Biodiesel is a re-emerging biofuel as an alternative to the traditional petroleum derived diesel. There are however, several factors that currently hinder the widespread uptake. Majority of the biodiesel are currently produced from edible oils thereby sparking the food versus fuel debate, the cost of feedstock is significantly high, there are problems experienced in the traditional production process and the resulting fuel is of inadequate quality. This work focused on addressing the issue of poor cold flow properties to improve the overall quality of biodiesel. The skeletal isomerisation of linear fatty acid methyl esters (FAMEs) into branched chain isomers, using solid acid catalysts, appears to be the most comprehensive solution in enhancing the cold flow properties of biodiesel. However, obtaining high branched chain yields, mitigation of undesired side reactions, achieving shorter reaction times, using fewer processing steps and lower operating conditions have still not been achieved to a large extent. Moreover, no studies were found to date investigating isomerisation of FAMEs as a continuous process. A trickle bed reactor (TBR) system has been identified to be an effective continuous reactor. Its key features of being a three phase system and allowing a high degree of contact between the reactant and the catalyst offering a high conversion per unit volume provides an encouraging opportunity to lower reaction times, reaction steps and conditions whilst increasing branched chain yields. This thesis explores the use of the TBR system, for the first time, to enhance the cold flow properties of biodiesel through molecular modification using zeolite beta catalyst with Si/Al ratios of 180 and 12.5. A range of reactions have been investigated including isomerisation, dewaxing (hydroisomerisation and hydrocracking) and decarboxylation on biodiesels derived from camelina, palm and coconut oils. Significant progress has been made in this research area with a 7 °C drop in MP being achieved upon the dewaxing of the coconut biodiesel at 250 °C, 1.01 bar pressure, 0.2 ml/min LF and 37.5 ml/min GF. To achieve greater drops in melting points it has been suggested to investigate mesoporous catalysts as they will ensure greater facilitated molecular access to the active sites, resulting in a higher conversion by preventing pore blockages. All in all, a series of key findings and serendipitous discoveries have brought to surface an array of new challenges as well as paving the way for a host of exciting opportunities for future research. The ability to continuously produce high quality renewable fuel offers a fascinating prospective for various industrial associates such as Argent Energy, Olleco, Neste Oil and ConocoPhillips.

No / The growing demand for high-quality middle distillates is increasing worldwide, whereas the demand for low-value oil products, such as heavy oils and residues, is decreasing. Thus, maximizing the production of more liquid distillates of very high quality is of immediate interest to refiners. At the same time, environmental legislation has led to more strict specifications of petroleum derivatives. Hydrotreatment (HDT) of crude oil is one of the most challenging tasks in the petroleum refining industry, which has not been reported widely in the literature. In this work, crude oil was hydrotreated upon a commercial cobalt¿molybdenum on alumina (Co¿Mo/¿-Al2O3) catalyst presulfided at specified conditions. Detailed pilot-plant experiments were conducted in a continuous-flow isothermal trickle-bed reactor (TBR), and the main hydrotreating reactions were hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodeasphaltenization (HDAs), and hydrodemetallization (HDM), which includes hydrodevanadization (HDV) and hydrodenickelation (HDNi). The reaction temperature (T), the hydrogen pressure (P), and the liquid hourly space velocity (LHSV) were varied with certain ranges, with constant hydrogen to oil (H2/Oil) ratio. The effects of T, P, and LHSV on the conversion of sulfur, nitrogen, vanadium, nickel, and asphaltene were studied. The results showed that high T and P and low LHSV in HDS, HDN, HDV, HDNi, and HDAs of crude oil improve the sulfur (S), nitrogen (N), metals [vanadium (V) and nickel (Ni)], and asphaltene (Asph) conversion. The hydrotreated crude oil has been distilled into the following fractions: light naphtha (LN), heavy naphtha (HN), heavy kerosene (HK), light gas oil (LGO), and reduced crude residue (RCR), to compare the yield of these fractions produced by distillation after the HDT process to those produced by conventional methods (i.e., HDT of each fraction separately after the distillation). The yield of the middle distillate showed greater yield compared to the middle distillate produced by conventional methods. The properties of RCR produced using both methods are also discussed.

