Based on the success of the first installation, Blalock installed a second OptiBlend system in March 2012 at their Kodak, TN plant. The conversion kit was installed on a Caterpillar 3412 generator set. With this system in place, the plant is able to reduce their diesel usage by up to 65% across the load range of the generator set. Operational savings are greater than 35%, which will provide a return on investment of less than one year.

“These systems have been very beneficial because they’ve allowed us to reduce our operating cost while not sacrificing performance,” says William Smith, asphalt manager for Blalock.

Dual fuel vs. natural gas

Blalock considered installing a dedicated natural gas generator set, but found the use of dual fuel on their existing system made more sense.

By using their existing diesel generator sets already installed at their asphalt plants, Blalock was able to avoid the large capital costs involved in purchasing a dedicated natural gas engine. As compared to a diesel generator set, a dedicated natural gas system is two to three times more expensive and requires a significantly larger footprint, as well.

They were also able to minimize installation time, since removing the diesel system and installing a dedicated natural gas system would have been very time consuming. The OptiBlend system was installed over a weekend and therefore did not affect the plant production schedule.

Dedicated natural gas systems create dependence on a single fuel, leaving the operator without power if the natural gas supply is lost. Using a dual fuel system provides the security of the fuel stored on-site but allows the operator to take advantage of the cost savings of using natural gas.

Other benefits

Aside from the obvious monetary benefits, this project has two other advantages.

The first is by using domestically-produced natural gas in place of diesel, Blalock is helping to decrease the country’s dependence on foreign oil.

There is also a large environmental benefit to the project. The key emissions created from a diesel generator set, NOx and particulate matter (PM), are reduced by approximately 50% when running in dual fuel mode. NOx is one of the main components in the formation of smog, making this a critical pollutant to reduce. The CO2 in the engine exhaust, a greenhouse gas associated with climate change concerns, is also reduced by about 10%, which is another welcome benefit to the environment.

Although dual fuel technology has been in existence since the creation of the diesel engine itself, the installation of an off-the-shelf system on an asphalt manufacturing plant in Tennessee is a new application.

The project could not have been a success without the willingness of Blalock to try this new technology. With the cost savings and emissions reduction that they have seen since the projects began, Blalock is very happy they made this decision.