Eric M Kennedy

The University of Newcastle, Australia · Department of Chemical Engineering

Catalytic cracking of high molecular weight hydrocarbons underpins the production of fossil fuels from petroleum vapour and the recycling of polyolefin waste plastic. However, thermal cracking over conventional microporous solid acids is hindered by poor mass‐transport. Here we explore the performance of hierarchical H−Y zeolites and Al‐SBA‐15 for...

Zeolite-supported metal nanocluster catalysts have attracted significant attention due to their broad application in heterogeneously catalyzed reactions. The preparation of highly dispersed metal catalysts commonly involves the use of organic compounds and requires the implementation of complicated procedures, which are neither green nor deployable...

Catalytic hydropyrolysis of eucalyptus leaves was investigated in a batch reactor over four catalysts (H-BEA, Ni/BEA, Ni/Fe-BEA and Fe/BEA). HBEA catalyst exhibited a higher monoaromatic hydrocarbons (MAHs) selectivity compared to non-catalytic pyrolysis. However, the selectivity to polyaromatic hydrocarbons (PAHs) was not significantly reduced by...

A highly-dispersed Ni catalyst with an increased number of Ni sites selectively distributed in the mesopores of HBEA has been developed and applied in anisole hydrodeoxygenation (HDO) in a continuous-flow...

Formation of silica-rich passivation layers formed on the periphery of reacting feed particles is one of the primary obstacles in obtaining high magnesite yields during direct aqueous mineral carbonation of peridotites and serpentinites. The disruption of the silica-rich layer around partially reacted grains as a result of concurrent grinding on th...

Single-stage mineral carbonation is undertaken at relatively high pressures (up to 18 MPa) and high temperatures (up to 185 °C), where in contrast, two-stage mineral carbonation operates at low pressures (<1 MPa) and mild temperatures (<100 °C). This article describes the development of concurrent grinding for application during the initial dissolu...

This work investigates chemical stability of Mg-silicates and silica in aqueous systems in order to gain in-depth understanding of their dissolution and precipitation behaviour under different conditions. The aim was to utilise the knowledge gained to develop an engineered carbon mineralisation technology for an efficient and cost competitive CO 2...

Chlorpyrifos (CPF) is a widely used pesticide; however, limited experimental work has been completed on its thermal decomposition. CPF is known to decompose into 3,5,6-trichloro-2-pyridinol (TCpyol) together with ethylene and HOPOS. Under oxidative conditions TCpyol can decompose into the dioxin-like 2,3,7,8-tetrachloro-[1,4]-dioxinodipyridine (TCD...

Hydrodeoxygenation (HDO) of guaiacol over Ni metal supported on zeolites (H-Beta and H-ZSM-5) with different Si/Al ratios (12.5, 25, 175) and different metal loadings (2.3–23.4 wt%) was investigated in order to elucidate the role of catalyst acidity and the structure of Ni in the HDO reaction. Results show that the deoxygenation activity and produc...

The promoting effect of manganese on Ni/Al2O3 catalyst for the hydrogenation of carbon oxides, in presence of light hydrocarbons, was studied. Ni/Al2O3 displayed a high activity for the complete conversion of CO and CO2 to methane and C2+ hydrocarbons. Moreover, over a discrete and relatively narrow temperature range, the net concentration of light...

Formation of active oxygen species from N2O over Fe-FER catalyst prepared by solid state ion exchange method at moderate temperatures was studied using spectroscopic and solid characterisation techniques including H2-TPR, N2O-TPD and in situ FTIR. The utilization of active oxygen species for the direct conversion of methane to value-added products...

The stability of Pd/TS-1 and Pd/Silicalite-1 catalysts was assessed for catalytic combustion of fugitive methane emissions at low concentrations, aiming to understand the role titanium plays for the stability of the catalyst. The long-term stability of both catalysts is attributed to both hydrophobicity and low acidity of the aluminium-free zeolite...

This research aims to provide insight into the structure and reaction mechanism of silica-rich phases formed as undesirable by-products in direct aqueous carbonation of heat-activated lizardite. In undertaking this work, we employed analytical techniques such as Thermogravimetric Analysis (TGA), X-ray Powder Diffraction (XRPD), Fourier-Transform In...

