This presentation was given at the Philadelphia AiChE continuing education meeting of 23 April 2018. HiGee (high gravity) technology for gas-liquid mass transfer is discussed, as one means of process intensification. The history of its development is treated, along explanation of the technology and the evolution of the equipment designs. Literature examples of applications are listed, with some data for a few of these, comparing to conventional distillation and mass-transfer technologies. An evaluation of the technology is given. While fouling services may be a challenge, this technology would have a place in certain applications in US industry.

1. HiGee gas-liquid mass transfer
S. GALANTE
AICHE
APRIL 2018
CONTENT REFLECTS MY OWN PERSONAL VIEWS, NOT
THOSE OF MY EMPLOYER, ARKEMA

2. BACKGROUND
 In preparing my DEBOTTLENECKING talk for AIChE Phila (Nov 2016), “Hi-Gee”
technology kept appearing as debottlenecking technique.
 My focus then, was conventional technologies, not new ones.
 Today we focus on Hi-Gee “It’s big in China. Are we US people missing
something?”
 OUTLINE:
 Process intensification (PI)
 Description of Hi-Gee
 Technical basis & why conceived
 Examples
 Current status in industry
Development
Used where/how
 Evaluation
 Future

3. Keller’s process-design vision (2000) still true today:
Themes for Future Process-Design Improvements
• Raw material cost reduction • Greater emphasis on
process safety
• Capital cost reduction • Increased attention to
quality
• Energy use reduction • Improved environmental
performance:
• Emissions reduction
• Net water use reduction
• Increased process flexibility
and inventory reduction
Process reliability could arguably be added to the list - “design
for reliability”

4. TYPICAL COST BREAKDOWN FOR CHEMICAL PRODUCTION
% of SALES PRICE (Keller, 2000)
SMALL VOLUME
PRODUCTS (<10 MM
lb/year)
LARGE VOLUME
PRODUCTS (>100
MM lb/year)
Raw materials 5-20 40-70
Capital Cost,
including ROI &
depreciation
5-30 25-50
Labor and indirects 10-50 <10
Energy 5-30 <10
Maintenance, taxes,
waste disposal
10-30 <10
Keller’s cost breakdown is dated, but key points still true: The big money
for big production plants is in raw materials and capital cost.

5. Attack capital cost  Process intensification
 Effect a major reduction in the size, weight & cost of process
plant; reduce plant size by 10-1000 times for a given
throughput
 Consists of :
 Increasing the heat/mass transfer coefficients
 Increasing the interfacial area
 Increasing the driving force for heat/mass transfer
 Hybridization of different unit operations (such as dividing
wall distillation, not discussed here).
 HIGee (“high –g” i.e. high gravity) is one path of process
intensification (PI)

6. Earth’s Gravity establishes limits in distillation. I.
 Gravity brings the requirement for height of separation columns
(fractionators, absorbers and extractors.)
 Heavy phase flows down under influence of gravity, which
dictates allowable phase flows & achievable mass transfer rates.
Vapor rate too high,
blows liquid onto tray
aboveLow vapor rate; liquid
drips down
PROBLEMS WITH TRAYS
Jet
Flooding
Weeping
Souders-Brown
Flooding correlation
Simple Theory:
#1 #2

7. Earth’s Gravity establishes limits in distillation II.
DOWNCOMER FLOODING
Holes in
sieve trays
DowncomerDowncomer
backup
New Liquid
Level
Froth
#3

8. Columns can be tall!
 Example: typical isomer separation ~90 stages, 2 ft per stage
180 ft column!
 >200 ft is not uncommon
 Challenges: installation (crane), supporting steel structure,
cleaning, maintenance, inspection
  Height/size of columns inspired practitioners to develop new
technology equipment, enhancing gravitational fields via rotation.
 Rotating contactors were developed in 1930’s (Podbielnak
column). Resurgence started as a spinoff of a NASA microgravity
project in 1970’s, and the concept was repopularized in early 80’s
by Ramshaw et al and the advent of Process Intensification. (See
Review by Rao 2015. )
 HiGee is a modern name for the concept

