Organic Materials Management

Conversion Technologies

Many people know that organic materials--also known as biomass--can be used to produce compost and mulch. But organic materials can also be used to produce electricity (bioenergy), fuel (biofuel), and other industrial products. Examples of organic materials feedstocks include yard, tree, and brush trimmings; construction leftovers such as sawdust and wood debris; agricultural residues like corn stalks, rice and wheat straw; used vegetable oils; and paper.

Each year California generates more than 20 million tons of organic materials. Between 6 and 8 million tons are composted and mulched, including about 1.5 million tons used as feedstock for the traditional biomass-to-energy industry. But what about the almost 15 million tons of organic material now landfilled each year?

A Vision for the Future

Imagine millions of tons of yard trimmings and wood that cannot be composted, and low-value paper residuals from material recovery facilities for which there is no recycling market demand. Today, all of these materials are sent to landfills at great cost to the environment. In the future, more materials such as agricultural residues that can no longer be burned in the fields may also end up in our landfills.

What if there was a way to convert these unwanted materials into high-value products such as energy, alternative fuels, and other industrial products? New conversion technologies have the potential to help solve some of these vexing environmental problems. These technologies differ from incineration and traditional biomass-to-energy approaches because they do not involve combustion. The Department of Resources Recycling and Recovery (CalRecycle) is exploring a new vision for the future that could involve these conversion technologies to convert organic materials into energy, fuels, solvents, and other products. CalRecycle and others have hosted major conversion technology forums dealing with these technologies and more.

Getting Started

• Seminar Video: Evaluating Conversion Technologies for Municipal Waste Management.
• Guidance on how anaerobic digestion fits in CalRecycle's current regulatory structure. (2009)
• The guidance document on how conversion technologies fits in CalRecycle’s regulatory structure (2007), is currently under review. The guidance document should not be relied upon until that review is completed as the 2007 version does not necessarily reflect the Department’s current interpretation of statute.
• Current Anaerobic Digestion Technologies Used for Treatment of Municipal Organic Solid Waste. (2007) Note: This document was written prior to the enactment of SB 1016 (Wiggins, Chapter 343, Statutes of 2008), which changed how jurisdiction diversion rates are calculated. As a result, portions of the discussion in this document about diversion calculations are out of date. They will be updated in the near future.
• Conversion Technologies Status Update Survey (4/09)
• New and Emerging Conversion Technologies: Report to the Legislature
• Biofuels from Municipal Solid Waste (PDF, 409 KB)
• List of Anaerobic Digestion Projects in California - April 2013 (PDF, 204 KB)