Bioenergy, Solar

Solar Hydrogen Pilot Plant to Tap Landfill Gas

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. 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.