With health concerns developing about the use of glyphosate (PMG), the world’s most used herbicide, the possibility of destruction of stockpiles via incineration arises. Little is known, however, about possible toxic products of decomposition. We have made a quantum chemical computation of the mechanism of thermal decomposition of PMG. Two initiati...

In this study, the activity and selectivity to Fe-ZSM-5, Fe-Beta and Fe-FER catalysts were studied at 350 °C for the partial oxidation of methane using N2O as oxidant. Spectroscopic and solid characterisation tools including H2-TPR, in situ IR, N2 gas adsorption, CO chemisorption and TGA-MS were used in the investigation. Ammonia adsorption data su...

Density functional theory, in conjunction with ab initio atomistic thermodynamics, were used to investigate the stability of the low index cuprous chloride surfaces, and predict the morphology of CuCl nanocrystals under high pressures of chlorine. The rocksalt orientation of the lattice was adopted to resemble a CuCl crystal under high pressure. Un...

This work examines factors, which can influence the formation of magnesium (Mg) carbonate phases produced during direct aqueous carbonation of heat‐activated lizardite, hydromagnesite, and the targeted magnesite phase. Carbon dioxide mass transfer and mixing during the course of the reaction was examined by varying impeller positioning and stirring...

This paper examines the gas phase thermal decomposition of dieldrin and associated formation of toxic combustion products including polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F). Volatile Organic Carbon (VOC) analysis revealed the formation of pentachlorostyrene (PCS), hexachlorostyrene (HCS) and polychlorinated naphthalene as toxic co...

An increase in biodiesel production has seen a dramatic increase in the production of glycerol, the main by-product. To maintain biodiesel production as economically viable, processes for valorising the 10 wt% glycerol waste stream need to be developed. The content of this chapter discusses recent work which examines potential catalytic processes f...

The dissolution of magnesium silicate minerals such as serpentine in aqueous solutions saturated or near saturated with carbon dioxide (CO2) enables its subsequent reaction to form magnesium carbonate, a process called aqueous mineral carbonation. The dissolution rate of magnesium ions (Mg²⁺) from thermally activated serpentine and the factors infl...

Catalytic coupling of CH4 with potent greenhouse gas, CHF3 to vinylidene fluoride (VDF) were investigated over composite catalysts. Carbon partitioned LaF3-BaF2 catalysts were prepared by PVDF (polyvinylidene fluoride) mediated calcination. During catalyst preparation, PVDF functions as the fluorine source and carbon source. Compared with the catal...

To address pressures associated with the increasing demand for the use of renewable liquid fuels, production of biodiesel has increased significantly resulting in a concomitant increase in glycerol production. A potential technology which has been examined in this study for utilising this potential waste product is to consider glycerol as well as i...

Liquid phase Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate was studied over ZnO under solvent-free conditions. An induction period of approximately 1 h was observed, the duration of which is dependent on the pre-treatment method adopted for the catalyst and whether the catalyst was exposed to either ethyl cyanoacetate or benzaldeh...

In the present study, we have assessed the effect of mass transfer on the both steps of the zeolite catalysed oil hydroesterification to produce biodiesel (hydrolysis of the feed soybean oil producing free fatty acid and free fatty acid esterification). Both reactions were conducted over BEA zeolite in a batch reactor. Experimental results indicate...

While biodiesel manufacturing using transesterification is a mature process, a number of key issues need to be addressed for widespread application. These include amongst others feedstock availability and waste products. In this paper, we report on a different approach to synthesize biodiesel, namely a two-stage process which alleviates the need to...

We present a model to describe carbon dioxide (CO2) capture using reactive silicate based mineral slurries exposed to a gas flow containing CO2. The model is validated through experimentation using thermally conditioned or heat-activated serpentinite (hydrous metamorphic ultramafic rock) in a laboratory scale bubble column reactor. The kinetic mode...

Vast reserves of peridotite and serpentinite rocks can be utilised for the safe and permanent sequestration of global CO2 emissions via aqueous mineral carbonation. These, and indeed most feedstocks used in mineral carbonation require ultrafine grinding and/or heat-activation, to engender significantly enhanced reactivity in the rock such that it c...

This research explores the use of serpentinized dunite (which is comprised of 61% lizardite) as a feedstock for aqueous mineral carbonation. In initial experiments, dunite was heat‐activated (630°C, 4 h), adopting a procedure which is similar to that used for serpentinite to enhance their carbonation reactivity. Heat‐activation converts crystalline...

