Novel Flex Fuel Oxidation for Distributed Generation
Near Zero Emissions Combined Heat and Power Process
ZERE Energy and Biofuels, Inc.
Recipient
San Bruno, CA
Recipient Location
13th
Senate District
22nd
Assembly District
$998,346
Amount Spent
Completed
Project Status
Project Result
A two reactor prototype was deployed at the San Jose Environmental Innovation Center from November 2015 through March 2016. All components of the system were successfully tested in isolation except for the steam turbine. Testing of the full system was not achieved due to instabilities encountered during system shakedown and the project term ending before controls could be modified to smooth system operation. Lab experimentation demonstrated copper on an alumina to have good cycling behavior between oxidized and reduced states and to deliver heat during both redox phases of the substrate. NOx emissions were shown to be less than 1 ppm with CO between 300 and 700 ppm. The project is completed.
The Issue
Venting and flaring biogas have serious shortcomings since neither produces a useful product and both have serious air pollution and greenhouse gas impacts. Using biogas in CHP applications suffers from the presence of performance-reducing contaminants such as CO2, H2S or siloxanes, which must often be scrubbed prior to combustion in conventional prime movers. Additionally, the presence of SOx, NOx and other pollutants in the exhaust of microturbines and internal combustion engines requires the use of expensive post-combustion treatment to obtain necessary air permits.
Project Innovation
ZERE Energy and Biofuels is developing a proof-of-concept scale CHP system that will eliminate both the need to pre-treat biogas prior to combustion and post-treat exhaust prior to release to the atmosphere. This is being achieved through its Air Independent Internal Oxidation process which bypasses conventional combustion and produces steam directly via a two-stage process whereby oxidation of the fuel take place in absence of air, thereby eliminating NOx formation. This is done via a fluidized bed which captures oxygen from air and transfers it to fuel in the presence of steam so that the only products are steam and CO2. Siloxanes and sulfur compounds are captured in the first stage also, thereby negating any need to pre-treat the fuel. Electricity generation takes place via a conventional steam turbine and generator, and CO2 is separated from the working steam prior to exhausting to the atmosphere.
Project Benefits
Via lab experimentation and demonstration of the prototype subsystems, ZERE showed that the fully developed technology will be able to supply heat and power to moderately-sized facilities (<5MW) with near-zero emissions and an exhaust stream amenable to CO2 separation via condensing heat exchangers (not demonstrated) for additional revenue streams or possible sequestration.
Affordability
This system eliminates the need for pre-treatment of biogas fuels and of post-treatment of combustion products prior to exhaust, which reduces generation costs.
Environmental Sustainability
With sequestration, each MW of capacity installed using ZERE technology with CO2 sequestration, the yearly negative emissions factor would be at least -8,682,036 kg CO2. Subsystem testing consistently showed NOx emissions to significantly less than 1 ppmv.
Key Project Members
George Touchton
Subrecipients
University of Nevada, Reno
Match Partners
University of Nevada, Reno
ZERE Energy and Biofuels, Inc.
