this invention provides novel compositions comprising substituted polyamines as acid gas scrubbing solutions and methods of using the compositions in an industrial system . the invention relates to the use of such polyamine compounds in industrial processes to remove acidic contaminants from natural and industrial fluid streams , such as natural gas , combustion gas , natural gas , synthesis gas , biogas , and other industrial fluid streams . the compositions and methods of the invention are useful for removal , absorption , or sequestration of acidic contaminants and sulfide contaminants including co 2 , h 2 s , rsh , cs 2 , cos , and so .