Jim Turner -- April 27th, 2010
Guest blogger Jim Turner continues his series on the Fibrowatt power plant:
When I first came across the news about the prospect of Fibrowatt locating in Page County, I’ll be the first to admit that I thought it was an exciting opportunity. But I also immediately recognized the controversy this prospect would raise – some kind of balance between environmental concerns and business/economics had to be found when we talk about a new business with an industrial process coming to town.
One of the value statements with the Fibrowatt process is the idea that this is a kind of renewable or sustainable energy that provides an alternative means of disposal for chicken litter. Fibrowatt’s materials mention pending legislation that would ban spreading the litter – that stuff has to go somewhere, and often the poultry farmer’s least expensive means of getting rid of it is to spread it.
We hear that chicken litter has a negative impact on the Chesapeake Bay, which is connected to our area via the Potomac River and then the Shenandoah River watershed as you go upstream. Why not burn it – call it incineration or combustion – but what’s the impact of current poultry litter disposal processes and will a Fibrowatt plant contribute to reducing that?
That, said, from the company’s web site, here is a summary of how they make power:
Fibrowatt assists area growers with poultry litter removal and then transports the poultry litter in tightly covered trucks on prearranged routes to the facility. The trucks then discharge the litter within a specially designed fuel storage building, which is kept at negative pressure to prevent the escape of odors. The litter is combusted at more than 1,500° F, ensuring the destruction of odor and pathogens. Water is heated in a boiler to produce high-pressure, high-temperature steam, which drives a turbine and generates electricity. The remaining ash by-product is beneficially used as a nutrient-rich fertilizer.
There are other ways to produce energy from poultry litter, which I found with a quick Google search:
“A gasifier converts organic materials into gas rather than burning it,” said Plodinec, noting the units would be sited at poultry houses around the state. “Then, the gas can be moved somewhere else and burned cleanly. You can generate relatively small but significant amounts of electricity right there for the person who needs it.”
This is from a Mississippi State article, which goes on to describe an alternative process that can produce commercial chemicals as opposed to fuels.
I also found a 2002 article that discussed various ways that litter can be used for energy, emphasizing what were then emerging farm-scale technologies, but it [was] also referring to some of the issues that larger scale operations need to be aware of and manage, including ash management (the ash can be used as fertilizer, a byproduct of the process), plant emissions, and other regulatory concerns. That article even references Fibrowatt’s plants in England, highlighting their emissions control systems.
The Department of Energy mentions two processes:
- Anaerobic Digestion – converting biomass, especially human, animal, and agricultural waste, into methane and carbon dioxide. The biomass is mixed with water and stored in an airtight tank, where a natural process does its work – this is considered a costly but efficient process for biomass energy production.
- Pyrolysis – this process heats biomass in sealed containers without oxygen, producing gas and charcoal from the decomposition of the materials. While the process reduces carbon dioxide output, which is one of the side effects of the other processes, it requires the biomass to be heated to 1,000 degrees Fahrenheit – a process that requires significant amounts of energy in its own right.
As my research went on, I realized that all of the resources I reviewed mention the potential for gas and particulate emissions from the biomass combustion process – greenhouse gases that contribute to climate change, and particulates and hydrocarbons that contribute to effects such as acid rain. Modern combustion technologies are designed to improve management of these byproducts, so that the effects are reduced or even eliminated. From Wikipedia:
A problem with the combustion of raw biomass is that it emits considerable amounts of pollutants…even modern pellet boilers generate much more pollutants than oil or natural gas boilers. Pellets made from agricultural residues are usually worse than wood pellets…However,…numerous studies have shown that biomass fuels have significantly less impact on the environment than fossil based fuels.
Let’s summarize the pros and cons based on this review of the biomass combustion process.
Pros – offers an alternative method for disposing of poultry waste, instead of spreading it or land filling it. It has a reduced environmental impact when compared to the combustion of other fuels. Poultry litter, as an industrial-agricultural by-product, is readily available.
Cons – there is the potential for particulate pollution and greenhouse gas emissions from the combustion process. Due to transport and other requirements, it is not the most efficient energy production methodology, and therefore, it is likely to be more expensive energy than other processes. [In this author’s conclusion, based on his research]
You can read more about Fibrowatt on my Hawksbill Cabin blog – just look for the “Fibrowatt” label in the right column, and it will take you to the whole history of the Page County experience last January through March, 2010.
Jim Turner is a management consultant in his day job, but his real passion is the weekends he spends at the Hawksbill Cabin, near Stanley and Luray, Virginia. He keeps a blog on the weekender lifestyle, which is where this material about Fibrowatt and Page County was first published.