Novel processes developed to make faux wood, synthetic fuel

By Bryan Sims
A university and a plastic recycling company are taking the lead in developing novel, cost-effective methods to produce saleable biobased products.

Researchers at Stanford University have developed a synthetic wood substitute made from hemp fibers fused with a biodegradable plastic resin called polyhydroxybutyrate (PHB), which can be recycled to produce more of the same. PHB can also be used to replace the petrochemical plastics used to manufacture disposable water bottles, according to Sarah Billington, an associate professor of civil and environmental engineering at the university.

Last year, the California Environmental Protection Agency awarded Billington and her colleagues a three-year $1.5 million grant to help the researchers develop biodegradable plastic beverage bottles. In 2004, the group received a two-year Environmental Venture Projects grant from Stanford University's Woods Institute for the Environment to develop durable and recyclable faux wood.

The hemp-PHB biocomposite material has several characteristics similar to wood from trees, according to Craig Criddle, a professor of civil and environmental engineering, who collaborated on the project. "It's quite attractive looking and very strong," he said. "You can mold it, nail it, hammer it and drill it a lot like wood. But, bioplastic PHB can be produced faster than wood, and hemp can be grown faster than trees."

The biocomposite material is also stable enough to be used for furniture, floors and a variety of other products, Criddle added. The material is also degradable in anaerobic environments such as a landfill, where methane emissions can be captured and burned for energy recovery or reused to make more biocomposites.

The research has attracted the attention of private investors and, at press time, the group said it intends to form a new company within a few months.

While Stanford researchers concentrate on biocomposites, Agri-Plas Inc. is focusing its efforts on producing synthetic oil.

Agri-Plas uses a patent-pending "thermal reclamation" technology developed by Longview, Wash.-based Plas2Fuel Corp. that converts unwanted and unrecyclable agricultural plastics into a high-quality synthetic crude oil at its recycling facility in Brooks, Ore. The company is selling this reclaimed crude oil product to U.S. Oil & Refining in Tacoma, Wash.

In December 2008, Agri-Plas delivered its first full shipment of 8,200 gallons of oil.

According to Mary Sue Gilliland, vice president of operations and business development for Agri-Plas, the company currently recovers approximately 750 pounds of oil, 90 pounds of char and 160 pounds of nondestructible gases. The gases are burned and the heat from the process is recycled.

Gilliland said the company is adding a four-vessel unit at its recycling center to increase throughput capacity. The company aims to have 20 plastic-to-oil vessels installed, which will have the capability to process approximately 30 million pounds of waste plastic per month.

Agri-Plas will operate its oil reclamation expansion under the name Agri-Plas2Crude.