Abstract: A new alkaline absorbent solution containing a severely-hindered amine and a severely-hindered aminoacid is provided. A process for the removal of H.sub.2 S from fluid mixtures using this absorbent solution to produce a very low level of H.sub.2 S in the treated fluid is also provided. The process is also suitable for the selective removal of H.sub.2 S from fluid mixtures comprising H.sub.2 S and CO.sub.2. Use of the above absorbent solution leads to higher selectivity for H.sub.2 S than observed when the severely-hindered amine is used alone without the severely-hindered aminoacid.

Abstract: The present invention relates to a mixture of severely-hindered amines, such as bis-(tertiarybutylaminoethoxy)-ethane (BTEE) and ethoxyethoxyethanoltertiarybutylamine (EEETB), and a one-step synthesis method for its preparation. Besides, this invention describes the use of the mixture for the removal of H.sub.2 S, especially the selective removal of H.sub.2 S in the presence of CO.sub.2.

Abstract: A new alkaline absorbent solution containing the additive of a severely-hindered amine salt and/or a severely-hindered aminoacid to a non-hindered amine such as N-methyldiethanolamine (MDEA) is provided. A process for the removal of H.sub.2 S from fluid mixtures using this absorbent solution to produce a very low level of H.sub.2 S in the treated fluid is also provided. The process is also suitable for the selective removal of H.sub.2 S from fluid mixtures comprising H.sub.2 S and CO.sub.2. Use of the above absorbent solution leads to higher selectivity for H.sub.2 S than observed when MDEA is used alone without the additives.

Abstract: A novel class of diaminoether compounds wherein one amino group thereof is a tertiary amine in N-heterocyclic form and the other amino group is a severely sterically hindered secondary amino group may be prepared by a three-step process and are useful in the selective removal of H.sub.2 S from mixtures containing H.sub.2 S and CO.sub.2.

Abstract: Disclosed are primary sterically hindered aminoacids for use as promoters for alkali metal salts in acid gas scrubbing. The primary sterically hindered aminoacid is selected from 1-amino-cyclopentane carboxylic acid and those represented by the formula: ##STR1## where R.sub.1 and R.sub.2 are independently selected from CH.sub.3, C.sub.2 H.sub.5, and C.sub.3 H.sub.7 ; R.sub.3 and R.sub.4 are independently selected from hydrogen and CH.sub.3 : and n is 0, 2, or 3.

Abstract: An alkaline absorbent composition comprising a severely hindered amino compound and an amine salt is provided. A process for the removal of H.sub.2 S from fluid mixtures using this absorbent composition to produce a very low level of H.sub.2 S in the treated fluid is also provided. The process is also suited for the selective removal of H.sub.2 S from fluid mixtures comprising H.sub.2 S and CO.sub.2.

Abstract: The present invention relates to an alkaline salt promoter system which includes an N-aminoalkyl alkylpiperazine, preferably the compound 1-(3-aminopropyl)-2,5-dimethylpiperazine (APDP), an alkali metal salt or hydroxide (e.g., K.sub.2 CO.sub.3) and water. These scrubbing compositions may be used for removing CO.sub.2 from gaseous streams containing CO.sub.2.

Abstract: The present invention relates to the preparation of mixtures of sterically hindered substituted N-secondary amino acids or their alkali metal salts by a one-step reductive condensation of an amino acid or its alkali metal salt containing a primary amino group and a ketone to thereby form a mono-substituted amino acid or alkali metal salt thereof, followed by preparing the corresponding sterically hindered tertiary amino acids or alkali metal salt thereof by reacting the mono-substituted amino acids or alkali metal salt thereof with an unhindered aldehyde under reducing conditions in the presence of a hydrogenating catalyst. The novel mixtures of the sterically hindered mono-substituted amino acids and the tertiary amino acids and their alkali metal salts are useful promoters for alkaline salts in "hot pot" acid gas scrubbing processes.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a strongly basic tertiary amino compound having a pK.sub.a at 20.degree. C. greater than 8.6 and a boiling point at 760 mm greater than 180.degree. C. whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: The present invention relates to a process for selectively preparing severely sterically hindered secondary aminoether alcohols by reacting a primary amino compound with a polyalkenyl ether glycol in the presence of a hydrogenation catalyst at elevated temperatures and pressures. The severely sterically hindered secondary aminoether alcohols are useful in acid gas scrubbing processes, particularly in the selective removal of H.sub.2 S from gaseous streams containing CO.sub.2 and H.sub.2 S.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a nitrogen heterocyclic tertiary aminoalkanol or aminoetheralkanol whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: The present invention relates to an alkaline salt promoter system comprising specific mixtures of sterically hindered monosubstituted alpha-amino acids and tertiary amino acids and its use in acid gas scrubbing processes. The preferred promoter system comprises a mixture of N-secondary butyl glycine and N-methyl-N-secondary butyl glycine.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a severely sterically hindered secondary amino compound having a cumulative .sup.- E.sub.s value (Taft's steric hindrance constant) greater than about 1.75 whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: A novel class of severely sterically hindered tertiary amino compounds having a pK.sub.a value at 20.degree. C. greater than 8.6, preferably ranging from 9.3 to about 10.6, and a cumulative -E.sub.s value of at least 1.9 are found to be useful in selective removal of H.sub.2 S from a normally gaseous mixture containing H.sub.2 S and CO.sub.2.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a diaminoether wherein at least one amino group is a tertiary amine whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: The present invention relates to an alkaline promoter system comprising specific mixtures of nonsterically hindered amino compounds and sterically hindered amino acids and their use in acid gas scrubbing processes. The preferred promoter system comprises a mixture of (i) diethanol amine or 1,6-hexanediamine and (ii) N-secondary butyl glycine or pipecolinic acid.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a di-secondary aminoether wherein each amino group has a severely sterically hindered secondary amino moiety whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a tertiary amino azabicyclic alcohol whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: The present invention relates to an alkaline salt promoter system which includes N-secondary butyl glycine and its use in acid gas scrubbing processes.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a severely sterically hindered secondary aminoether alcohol having a cumulative .sup.- -E.sub.s value (Taft's steric hindrance constant) greater than about 1.75 whereby H.sub.2 S is selectively absorbed from the mixture.