Hawaii facility to turn C&D waste into biofuel and bioenergy

Kailua, Hawaii-based Simonpietri Enterprises LLC has plans to produce biofuel and bioenergy from construction and demolition (C&D) waste at its Aloha Sustainable Materials Recycling and Fertilizer Facility, currently in development in Kapolei, Hawaii, Honolulu Civil Beat reports. Additionally, the $40 million facility plans to transform invasive plants and grasses into biochar, a fertilizer prized by farmers.

RELATED: Demand for biochar on the rise

In 2022, one quarter of Oahu’s 1.6 million tons of waste came from C&D, according to the article, and 11 percent of that waste was not recycled.

Simonpietri Enterprise’s proprietary technology will use pyrolysis, a low-emissions process, to convert about 200 tons a day of that waste into power, gas and ash. The gases harnessed in the process will be used to create biofuels, and the only material that will need to be thrown away is ash, about 10 percent of the total mass originally fed through the equipment.

Initially, according to the article, the Kapolei project was intended to focus solely on construction waste. But community input over the last two years made it clear there was also a need to dispose of invasive grasses and plants that are proliferating in Hawaii.

“Fast forwarding to now, we’re planning for our plant to have two different waste streams coming in,” Simonpietri tells Civil Beat.

Invasive species, long a concern in Hawaii, have gotten more attention since the August wildfires on Maui because non-native African grasses were shown to be particularly problematic in helping to fuel those fires, according to the story. Guinea grass collected on Oahu has already been converted into biochar and syngas at the U.S. Department of Energy’s National Center for Hydrogen Technology in the first phase of Simonpietri’s research.