1. D.B.E.B. Indian Institute of Technology-Delhi
Industry Day Theme # 4: Sustainable Habitat
Biological upgradation of heavy crude oil
an alternative to conventional petroleum
Arif Nissar Zargar, Manoj Kumar* and Preeti Srivastava*
ABSTRACT
The depletion of conventional petroleum is creating an alarming situation and therefore a need is felt to shift to some alternative resource. Two types of crude oil reserves present in the nature include light crude oil reserves and heavy crude oil. The reserves of heavy crude oil are seven times more as compared to that of light crude oil reserves. But due to higher viscosity, specific gravity and tendency of some components of heavy oil to precipitate, it is not used as fuel. If the viscosity, density and amount of asphaltene of heavy crude oil can be reduced it could serve an alternative to conventional petroleum. We have isolated a 9 membered consortium by enrichment culture of oil contaminated soil taken from IOC R & D Faridabad. The consortium has been used for biotransformation of asphaltene in order to upgrade heavy crude oil. It was found that the consortium was successful in biotransforming 78% asphaltene in 3 weeks and reduce the viscosity of heavy oil by 91% in two weeks without affecting the calorific value of the fuel. The consortium was also successful in reducing the sulfur and nitrogen content of heavy oil by 80%.
RESULT
INTRODUCTION
Depletion of energy resources is of major concern.
A need is felt to shift to some alternative form e.g. nuclear energy, electricity, wind energy, solar energy and biofuels.
MATERIALS AND METHODS
Fig 8: Isolated members of consortium
Properties
Light
crudes
Heavy Crudes
API gravity
> 22.9
8 - 22
Sulfur (wt %)
1.13
Nitrogen(wt %)
0.22
Asphaltene (wt %) 2
11-45
Vanadium (ppm) 49
Nickel (ppm) 11
Viscosity at 50˚
0.074 Pas
15 – 21 Pas
Pour point ˚C
<-30 27
Fig 1: Types of crude oil
Fig 2: Comparison of light and heavy crude oil
Fig 3: Limitations of heavy crude oil
Fig 9: Growth curves of consortium on different carbon sources
Fig 10: Asphaltene biodegradation and biotransformation by consortium
Fig 4: Structure of asphaltene
Fig 5: Asphaltene precipitation in pipes
Fig 6: possible methods of asphaltene removal
D.B.E.B. Indian Institute of Technology-Delhi
Fig 11: Elemental changes in asphaltene due to biotransformation
Fig 12: NMR analysis of untreated and biotransformed asphaltene
By FTIR, NMR and CHNS analysis
By CHNS analysis and rheology studies
Fig 7: Schematic representation of methodology followed
Fig 13: FTIR analysis of untreated and biotransformed asphaltene
CONCLUSIONS
A nine membered consortium has been isolated.
The consortium has been successful in biotransforming 78% of asphaltene.
Upgradation of heavy crude oil resulted in viscosity decrease of 91%.
No decrease in carbon and hydrogen has been observed which means that the calorific value of the fuel is remaining intact.
80% reduction in sulfur and nitrogen content of asphaltene due to its biotransformation has been observed.
Heavy oil upgradation resulted in 20% decrease in nitrogen content and 80% decrease in sulfur content of heavy crude oil.
INDUSTRIAL SIGNIFICANCE
The isolated consortium can be used to reduce the viscosity of heavy crude oil at industrial scale.
TECHNOLOGY READINESS LEVEL
Lab scale technology has been developed. The process needs to be scaled up to industrial scale .
Fig 11: Viscosities of untreated and upgraded heavy oil
Fig 11: Elemental changes in heavy oil due to biotransformation
REFERENCES
Ali, H.R., El-Gendy, N.S., Moustafa, Y.M., Roushdy, M.I. and Hashem, A.I., Degradation of asphaltenic fraction by locally isolated halotolerant bacterial strains. ISRN Soil Science, 2012.
Uribe‐Alvarez, C., Ayala, M., Perezgasga, L., Naranjo, L., Urbina, H. and Vazquez‐Duhalt, R., First evidence of mineralization of petroleum asphaltenes by a strain of Neosartorya fischeri. Microbial biotechnology, 4(5), pp
Lavania, M., Cheema, S., Sarma, P.M., Mandal, A.K. and Lal, B., Biodegradation of asphalt by Garciaella petrolearia TERIG02 for viscosity reduction of heavy oil. Biodegradation, 23(1), pp
Tavassoli, T., Mousavi, S.M., Shojaosadati, S.A. and Salehizadeh, H., Asphaltene biodegradation using microorganisms isolated from oil samples. Fuel, 93, pp
ACKNOWLEDGEMENT
Authors would like to thank IIT-Delhi for providing basic infrastructure and Department of Biotechnology, Government of India for funding the project. Authors would also like to express profound gratitude to Indian Oil Corporation Limited for providing asphaltene and heavy crude oil for the research work.