1. Reactor Optimization
Introduction Produced Water
Microalgae Growth and Bio-crude Conversion
• Within the Uintah Basin
(defined as Uintah and
Duchesne Counties within
Utah) approximately 93
million barrels of water were
produced in 2013
• Only 11% of the water was
disposed of through
evaporation with the national
average at 2%. The rest is
reinjected into the subsurface
Utah produced water lagoon
(image: Marc Silver)
Microalgae Cultivation in Produced Water for Conversion into
Contact: Peterson.B1993@gmail.com
Ben Peterson, Jay Barlow, Dr. Jason Quinn, and Dr. Ron Sims
Hydrothermal Liquefaction (HTL)
Unit for biocrude conversion
Bio-crude oil produced from
microalgae cultivated on produced
water
• Wet algal biomass is converted at
high temperature and high
pressure in a hydrothermal
liquefaction reaction (HTL)
• HTL operating conditions:
 Temperature: 325 °C
 Pressure: 14 MPa (2000 psi)
 Retention time: 60 min
Polystyrene disk RABR for side by side comparisons
Rotating Algal Biofilm Reactor (RABR) Hydrothermal Liquefaction (HTL)
Rotational Speed Trial Results
Utah’s hydraulic fracturing industry produces large
quantities of wastewater, also known as produced water. This
water contains high levels of contaminates such as salts and
hydrocarbons, and variable concentration of nitrogen and
phosphorus. Current technologies for dealing with this
produced water are costly, with conventional methods including
sub-surface injection and evaporation. Due to high cost, most
produced water is treated as waste and dealt with accordingly.
This project approaches this water as not waste but as a
source of nutrients that can be used to grow and cultivate
microalgae, which can be converted into a product stream.
• Rotating Algal Biofilm Reactor (RABR) consisting of 23
polystyrene disks suspended over raceway containing produced
water
RPM trial comparing total energy consumption
for motors rotating at 1 rpm vs. 2 rpm Statistical analysis for 3 factors (rpm, direction of
sun, and disk position) and the interactions between
them. Factors of rpm and disk position were
statistically significant.
• To optimize the RABR design
an experiment to reduce energy
consumption was carried out
• Two lanes of 23 polystyrene
disks were rotated in the same
produce water
• One lane was rotated at 1 rpm
while the other was rotated at
2 rpm
• Total energy consumption was
monitored
• Additional testing at 0.5 rpm
and 5 rpm are being conducted
to further quantify optimal spin
speed
• Statistical Analysis was carried out to test which spin speed
was best
• We can conclude that the rate of disk rotation and the disk
positions within the raceway are the two significant factors
• Using the REGWQ
method we are able to
conduct individual
factorial analysis.
• We can conclude that
there is a statistically
significant difference
between the two
rotation speeds with
the 1 rpm showing a
higher yield.
• Bio-crude chemical composition and
energy content are comparable to
petroleum crude
• A yield of 35% ash free dry weight
was obtained in laboratory HTL tests
and 58% of feedstock energy was
recovered in the bio-crude
• A techno-economic
and life-cycle
assessment of biofilm
growth of microalgae
was conducted
• It demonstrated that
integrating microalgae
cultivation with
wastewater treatment
significantly reduces
environmental impact
Tenth Annual Algae Biomass Summit 2016 | Funded by Utah Governor's Office of Energy Development
Bio-crude Oil