Back to results
US 4,508,693 AGranted
Solution removal of HCN from gaseous streams, with pH adjustment of reacted solution and hydrolysis of thiocyanate formed
AssigneeShell Oil Company
InventorZaida Diaz
Life of this patent
Estimating the term…
Abstract
A process for the removal of HCN from gaseous streams is described, the process being characterized by reaction of the HCN in the gaseous stream with an ammonium polysulfide solution and formation of ammonium thiocyanate in solution, precipitation and removal of sulfur from the ammonium thiocyanate-containing solution, and hydrolysis of the ammonium thiocyanate. Provision is made for recycle of hydrolysis products.
Claims4
A process for removing hydrogen cyanide from a gaseous stream containing hydrogen cyanide comprising
- (a) contacting said gaseous stream in a contact zone with a solution containing ammonium polysulfide under conditions to convert hydrogen cyanide, and producing a solution containing ammonium polysulfide and ammonium thiocyanate, and a gas stream having reduced hydrogen cyanide content;
- (b) removing solution containing ammonium polysulfide and ammonium thiocyanate from the contact zone;
- (c) lowering the pH of the removed solution to decompose ammonium polysulfide and precipitate sulfur, and producing hydrogen sulfide, sulfur, and a remaining ammonium thiocyanate-containing solution, and removing sulfur from said remaining solution;
- (d) hydrolyzing the ammonium thiocyanate in said remaining solution and producing ammonia, hydrogen sulfide, and carbon dioxide.
1 more element
Dependencies are inferred from the claim text.