mimoun. hadj and boukhemkhem. ali university of boumerdes algeria email :...
TRANSCRIPT
Aromatic hydrodecyclization of using catalysts based on molybdenum and tungsten supported on the Remblend of Kaolin( local clay based on bentonite)
Abstract
• what is the news of the study? What is the interest?our interest is eliminate the harmful effects of sulfur (reduce air pollution sulfur) improve quality for the recovery of the oil products
what guidance track?
synthesizing a catalyst ensuring to : open aromatic cycles reduce the aromatic content in fuels. Reduce the sulfur content in products
the work is structured in three steps• 1-preparation and characterization of catalysts
2- use of catalysts prepared in the method craking3-analyzes of the products obtained and discution
1-Introduction.
• The very stringent specifications are adopted in several countries to minimize the negative harmful exhaust emissions impact.
• Reducing the concentration of the sulfur content of the polycyclic aromatic compound in oils and diesel fuels.
• The high and exigent demand for diezel refiners requires increased recovery of aromatic fractions from the catalytic cracking process using novel catalysts which provide aromatic hydrogenation followed by selective ring opening of naphthenes.
1.Introduction.
The study consist of the valorization of petroleum fractions rich on polyaromatics diesel fuel using clay catalysts. is based on the change in the content of aromatics in terms of temperature, under constant hydrogen pressure
preparation and characterization of catalysts This part is based on the preparation of two catalysts from the
Kaolin Remblend. The first is monometallic, consisting of molybdenum Mo / Kaolin. second bimetal is composed of tungsten and molybdenum Mo-
W / Kaolin .
1-Introduction.The kaolin used is subjected to physical-
chemical analyzes to determine the mineralogical composition and physical-chemical and mechanical properties of the clay.
2-catalytic test performed on the prepared catalysts
The second is to develop the petroleum fractions containing high levels of polyaromatic diesel fuel by the methods of déshydrodécyclisation aromatics using a vast catalysts prepared.
Introduction.
• A third part is devoted to the chromatographic analysis of products to develop the conversion and selectivity of catalysts .
2. Experimental
• A series of analysis was performed to characterize the natural clay used as carrier for catalysts.
• 2.1. Infrared spectroscopy Analys• Figure 1 : Infrared spectrum of natural Kaolin Remblend
5007501000125015001750200025003000350040001/cm
0
5
10
15
20
25
30
35
40
%T
13
84
,89
10
95
,57
2. Experimental
• According the FTIR spectrum, the following bands are observed: • 3400-3500 Cm-1: Broad band attributed to hydroxyl groups OH. • 1630-1700 Cm-1: Assigned to the vibration of the water molecule.• 752-789 Cm-1: Denotes the elongation of the vibration of Si-O-Al
bond. • 1095 Cm-1: Denotes the elongation of the Si-O bond. • 540 Cm-1: Characterize the elongation of the Al-O-OH bond. • 913 Cm1: Characterize the elongation of the Al-OH bond. • 570 Cm-1: characteristic of the Si-O deformation binding [4]
2. Experimental
• 2.2. Mineralogical structure of the kaolinite • Mineralogical analysis was Scanning electron
microscope PHILIPSE FX30. kaolin structure is shown below in figure 2
Figure 2 : MEB Image of natural kaolin Remblend
2. Experimental
• The kaolinites are minerals clay formed by stacking sheets identical, of type 1: 1 of structural formula Si2Al2O5(OH)4.
• 2. 3. Determination of the chemical composition.
Data analysis of fluorescence X (XRF) is given by table 1
• table 1: Chemical composition of kaolin Remblend.
2. Experimental
Figure 4 : Steps of catalysts preparation
• Draying Kaolin Filtration and washing • impregnating the activated Kaolin
by metal salts drying in an ovenat 180°C• Air drying calcination analys and
test catalysis•
Acide activation of Kaolin(HCl)
Air dryingFormatting
Figure 5 : FTIR spectrum of the prepared catalysts
5007501000125015001750200025003000350040001/cm
0
5
10
15
20
25
30
%T
13
84
,89
10
91
,71
45
9,0
6
3.1. Characterization of the catalysts used
• 3.1. Characterization of the catalysts used • 3.1.1. Analysis by infrared spectroscopy • The catalysts obtained are characterized by infrared spectroscopy,
the spectra obtained for the two catalysts have the same general shape, the observed bond are:
• 3400-3500 Cm-1: Broadband attributed to hydroxyl groups OH. • 1630-1700 Cm-1: Assigned to the vibration of the water molecule.• 752-789-803 Cm-1: Denotes the elongation of the vibration of Si-O-
Al bond. • 1095-1171 Cm-1: Denotes the elongation of the Si-O bond. • 500-450 Cm-1: Denotes bands metal oxides. • 913 Cm-1: Characterize the elongation of the Al-OH bond • 570 Cm-1 : characteristic of the Si-O deformation [10] binding
3.1.2. Analysis by electron microscopy (SEM)
Analys material• 3-analyzes of the products obtained and discution• The product used is the average aromatic, resulting from the
process of aromatic extraction contained in the basic oils. We study the elemental composition of paraffins, olefins, naphthenes and aromatics, for that chromatographic analysis were performed by gas chromatography (GC).
we are only interested by: P, O, N, A. The operating conditions :The catalyst was tested at different temperatures• at 450, 470, 490 and 540°C. • * Space velocity PPH = 2h-1. • * Hydrogen pressure = 6 bar
Resultats
discusion Catalytic tests performed on hydrodecyclization reactions of
aromatics contained in the medium aromatic extract, led to the following results:
• The Bimetallic catalyst (MoO3-WO3 / Kaolin) is more active than monometallic.
• Under a pressure of 6 bar hydrogen, increases temperature leads to the formation of products derived from aromatic hydrocyclisation, but beyond the temperature of 490 ° C the cracking reaction are predominate.
• Both catalysts show good activity for mercaptans. • The deposit of coke on the two catalysts becomes increasingly
significant with increasing temperature, this coke poisons the catalysts.