Process for scavenging H.sub.2 S by mixtures of hexahydrotriazines

A method for reducing the levels of hydrogen sulfide (H.sub.2 S) in a gaseous or liquid stream containing H.sub.2 S comprising adding to said stream an amount of a composition effective to reduce the H.sub.2 S level, where the composition comprises:

• (i) at least one hexahydrotriazine of the formula:
• ##STR7## where R.sup.1, R.sup.3 and R.sup.5 are independently selected from the group consisting of hydrogen and an alkyl radical, including substituted alkyl radicals, where when R.sup.1, R.sup.3 and R.sup.5 are not hydrogen, they each have a total of 1 to 5 carbon atoms and
• where R.sup.2, R.sup.4 and R.sup.6 are independently selected from the group consisting of hydrogen and an alkyl radical, including substituted alkyl radicals, where when R.sup.2, R.sup.4 and R.sup.6 are not hydrogen, they each have a total of 1 to 5 carbon atoms;
• and
• at least one amine selected from the group consisting of
• (ii) RN=CHR;
• (iii) R.sub.2 NCH.sub.2 (R')NR.sub.2 ;
• and
• (iv) R.sub.2 NCH.sub.2 (R')OH;
• where R independently is R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6, and where R' independently is an alkylene radical equivalent to R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6, except that when R is hydrogen, R' is a chemical bond;
• and
• where at least one of the R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 groups of the hexahydrotriazine (i) is an alkoxyalkylene group.

A method for reducing the levels of hydrogen sulfide (H.sub.2 S) in a gaseous or liquid stream containing H.sub.2 S comprising:

• (1) reacting at least one amine compound selected from the group consisting of R.sup.1 NH.sub.2 ;
• R.sup.3 NH.sub.2 ;
• R.sup.5 NH.sub.2 and R.sup.7.sub.2 NH with at least one aidehyde compound selected from the group consisting of
• R.sup.2 CHO, R.sup.4 CHO and R.sup.6 CHO to form a composition;
• where R.sup.1, R.sup.3 and R.sup.5 are independently selected from the group consisting of hydrogen and an alkyl radical, including substituted alkyl radicals, where when R.sup.1, R.sup.3 and R.sup.5 are not hydrogen, they each have a total of 1 to 5 carbon atoms;
• and R.sup.7 is independently R.sup.1, R.sup.3 or R.sup.5 ;
• and
• where R.sup.2, R.sup.4 and R.sup.6 are independently selected from the group consisting of hydrogen and an alkyl radical, including substituted alkyl radicals, where when R.sup.2, R.sup.4 and R.sup.6 are not hydrogen, they each have a total of 1 to 5 carbon atoms;
• where at least one of the R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 groups is an alkoxyalkylene group;
• and
• where at least one hexahydrotriazine is formed which has at least one R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 group as an alkoxyalkylene group;
• (2) adding to said stream an amount of the composition effective to reduce the H.sub.2 S level.