9. HiGee Unit (early, simple design)
𝝎𝝎
LIQUID INLET
VAPOR OUTLETMECHANICAL
SEAL
LIQUID
OUTLET
VAPOR INLET
MOTOR
STATIONARY
LIQUID
DISTRIBUTOR
SHAFT
ROTOR
WITH
PACKING
MECHANICAL
SEAL
CASING BASE PLATE
Packing bed=wire mesh or
high porosity metal foam
Liquid flows into bed as
droplets or fine spray
Thin films on high area
packing improved
liquid-side mass transfer
coefficients

10. Vertical or horizontal orientation
Note: G force (~rω2) and angular velocities (~rω) vary with radial
position r. Film thickness & mass transfer does as well.
Complicates modeling.

11. 1ST COMMERCIAL UNIT – ICI 1982
 £1.2 million (2018: £4.4 million ~$6.2 million), 40T stainless steel.
 Vertical shaft, 1800 rpm, 22 bar design; 1000*g is reported elsewhere
to be typical
 18 stages in 300 mm height. Retimet metal foam packing, surface
area density of 2000m2/m3. 5-8x higher than most column packing.
 Concluded that the best place to use it was offshore. Concept was
used for cleaning the air in submarines (CO2 removal).

12. HiGee has not taken off in US – probably for
commercial rather than technical reasons.
 Ownership of the technology changed hands through the years. The technology
was subsequently licensed to Glitsch in 1980’s because of their well established
business with conventional distillation & absorption equipment. (Glitsch acquired
by Koch)
 Competes with existing equipment (The “digital camera phenomena” at KODAK:
Businesses for existing technology are slow to promote new)
 Retrenchment by both the chemical and oil industries, coupled with ICI’s
subsequent acquisition
 We can’t find a US supplier at this time, but
 Chinese supplier(s) have been reported.
 Andritz (DE) reports supplying “rotating packed-bed centrifuge RPB” units to Dow:
https://www.andritz.com/products-en/group/separation/filter-centrifuges/rotating-
packed-bed-centrifuge-rpb
 >200 units are reportedly used in distillation world wide as of 2011: chemical,
pharmaceutical, fine chemical, biochemical and environment protection
applications.
 Development work continues in Europe and particularly in Asia.

13. ACTIVE R&D TOWARD IMPROVEMENTS & APPLICATIONS
 CHINA: Seems to be world leader, probably because of new
plants and new opportunities for application.
 Hi Gravity Engineering and Technology Centers in Beijing
University of Chemical Technology (Zheng) & other Chinese
universities.
 Taiwan, Chang Gung University
 INDIA:
 Indian Institute of Technology Kanpur and Jadavpur University,
Kolkata
 EUROPE:
 PI center at New Castle University Upon Tyne, & BHR GROUP UK;
 PI center at Delft University of Technology, the Netherlands;

14. HiGee Unit (early improvements)
𝝎𝝎
LIQUID INLET
VAPOR OUTLETMECHANICAL
SEAL
LIQUID
OUTLET
VAPOR INLET
MOTOR
STATIONARY
LIQUID
DISTRIBUTOR
SHAFT
ROTOR
WITH
PACKING
MECHANICAL
SEAL
CASING BASE PLATE
LIMITATION:
Vapor-side mass transfer
coefficients (usually
controlling in distillation)
are in same range as for
conventional columns
Why? Solid-body rotation of
liquid & gas  same slip
velocities as conventional
columns

15. Later Designs Hi-Gee Units
2 counter rotating disks
increase gas/liquid slip
velocities
Packing on disk 1
Packing on disk 2
SPLIT PACKING DESIGN 2005 ROTATING ZIG-ZAG DESIGN (RZB) 2007
1 ROTATING + 1 STATIONARY DISK
(Concentric cylindrical baffles: No
packing)
DIFFICULT TO BUILD –
2 ROTORS

16. MASS TRANSFER ZONES IN RZB – 3 steps
 Step I is crosscurrent contact of gas with
liquid droplets.
 Step I, gas countercurrently contacts liquid
falling down stationary baffles.
 Step III, is crosscurrent contact of two phases
when liquid travels through space between
the stationary baffle and rotating disk
 The second step seems most important
the turbulent surfaces of falling liquid renew
rapidly due to friction imposed by rotational
gas flow and the continual impact of liquid
droplets.
 This is equivalent to a small wetted-wall
column in a centrifugal field and the rotor of
the RZB can be considered as a cluster of
wetted-wall columns.

