Siemens Energy has successfully completed the first firing of PetroAlgae Inc.’s biocrude fuel, a plant-based, micro-crop biomass material that is processed into a solid residue. The biocrude fuel was combined with pulverised coal in a pilot-scale burner with a thermal capacity of approximately 4 MBtu/hour. The testing was performed at a test bed installed at the University of Utah, Salt Lake City, Utah, and results show that the biocrude/coal fuel mixture burned well and produced 20% lower NOx emissions than coal alone.
In the pilot-scale test, which was conducted in a scaled-down version of Siemens’ current pulverised coal burner design, the biocrude was blown into the fuel injector separately from the pulverised coal. Some mixing of the pulverised coal and biocrude took place within the fuel injector before combustion of the mixture. Up to 10% of the total heating value was provided by the biomass in these tests.
The testing showed that the biocrude was easy to handle and inject into the burner, unlike some other biomass fuels. The fuel burned well and emissions testing showed that the biomass/coal fuel mixture produced lower NOx emissions than coal alone. Tests were conducted with and without external air staging. The biomass and coal mixture produced lower emissions with staging than without, as expected. Siemens intends to conduct further tests of the pilot-scale burner with increased quantities of PetroAlgae’s biocrude fuel in the near future.
Before the pilot plant-scale testing with Siemens, PetroAlgae conducted combustion testing at the University of Utah in a bench-scale burner with the biocrude providing up to 100% of the heating value. These tests were performed with and without external air staging, and they showed similar positive results in terms of handling, injection and burning. Firing the biomass fuel alone produced lower NOx emissions than the coal alone, and the NOx reduction was more pronounced under staging conditions.
Read the article online at: https://www.oilfieldtechnology.com/drilling-and-production/09062010/siemens_successfully_co-fires_coal_with_petroalgae_biocrude/