, 2020

Hydrogen was produced from waste plastic (polyethylene) using a novel two-stage pyrolysislow temp... more Hydrogen was produced from waste plastic (polyethylene) using a novel two-stage pyrolysislow temperature (250 °C) plasma catalytic steam reforming process. Pyrolysis of the polyethylene generated pyrolysis gases which were catalytically steam reformed in the presence of low temperature non-thermal plasma (dielectric barrier discharge) to produce hydrogen gas. In the absence of catalyst, increasing the plasma power resulted in a significant increase in hydrogen yield. Different catalysts (Ni/Al2O3, Fe/Al2O3, Co/Al2O3 and Cu/Al2O3) were incorporated in the discharge region of the plasma reactor and the Ni/Al2O3 produced the highest yield of hydrogen at 1.5 mmol g-1 plastic. Addition of steam to the plasma catalytic process was investigated at different steam weight hourly space velocities (WHSV) using the Ni/Al2O3 catalyst. The addition of steam to promote catalytic steam reforming reactions resulted in a marked increase in hydrogen yield, producing the highest hydrogen yield of 4.56 mmol g-1 plastic at a WHSV of 4 g h-1 g-1 catalyst.