17. Recent Design HiGee Unit (2010)
MULTI ROTOR ZIG-ZAG DESIGN (RZB)
3-level Rotating Zigzag Bed
(3-level RZB)
(Concentric cylindrical
baffles: No packing)
On each level, top plates are
stationary, bottom plates
rotate.
Note multiple liquid feed
points

18. 2010 Design HiGee Unit Configured for Distillation

19. Diverse Applications, including:
 Dehydration and CO2 removal from natural gas by Statoil w/ Glitsch (1989)
 Shengli Oil Field in China, where 1.5-m-dia. Rotating strippers (500-2000 rpm)
replaced 30-m-high vacuum towers for the deaeration of water (1997)
 Synthesis of petroleum sulfonate (PS) surfactant used for enhanced oil
recovery at Shengli (2010)
 Dow Chemical Co. used HiGee as a rotating packed-bed reactor in its
hypochlorous acid process (2001)
 Desulfurization of a gas stream in oil refinery (Visakhapatnam, India).
 Nanoparticle synthesis applications of CaCO3 (fast reaction, short residence
time) reported (2010)
 Many others

20. Methanol distillation, HiGee (3-level RZB) and Conventional
Compared
EQUIPMENT:
PARAMETER:
RZB PACKED
COLUMN
Diameter/m 0.83 0.6
Total height/m 0.80 11.0
Volume/m
3
0.433 3.11
Height ratio/- ~0.07
Volume ratio/- ~0.14
Methanol mass feed composition=70%,
Overhead purity=99.8%
Bottoms residual =0.2%

21. Ethanol distillation, HiGee (3-level RZB) and Conventional
Compared
EQUIPMENT:
PARAMETER:
RZB PACKED
COLUMN
Diameter/m 0.80 0.4
Total height/m 0.55 9.0
Volume/m
3
0.276 1.13
Height ratio/- ~0.06
Volume ratio/- ~0.24
Ethanol mass feed composition=45%,
Overhead purity=95%
Bottoms residual =0.5%

22. Selective Absorption of H2S from Natural Gas, HiGee
and Conventional Compared
EQUIPMENT:
PARAMETER:
Simple
HiGee
PACKED
COLUMN
Packing Volume/m
3
0.031 14
Solvent Circ rate (ton/hr) 21 30
Power Consumption (kW) 217 250
Steam for solvent
regeneration (ton/hr)
8.5 9.5
Absorption of H2S (as % from
Feed)
~99.9 ~99.9
Absorption of CO2 (as % from
Feed)
8.9 79.9

23. Offshore Oil field Application in China –
Water De-aereation
De-aereation is needed for water injected in oil recovery- O2 concentration must be
reduced to only several ppb, by a stripping technique to:
Avoid biological contamination and blockage of the oil-bearing rock,
Avoid pipework corrosion

24.  Electrical Power higher, for rotation (but some is dissipated as heat)
 Heating, cooling probably same as in traditional units – reboiler/condenser. Losses
probably lower in HiGee
 Gas phase pressure drop higher
Packing volume is much reduced over conventional equipment  the gas side pressure
drop is greater than in larger equipment.
Two components:
(1) Friction - i.e. the pressure drop required to create a flow of gas through the small packed
volume (liquid effects are reported to be small in literature) and,
(2) Rotational - On rotating the packing can act as a fan or blower transporting gas from
center to periphery of the rotor. The rotational component of the pressure loss is that
required to overcome this effect and force the gas from periphery to center of the rotor.
Energy Consumption Reported to be an advantage in
HiGee, but probably is not