In this experimental work we synthesized, characterized, and investigated the reactivity of silica‐enriched residue materials produced from low pressure, low temperature dissolution applicable to a two stage mineral carbonation process. XRF and XRD analysis indicated that 66 wt % of silica‐enriched residue (SER) produced from dissolution of heat ac...

This investigation examines the experimental data obtained from a 30 L pilot batch reactor, used for single stage aqueous carbonation and for the dissolution of heat activated lizardite and compares this data to the laboratory scale data obtained under similar reaction conditions. Two mineral feeds, heat activated lizardite produced in large quanti...

Mechanisms of pyrolysis of several representative cyclodiene pesticides, viz., dieldrin, aldrin and isodrin, have been studied by quantum chemical techniques and dieldrin and isodrin have been subjected to experimental pyrolysis investigation. Comparison is made with earlier studies on another cyclodiene - endosulfan. Cyclodienes which are initiall...

This paper describes an alternative process for chloroform decomposition via non-thermal plasma polymerisation at atmospheric pressure and investigates the effect of methane and hydrogen addition on the process. The effect of both additives was assessed separately, where experiments were conducted in a double dielectric barrier discharge reactor un...

Probable reaction intermediates and mechanistic steps involved for the selective oxidation of methane (CH4) with nitrous oxide (N2O) forming synthesis gas (CO + H2) over Co-ZSM-5 was examined. To assess the reaction kinetics reactions were conducted within a temperature range of 300 °C–550 °C and at atmospheric pressure, and the composition of reac...

This study investigates the formation of polychlorinated dibenzo- p -dioxins and polychlorinated dibenzofurans (PCDD/F) in oxidation of 4,4' -dichlorobiphenyl (4,4' -DCB) under gas phase conditions over a temperature range of 400-800 °C. The experiments involved an isothermal flow reactor equipped with a sample collection system to adsorb PCDD/F. W...

Catalysts of iron oxide on γ-alumina and silica which were prepared by an incipient wetness impregnation technique have been investigated in an effort to understand how the surface chemical properties are influenced by the nature of the supports. Surprisingly, this is the first study to compare in depth the influence of the supports on physicochemi...

Thermal decomposition of the pesticide, chlorpyrifos (CPf) and its major degradation product, 3,5,6-trichloro-2-pyridinol (TCpyol), has been studied by quantum chemical calculation using density functional methods at the M06-2X/GTLarge//M06-2X/6-31+G(d,p) level of theory. Chlopyrifos was found to undergo a series of unimolecular stepwise eliminatio...

The primary aim of this research is to study the influence of various experimental parameters on the reaction in order to establish the optimum conditions for which the highest conversion level of zeolite-catalysed oil hydroesterification (two-step reaction: oil hydrolysis and fatty acid esterification) can be achieved. The experimental results ind...

The oxidative coupling of methane (OCM) with CHF3 facilitates the synthesis of vinylidene fluoride (VDF). The aim is to utilize CHF3, which is otherwise considered a waste with a very high global warming potential. This study focuses on the effect of a LaOF catalyst on OCM occurring in the presence of CHF3, which engenders a promoting effect of O2...

Utilising the byproducts of mineral carbonation processes contributes to rendering the technology environmentally benign and enhances the economically viability of the process. In this work we synthesised, characterised and investigated the technical feasibility and environmental benefits of utilising feed and byproducts of mineral carbonation tech...

The mechanism of pyrolysis of dieldrin, a now - banned member of the cyclodiene group of pesticides, has been studied by quantum chemical calculation. The pyrolysis is initiated by retro Diels - Alder dissociation into hexachlorocyclopentadiene and norbornadiene o xide. At low temperatures (623 - 800 K) intramolecular processes lead to benze...

This article investigates the gas phase pyrolysis of dieldrin, one of the most common derivatives of the cyclodiene-based group of pesticides, used extensively in the agricultural sector until its use was banned in most countries (including Australia) in the 1980s. The objective of the present study was to identify its thermal decomposition pathway...

A Knoevenagel condensation reaction between benzaldehyde and ethyl cyanoacetate was performed in the liquid phase under mild and solventless conditions using a series of catalysts modified by impregnating magnesium and barium cations on different supports (SiO2, ZnO, γ-Al2O3 and Fe2O3). The highest reaction rates and yields (after 6 hours) were obs...

