Pyrolysis Process Development Unit

Center for Sustainable Environmental Technologies

Pyrolysis Process Development Unit

Fast pyrolysis research at Iowa State University has been centered for the past 7 years on a process development unit (8 kg/hr biomass) system located at the BECON Energy Conversion Facility in Nevada, Iowa.  This unit converts dry biomass into bio-oil through a thermochemical process that includes rapidly heating the biomass to high temperatures (450C to 550C) in an oxygen free environment.  The current system utilizes a fluidized bed of sand to provide the necessary heat transfer to reach the rapid heating that is necessary.  The sand is fluidized by compressed nitrogen.  Fast pyrolysis has three main products which include bio-oil, char and various gases. Research at Iowa State has been focused on many aspects of the fast pyrolysis process of the past seven years. The first work that was performed dealt with the fast pyrolysis process, concentrating on the reactor and the products leaving the reactor.  The enthalpy of fast pyrolysis was studied as well as the presence of aerosols.  Further research was conducted on the filtering of fast pyrolysis gases to remove solid particulate from the flow.  This research was performed with a combination of gas cyclones and a moving bed granular filter.  Currently, research is being preformed into the consistent production of bio-oils with a high yield. 

The next step for fast pyrolysis for ISU at the Process Development Unit scale is a second system to be built within the next year.  This system will also be an 8 kg/hr unit, but there will be some major changes/improvements compared to the current system.  This new fast pyrolysis system is currently being built and will soon be installed at the BECON Facility in Nevada, IA. The system features a bubbling fluidized bed fast pyrolysis reactor that will be used to feed modular hot gas filtration technologies as well as multiple bio-oil condensation technologies.  The system will be entirely automated and it will have the ability to record all the data that is needed to perform mass and energy balances on the system.  The overall goal for the updated system is to run test for an extended period of time and to study the effects of bio-oil condensation on the products from the system. 

 

Bio-oil from fast pyrolysis
Process Development Unit- 3-D Model

 

PI:
Dr. Robert Brown, Dr. Samuel Jones

Participating/sponsoring organizations:
DOE

Research By:
Anthony Sherwood-Pollard

 

References

  1. Daugaard, D. E. and Brown, R. C., Enthalpy for pyrolysis for several types of biomass, 934-939, 2003.
  2. Daugaard, D. E. and Brown, R. C., The transport phase of pyrolytic oil exiting a fast fluidized bed reactor, Science in Thermal and Chemical Biomass Conversion Conference, Victoria, B.C., Canada, Aug. 30 Sept. 2, 2004.
  3. Ritzert, J., Brown, R. C., and Smeenk, J., Filtration efficiency of a moving bed granular filter, Science in Thermal and Chemical Biomass Conversion Conference, Victoria, B.C., Canada, Aug. 30 Sept. 2, 2004.
  4. So, K. and Brown, R.C., Economic analysis of selected lignocellulose-to-ethanol conversion echnologies, Applied Biochemistry and Biotechnology, 77-79, 633-640, 1999.
  5. Sandvig, E., Walling, G., Daugaard, D. E., Pletka, R., Radlein, D., Johnson, W., Brown, R. C., The prospects for integrating fast pyrolysis into biomass power systems, International Journal of Power and Energy Systems, to appear 2004.