1. Bioenergy from Oilfield Produced Water Hydrothermal Liquefaction
Ben Peterson1, Jay Barlow1, Jason C. Quinn2, Ron C. Sims1
Utah State University Logan, UT
1Biological Engineering
2Mechanical and Aerospace Engineering
Bioenergy from Oilfield Produced Water
Background
Objectives
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.
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
Uintah Basin petroleum resources (image: ShaleExperts) Utah produced water lagoon (image: Marc Silver)
Biofilm Reactors
Biomass Harvest
Hydrothermal Liquefaction
Produced Water
Biocrude
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.
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.
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