Grass pellets (Please see Switchgrass) can be burned without carbon emissions problems, and they have 96 percent of the BTUs of wood pellets. However, grass produces more ash than wood -- meaning more frequent cleaning -- of stoves. And there though burning the plant matter itself is carbon neutral, there are still carbon based fuels involved in it's harvesting. Additionally, there are particulate matter emissions, such as PM 2.5 just as with burning any solid fuel.
Currently, tests of the burning pellets made from grasses, such as timothy and orchard grass, as well as weeds, such as goldenrod, in pellet stoves have been done at Cornell's Mt. Pleasant Research Farm. This demonstration project is funded by Cornell's Agricultural Experiment Station.
Grass biofuel pellets are much better for the environment because they emit up to 90 percent less greenhouse gases than oil, coal and natural gas do. Furthermore, he says, grass is perennial, does not require fertilization and can be grown on marginal farmland.
The cost-effectiveness of pelletized grass as a fuel results from:
- efficient use of low cost marginal farmland for solar energy collection
- minimal fossil fuel input use in field production and energy conversion
- minimal biomass quality upgrading which limits energy loss from the feedstock
- efficient combustion in advanced yet modestly priced and simple to use devices
- replacement of expensive high-grade energy forms in space and water heating
Switchgrass, when pelletized, has considerable potential to displace oil, natural gas, and electricity used for heating fuel. This development can significantly reduce greenhouse gases and heating costs and sustainably assist the development of rural communities. Fast growing warm season perennial grasses have been identified as ideal candidates for biomass fuel production due to their high net energy yield per hectare and low cost of production. Switchgrass is one type of warm season perennial grass native to the Great Plains and eastern North America. It is favorably viewed as it easily adapts to marginal soils and arid climates with minimal fertility and management requirements.
Quoting Jerry Cherney of Cornell University: "Burning grass pellets makes sense; after all, it takes 70 days to grow a crop of grass for pellets, but it takes 70 million years to make fossil fuels," says Cherney, who notes that a grass-for-fuel crop could help supplement farmers' incomes.
Cherney points out that grass biofuel pellets are much better for the environment because they emit up to 90 percent less greenhouse gases than oil, coal and natural gas do. Furthermore, he says, grass is perennial, does not require fertilization and can be grown on marginal farmland."