Polyhydroxyalkanoates (PHAs) are biodegradable polymers that are positioned as a promising alternative to conventional plastics. They can be produced from a variety of biological and renewable feedstocks. Mango Materials (MM; Vacaville, Calif.; www.mangomaterials.com) produces PHAs at a pilot plant and production facility using methane-rich off-gases at the Easterly Wastewater Treatment Plant in Vacaville, Calif. This biomanufacturing technology developed by MM harnesses powerful methanotroph bacteria that feed on methane and oxygen. “These bacteria naturally generate PHA through their metabolic pathways. After the PHA is produced by the bacteria, a series of downstream processing steps are employed to yield PHA in powder form. This powder is then blended with minor components and compounded into formulated pellets, which can be customized to meet specific end-use requirements,” explains Molly Morse, CEO and co-founder of MM.
Source: Mango Materials
In parallel with the microbial process, the company is also scaling up its unique processes to produce biopolymer pellets and specific end products. “To date, MM has vetted its methane-to-PHA technology through over a decade of fermentation testing, both in the laboratory and in the field. These efforts span scales ranging from small laboratory fermenters to a pilot-scale test unit, and now to the current Launch Facility — a fully integrated methane-to-PHA production unit,” notes Allison Pieja, chief technology officer and co-founder of MM. The Launch Facility was originally located and commissioned at a wastewater treatment plant in Redwood City, Calif. in 2020. In 2023, the Launch Facility was moved to Vacaville to expand biomanufacturing opportunities, and this year, MM expects to start up a new, pilot-scale gas-fermentation unit in conjunction with BEAM Circular.
The Vacaville site illustrates the viable economies of scale for the MM process. “The pilot facility in Vacaville operates directly at a wastewater treatment plant, using the site’s off-gases as its primary feedstock. This fully integrated setup captures methane and converts it into a high-value material at the point of emission, eliminating the logistical challenges of transporting gas,” says Ashley Arnell, program manager, Technology and Innovation at BioMADE (www.biomade.org), which provided funding and support for the project. “By demonstrating that high-quality plastic can be produced in resource-limited or remote environments, MM has shown that this technology is uniquely positioned to support rural or isolated communities,” she adds.
The company is currently scaling up production of PHA pellets and has commercialized sales of its injection-molded grade through projects in the home-care and footwear sectors. Work is also ongoing to develop grades of formulated pellets for targeted applications, including fibers, filaments, extruded sheets for films and more. “Our biopolymer is resin-formulated and compatible with existing plastic-manufacturing infrastructure, and it can be extruded into filament for 3D printing. Several groups have already produced elaborate prototypes using 3D filament from our PHA,” comments Anne Schauer-Gimenez, chief operating officer and co-founder of MM.