Global Journal of Energy Technology Research Updates, 2015, 1, 25-32 25
E-ISSN: 2409-5818/14 © 2014 Avanti Publishers
Catalytic Cracking of Vacuum Gas Oil and Used Lubricating Oil on
Oil Shale Ash
Omar Al-Ayed
*
Al-Balqa Applied University, Faculty of Engineering Technology, Department of Chemical Engineering, Marka
11134 Amman Jordan
Abstract: In this research, Vacuum Gas Oil and/or used lubricating oil is subjected to thermal cracking (pyrolysis) after
impregnation on oil shale ash to obtain lighter molecular weight components. The spent oil shale of the thermal cracking
step is subjected to further heat treatment in open air at 950
o
C to react any organic compounds and mineral carbon to
metal oxide. Used and/or fresh lubricating oils are impregnated on oil shale ash particles. Ash is soaked for 24 hours to
allow absorption of the VGO or lubricating oils into the pores of the ash material. Oil shale ash which is known to contain
several metal oxides such as CaO, SiO2, and lesser quantities of Fe2O3, Al2O3, K2O, Na2O, etc. possesses inherent
catalytic nature to crack heavy hydrocarbons to produce lighter components.
The absorbed Vacuum Gas Oil and/or lubricating oil inside the pores of the oil shale ash, is allowed to crack at 600
o
C
temperature. Cracking of VGO is conducted in a fixed bed reactor under nitrogen, steam environments. The weight ratio
of the absorbed oil into the pores to oil shale ash is 1:1 ratio.
The particle size was in the range of 20-25 mm. The liquid products indicated 20 vol% falls in the kerosene fraction
specifications where as Approximately 50 vol% is diesel cut. Residue which boils at higher than 370
o
C constituted about
30 vol% of the liquid distillate.
Steam presence in the reaction media affected the composition of the product as measured in density increase. The
sulfur content of the produce is found to be 0.75 wt%.
Keywords: Cracking, lubricating oil, oil shale ash, fractionation, catalyst.
INTRODUCTION
Crude oils contain a large fraction of heavy products
for which only few outlets exist. Indeed, the world
demand for light and middle distillate continually
increases, while at the same time, the available crude
oil becomes heavier [1]. Therefore, upgrading of heavy
crude oil fraction to more useful lighter products is
indispensable. Hydrocracking and hydrotreating are the
most important processes in a modern refinery to
produce low sulfur diesel. The versatility and flexibility
of the process makes it economically attractive to
convert different types of feedstock into various yields
including gas, LPG, naphtha, kerosene and diesel,
leading to its widespread applications.
Millions of barrels of waste automobile lubricating oil
are generated every year in the world. Some of the
technologies successfully applied the operation of
regenerating plants and obtained the re-refined
lubricating oil, which has equivalent quality to the new
lubricating oil [2-4]. Kim et al. [5,6] investigated a novel
technology for obtaining more valuable product oils
from the waste lubricating oils. The waste lubricating
oils were mixed with atmospheric distillation residuum
*Address correspondence to this author at the Al-Balqa Applied University,
Faculty of Engineering Technology, Department of Chemical Engineering,
Marka 11134 Amman Jordan; Tel: +962 6 4790333; Fax: +962 6 4790350;
E-mail; omar.alayed@bau.edu.jo, omar.al-ayed@jordanoilshale.net
from crude oil and then were distilled under a vacuum.
These methods of disposal are no longer practicable,
because these treatment processes have several
problems such as low yield, environmental pollution
and sludge disposal. Therefore, it is necessary to seek
a suitable method to solve the disposal problems.
Many pyrolysis studies have been applied to
organic materials such as coal, waste tires, waste
plastics, waste woods, and oil shales [7-9]. Pyrolysis
process has certain advantages over other treatment
methods of waste disposal [7, 10, 11]. [Pyrolysis
products such as gases, liquid oils and char can be
used as fuels. Some studies have elucidated the
mechanism of the degradation of organic materials.
Ballice et al. [11] and Prakash [12] proposed a
combined parallel and series reaction scheme for the
pyrolysis mechanism of oil shale. Waste oils are an
excellent example of a high-volume waste that can be
processed into valuable products [13-14]. Pyrolysis
may be one option for conversion of waste oils into a
more useful product and has received special attention
due to the multiphase product variation with different
yields in solid, liquid and gas form depending on the
process conditions.
Large and increasing volumes of used lubricating oil
are produced each year that, after use, are considered
hazardous wastes. The used oils are disposed in many