June 11, 2005
Solar Plant to Tap Landfill Methane
Iran Daily
Canada's SHEC Labs announced preliminary plans to move ahead on a
demonstration project that would involve as many as 30 prototype solar
units tapping landfill-generated methane for solar powered hydrogen
production. The company has been developing a dish-style solar thermal
concentrator for the production of electrical power and hydrogen
production.
According to the Saskatoon-based company, their prototype solar hydrogen
generator has now operated for approximately 1,200 hours with no
noticeable coking or degradation of the catalysts. Hydrogen production
is near the theoretical maximum at approximately 66 percent in the
product gas stream with a 98.2 percent mol conversion of the feed
methane. The estimated maximum hydrogen production with the unit is
approximately 3,500 kg per year with minor modifications to the
operating pressure and reactor configuration and an increase in the
solar mirror area.
The next stage of development still in the planning stage is a
commercial-scale demonstration at a landfill gas site using 40,000 kg
per year hydrogen production modules. This one project (a
small-to-medium sized landfill gas project) will prevent more than 1.6
million tons of carbon dioxide equivalent (CO2e) from
entering the atmosphere over the next twenty years and will
significantly improve local air quality and reduce smog. This one plant
would consist of 30 modules for a total annual production of 1.2
million kg of hydrogen per year. (550 million cubic feet).
SHEC-Labs is currently in the process of capitalizing to deploy this
first commercial scale plant. Once this plant is operational, the
company says they will be able to replicate it elsewhere,
solaraccess.com reported.
More than 95 percent of hydrogen produced today is by the Steam Methane
Reformation (SMR) of fossil fuels such as oil, coal, and natural gas, a
process that liberates massive amounts of carbon dioxide and other
pollutants to the atmosphere. The SMR process provides a net energy
loss of 30 to 35% when converting methane into hydrogen since a great
deal of fossil energy or electrical power is required to operate the
process. Hydrogen is also produced by electrolysis, a process that uses
electricity to convert water into hydrogen and oxygen. Although
electrolysis itself can be quite efficient in converting electricity
into hydrogen, the electricity used for electrolysis is often primarily
generated from fossil fuels. Therefore, traditional hydrogen production
methods result in a net increase in air pollution and are highly
inefficient from an energy conversion perspective.
Solar hydrogen production provides a net energy gain when converting
methane into hydrogen since the energy used to drive the process is
from the sun, says SHEC. Since SMR is not typically cost-effective at
small to moderate production levels, SHEC's technology is particularly
attractive for smaller and distributed hydrogen production. The
environmental benefits of generating hydrogen using renewable energy
include significant greenhouse gas reductions, and the reduction of
smog precursors, acid gases, and mercury as a result of reduced local
need for oil, coal, and natural gas.
To add even greater value, the process has the ability to use a
renewable source of methane and carbon dioxide, such as biogas from
municipal wastewater plants and landfill gas. Renewable methane
generated from biomass results in no net increase of carbon dioxide
levels in the atmosphere when the methane is converted into hydrogen
by SHEC's solar hydrogen generator.
The next generation of solar hydrogen involves direct water splitting
with only water as the primary feed component. According to SHEC
scientists, six of the ten steps needed for this process are already
integrated into the current system.
In a related note, the company was recently published in the May 2005
edition of Environmental Science and Engineering Magazine. For the
doubters, the cover story was peer reviewed by a number of professional
engineers and Ph.D. scientists, according to the company.
