Hydrogen sulfide scavenger
The present disclosure is related to a family of metals chelates for use as a hydrogen sulfide scavenger in asphalt, and the preparation thereof. The metal chelates, in particular amino acid metal chelates, are particularly efficient at reducing the hydrogen sulfide emissions of asphalt.
1. A method of reducing hydrogen sulfide emission from asphalt or from the preparation of asphalt, the method comprising:
adding a liquid scavenger composition to asphalt or asphalt mix,
wherein the liquid scavenger composition comprises 5 wt % to 90 wt % of a metal chelate chosen from copper aspartate; copper gluconate; copper bis-glycinate; iron aspartate; iron glycinate; iron fumarate; iron gluconate; molybdenum chelate; molybdenum trit; zinc arginate; zinc ascorbate; zinc aspartate; zinc gluconate; zinc bis-glycinate; zinc methionate; zinc picolinate; and mixtures thereof; and
a solvent having a flash point compatible with asphalt,
wherein the liquid scavenger composition is added to the asphalt or asphalt mix in an amount of 0.05 wt % to 5 wt %, based on total weight of the asphalt or asphalt mix, and is able to reduce hydrogen sulfide emissions from the asphalt or asphalt mix.
2. The method of claim 1 , wherein the metal chelate is selected from the group consisting of copper bis-glycinate and zinc bis-glycinate.
3. The method of claim 1 , wherein the asphalt or asphalt mix comprises an acid.
4. The method of claim 3 , wherein the acid is selected from the group consisting of phosphoric acid and polyphosphoric acid.
5. The method of claim 3 , wherein the acid is added to the asphalt or asphalt mix prior to addition of the liquid scavenger composition.