At the Grant County Commission work session on Tuesday, March 11, commissioners heard a presentation on using old tires as fuel for a cement plant.
Saul Alvidrez, GCC Tijeras plant manager, said the group presented to the New Mexico Association of Counties recently, and "we are now presenting to you to give you information and ask for possible support."
"We have been in the state for 55 years and have 78 employees here," Alvidrez said. "Part of our chairman's philosophy is for us to bond with the community. We are environmentally responsible and are aware of the tire problem. We are aware that we are also part of the solution."
The plant he manages has a 500,000 metric ton capacity of cement, with two long dry kilns, three finish balls mills, making 52 megatons of cement. The plant contributes $1.5 million in taxes to the state and pays $7 million in salary and benefits. It also provides $28 million in business to the community. The average salary and benefits for an employee is $85,000 to $86,000.
He cites the statistic that the U.S. population generates 1.1 tires per year per person, with New Mexico generating about 2 million used tires per year, with many still in landfills or illegally dumped.
"The most economic use of tires is as fuel," Alvidrez said. "About 60 percent are used as fuel.
"Why do we want to use tire-derived fuel (TDF) in the cement kiln?" he asked. "Per 100 tires, 15,000 BTU are generated, which saves between one and one-and-a-half tons of coal or 100 gallons of fuel. It keeps tires out of landfills and mosquitoes cannot breed in them. Cement kilns represent the largest use of TDF."
The company will start commissioning a plant in Pueblo, Colo., using shredded or whole tires.
When the tires are fed into the kiln, within 15 seconds the temperature rises to 1,100 degrees Fahrenheit and ultimately to 3,400 degrees F. At that temperature, according to Alvidrez, everything is destroyed so there is no smoke from the tires.
Environmental controls will be in place by 2015 to monitor and measure all emissions. "We use coal, natural gas and alternative fuels to run the kilns. There is a narrow window of temperature to create a quality product."
The use of tires as a fuel replacement reduces the mono-nitrogen oxides NO and NO2 (generically known as NOx), as well as reducing the SOx (sulfur oxides).
He pointed out that using tires as fuel would also reduce the uncontrolled fires that occur when tires catch fire, create oils and keep burning. "With the controlled burn of fires, there are no emissions."
GCC is working with market education and the permitting phase. "We are finishing the technology research on whether it is better to feed the tires to the kiln or use front-end injection."
The permitting phase can take anywhere from 12 to 18 months. "As soon as the permits are received, we will buy the equipment, install it and commission it," Alvidrez said.
In the PowerPoint presentation, he showed the patented CEMEX system, which puts the tires into the hottest part of the kiln. Another system, the Cadence System, drops the tires into the kiln to burn. "It takes 45 minutes to one hour to get to the high temperature to burn one tire. Injecting extra air speeds up the process and avoids sending emissions into the atmosphere.
"We need 7,000 metric tons of TDF per kiln," Alvidrez said. "For two kilns, we will need 1.4 million tires per year."
The Environmental Protection Agency agrees that the best use of old tires is in kilns, according to Alvidrez.
Commissioner Gabriel Ramos called the plan "one heckuva project, and a good way to get rid of our tires. Are you thinking about this area?"
Alvidrez said County Manager Jon Paul Saari had asked him to make the presentation.
Commission Chairman Brett Kasten said he had seen the presentation twice and "I know how bad our tire problem is."
Commissioner Ron Hall asked if the company had anything, such as a brochure, to hand out to people. "We definitely have a tire problem and it would be good to put them to good use. My concern is about the environment. You don't see smoke, but what else goes into the air??
Alvidrez said he could schedule a visit to the plant. "The Pueblo plant is a bit ahead, but the process will come to Tijeras in 2015."
Saari said the New Mexico Environment Department is starting to tell landfills not to store tires.
Kasten asked about residue remaining after the tires are burned.
"There is nothing," Alvidrez said. "The extra air ensures full combustion."
Kasten asked if truck tires, as well as automobile tires, could be used.
"We are researching 42-inch tires," Alvidrez said.
Kasten asked who would pay for the transportation of the tires.
"We are talking with the Solid Waste Department," Alvidrez said. "We will accept them at no cost. But we cannot yet receive tires until we are permitted."
Randy Villa, county fire management officer, said during the Quail Ridge Fire, a pile of tires caught fire. "We could not put it out, and it was emitting lots of combustibles. We finally buried them."
Terry Timme of the Silver City Office of Sustainability, said starting this week, a grant would pay for transportation of tires to Denver City, Texas, to shred them and mix them with asphalt. "It's not sustainable. We would like to take them to Tijeras."
The rest of the meeting will be covered in subsequent articles.