Method to produce a urea ammonium sulphate-based composition
The present disclosure is related to a pipe reactor. In its broadest aspect, the present disclosure is related to a method for producing a urea ammonium sulphate-based composition in a pipe reactor comprising a first and a second mixing zone. The method comprises the steps of: a) directing a liquid stream comprising ammonium bisulphate to the first mixing zone of the pipe reactor; b) directing a first stream of ammonia to the first mixing zone of the pipe reactor for reacting with the liquid stream comprising ammonium bisulphate, provided in step a), to obtain a liquid stream comprising ammonium sulphate; c) directing the liquid stream comprising ammonium sulphate, provided in step b), to the second mixing zone of the pipe reactor; and d) directing a liquid stream of urea to the second mixing zone of the pipe reactor for mixing with the liquid stream comprising ammonium sulphate.
1 . A method for producing a urea ammonium sulphate-based composition in a pipe reactor comprising a first and a second mixing zone, the method comprising the steps of:
a) directing a liquid stream comprising ammonium bisulphate to the first mixing zone of the pipe reactor;
b) directing a first stream of ammonia to the first mixing zone of the pipe reactor for reacting with the liquid stream comprising ammonium bisulphate, provided in step a), to obtain a liquid stream comprising ammonium sulphate;
c) directing the liquid stream comprising ammonium sulphate, provided in step b), to the second mixing zone of the pipe reactor; and
d) directing a liquid stream of urea to the second mixing zone of the pipe reactor for mixing with the liquid stream comprising ammonium sulphate, provided in step b), to obtain a urea ammonium sulphate-based composition;
wherein in step b), the first stream of ammonia is preheated to a temperature of at least 100° C. prior to being directed to the first mixing zone of the pipe reactor.
2 . The method according to claim 1 , further comprising, in step a), preparing the liquid stream comprising ammonium bisulphate in a pre-reactor fluidly connected to the pipe reactor, by reacting a stream of sulphuric acid, a stream of water and a second stream of ammonia.
3 . The method according to claim 2 , wherein the temperature of the second stream of ammonia directed in the pre-reactor is below 10° C.
4 . The method according to claim 2 , wherein the pre-reactor is an annular pipe reactor.
5 . The method according to claim 1 , wherein the pipe reactor is an annular pipe reactor.
6 . The method according to claim 1 , wherein the liquid stream of ammonium bisulphate and/or the liquid stream of urea comprises aluminium sulphate.
7 . The method according to claim 6 , wherein the urea ammonium sulphate-based composition obtained in step d) comprises from at least 0.1 to at most 1.0 weight % of aluminium sulphate.
8 . The method according to claim 1 , wherein the temperature of the first stream of ammonia directed to the first mixing zone of the pipe reactor is at least 120° C.
9 . The method according to claim 1 , wherein the urea ammonium sulphate-based composition obtained in step d) comprises from at least 1 to at most 35 weight % of ammonium sulphate, and from at least 50 to at most 95 weight % of urea, wherein all weight % are based on the total weight of the urea ammonium sulphate-based composition.
10 . The method according to claim 6 , wherein the liquid stream of urea comprises aluminium sulphate.