The rate-determining step in the aqueous carbonation of serpentine minerals is the dissolution of Mg from serpentine. The dissolution rate of minerals largely depends on the pH of the solution and the size of serpentine particles. In the present work, an experimental method has been developed to study the dissolution rate of heat activated serpenti...

Thermal decomposition of hexachlorocyclopentadiene (HCCP) has been studied in inert gas and under oxidative conditions in a silica flow reactor at a residence time of 5.0 s between 690 – 923 K and 1 atm pressure. Pyrolysis was initiated by Cl bond fission to form pentachlorocyclopentadienyl radical; two such radicals then combine to undergo a serie...

A new coupled thin layer chromatography-imaging mass spectrometry method was developed to investigate solvent extracts from a coal. The technique was used to assess the separation of complex molecular structures in a tetrahydrofuran (THF) soluble extract taken from a semi-coke (the solid residue obtained after thermal pre-treatment of coal at 430 °...

The effect of transition metals on the activity and selectivity of a Ni/Al2O3 catalyst for carbon oxides hydrogenation was studied. It is found that each transition metal has different and distinct promoting or inhibiting influence. Nitric oxide was used as a probe molecule to study the electronic structure of a primary and two bi-metallic catalyst...

The economy of Pakistan is strongly reliant on agricultural activities. Nitric acid plants are operating in different locations of the country for the production of ammonium nitrate fertilizers. Unfortunately, N2O is one of the by-products formed, particularly in older nitric acid plants. N2O is a potent greenhouse gas and has a higher global warmi...

The primary use for Nitric acid is for the production of ammonium nitrate fertilizers. Unfortunately, N2O is a potent greenhouse gas, and is one of the by-products formed during nitric acid production, particularly in older nitric acid plants. At present, the production of nitric acid is the single largest point source of N2O emissions. In the curr...

Chlorine and HCl are adsorbed dissociatively on the Cu(100) surface. The exposure of Cl to copper surfaces lead to the formation of CuCl, which develops later to CuCl2. In this paper, we show, using density functional theory calculations, that the presence of adsorbed water on a Cl-Cu(100) modified surface leads to a low energy pathway to a direct...

This article presents a novel study of the role of the catalyst support towards the formation of active cobalt sites for N2O conversion reactions within a temperature range of 300-600°C. These reactions were examined in a fixed bed tubular reactor. ZSM-5 (Si/Al≤15), TS-1, and amorphous silicates were used as catalyst supports for cobalt loadings. A...

This contribution reports results from the gas-phase oxidation of 4-bromo-4'-chlorobiphenyl (4,4'-BCB) in order to fathom the formation of toxic species produced during the combustion of mixed halogenated aromatics. In their own right, mixed polybrominated/polychlorinated biphenyls (PXBs) represent a new class of environmental contaminants, recentl...

The aim of the present study is to explore the coherence of thermodynamic equilibrium predictions with the actual catalytic reaction of CH4 with N2O, particularly at higher CH4 conversions. For this purpose, key process variables, such as temperature (300°C–550°C) and a molar feed ratio (N2O/CH4 = 1, 3, and 5), were altered to establish the conditi...

CPh) adsorption on the surface of silica, alumina, silica- and alumina- supported iron oxides at 30 °C and 250 °C was examined. The formation of a carbanion chlorophenolate/chlorophenoxy radical intermediate on the surface of silica and alumina surfaces is identified by in-situ FTIR analysis. The IR spectra of 2-CPh adsorbed on the supported iron o...

This paper investigates the thermal decomposition of technical grade endosulfan under oxidative conditions and the subsequent formation of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/F, dioxins) and their precursors. Quantum chemical calculations have been employed to investigate the pathways of oxidation of endosulfan. T...

Fugitive gas emissions from coal mining are widely known as significant contributor to the emission of alkanes, mainly methane to the receiving environment. Utilization of coal mine ventilation air methane (VAM) is a crucial mission in order to minimize methane emission in atmosphere. This paper reviews current technological option for mitigation a...

This article reports the results of a computational and experimental study on the thermal degradation of endosulfan, a broad-spectrum chlorinated cyclodiene insecticide. The objective of the study was to identify its decomposition pathways, and to gain an understanding of the mechanism of formation of toxic species including polychlorinated dibenzo...

