The UNIDENSE® technology was developed by Mr G. Ryntveit as employee of Yara International (previous North Hydro Agri). Development took place at the Hydro's Research Center in Porsgrunn, Norway, during 1991 in order to improve the quality of the primary reformer catalyst loading in ammonia plants within Hydro. Test results and the result from the first loading were presented at the AIChE conference in San Antonio in 1992. Hydro Agri has since utilized the technology for all replacements of primary reformer catalysts, and the technology has since been made available for companies outside of the Hydro group.
The technology has successfully been used to load tubes with internal diameter ranging from 2.8" to 6" and all common catalyst types and sizes have been loaded. G. Ryntveit was responsible for the UNIDENSE® technology as employee of Hydro until October 2001, when he took early retirement. He was granted a license to use the UNIDENSE® technology worldwide. As from April 1st 2005 UNIDENSE® Technology GmbH with assistance of G. Ryntveit is the owner of the UNIDENSE® technology.