Adsorption of 1,1-Dimethylhydrazine by Hydrolysis Lignin

Many modern launch vehicles use unsymmetrical dimethylhydrazine (UDMH) as liquid fuel in the space program. UDMH is highly toxic and poses a serious threat to the environment and to humans. One of the most effective methods of UDMH neutralization in case of fuel spills is adsorption. This paper is the first to suggest using hydrolysis lignin as rocket fuel adsorbent. The research was based on the use of ion chromatography with amperometric detection and gas chromatography-mass spectrometry methods. The adsorption experiment resulted in finding the conditions that correspond to the residual UDMH concentration that does not exceed maximum permissible concentration in water. Also, it was investigated the effect of moisture content of hydrolysis lignin and ambient temperature on the dynamics of UDMH adsorption from the gaseous phase. We determined the kinetic and thermodynamic parameters of the adsorption process. It was demonstrated that the reaction between 1,1-dimethylhydrazine and active adsorbent centers (carbonyl and carboxyl groups) is close to the first order. The value of activation energy (85.9 kJ/mol) corresponds to that of chemisorption.