A project thesis submitted to the Chemical Engineering Program Universiti Teknologi PETRONAS in partial fulfillment of the requirement for the. I hereby certify that I am responsible for the work submitted in this project, that the original work is mine except as specified in the references and acknowledgments, and that the original work contained herein was not performed or performed by -specified sources or persons. . The primary goal of this work is to prepare and characterize Fe/TiO2 for deep desulfurization in visible light.
Thus, Fe loading on TiO2 is used in this experiment to investigate the desulfurization performance under visible light. First and foremost, I would like to express my gratitude to God for His kind blessings in giving me the strength and determination to complete this Project 2 Final Year course after stressing with all the hardships and challenges of several months the last. I would also like to take this opportunity to express my utmost gratitude to Universiti Teknologi PETRONAS (UTP) for providing me all the facilities to complete my project within the stipulated time.
My thanks are also expressed to a PhD student, Mrs. Hayyiratul, for her efforts to assist me in all possible ways. Last but not the least, my appreciation goes to all the staff members in the ionic liquid station, centralized analytical laboratory (CAL), mechanical engineering department and chemical engineering department for their contributions and equipment which helped me a lot to make sure that this project ended successfully.
Background
Currently, the sulfur content for diesel in Malaysia is 500 ppm, which is a Euro II equivalent standard (Singh, 2009). June 1, 2015 is the rollout date for Malaysia to raise the standard from Euro II to Euro V, reducing the sulfur content from 500 ppm to 10 ppm. With the current diesel desulfurization technology, the hydrodesulfurization method (HDS) is not effective for removing the high stearic hindrance sulfur component.
In addition, this process has to be carried out at high temperatures (300-400oC) and pressures (20-100 atm H2) and has led to high operating costs. It is effective in removing thiols, sulfides and thiophenes, but less effective for benzothiophene, dibenzothiophene and their alkyl derivatives (Kulkarni & Afonso, 2010). Due to the great concern about sulfur dioxide, there is a plethora of studies or ways to remove sulfur, such as photo-oxidative desulfurization, oxidative desulfurization, biodesulfurization, reactive adsorption, non-destructive adsorption, N adsorption, extraction and various processes (Kulkarni & Afonso, 2010).
Problem Statement
Objectives
Scope of Study
Photocatalyst
For example, the surface area, active sites, absorption of photon energy and band gap energy have the function to effect the organic component degradation (Al-Rasheed, 2005). Moreover, TiO2 could be synthesized by TiCl4 with the addition H2SO4 which could assemble TiO2 in anatase phase (Li & Zeng, 2011). The use of H2O2 in desulfurization improves the performance of photocatalyst slightly and due to the presence of oxidant.
However, flow rate and bed height can affect sulfur species removal performance. With the current HDS process, converting refractory sulfur components such as dibenzothiophene (DBT) to H2S is less competent due to the steric hindrance on the catalyst surface. Abundant research into removing the sulfur component using ionic liquid extraction has shown the potential of achieving a low sulfur concentration in diesel fuel.
It has a wide range of applications that has the potential to use its polarity for the removal of sulfur and organic nitrogen compounds in fuels under mild conditions. For example, imidazolium-based ionic liquids, pyridinium-based ionic liquids, acidic Lewis and Brønsted ionic liquids or redox ionic liquids (Kulkarni & . Afonso, 2010).
Ionic Liquid
The increase in mass ratio of ILs to the model oil (1:1), [BPy]BF4 showed the best absorption thiophene capacities from the model oil among the six ILs. It was also concluded that with the increase in mass ratio of ILs to the model oil the more ability to extract thiophene. The cation or anion structure and the size of ILs play an important role as they can affect the ability of sulfur extraction.
As the temperature increases, the viscosity of ILs decreases and their residence time in contact with sulfur species in the model oil is high. Zhao, Wang, and Zhou (2007) used a Brønsted acid IL with the presence of H2O2 for diesel fuel desulfurization. H2O2 acts as an oxidizing agent as it can increase the efficiency of conversion of sulfur species to their corresponding sulfones.
