Doosan Lentjes
German engineering company specialising in thermal waste and sewage sludge treatment, steam generation and flue gas cleaning, part of the Doosan Group.
Last updated September 28, 2026
AI crawler reads
No AI crawler has read this profile since Oct 28, 2026.
Overview
Doosan Lentjes GmbH is a German plant engineering company headquartered in Ratingen, North Rhine-Westphalia. Founded in 1927 by Ferdinand Lentjes as a boiler manufacturer, the company has evolved into an internationally active provider of plant solutions for energy and waste management infrastructure. It uses proprietary processes for combustion, steam generation and flue gas cleaning to supply tailor-made plants for thermal waste and sewage sludge treatment. With more than 80 lines contracted worldwide for thermal waste treatment and over 35 reference lines in sewage sludge treatment, Doosan Lentjes has decades of experience in these fields. Its systems meet strict emission standards and support the circular economy by turning waste into clean energy and reusable materials. The company consists of the German headquarters in Ratingen and a Czech subsidiary in Prague. As part of the global Doosan Group, it delivers integrated solutions worldwide. The management team includes CEO Dirk Stokvis, Director Sales & Proposals Philipp Stolzenburg, Director Engineering Dr. Oğuzhan Narin, and Director Operations Jürgen Rasch. Recent projects include contracts for sewage sludge treatment plants in Cologne (2026), Flanders (2022), and waste-to-energy plants in Warsaw (2021), Wiesbaden (2021), and Olsztyn (2020).
History
Doosan Lentjes traces its origins to 1927/1928, when Ferdinand Lentjes founded the company in Düsseldorf under the name Rheinische Rohrleitungsbau-GmbH, soon also operating as Ferdinand Lentjes Kesselschmiede und Maschinenbau. After Ferdinand Lentjes died in 1955, the company passed into the ownership of the Ferdinand-Lentjes-Stiftung (Ferdinand Lentjes Foundation). Through the 1980s, the company grew through its core boiler-making business and acquisitions, including Burmeister & Wain A/S of Denmark (1980), Gottfried Bischoff GmbH & Co. KG (1984), and Standardkessel (1985). The 1990s and early 2000s were marked by a prolonged crisis in the German power plant engineering sector, numerous restructurings, and a gradual but steady shrinkage. This process occurred under Metallgesellschaft (today GEA Group), which took over Lentjes in 1990/1991. Activities and technologies of Lentjes and its subsidiaries and sister companies Lurgi, Standardkessel, Standard Fasel and Bischoff were reorganised. Lentjes and Metallgesellschaft cooperated closely with Deutsche Babcock during this period. At the end of the shrinkage process, the large boiler division was sold to Babcock in 1996 and the industrial boiler division (Standardkessel) to HTP in 2004, along with associated service operations (now ThyssenKrupp Xervon). From several thousand employees, only a few hundred remained. Lentjes no longer maintained its own manufacturing and became a pure engineering company focused on complete plant construction and firing and flue gas cleaning systems. From shortly after the turn of the millennium, GEA sought to divest its entire plant engineering division, including Lentjes. In preparation, in 2005 Lentjes GmbH took over the operating business from Lurgi Lentjes AG (today LL Plant Engineering AG). On 2 May 2007, Lentjes GmbH was sold for a symbolic price of 1 euro to Austrian Energy & Environment, a subsidiary of A-TEC. The European antitrust authorities initially raised objections, so the sale did not become legally effective. On 5 December, after an in-depth review, the sale was approved without conditions and completed on 21 December 2007. In early 2008, Lentjes GmbH changed its name to AE&E Lentjes GmbH and adopted the triangular AE&E logo. After A-TEC unexpectedly went bankrupt in October 2010, AE&E also had to file for insolvency, and buyers were sought for the various AE&E subsidiaries. On 28 November 2011, AE&E Lentjes GmbH was acquired by Doosan Power Systems Ltd. (DPS), a subsidiary of the Korean Doosan Group. Since then, the company has operated as Doosan Lentjes GmbH. In 2018, the company celebrated its 90th anniversary and announced its re-entry into the market for thermal treatment of municipal sewage sludge. It also received an order at the end of the year to supply CFB technology for the first fully biomass-fired power plant in Japan (Sodegaura). In 2020, it won a second contract for a thermal waste treatment plant in Poland (Olsztyn), securing market leadership in the country. In 2021, it received orders for grate and boiler technology for the new waste-to-energy plant in Warsaw, Poland, and for the new waste-to-energy plant in Wiesbaden, Germany. In 2022, it was awarded the contract to supply the new sewage sludge treatment plant in the Belgian region of Flanders. In 2023, it launched its new employer brand #YourVoiceMatters. In 2026, it secured the contract to supply the thermal sewage sludge treatment plant in Cologne, Germany, signed at IFAT Munich on 5 May 2026.
- 2026
Secured contract for thermal sewage sludge treatment plant in Cologne, Germany, signed at IFAT Munich on 5 May 2026.
- 2023
Launched new employer brand #YourVoiceMatters.
- 2022
Awarded contract for new sewage sludge treatment plant in Flanders, Belgium.
- 2021
Orders for grate and boiler technology for waste-to-energy plants in Warsaw, Poland and Wiesbaden, Germany.
- 2020
Won second contract for thermal waste treatment plant in Olsztyn, Poland; secured market leadership in Poland.
- 2018
90th anniversary; re-entry into municipal sewage sludge thermal treatment; order for CFB technology for first fully biomass-fired power plant in Japan (Sodegaura).
- 2011
Acquired by Doosan Power Systems Ltd. on 28 November.
- 2008
Renamed AE&E Lentjes GmbH.
- 2007
Sold to Austrian Energy & Environment (A-TEC) for 1 euro; completed on 21 December.
- 2005
Lentjes GmbH takes over operating business from Lurgi Lentjes AG.
Products and positioning
Internationally active provider of tailor-made plant solutions for energy and waste management infrastructure, with proprietary combustion, steam generation and flue gas cleaning processes.
Waste-to-energy plants
Sewage sludge incineration plants
Flue gas cleaning systems
Steam generators
Circulating fluidised bed (CFB) boilers
Grate and boiler technology
Sources6 sources
Cite this profile: Cite the canonical profile. /brand-wiki/lentjes · Editorial policy · How profiles are compiled