March 25, 2005

Grass as biofuel

On Monday afternoon, I went to see a presentation up on Mount Pleasant that may hold some promise for both agriculture and open space in Dryden. Cornell scientists have been working with various kinds of grass, working to find ways that grass can be burned in stoves for heat or in other systems for both heat and power. Wood pellet stoves have become fairly ordinary, and grass pellets can be made using similar technology.

Wood and grass pellets
Wood pellets and grass pellets

About 30 people attended the meeting, including Dryden's Zoning Officer and Environmental Planner, as well as people, largely farmers, from Tompkins, Tioga, Dutchess, Steuben, Broome, and Niagara counties. Jenifer Wightman introduced the session, which started with posters and stoves running. Then Professor Jerry Cherney, a forage specialist, gave a presentation about the mechanics and economics of using grass pellets as fuel.

The good news about grass pellets is that they're not that hard to produce, can use grasses grown with minimal (or no) care or fertilization, actually do better if they're left out in the rain for a while, and don't have a negative impact on greenhouse gas generation. It may even fit better with wildlife nesting patterns than regular hay fields. It's a great way to use marginal farmland, and a way to keep land in some kind of production that might otherwise grow back to woods. It's even possible to harvest land that's been somewhat overgrown and use that material to make these pellets.

Cherney also pointed out the disadvantages, however. Stoves built for wood pellets have problems with the higher ash content of grass pellets. While there are stoves built for corn, which has somewhat similar characteristics, stove manufacturers don't presently have much interest in burning grass, though some are working with the researchers at Cornell. Similarly, Cherney said, this isn't cool biotechnology or nanotechnology, and doesn't have a political lobby backing it up, so it's hard to find the funding needed to make this practical on either the production end (where pelleting devices are needed) or the consumption end (where appropriate stoves or other burners are necessary.)

A stove burning grass pellets
A stove burning grass pellets

One of the problems Cherney mentioned is also an opportunity - "No one is going to make millions from this." The economics of transporting grass argues against centralized processing, though the prices for the pellets and their energy should be comparable to hay despite fewer inputs. If this works, it's likely to be a distributed process, with mobile pelletizers and small-scall permanent systems running close to the fields, supplying customers who are relatively nearby.

I don't think it would be easy to get there, but it's at least a nice idea to think of farms in Dryden using their marginal land to produce grasses, harvesting them after the hay season is over, pelletizing them, and selling them to Dryden residents who use them for affordable heat. It could be a way to keep farmland in use, and keep money flowing within the community instead of out of it.

There's a lot more information about the process and the details of making grass pellet biofuels work in their posters and slides, which I've posted as a gallery. They'll also be having another session on Saturday, April 2nd. If you're interested, contact Jeni Wightman at 255-4230 or email jw93@cornell.edu.

For more information, please see Professor Cherney's site, which includes a list of answers to common questions.

Posted by simon at March 25, 2005 6:51 PM
Note on photos

Comments

where can i purchase grass pellets?
i live in nashua,nh... u s a

Sorry - I don't know where to buy the pellets. This was just a session on what might be involved in making them or consuming them.

Hi:

1) Can the same pelletizers used to make wood pellets be used for grass pellets?
2) Which (if any) pelletizer(s) are recommended?
3) Can the grass pellets be stored in wet conditions?

Thanks

I am looking to build a small pellet making machine. How do I make grass pellets.

since grass gives off lower BTUs than wood pellets, could wood & grass be burned in wood pellet wstove in a 50-50 ratio to help avoid the higher ash prolem of grass?

I would like to build a pellet making machine that could do either wood or grass pellets. What would I need and how would I make the grass pellets?

I'm looking to make or find a pellet machine to do grass or any bio mass pellet

It might be better to skip the pellets and make large bundles of grass. They could be compressed. Some grasses are very thick and substantial. (Miscanthus) etc. Then you could tie several bundles together, cut to the size of your stove. You could try compressing with weights also. A wood stove should work, especially if you incorporate some small wood into the load to keep the ashes burning for the next load.

Another idea is to use wood trimmings. They can be grown about as fast as grass by using the pollarding technique.

Grass stoves were commonly used by settlers on the plains. Do a search.

All the best,

Ron Wagner

I wonder if there is a pelletizer for tree leaves?? oak leaves and such??

pellet mill info pelletpro.com 1309 west south st suit 2 kewanee il 61443

Our company will be pelletizing leaves sometime late 2008.

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