SCAVENGERS
The implementations described herein generally relate to methods and chemical compositions for scavenging sulfur-containing compounds, and more particularly to methods and compositions for scavenging, for example, H 2 S and mercaptans from sulfur-containing streams. In one implementation, a method for scavenging a sulfur-containing compound from a sulfur-containing stream is provided. The method comprises contacting the sulfur-containing stream with a scavenging system for scavenging the sulfur-containing compound, wherein the scavenging system comprises urea formaldehyde reaction products.
1 . A method for scavenging a sulfur-containing compound from a sulfur-containing stream comprising:
contacting the sulfur-containing stream with a scavenging system for scavenging the sulfur-containing compound, wherein the scavenging system comprises urea formaldehyde reaction products.
2 . The method of claim 1 , wherein the scavenging system further comprises buffers, inorganic base additives selected from the group consisting of sodium hydroxide, potassium hydroxide, and combinations thereof, and combinations thereof.
3 . The method of claim 2 , wherein the scavenging system has a pH from 5 to 13.
4 . The method of claim 1 , wherein the urea formaldehyde reaction products have a formaldehyde to urea mole ratio from 0.5:1 to 20:1.
5 . The method of claim 1 , wherein the contacting the sulfur-containing stream with the scavenging system comprises contacting at a temperature range from about −50° C. to about 180° C.
6 . The method of claim 1 , wherein the urea formaldehyde reaction products have a free formaldehyde content from 0% to 70%.
7 . The method of claim 1 , wherein the scavenging system further comprises one or more additives selected from the group consisting of non-water solvents, dispersants, foam control agents, scale inhibitors, and combinations thereof.
8 . The method of claim 7 , wherein the solvents comprise alcohol and/or polyalcohol selected from the group consisting of methanol, ethylene glycol, propylene glycol, glycerol, and combinations thereof.
9 . The method of claim 1 , wherein the urea formaldehyde reaction products are selected from the group consisting of monomethylolurea, polyhydroxymethylureas, condensation products of monomethylolurea, condensation products of polyhydroxymethylureas, and combinations thereof.
10 . The method of claim 9 , wherein the urea formaldehyde reaction products are selected from the group consisting of monomethylolurea, dimethylolurea, trimethylolurea, tetramethylolurea, dimethylolruron, and combinations thereof.
11 . The method of claim 1 , wherein the scavenging system further comprises water, wherein the water is from about 10 wt. % to about 90 wt. % of the scavenging system.
12 . The method of claim 1 , wherein the urea formaldehyde reaction products comprise up to 95 wt. % of the scavenging system.
13 . The method of claim 1 , wherein the urea formaldehyde reaction products are obtained by the reaction of urea with formaldehyde.
14 . The method of claim 13 , wherein the urea formaldehyde reaction products are obtained by the reaction of 25% urea with 60% formaldehyde.
15 . The method of claim 1 , wherein the urea formaldehyde reaction products are obtained by reaction of methanol, air and urea in the presence of a catalyst.
16 . The method of claim 1 , wherein contacting the sulfur-containing stream with a scavenging system occurs at temperatures up to 180° C.
17 . A treated stream comprising:
a sulfur-containing stream;
a sulfur-containing contaminant; and
a scavenging system scavenging system comprises urea formaldehyde reaction products in an amount effective to at least partially remove the sulfur-containing contaminant from the sulfur-containing stream.