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Bioenergy from Oilfield Produced Water Ben Peterson1, Jay Barlow1, Jason C. Quinn2, Ron C. Sims1
Utah State University Logan, UT 1Biological Engineering2Mechanical and Aerospace [email protected]@[email protected]@usu.edu
Background
• Algal biomass is cultivated with a rotating algal biofilm reactor (RABR) developed at USU.
• Reactor materials include polystyrene (above), cotton rope (below left), and cloth pads (below right).
• Alternative reactor designs and materials are under investigation to improve biomass productivity with greater attachment and expanded surface area.
Produced Water
• Industry in the Uintah Basin generated approximately 93 million barrels of produced water in 2013 alone.
• The water has high salinity levels and is contaminated with hydrocarbons and numerous other compounds.
• The experimental water sample was obtained from produced water evaporation ponds in La Pointe, Utah.
• The water was collected in two distinct seasons to diversify water contamination concentrations.
• A 500-gallon sample was gathered for algal biomass cultivation.
Uintah Basin petroleum resources (image: ShaleExperts) Utah produced water lagoon (image: Marc Silver)
Biofilm Reactors Hydrothermal LiquefactionBiomass Harvest Biocrude
Objectives• Provide an alternative product for the hydraulic fracturing industry to
offset the high costs of produced water treatment
• Cultivate algal biomass in produced water with a rotating algal biofilm reactor (RABR) growth system
• Demonstrate remediation of produced water with algae cultivation
• Convert algal biomass to renewable fuels via hydrothermal liquefaction
• Algal biomass is mechanically harvested from the RABR by direct scraping.
• The biomass can be converted into bioproducts including fuels and feeds.
• Algal biomass is composed of a robust biofilm polyculture.
• The biofilm polyculture consists of several species of algae, one of which was isolated from the Great Salt Lake (below).
• 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
• HTL produces four products: Biocrude (energy product) Gas (energy product) Aqueous (fertilizer product) Solids
• Biocrude chemical composition and energy content are comparable to petroleum crude.
• A yield of 35% afdw was obtained in laboratory HTL tests and 58% of feedstock energy was recovered in the biocrude.
• Biocrude can be refined into an array of drop-in renewable fuels:
BIOCRUDE
RENEWABLE DIESEL
RENEWABLE GASOLINE
The extraction of oil and gas results in large quantities of wastewater, or produced water, with nutrients and residual organic chemicals that represent a significant resource for producing energy-related and value added products. The goal of this project is to demonstrate the production of these products and the simultaneous treatment of the produced water using algae cultivation in a unique engineered system to stimulate economic growth and to enhance human health and the environment in Utah’s Uintah Basin. This poster presents the USU part of the project; BYU (Dr. Hansen) tests biogas production from algae, and the UofU (Dr. Hong) treats produced water with ozone and filtration.