He then completed his PhD work in 1990 at the University of Wageningen in the Netherlands, focusing on enhancing the impregnation of wood through anatomical cell wall changes.

Militz along with his research corkers started up during the 90's at SHR the first feasible pilot plant, leading thus to the scaling-up of the today-commercial wood acetylation process, that had been initiated by American chemist, Alfred J. Stamm during the 1940's at Forest Products Laboratory.

He possesses over 600 publications in many scientific journals and book articles in the area of wood science and technology.

at Stanford University included Holger Militz in Elsevier Data 2022, where he was ranked in the top 2% of researchers in wood science (forestry – materials), having a c-score of 3.495, one of the highest three in this scientific area.

[9] In August 2024, Militz has acquired the same high international distinction for his research and scientific work in wood sciences (Elsevier Data 2023).