Lauritz Jenssen Dorenfeldt (engineer)

Lauritz Jenssen Dorenfeldt (23 January 1863 – 3 January 1932) was a Norwegian engineer.

He was born in Strinda as the oldest of seven sons of businessman Lauritz Jenssen (1837–1899) and Jørgine Wilhelmine Darre (1842–1910). He was a brother of Hans Jørgen Darre-Jenssen and Worm Hirsch Darre-Jenssen, and a nephew of Hans Jørgen Darre. He took the name Dorenfeldt in 1890.

In October 1890 he married physician's daughter Aagot Bødtker (1869–1963). They had the son Lauritz Jenssen Dorenfeldt, who made his career in law. Through his wife he was also a brother-in-law of Sigurd Bødtker.

He took the examen artium at Trondhjem Cathedral School in 1881, and graduated from Trondhjem's technical school in 1884. He was hired in his father's factory Ranheim Cellulosefabrik in 1884, was promoted to assistant engineer in 1885 and manager in 1888. By that time he had undertaken studies at the Royal Technical College of Charlottenburg. In 1891 the factory became the paper factory Ranheim Papirfabrikk. In 1894 he was hired as a technical director for a similar factory in Rheindürkheim, Rhineland Palatinate, and in 1902 he settled in Kristiania to work with technical consulting.

He was prominent in the development of pulp and paper industry. In the technical sphere, he was a proponent for using pyrite from Norway as well as natrium sulphite in the production of cellulose. He took part in a development of the Norwegian industry from exporting cellulose and pulp, to refining and exporting paper. He co-founded a research institute in 1922 and the association Norsk Celluloseforening. He died in January 1932 in Oslo.