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Dive into the research topics where Friedhelm Steffens is active.

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Featured researches published by Friedhelm Steffens.


Archive | 2002

Process for purification of anhydrous hydrogen chloride gas

Bill Brady; Guenther Dipl Phys Dr Weymans; Berthold Keggenhoff; Friedhelm Steffens


Archive | 2003

Process for the purification of mixtures of toluenediisocyanate incorporating a dividing-wall distillation column

Bill Brady; Friedhelm Steffens; Berthold Keggenhoff; Kai Verkerk; Gerhard Ruffert


Archive | 2007

Method for manufacturing isocyanates in the gaseous phase

Fritz Dr. Pohl; Klaus Dr. Biskup; Rainer Bruns; Friedhelm Steffens; Herbert Dr. Stutz


Archive | 2003

Method for refining mixture of toluene diisocyanate by using distillation column having partitioned wall

Bill Brady; Berthold Keggenhoff; Gerhard Ruffert; Friedhelm Steffens; Kai Verkerk; カイ フェアケルク; ゲルハルト・ルッフェルト; ビル・ブレイディ; フリードヘルム・シュテッフェンス; ベルトルト・ケッゲンホーフ


Archive | 2010

Process for the preparation of toluene-diisocyanate

Wolfgang Lorenz; Lars Dr. Padeken; Bernd Pennemann; Friedhelm Steffens; Lothar Weismantel


Archive | 1986

Method of liquid-liquid extraction using material exchange columns

Hans-Walter Brandt; Friedhelm Steffens; Johannes-Peter Schäfer; Jürgen Schröter


Archive | 2005

Process for the distillative separation of aqueous amine solutions

Friedhelm Steffens; Rainer Dr. Buse; Bill Brady


Archive | 2005

Process for separation of aqueous amine solutions by distillation

Bill Brady; Rainer Dr. Buse; Friedhelm Steffens


Archive | 2008

Method for manufacturing aromatic diisocyanates in the gaseous phase

Klaus Dr. Biskup; Rainer Bruns; Lars Dr. Padeken; Fritz Dr. Pohl; Friedhelm Steffens


Archive | 2007

Process for the production of the toluene diisocyanate

Joachim Zechlin; Bernd Pennemann; Friedhelm Steffens; Ji Wenbin

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