Energy crops may soak up methane water
Quicknote bioenergy technology
Earlier we reported about several studies, tests and projects dealing with the bioremediation of brownfields and mining sites using biofuel crops. Such energy crops can be planted on polluted sites to prevent erosion, remove pollutants from the soil, stop the spread of small toxic particles through the air and to clean up ground water. After having done their work, the crops can be harvested and used as a feedstock for biofuels.
Now a company in northern Wyoming is conducting tests to see if growing hybrid poplar trees might be a good way to use water produced from coal-bed methane wells. The study of the process known as "phytoremediation" is being conducted by water resource management group CBM Associates and methane producer Windsor Energy Group.
The extraction of coal-bed methane or coalbed gas consists of drilling a steel-encased hole into a coal seam (200 - 1500 meters below ground). As the pressure within the coal seam declines, due to the hole to the surface or the pumping of small amounts of water from the coalbed, both gas and 'produced water' escape to the surface through tubes. Then the gas is sent to a compressor station and into natural gas pipelines. The 'produced water' is most often released into streams or pumped back into the ground. This 'methane water' typically contains sodium bicarbonate and chloride and if left untreated, it pollutes ground water.
Phytoremediation is the removal of pollutants by the use of engineered tree systems. The hybrid poplars were selected because they absorb large amounts of water relative to their growth. One acre of trees will use 1 million to 1.5 million gallons of water per year, according to environmental engineer and project manager Chris Ewert.
Ewert said he has seen hybrid poplars planted on top of covered landfills because they soak up a lot of water and don't let it become groundwater that could become polluted. "The trees use so much water, so I figured why not?" Ewert said in proposing the study. In April about 3,000 poplars were planted in a three-acre site. Methane well water is irrigating the trees through a gravity-fed sprinkler system from a reservoir. Ewert said the trees will be monitored the rest of the summer. Some have already grown 2 feet since they were planted.
"Some can grow six to eight feet in one year," Windsor environmental specialist Patsy Ballek said. The study will continue for 10 years, Ballek said. If the study is successful, Ewert said, the trees could be planted in tree belts near coal-bed methane well water reservoirs to give producers another means of using the water. Water is pumped to the surface by wells in order to recover the methane. "The water will be used by the trees and not go in the ground," Ewert said. As the study continues, Ewert said planting the trees on a larger scale will be analyzed for cost-effectiveness. "It definitely could prove to be viable," Ewert said.
Hybrid poplars are known to be fast growing trees and are proposed as energy crops in fast rotation cropping systems. They yield up to 35 metric tonnes of dry matter per year, and are considered to be excellent carbon sinks.
[entry ends here].
biomass :: bioenergy :: biofuels :: energy :: sustainability :: phytoremediation :: hybrid poplar :: methane
Earlier we reported about several studies, tests and projects dealing with the bioremediation of brownfields and mining sites using biofuel crops. Such energy crops can be planted on polluted sites to prevent erosion, remove pollutants from the soil, stop the spread of small toxic particles through the air and to clean up ground water. After having done their work, the crops can be harvested and used as a feedstock for biofuels.
Now a company in northern Wyoming is conducting tests to see if growing hybrid poplar trees might be a good way to use water produced from coal-bed methane wells. The study of the process known as "phytoremediation" is being conducted by water resource management group CBM Associates and methane producer Windsor Energy Group.
The extraction of coal-bed methane or coalbed gas consists of drilling a steel-encased hole into a coal seam (200 - 1500 meters below ground). As the pressure within the coal seam declines, due to the hole to the surface or the pumping of small amounts of water from the coalbed, both gas and 'produced water' escape to the surface through tubes. Then the gas is sent to a compressor station and into natural gas pipelines. The 'produced water' is most often released into streams or pumped back into the ground. This 'methane water' typically contains sodium bicarbonate and chloride and if left untreated, it pollutes ground water.
Phytoremediation is the removal of pollutants by the use of engineered tree systems. The hybrid poplars were selected because they absorb large amounts of water relative to their growth. One acre of trees will use 1 million to 1.5 million gallons of water per year, according to environmental engineer and project manager Chris Ewert.
Ewert said he has seen hybrid poplars planted on top of covered landfills because they soak up a lot of water and don't let it become groundwater that could become polluted. "The trees use so much water, so I figured why not?" Ewert said in proposing the study. In April about 3,000 poplars were planted in a three-acre site. Methane well water is irrigating the trees through a gravity-fed sprinkler system from a reservoir. Ewert said the trees will be monitored the rest of the summer. Some have already grown 2 feet since they were planted.
"Some can grow six to eight feet in one year," Windsor environmental specialist Patsy Ballek said. The study will continue for 10 years, Ballek said. If the study is successful, Ewert said, the trees could be planted in tree belts near coal-bed methane well water reservoirs to give producers another means of using the water. Water is pumped to the surface by wells in order to recover the methane. "The water will be used by the trees and not go in the ground," Ewert said. As the study continues, Ewert said planting the trees on a larger scale will be analyzed for cost-effectiveness. "It definitely could prove to be viable," Ewert said.
Hybrid poplars are known to be fast growing trees and are proposed as energy crops in fast rotation cropping systems. They yield up to 35 metric tonnes of dry matter per year, and are considered to be excellent carbon sinks.
[entry ends here].
biomass :: bioenergy :: biofuels :: energy :: sustainability :: phytoremediation :: hybrid poplar :: methane
0 Comments:
Post a Comment
Links to this post:
Create a Link
<< Home