No / Petroleum contributes significantly to our lives and will continue do so for many years to come. Petroleum derivatives supply more than 50% of the world's total supply of energy (Jarullah, 2011). Traditionally crude oil goes though fractional distillation to produce different grades of fuel such as gasoline, kerosene, diesel oil, etc. providing fuel for automobiles, tractors, trucks, aircraft, and ships. Catalytic hydrotreating (HDT) is used to detoxify the oil fractions produced by fractional distillation in the petroleum refining industries which involve removal of pollutants such as sulfur, nitrogen, metals, and asphaltene in trickle bed reactors. Recently Jarullah and co-workers proposed detoxification of whole crude oil a priori before the crude oil enters further processing in a fractionating column. This chapter highlights this new technology.

Yes / The oxidative desulphurization (ODS) of light gas oil (LGO) is investigated with an in-house designed cobalt 11 oxide loaded on alumina (γ-Al2O3) catalyst in the presence of air as oxidizing agent under moderate operating 12 conditions (temperature from 403 to 473 K, LHSV from 1 to 3 hr-1, initial concentration from 500 to 1000 13 ppm). Incipient Wetness Impregnation method (IWI) of cobalt oxide over gamma alumina (2% Co3O4/γ-14 Al2O3) is used for the preparation of the catalyst. The optimal design of experiments is studied to evaluate the 15 effects of a number of process variables namely temperature, liquid hourly space velocity (LHSV) and 16 concentration of dibenzothiophene and their optimal values were found to be 473 K, 1hr-1 and 1000 ppm 17 respectively. For conversion dibenzothiophene to sulphone and sulphoxide, the results indicates that the 18 Incipient Wetness Impregnation (IWI) is suitable to prepare this type of the catalyst. Based on the 19 experiments, mathematical models that represent a three phase reactor for describing the behavior of the ODS 20 process are developed. 21 In order to develop a useful model for simulation, control, design and scale-up of the oxidation process, 22 accurate evaluation of important process parameters such as reaction rate parameters is absolutely essential. 23 For this purpose, the parameter estimation technique available in gPROMS (general Process Modelling 24 System) software is employed in this work. With the estimated process parameters further simulations of the 25 process is carried out and the concentration profiles of dibenzothiophene within the reactor are generated.

Yes / Energy saving is an important consideration in process design for low cost sustainable production with reduced environmental impacts (carbon footprint). In our earlier laboratory scale pilot plant study of catalytic wet air oxidation (CWAO) of phenol (a typical compound found in wastewater), the energy recovery was not an issue due to small amount of energy usage. However, this cannot be ignored for a large scale reactor operating around 140–160 °C due to high total energy requirement. In this work, energy savings in a large scale CWAO process is explored. The hot and cold streams of the process are paired up using 3 heat exchangers recovering significant amount of energy from the hot streams to be re-used in the process leading to over 40% less external energy consumption. In addition, overall cost (capital and operating) savings of the proposed process is more than 20% compared to that without energy recovery option.

No

No / One of the more difficult tasks in the petroleum refining industries that have not been considered largely in the literature is hydrotreating (HDT) of crude oil. The accurate calculations of kinetic models of the relevant reaction scheme are required for obtaining helpful models for HDT reactions, which can be confidently used for reactor design, operating and control. In this work, an optimization technique is employed to evaluate the best kinetic models of a trickle bed reactor (TBR) process utilized for hydrodenitrogenation (HDN) and hydrodemetallization (HDM) that includes hydrodevanadization (HDV) and hydrodenickelation (HDNi) of crude oil based on pilot plant experiments. The minimization of the sum of the squared errors (SSE) between the experimental and estimated concentrations of nitrogen (N), vanadium (V) and nickel (Ni) compounds in the products is used as an objective function in the optimization problem to determine the kinetic parameters. A series of experimental work was conducted in a continuous flow isothermal trickle bed reactor, using crude oil as a feedstock and the commercial cobalt¿molybdenum on alumina (Co¿Mo/¿-Al2O3) as a catalyst. A three-phase heterogeneous model based on two¿film theory is developed to describe the behaviour of crude oil hydroprocessing in a pilot¿plant trickle bed reactor (TBR) system. The hydroprocessing reactions have been modelled by power law kinetics with respect to nitrogen, vanadium and nickel compounds, and with respect to hydrogen. In this work, the gPROMS (general PROcess Modelling System) package has been used for modelling, simulation and parameter estimation via optimization. The model simulations results were found to agree well with the experiments carried out in a wide range of the studied operating conditions. The model is employed to predict the concentration profiles of hydrogen, nitrogen, vanadium and nickel along the catalyst bed length in three phases.

