@TechReport{	  it:2005-007,
  author	= {Linda Brus},
  title		= {Nonlinear Identification of an Anaerobic Digestion
		  Process},
  institution	= {Department of Information Technology, Uppsala University},
  department	= {Division of Systems and Control},
  year		= {2005},
  number	= {2005-007},
  month		= mar,
  abstract	= {Anaerobic digestion in bioreactors is an important
		  technology for environmental friendly treatment of organic
		  waste. To optimize and control such processes accurate
		  dynamic models of the process are needed. Unfortunately,
		  modeling of anaerobic digestion often results in high order
		  nonlinear models with many unknown parameters, a fact that
		  complicates controller design. This paper attempts to
		  circumvent this problem, by application of new recursive
		  system identification techniques, thereby radically
		  reducing the degree of the models and the number of
		  parameters. Experiments show that a second order nonlinear
		  model is sufficient for accurate modeling of the system.}
}