District Energy - 2006 Second Quarter

The scrap tires burned by Akron Thermal, purchased from an area tire recycler, arrive pre-shredded in approximately 1-inch-square chips with the bead wire removed.

its operation. This investigation gave the company the confidence to further pursue the possibility of TDF use.

As a fuel source, TDF is a petroleum byproduct; it has an energy value nearly equal to oil, 10 percent higher than coal and 2. 5 times higher than wood fuel. TDF helps the environment by reducing reliance on nonrenewable fuels such as coal, coke, oil and natural gas. TDF use helps reduce tire stockpiles that become breeding grounds for mosquitoes and other pests. TDF also burns cleaner than coal, benefiting air quality, and helps keep tires out of landfills or from being

Tire-derived fuel has an energy
value nearly equal to oil, 10
percent higher than coal and 2. 5
times higher than wood fuel.

illegally dumped. Testing done by the U.S. Environmental Protection Agency on air emissions from a variety of facilities – from industrial and electrical generating boilers to cement kilns – also showed that TDF could be burned with traditional fuels without exceeding the regulated emission rates for these types of facilities.

Despite these positive findings, Akron Thermal, like many companies, was reluctant to forego traditional fuels.

Based on its investigation and experience, Akron Thermal determined that switching from natural gas to waste wood and TDF would be complicated for a couple of reasons. It found that extensive testing and monitoring must accompany any changeover to TDF, which could lead to unanticipated expenses should problems arise.

A test burn exemption was therefore submitted to the Ohio EPA so the company could assess whether the air emission testing would fall within state mandates. The estimated time to complete this task was between six and 10 months (actual time frame was six months). The test burn indicated TDF was indeed a cleaner fuel alternative and boasted excellent operating data that assured success. Akron Thermal came away from its testing confident that it could successfully introduce TDF as a supplemental fuel.

Project funding was another issue for Akron Thermal. Given the ongoing maintenance of its two power-generating facilities, the needed capital for the TDF project was limited at best, despite the positive financial results of the company’s feasibility study.

A year earlier, however, the Ohio Department of Natural Resources (ODNR) Division of Recycling had created a pilot program to provide seed money to spur new market development to help alleviate the environmental impact of scrap

tire piles. Knowing about the program,

Akron Thermal approached the local Summit/Akron Solid Waste Authority, a quasi-government agency whose primary function is to manage the solid waste generation and recycling policies for Summit County, Ohio. With the agency’s assistance, Akron Thermal developed a project narrative to highlight the TDF retrofit project. This narrative and a preliminary application were submitted to the ODNR review board for consideration. These documents provided an overview of the project to redesign and/or retrofit existing solid fuel-handling equipment to accept, transfer and commingle TDF with waste wood fuel and to deliver the fuel mixture to both solid fuel boilers. Because of the project’s scale and the limited time frame to initiate and complete it – as well as limited grant funds available for each year – Akron Thermal decided to divide the project into Phase I and Phase II. The company applied for and received two market development grants: one for the 2002 grant year and, a year later, one for 2003. The company estimated that once both projects were

Courtesy Akron Thermal LP. Photo David Rodgers.

Scrap Tire Recycling in Ohio

Ohio is well ahead of other states when it comes to tire recycling: Around 70 percent of the state’s scrap tires are recycled, as compared with 26 percent nationally. What accounts for this? Scrap tires have been banned from disposal in Ohio landfills for nearly 10 years. Another factor is a lack of in-state users of tire-derived fuel chips.

Recycled uses include making the tires into new products like playground and garden mulch or rubber surfacing for walkways and doormats, shredding them as a substitute for gravel in landfill drainage systems and mixing with other solid fuels to produce electricity in industrial boilers and cement kilns.

For all its recycling success, Ohio still winds up with more than three million scrap tires illegally dumped around the state or in tire-only landfills. To encourage further scrap tire reuse, the Ohio Department of Natural Resources has created a Scrap Tire Market Development Grant Program to help manufacturers and utility companies cover the startup costs of incorporating TDF in their operations. Akron Thermal received a grant from this program, which helped fund its scrap tire test burn project.