A novel Pd supported on TS-1 combustion catalyst was synthesized and tested in methane combustion under very lean and under highly humid conditions (<1 %). A notable increase in hydrothermal stability was observed over 1,900 h time-on-stream experiments, where an almost constant, steady state activity obtaining 90 % methane conversion was achieved...

The Reflux Classifier (RC) is a separation technique which has been used in the coal and mineral processing industries. It uses water as a medium, and is therefore a suitable preparation device for studies on coking coal as other separation techniques may change coking properties. The separation process was conducted by using a channel spacing of 3...

In this contribution, the development of a process for the synthesis of potentially highly valuable polymeric products from the reaction of waste glycerol with ammonia is reported for the first time. The polymers were the result of a single step, continuous gas phase process, catalysed by an alumina-supported iron catalyst, operating under relative...

This paper presents the results of dichloromethane (DCM) decomposition to polymers under, utilising dielectric barrier discharge under non-oxidative reaction conditions. The conversion levels, mass balance, reaction mechanism and polymer characterisation in relation to DCM reaction are presented in this paper. Reaction pathways describing the decom...

The reaction of CCl3F (CFC-11) with CH4 (in an argon bath gas) in a dielectric barrier discharge nonequilibrium plasma was examined. Oxygen and nitrogen were excluded from the feed stream and the reactions resulted in the production of fluorine-containing polymers, as well as a range of gaseous products including H2, HCl, HF, C2H3F, C2H3Cl, C2H2ClF...

This contribution studies partial oxidation of 2-chlorophenol on surfaces of neat silica at temperatures of 250, 350 and 400 °C; i.e., temperatures that frequently lead to catalytic formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) from their precursors. We have identified 2,6-dichlorophenol (2,6-DCPh), 2,4-...

This work has used high range imaging mass spectrometry to study a coal sample that has undergone heating with a temperature gradient. A custom made hotplate was heated to 1000°C and the coal was allowed to heat naturally through conduction to produce a large thermal gradient typical of conditions in a coke oven. The sample was quenched, sectioned...

Under most reaction conditions studied, acrolein is reported as the primary product in the conversion of glycerol over zeolites. In such processes, acrolein forms at relatively high yields, with negligible allyl alcohol selectivity. In this contribution, we report the development of ZSM5-supported iron catalysts, modified by rubidium deposition, as...

The effect of methane on the conversion of HFC-134a (CF3CH2F) in a dielectric barrier discharge non-equilibrium plasma reactor was examined. Reactions were conducted in an argon bath gas and in the absence of oxygen and nitrogen. The products of the reaction include H2, HF, CHF3, CH2F2, C2H6, C3H8, C2H3F, CHF2CHF2, C2H4F2, C3H7F as well as a polyme...

An increased interest in using hydrocarbons in solid oxide fuel cells for the production of power has led to research into operation on synthesis (syn) gas, a mixture of hydrogen and carbon monoxide. Hydrocarbons are typically reformed, either internally or in an external reformer prior to the fuel cell, producing syngas with various H2:CO ratios d...

Nitrosation reactions span a diverse range of applications, from biochemistry to industrially important processes. This study examines nitrosation of aminothiones in acidic solutions and re-evaluates currently accepted diffusion limits and the true nature of the nitrosating agent for nitrous acid initiated reactions. Experimental measurements from...

In this report, the characteristics of Pd/Al2O3 catalyst after long-term stability tests in catalytic combustion of simulated ventilation air methane gas were investigated with the objective of understanding catalyst deactivation phenomena. It was found that the deactivation is primarily due to palladium migration and particle growth and is the mos...

The reaction of CCl 3 F (CFC-11) with CH 4 in a non-equilibrium plasma has been examined. CFC-11 has the highest ozone depleting potential (ODP) among all refrigerants used commercially (ODP value of 1) and also has very high global warming potential (GWP) of 4680 and an atmospheric lifetime of 45 years. 1 The manufacture of CFC-11 was banned by th...

Nitrosation reactions and subsequent decomposition of S-nitroso (RSNO+) species remain important in many biochemical processes as well as in industrial applications such as chemical gassing of emulsion explosives. This paper develops kinetic mechanisms of gas formation pathways in the decomposition of RSNO+ species, particularly S-nitrosothioacetam...