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While Jenkins Brick was not the first plant to convert to LFG (Cherokee Brick & Tile in Macon, Ga., converted its plant in the 1980s), few other brick manufacturers have followed suit. Recently, however, as the cost of natural gas has continued to skyrocket, an increasing number of companies have begun taking a closer look at this alternative fuel.
"We've definitely seen an increase in the number of inquiries related to using landfill gas," notes James E. Houseman, Ph.D., president of Harrop Industries, Inc., Columbus, Ohio. "More and more brick manufacturers are considering the location of landfills when siting a new plant, and that never used to be a factor-it used to just be the raw materials and the transportation infrastructure. Energy is a much more important parameter than it was 10 or 12 years ago."
Landfill gas is created as solid waste decomposes in a landfill. This gas consists of about 50% methane (CH4), the primary component of natural gas; about 50% carbon dioxide (CO2); and a small amount of non-methane organic compounds. LFG is extracted from landfills using a series of wells and a blower/flare (or vacuum) system, which directs the collected gas to a central point where it can be processed and treated, depending on the ultimate use for the gas. From this point, the gas can be simply flared or used to generate electricity, replace fossil fuels in industrial and manufacturing operations, fuel greenhouse operations, or be upgraded to pipeline quality gas. As of December 2004, approximately 380 LFG energy projects were operational in the U.S., and more than 600 landfills were good candidates for projects.
Although the majority of LFG energy projects are in electricity generation, approximately 100 are in direct-use applications, such as manufacturing, where the significantly lower cost of LFG compared to other fuels provides an economic benefit, often saving plants hundreds of thousands of dollars in operating costs each year. But this isn't always the case-factors such as LFG availability and transportation issues must be carefully considered when evaluating any potential LFG project.
"Not all landfills generate enough methane to use in industrial processes. Additionally, it costs a certain amount of money to transport the gas from the landfill, and it's not always economically viable to do so," says Chris Voell, program manager of the U.S. Environmental Protection Agency's (EPA) Landfill Methane Outreach Program (LMOP). Fortunately, tools exist that can help plants identify prospective LFG sources, model the availability of gas from those sources and evaluate the various cost factors.
"We maintain an extensive database of landfills, developers and others who are experienced in the use of landfill gas, and this database is growing all the time," Voell says. "We can help companies pinpoint prospective landfills and model the gas generation capabilities of those landfills. We also have a cost feasibility tool that allows us to model costs based on other project experience. Once a company decides to proceed, we can help match the company with developers, consultants and equipment suppliers, and locate financing for projects. And it's all free-federal tax dollars cover these services.
"We like to say we should not be the last stop in evaluating a project, but we certainly are a good place to start," Voell adds.
Talking to SuppliersOnce a company has discovered that sufficient LFG resources are available and can be economically transported to the plant, it must then consider the cost of retrofitting its existing operating equipment to successfully use LFG. For brick and ceramic plants, this means contacting suppliers that are experienced in dealing with combustion system modifications.
According to Paul Palkovic, product manager - Ceramics, Hauck Manufacturing Co., Lebanon, Pa., the key to the efficient use of LFG in brick and ceramic kilns is that it must be cleaned, dewatered and provided at the same consistent pressures as natural gas. Modifying a plant to accept landfill gas might require installing a booster pump as the gas enters the facility to ensure constant pressure to the system and eliminate problems with surge. Methane monitors are also suggested to track the consistency of the incoming gas. Since LFG has only about half of the BTU content of natural gas (~450 to 550 BTU/cu. ft.), approximately twice the volume of LFG must be supplied to the burners to get the same heat input to the kiln in the same amount of time. In addition to these modifications, larger capacity burners (or modified burners) may be required. If burners are already oversized, a larger orifice plate will be needed to provide the additional flow.
While such modifications can seem intimidating to many brick and ceramic plants, suppliers note that they're actually quite simple.
"Methods, devices and systems are commercially available to clean the gas to pipeline quality, as well as to continuously monitor the heat value of the fuel and augment the heat value as needed to bring it to a constant level. Additionally, combustion systems and burner designs are available to enable plants to take advantage of landfill gas. I think it's much more intimidating to get a consistent fuel source to the plant, than within the plant itself," says Harrop's Houseman.
Jim Hopkins, sales manager for Swindell Dressler in Pittsburgh, Pa., and Bruce Geisendorfer, product manager, Combustion Business Group for North American Mfg. Co., Inc., Cleveland, Ohio, agree. "We know the combustion systems are there to burn landfill gas, and we know landfill gas will work. It's just a matter of a company deciding that there s a landfill close enough that makes it a viable alternative and deciding to move forward. As far as conversions to alternative energy sources go, landfill gas is probably the most straightforward. Once you have the combustion system on and operational, you probably wouldn't know whether you're burning landfill gas or natural gas," says Hopkins.
"You will almost assuredly have to make adjustments to your burners to get landfill gas to work right. But making those adjustments doesn't have to be really expensive or daunting, especially if you're working closely with a supplier. We are all willing to guide the user through the process," adds Geisendorfer.
Reducing Energy ConsumptionWhile LFG can be viable way for some brick manufacturers to save on energy costs, it's not a panacea. Harrop's Houseman cautions that only a small minority of U.S. brick plants will likely be candidates for landfill gas as a cost-saving measure, simply due to the huge volume of gas required. "From the studies we've seen, there don't appear to be many landfills that could come close to supplying the needs of the brick industry, even if they were all located in close proximity to the plants," he says.
Additionally, like all energy sources, the lower cost of LFG isn't guaranteed long-term. "The price of all energy is probably going to seek its own level based on demand," Houseman says. "As soon as other industries see that they have an application or need for this, I believe the price of landfill gas is going to skyrocket just as other energy sources have."
That doesn't mean that brick manufacturers should dismiss the idea of using LFG or any other form of alternative energy out of hand. As the cost of natural gas continues to climb, using alternative energy sources can be crucial to maintaining profit margins, especially in the near term. However, the energy source should not be a plant's only-or most important-consideration.
"Companies need to try to evaluate other sources of energy, but that can't be their only consideration. They primarily need to focus on how they're using that energy within their plant. That's where the real energy savings can accrue," says Houseman.
Editor's note: Contact information for the suppliers quoted in this article, as well as other suppliers with brick and ceramic firing experience, can be found in Ceramic Industry's Data Book & Buyers' Guide in print or online at http://www.ceramicindustry.com.
For more information about using landfill gas, call LMOP at (888) 782-7937 or visit http://www.epa.gov/lmop/index.htm.
- "Landfill Gas: An Alternative Fuel," Ceramic Industry/Brick & Clay Record, Vol. 150, No. 1, January 2000, pp. 13-14, online at http://www.ceramicindustry.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2710,7151,00.html.
- Palkovic, Paul, "Cheaper Gas," Ceramic Industry, Vol. 151, No. 5, May 2001, pp. 29-32, online at http://www.ceramicindustry.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2710,25146,00.html.