AES Shady Point: A cleaner approach to coal

Source: Energy Digital

Date :7/21/2008 10:02:35 AM

Located in rural Oklahoma, Shady Point is the first coal-fired plant in the US to produce food-grade carbon dioxide from fossil fuel.

Written by Megan Santosus and Produced by James McCann

From the outside the AES Shady Point LLC power plant in Panama, OK, looks different from most other coal-fired electricity plants. That’s because the plant’s boiler’s stack doesn’t churn out visible emissions. As a fluidized bed plant utilizing clean coal technology, Shady Point has combustion technology on the inside that makes the production of its electricity a more efficient and cleaner process.

Shady Point is also different from many power plants in that it produces food-grade carbon dioxide (CO2) as a byproduct of its electricity production. The plant uses the thermal heat generated in the production of electricity to produce up to 200 tons of liquid CO2 daily. A portion of that liquid is then frozen to create dry ice that is sold to Continental Carbonic as it was for many years to Tyson Foods. “We are the first plant in the US to make food-grade CO2 from utilizing a fossil fuel,” says Lundy Kiger, Shady Point’s vice president.

The company’s primary business however is producing electricity, and the plant - which is located on a 393 acre site in rural Le Flore County - has a capacity of 320 megawatts and sells the entire electrical output to Oklahoma Gas & Electric.

A different kind of plant

The plant first went online in 1991 and includes four boilers and two steam turbine generators. According to Kiger, the plant was built as a result of the Public Utility Regulatory Policies Act, or PURPA, passed in 1978 by the United States Congress on the heels of the Arab oil embargo. PURPA was expressly designed to promote renewable energy by encouraging power plants to harness thermal energy in the form of steam to make a byproduct. That’s precisely what AES Shady Point does.

As a fluidized bed plant, Shady Point uses a combustion technology called Ciruclating Fluidized Bed technology (CFB) that allows the facility to burn Oklahoma-sourced coal which typically has higher sulfur content. In a fluidized bed plant, the way the coal is burned is different than found in a pulverized coal (PC) plant.

“In a fluidized bed plant, coal is crushed and sent into silos where feeders deliver it into the furnace from the bottom. Upward-blowing jets then propel the dust vertically to be burned. Unburned, larger particles are sent back into the furnace for further burning. The ash that results from the burning contains much less carbon than more traditional ‘pulverized’ technology,” explains Ruben Soroeta, Shady Point’s president and plant manager.

“This newer process is more efficient and cleaner,” Soroeta says. “The combustion technology allows for lower sulfur dioxide and nitrogen oxide emissions. By adding limestone into the combustion process there is a combustion gas reaction with limestone for sulfur dioxide capture. Nitrous oxides (NOx) emissions are reduced as the CFB technology is a highly efficient combustion that fires at lower temperatures. Sulfur dioxide or (SO2) and nitrous oxides (NOx) are sources of acid rain.

Safety is job one

While Soroeta is proud of Shady Point’s cleaner approach to burning coal, he is also eager to boast of the plant’s safety track record. Over the past 15 years, the plant “has never had a loss-time accident,” Soroeta says. No employee has sustained an injury serious enough requiring him or her to miss work, an impressive statistic in the world of power plant operations. “Safety is our number one priority here,” Soroeta adds, and the plant’s injury rate certainly backs that up.

The company has a safety management system in place that outlines step-by-step procedures for every area of the plant’s operations. Employees participate in mandatory safety training, and all incidents - including so-called “near misses” - are reported and communicated during monthly plant-wide company meetings.

Teams, community

Plant-wide meetings are held monthly while area meetings are held weekly and both are important vehicles for instilling a sense of teamwork for the plant’s employees. Shady Point’s employees are organized into cross-functional teams and the monthly meetings allow team members to share information about their particular area of the operation, as well as to learn about the plant’s business and environmental initiatives. “We don’t work in silos,” Soroeta says. “We want full interaction among the teams.”

For example, the leaders of the teams operating the control room, boiler and turbine have different leaders and rules, but each team depends on the other in order for the plant to run properly. Like the manufacture of nearly every product, electricity is produced through sequential steps, each of which has an effect on the subsequent steps. At Shady Point, “each team member is encouraged to become qualified in the next step in the process,” Soroeta adds.

The plant-wide meetings provide the forum in which each team provides updates to every other team. “Everyone has daily duties, but they know the effect their actions have on the rest of the plant.”

As one of the biggest employers in rural Oklahoma with direct and in-direct jobs created, Shady Point takes its position in the community seriously and is committed to being a socially responsible corporate citizen. That commitment manifests itself in numerous ways. The plant makes an effort to hire veterans (19 percent of the plant’s workforce are veterans), and was recently honored by the Veterans of Foreign Wars as an employer of the year in the State of Oklahoma. In addition, the plant stepped up to build an elementary school in a neighboring town when the local bond issue failed to pass. The 22-classroom school cost US$1.8 million and is located about five miles from the plant.

Shady Point was also recently inducted into the Carl Albert State College Hall of Fame. Since it opened, it has been a key supporter of the college’s functions such as the Coaches Golf Tournament, Chili Cooking Contest and Gold Dust Gala. The plant has contributed in excess of US$200,000 to the CASC Development Foundation.

As for the future, AES Shady Point hopes to expand its operations in the state. The plant recently purchased 60 adjacent acres and has filed permits with the state seeking to build a facility with a capacity to produce an additional 650 megawatts of electricity. As part of the expansion, AES Shady Point is also seriously exploring the possibility of burning excess poultry litter to produce electricity, something that is already done in Europe. “Some of the excess litter in the state contributes to water quality problems in both Oklahoma and Arkansas,” Kiger says. “We can do something about that by using it to make electricity.”