No / Fossil fuel is still a predominant source of the global energy requirement. Hydrotreating of whole crude oil has the ability to increase the productivity of middle distillate fractions and improve the fuel quality by simultaneously reducing contaminants such as sulfur, nitrogen, vanadium, nickel and asphaltene to the levels required by the regulatory bodies. Hydrotreating is usually carried out in a trickle bed reactor (TBR) where hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodemetallization (HDM) and hydrodeasphaltenization (HDAs) reactions take place simultaneously. To develop a detailed and a validated TBR process model which can be used for design and optimization of the hydrotreating process, it is essential to develop kinetic models for each of these reactions. Most recently, the authors have developed kinetic models for all of these chemical reactions except that of HDAs. In this work, a kinetic model (in terms of kinetic parameters) for the HDAs reaction in the TBR is developed. A three phase TBR process model incorporating the HDAs reactions with unknown kinetic parameters is developed. Also, a series of experiments has been conducted in an isothermal TBR under different operating conditions affecting the removal of asphaltene. The unknown kinetic parameters are then obtained by applying a parameter estimation technique based on minimization of the sum of square errors (SSEs) between the experimental and predicted concentrations of asphaltene compound in the crude oil. The full model with the estimated kinetic parameters is then applied to evaluate the removal of asphaltene (thus affecting fuel quality) under different operating conditions (than those used in experiments).

Yes / The present study explored a novel oxidative desulfurization (ODS) method of light gas oil fuel, which combines a catalytic oxidation step of the dibenzothiophene compound directly in the presence of molecular air as oxidant to obtain high quality fuel for light gas oil. In chemical industries and industrial research, catalysis play a significant role. Heightened concerns for cleaner air together with stricter environmental legislations on sulphur content in addition to fulfill economic have created a driving force for the improvement of more efficient technologies and motivating an intensive research on new oxidative catalysts. As the lower quality fuel becomes more abundant, additional challenges arise such as more severe operation conditions leading to higher corrosion of the refinery installations, catalyst deactivation and poisoning. Therefore, among the technologies to face these challenges is to develop catalysts that can be applied economically under moderate conditions. The objective of this work is to design a suitable synthetic catalyst for oxidative desulfurization (ODS) of light gas oil (LGO) containing model sulphur compound (dibenzothiophene (DBT)) using air as oxidant and operating under different but moderate operating conditions. The impregnation method is used to characterize two homemade catalysts, cobalt oxide (Co3O4/γ-Al2O3) and manganese oxide (MnO2/γ-Al2O3). The prepared catalysts showed that the manganese oxide has a good impregnation (MnO2=13%), good pore size distribution and larger surface area. A set of experiments related to ODS of dibenzothiophene has been carried out in a continuous flow isothermal trickle bed reactor using light gas oil as a feedstock utilizing both catalysts prepared in-house. At constant pressure of 2 bar and with different initial concentration of sulphur within dibenzothiophene, the temperature of the process was varied from 403K to 473K and the liquid hourly space velocity from(LHSV) was varied from 1 to 3 hr-1. The results showed that an increase in reaction temperature and decreasing in LHSV, higher conversion was obtained. Although both catalysts showed excellent catalytic performance on the removal of molecule sulphur compound from light gas oil, the catalyst MnO2 catalyst exhibited higher conversion than Co3O4 catalyst at the same process operating conditions.

Yes / Among several treatment methods Catalytic Wet Air Oxidation (CWAO) treatment is considered as a useful and powerful method for removing phenol from waste waters. In this work, mathematical model of a trickle bed reactor (TBR) undergoing CWAO of phenol is developed and the best kinetic parameters of the relevant reaction are estimated based on experimental data (from the literature) using parameter estimation technique. The validated model is then utilized for further simulation and optimization of the process. Finally, the TBR is scaled up to predict the behavior of CWAO of phenol in industrial reactors. The optimal operating conditions based on maximum conversion and minimum cost in addition to the optimal distribution of the catalyst bed is considered in scaling up and the optimal ratio of the reactor length to reactor diameter is calculated with taking into account the hydrodynamic factors (radial and axial concentration and temperature distribution).