1. MODELING OF MAGNETO-RHEOLOGICAL FLUID FLOW BEHAVIOR FOR EFFICIENT
CLEAN UP OF OIL SPILLS
Dept. of Chemical & Natural gas Engineering, TAMUK
Graduate Student: Purushothkumar Santhanamahalingam
Advisor : Dr. Chongwei Xiao
Abstract
Oil spill in Gulf Mexico, 2010 has induced an increasing interest in new
techniques for reducing environmental impact and cost of future oil spills from
both industries and government.
Currently, two major methods used are: chemical dispersants and mechanical
methods. Chemical dispersants is less desired because it can have negative
impacts on marine life. The mechanical methods do not work efficiently with
high-viscosity oil and could be hampered by bad weather. This study
numerically modeled the flow behavior of MRF subjected to external magnetic
field. When subjected to a magnetic field, the fluid greatly increases its
apparent viscosity, to the point of becoming a viscos-elastic solid. Importantly,
the yield stress of the fluid when in its active ("on") state can be controlled
very accurately by varying the magnetic field intensity. The advantages are the
oil spill cleanup by MRF is faster, and spilt oil can be collected by controlling
electromagnetic strength which avoids the need of physical transportation of
the oil and MRF can be recycled.
2) Properties of MAGNETO RHEOLOGICAL(MR) FLUID
Model of MRF flow
Behavior of MRF is represented as Bingham plastic having variable strength
(e.g., Phillips, 1996).
τ = τy (H) + η γ& , τ≥ τy
τ is greater than field dependent yield stress τy. Yield stress material behaves
visco elastically.
τ = G γ , τ< τy G is complex material modulus
Calculation of magnetic particle velocity due to gravity in viscous oil with no
magnetic field applied
∪=
2
9η
𝜌 𝑝− 𝜌 𝑜𝑖𝑙 𝑔𝑅2
= 9.4189 × 10−7
𝑀
𝑆
Time to fall 1 cm through the oil is 10000 seconds which is more than the time
required to remove oil by magnets
5) Research Objectives
1. Minimize the net environmental injury
2. Provide an efficient way of recovering hydrocarbon spills
3. Calculate the cost ratio analysis
Acknowledgement
I extent my sincere thanks and gratitude to, Dr. Chongwei Xiao for the
motivation and patience during the development of the project.
3) Previous methods of oil spill recovery
The following methods have been successfully implemented in oil spill
recovery:
•Oil Skimmers,
A)Weir skimmers, B) Vacum skimmers, C) Oleophilic skimmers,
and D) belt skimmers/Disc skimmers.
•Chemical Treatment
A)Emulsifiers, B)Dispersant, C) Surfactant D) Solvent
• Sorbents
A)Natural organic sorbents, B)Natural inorganic sorbents , C) Synthetic
sorbents
7) Methodology
Advantages Drawbacks
•High impact strength
•Vibration damping
•Tailaroble non-linear properties
•Good in plane stiffness
•High viscosity
•Short cure times
•Difficulty in testing
•Non-linear properties
6) Laboratory appearance of MR fluid
4) Disadvantages of existing methods
Skimmers Chemical treatment Sorbents
•Do not recover high
viscosity oil easily
•Difficult to install
•Recovers lot of water
with oil
•Transportation and
portability issues when
skimmers are required for
large area.
•Environmental
constraints
•Extended treatment time
•Secondary effects are
not completely studied.
•Negative impacts on the
marine life
• Ineffective in marine
environment
• Excessive use of
sorbent cause
secondary
contamination
• More adsorption of
water than oil takes
place
Step 1 : Addition of
oil to water
Step 2 : Addition of
MRF to the mixture
Step 3 : Formation
of Viscoelastic
solid
Step 4 :Movement of
mixture towards the
magnetic field
8) Future work
Flow behavior of MRF will be analyzed using ANSYS and compared with
simulated laboratory datasets. It is also expected to quantify the Increase maximum
recovery of oil by using Low HLB value surfactants. The last lap of the project is
to perform cost comparison among the existing oil recovery methods and the
proposed methods.