25. Pressure drop – strong function of Gas flow and rpm

26. Pressure drop – weak function of Liquid flow rate
Q=gas flow rate; L=liquid flow rate

27. TECHNOLOGY EVALUATION OF HiGee
ADVANTAGES DISADVANTAGES
1. Compact compared to conventional towers
a. Good for tight spaces, low height/area
installations.
b. Higher mass transfer coefficients
c. Low liquid holdup and residence time
d. Potential for lower capital cost (to be
verified – for distillation we still need
reboiler, condenser, piping, PLUS motor
and controls, and installation)
2. Resistant to orientation & motion.
3. Additional degree of freedom: rotational
speed
1. Restriction to clean service—small channels
and small pores clog easily.
2. High gas-phase pressure drop (liquid effects
are small) probably not suited for high-
vacuum applications
3. Power required to rotate the device and spin
gas & liquid to high tangential velocities.
4. Seals and leaks, as with all rotating
equipment.
5. Need for careful balancing (has been has
been over-come by centrifuge
manufacturers),
6. Additional point of failure, in motor and
electrical

28. CONCLUSIONS
 A worthy new technology with a place in US industry:
 Low space, low footprint applications
 Encourage more US university work (seems to be happening at Oklahoma
State University?)
 Encourage FRI (Fractionation research institute) to develop a consortium.
 Start to Develop Aspen models – some modeling has started, but difficult
 Must deal with mechanical aspects- reliability and seals as part of any
development program.

29. References I.
Keller, G. E, II; Bryan, P. F, “Process engineering: Moving in new directions” Chemical Engineering Progress; Jan 2000.
Wem, J. (ICI), “Designing building and operating the first commercial size HiGee machine set,” 20th PROCESS INTENSIFICATION NETWORK (PIN) MEETING,
'What's New in PI 2012?‘, The Beehive, Newcastle University, 2 May 2012
Hawkins, G. B., “Methanol Plant Theory of Distillation,” https://www.slideshare.net/GerardBHawkins/methanol-plant-theory-of-distillation, downloaded 22
April 2018
D.P. Rao (2015) The Story of “HIGEE”, Indian Chemical Engineer, 57:3-4, 282-299
Y. Tamhankar, MS The-sis, Oklahoma State University, Dec., 2010).
“Centrifugal Processing: So Just What is HIGEE?” The Contactor, Optimized Gas Treating, Inc. (, Trade Publication) Volume 10, Issue 4, April, 2016
Wang G. Q., Xu Z. C., Li X. H., Ji J. B., “AN INTRODUCTION TO NEW HIGEE DEVICE AND ITS INDUSTRIAL APPLICATIONS,” DISTILLATION ABSORPTION 2010, 271-276.
G.Q. Wang, Z.C. Xu, J.B. Ji “Progress on Higee distillation—Introduction to a new device and its industrial applicationS,” chemical engineering research and
design 8 9 ( 2 0 1 1 ) 1434–1442
Shivhare M.K., Rao D.P, Kaisthaa, N.“Mass transfer studies on split-packing and single-block packing rotating packed beds,” Chemical Engineering and
Processing 71 (2013) 115– 124
G.Q. Wang, Z.C. Xu, Y.L. Yu, J.B. Ji, “Performance of a rotating zigzag bed—A new HIGEE,” Chemical Engineering and Processing 47 (2008) 2131–2139
D. P. Rao, “Process Intensificaction in Process Retrofitting and Revamping,” in GP. Rangaiah, Chemical Process Retrofitting and Revamping, Wiley, 2016, pp.
129-165
Stankiewicz, A I;Moulijn, JA, Process intensification: Transforming chemical engineering, Chemical Engineering Progress; Jan 2000; 96, 1
Reay, David, et al. Process Intensification : Engineering for Efficiency, Sustainability and Flexibility, Elsevier Science, 2013.
Tsouris, Costas;Porcelli, Joseph V , Process intensification - has its time finally come?, Chemical Engineering Progress; Oct 2003; 99, 10;

30. References II.
PATENTS:
Ramshaw, C., Mallinson, R. H., European patent 0002568, (1979)
Ramshaw, C., Mallinson, R. H., United States patent 4383255, (1981)
Todd, D. B., US Patent 3,486,743, (1969)
Ji, J. B., Wang, L. H., Xu, Z. C. et al. China patent 01134321.4 (2004)
Ji, J. B., Xu, Z. C.,Yu, Y. L. et al., China patent 200520100685.3 (2006)
Ji, J. B., Xu, Z. C.,Yu, Y. L., United States patent 7,344,126 B2 (2008)