They also tested that Brønsted acid IL must be used at a higher temperature to achieve 100% conversion of DBT within 1 hour. In addition, the ionic liquid [Hnmp]BF4 can be recycled and act as a catalyst and extractant. Because it has reduced the viscosity of IL in order to increase the contact time with the sulfur species in diesel oil.
Photo-oxidative extraction deep desulfurization
Project Flow Chart
Key milestone/Gantt Chart
Proposed Experiment Procedure
Characterization of the samples was performed to determine the physical and chemical properties of the photocatalysts. Thermal gravimetric analyzes (TGA) were performed using a Perkin Elmer TG system (Pyris 1) to determine the approximate decomposition temperature of Fe/TiO2 feedstock. Samples were weighed in the 2–5 mg range using a built-in microbalance attached to the instrument, which automatically reads the sample weight.
Fourier transform infrared spectroscopy (FTIR) is used to identify the functional groups present in the samples. FTIR spectra of Fe/TiO2 catalysts with different calcination temperatures were scanned from 4000 cm-1 to 450 cm-1 by Perkin Elmer spectrophotometer. The samples were then transferred to a coverslip and pressed into a pellet using a hydraulic hand press.
During the analysis, some of the infrared radiation was absorbed and some of it was passed through the sample. The molecular absorption and transmission is shown in the spectrum result in the form of functional group fingerprints, which could be identified by characteristic peaks in the spectrum. The samples were scanned at 5,000X magnification, where they could magnify from 20X to approximately 30,000X and spatial resolution of 50 to 100 nm.
SEM micrographs are expected to generate a variety of signals on the surface of Fe/TiO2 specimens. Signals derived from electron-sample interactions reveal information about the sample including the external morphology, structure, chemical composition, and orientation of the materials that make up the sample (Swapp, 2013). The TEM sample stage incorporates airlocks to allow introduction of the sample holder into vacuum with minimal pressure build-up.
Once the photocatalyst is placed in TEM, the sample must be manipulated to present the region of interest to the beam. The sample is placed in the sample container and make sure that the sample container is completely covered. The band gaps for all the photocatalysts were determined from the extrapolation of the absorption edge to the energy axis (Bv).
Characterization of Fe/TiO 2 photocatalyst
Thermal Gravimetric Analysis (TGA)
Fourier Transform Infrared Spectroscopy (FTIR)
Scanning Electron Microscope/Energy Dispersive X-ray (SEM/EDX)
Transmission Electron Microscopy (TEM)
Brunauer-Emmette-Teller (Surface Area & Porosity)
Diffuse Reflectance UV-visible spectra (DRUV-Vis)
In conclusion, this project is important as it could find alternative ways to desulfurize diesel oil by using TiO2 followed by metal ion in visible light. From the TGA results, it shows that starting from 350oC is the best calcination temperature. With the high concentration of Fe loading on TiO2, it would reduce the particle size and so it reduces the band gap of photocatalyst, which could increase the photonic efficiency.
Preparation of Fe/TiO2 by different methods such as sol-gel method and more which gives smaller particle size and can perform better. A facile strategy for the preparation of well-dispersed bimetallic oxide CuFe2O4 nanoparticles supported on mesoporous silica. Photocatalytic activity of titanium dioxide coatings: Influence of the firing temperature of the chemical gel.
Ultrasonic synthesis and photocatalytic performance of metal-ion doped TiO2 catalysts under sunlight irradiation. Synthesis and Characterization of Nanocomposite Films with a Titania Glass Matrix by the Sol±gel Route. Visible-light driven nitrogen doped TiO2 photocatalysis: effect and nitrogen precursors on their photocatalysts for decomposition of gas-phase organic pollutants.
Retrieved from http://www.theedgemalaysia.com/commentary/17877-my-say-malaysia-slow-on-clean-fuel-initiatives.html. Catalytic oxidation of thiophene and its derivatives via dual activation for ultra-deep desulfurization of fuels. Oxidative desulphurisation of diesel fuel using a Brønsted acid room temperature ionic liquid in the presence of H2O2.