References
1. Kim, M.S., et al., Carbonyl iron particles dispersed in a polymer solution and
their rheological characteristics under applied magnetic field. Journal of
Industrial and Engineering Chemistry, 2012. 18(2): p. 664-667.
2. Zahn, M., T.A. Hatton, and S.R. Khushrushahi, Magnetic colloid petroleum oil
spill clean-up of ocean surface, depth, and shore regions. 2012, Google Patents.
Activation of MR fluid: (a) no magnetic field applied(b) magnetic field applied;
(c) ferrous particle chains have formed
𝐹𝑖𝑗 = 𝑚𝑎𝑔𝑛𝑒𝑡𝑖𝑐 𝑓𝑜𝑟𝑐𝑒 ; 𝜇 𝑝 = 𝑠𝑝𝑒𝑐𝑖𝑓𝑖𝑐 𝑝𝑒𝑟𝑚𝑒𝑎𝑏𝑖𝑙𝑖𝑡𝑦 𝑜𝑓 𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒𝑠 ;
𝜇0 = 𝑣𝑎𝑐𝑢𝑚 𝑝𝑒𝑟𝑚𝑒𝑎𝑏𝑖𝑙𝑖𝑡𝑦 ;
𝑟𝑖𝑗 = 𝑝𝑜𝑠𝑖𝑡𝑖𝑜𝑛 𝑓𝑟𝑜𝑚 𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒 𝑗 𝑡𝑜 𝑖;
𝑚 = 𝑚𝑎𝑔𝑛𝑒𝑡𝑖𝑐 𝑑𝑖𝑝𝑜𝑙𝑒 𝑚𝑜𝑚𝑒𝑛𝑡 𝑖𝑛𝑑𝑢𝑐𝑒𝑑 𝑖𝑛 𝑡ℎ𝑒 𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒;
𝐻 = 𝑢𝑛𝑖𝑓𝑜𝑟𝑚 𝑚𝑎𝑔𝑛𝑒𝑡𝑖𝑐 𝑓𝑖𝑒𝑙𝑑;
𝜇 𝑓 = 𝑠𝑝𝑒𝑐𝑖𝑓𝑖𝑐 𝑝𝑒𝑟𝑚𝑒𝑎𝑏𝑖𝑙𝑖𝑡𝑦 𝑜𝑓 𝑐𝑎𝑟𝑟𝑖𝑒𝑟 𝑙𝑖𝑞𝑢𝑖𝑑.
𝐹𝑖𝑗=
3
4𝜋𝜇 𝑝 𝜇0
𝑚2
𝑟𝑖𝑗
𝑟5
𝑖𝑗
− 5 𝑚 𝑟𝑖𝑗
2 𝑟𝑖𝑗
𝑟7
𝑖𝑗
+ 2 𝑚𝑟𝑖𝑗 𝑚
1
𝑟5
𝑖𝑗
𝑚 = 4𝜋𝜇 𝑓 𝜇0 𝛽𝛼3
𝐻
𝛽 =
𝜇 𝑓 − 𝜇 𝑝
𝜇 𝑓 − 2𝜇 𝑝1) Introduction
MRF is a type of smart fluid and can be moved by application of magnetic
field. In the recent days it is studied as an innovative technology to clean up oil
spill. MRF are composed of microscopic iron-containing particles suspended
in a matrix fluid. Several published articles suggest that this “smart fluid” is
efficient compared to existing oil recovery methods. Its important
characteristics like yield stress and viscosity can be used modified by applying
magnetic field. This property is effectively applied in oil spill recovery.
• When MRF is added to the oil, MRF behaves like Newtonian fluid in
absence of magnetic field.
• On application of the magnetic field it forms in to a viscos-elastic solid.
The mixture moves towards the direction of magnetic field
• Magnetic fluid is separated from non-magnetic phase by using magnetic
separation techniques.
• Oil is then separated by passing into high pressurized separator and MR
GEL is also obtained.
• Separated oil is sent to refineries for further separation These steps are
represented in the following equations: