Scientists with the Pacific Northwest National Laboratory have successfully created a chemical process that produces crude oil from algae. The process takes less than an hour, is cost-saving, and is a significant discovery in biofuel science.
In less than 60 minutes, scientists are able to recreate a natural process that takes millions of years. During the process, wet algae slurry, likened to pea soup, is pumped into a chemical reactor and, under high temperatures and great pressure, crude oil is produced, along with water and a few other byproducts.
“It’s a bit like using a pressure cooker, only the pressures and temperatures we use are much higher,” said Douglas Elliot, the team’s research leader. “In a sense we are duplicating the process in the Earth thtat converted algae into oil over the course of millions of years.”
According to the Pacific Northwest National Laboratory (PNNL), the most important cost-saving aspect of their process is the use of wet algae on the front end. Most similar systems require algae to be dried in a process that is costly uses a lot of energy.
“Cost is the big roadblock for algae-based fuel,” Elliot said. “We believe that the process we’ve created will help make algae biofuels much more economical.”
All of the products of the process – crude oil, clean water, fuel gas, and nutrients such as nitrogen, phosphorus, and potassium – can be used or recycled. The crude oil can be further converted into aviation fuel, gasoline, or diesel and the clean water can be used to grow more algae. Fuel gas can be used to make electricity or cleaned to make natural gas for vehicle fuel. Nitrogen, phosphorous, and potassium are the key nutrients for growing algae and so can be recycled to grow more.
While others have tested systems to create biofuel from wet algae, their processes usually produced only one batch at a time. PNNL researchers have created a continuous process that processes about 1.5 liters of algae slurry every hour. Of that 1.5 liters, about 50 to 70 percent of the algae’s carbon is converted to energy in the form of crude oil.
PNNL’s work is part of the Department of Energy’s National Alliance for Advanced Biofuels and Bioproducts, a research collaborative to investigate and commercialize algal biofuels. The goal of the collaborative is to develop renewable, sustainable, and carbon-neutral sources of transportation fuel.