A collaboration between researchers at the Department of Energy's (DOE) Pacific Northwest National Laboratory (PNNL) and Washington State University (WSU) has led to the development of a method for converting hydrothermal liquefaction wastewater into a usable and valuable commodity. The method utilizes the byproduct wastewater stream from the continuous thermo-chemical process that PNNL researchers developed to produce biocrude from algae. The wastewater contains a variety of different chemicals in small concentrations, such as carbon and nutrients from the algae, and accounts for approximately 90 percent of the output. Researchers at WSU Tri-Cities’ Bioproducts, Sciences and Engineering Laboratory have developed a method to process the wastewater using anaerobic microbes. The microbes break down the components of the wastewater to produce bionatural gas and a solid byproduct that can be recycled back into the hydrothermal liquefaction process or used as a fertilizer. Following the success of the partnership, PNNL and WSU researchers are collaborating on the conversion of sewage sludge to biofuel, bionatural gas, and nutrients using a similar strategy.