Anthony
March 5th, 2003, 06:01 PM
shady mutha
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted February 08, 2001 11:30 PM
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OLD PROCESS
The oldest method of manufacturing nitroglycerine was a most primitive process that consisted of dropping small amounts of glycerine into a cast iron pot containing a mixtuer of nitric acid and sulphuric acid.The pot was cooled by standing in a larger,stoneware vessel containing water and ice,and hand stirring was performed with an iron rod.When the nitration was completed{or danger of decomposition arose}the contents of the cast iron pot were turned out inti the water and ice.water was then removed by decantation and the blasting oil washed.In that way a 200% yield of nitroglycerine was obtained.
pete
Frequent Poster
Posts: 56
From: u.k
Registered: JAN 2001
posted February 09, 2001 05:48 PM
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A 200% yield?
shady mutha
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted February 10, 2001 01:53 AM
--------------------------------------------------------------------------------
PART 2
The design of apperatus to facilitate rapid and efficent revovel of the heat produced during nitration was not known at that time.Solution of these difficulties was therefore sought in modifacation of the manufacturing process itself,as suggested by Boutmy and Faucher.they divided the nitrating process into two stages.At each stage a certain amount of heat is developed,which is less,off course,than the total heat of nitration.
The stages suggested byBoutmy and Faucher are as follows.
1.Dissolving the glycerine in sulphric acid to form glycerl-sulphuric acid;
2.Adding nitric acid to the solution of glycerine in sulhuric acid.
The greater part of the heat is produced during the relatively save process[1].The amount of heat developed during nitration proper[2]is therefore relatively small and the temperature can be controlled easily even if primitive methods are used.
For several years[untill 1882]the bounty-Faucher method was used in France and Great britain.In completey primitive apparatus,about 680kg nitroglycerine were made at a time.The disadvantage of this method was that thr nitroglycerine obtained by nitrating according to reaction[2]seperated only very slowly from the acid.In the standard method the contents of the nirator were allowed to stand overnight to permit seperation of the nitroglycerine.This lenghy contact between the nitroglycerine and the acid involved the danger of decomposition.Indeed,in factories where this method of nitroglycerine was practices frequent explosions occurred durring the seperation stage.
c0deblue
Frequent Poster
Posts: 229
From:
Registered: JAN 2001
posted February 10, 2001 04:35 AM
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In various texts I've come across references to a "Biazzi Nitrator", which by inference I take to be some sort of continuous-process nitration system in which (for safety) the volume of reactants is kept to a minimum during the critical (i.e. heat-producing) phase.
The above-described Boutmy-Faucher method of reacting with sulphuric first and dissipating excess heat prior to nitration would seem to lend itself to this process (although the increased separation time could be a problem), but while I can envision a continuous drop-by-drop "conveyor-like" system I've never seen a description of the actual apparatus.
In my mind's eye such a system might involve a controlled (but un-pressurized) flow of reactants through a small-diameter tube - water-jacketed for cooling. The glycerine injection- and reactant flow-rates (these rates would determine the nitration time for the design stage length) would be carefully proportioned and controlled so that correct mix ratio would be maintained and nitration complete at a predetermined point downstream. The flow and injection rates could be precisely controlled using variable-speed peristaltic pumps (assuming one could find reliable acid-resistant pump tubing) or similar metering devices. Intimate mixture of the reactants would be effected by a baffle rod or turbulator within the tube, and process temperature would be maintained by adjusting the flow rate through the water jacket. The reaction tube would be vented to eliminate gaseous byproducts as they were produced, perhaps via a series of vertical Tees in the line.
At the point where reaction is complete, the product would be separated, washed, and neutralized - also in a continuous process - and transferred to a remote collection vessel. The only product subject to catastrophic runaway would be the minimal volume present in the reaction portion of the tube, and such runaway could only occur in the event of coolant flow failure or breakage.
Obviously such a system would be much safer to operate, since only a very limited quantity of product is in "critical phase" at a given time. The only downside to all this is that the variables in the process would need to be determined empirically. However, knowing the time of nitration required for full conversion would allow these to be estimated for the design stage-length/diameter, and initial settings could be made using non-reactant materials and measuring the outflow per unit of time.
OK, lol, having pretty much answered my own question by re-inventing the wheel, does anyone know the details of the so-called Biazzi system or its commercial equivalent?
PS to pete: I believe the "200%" refers to 2X the volume of glycerine processed - which according to the texts is the optimal yield for NG.
[This message has been edited by c0deblue (edited February 10, 2001).]
shady mutha
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted February 11, 2001 10:01 PM
--------------------------------------------------------------------------------
Theoretical calculation based on the quation of nitration shows that when 100 parts of glycerine are added to 205.4 parts of hno3 the yield is 246.7 parts of nitroglycerine.At the same time 58.7 parts of water are formed.In practice this yield cannot be obtained because nitration of glycerine,like every esterification reation,is in principal a reversible one.the yield is partly defined by the number of O-nitro groups introduced into the molecule of glycerol.
The stronger the acid concentration,the higher the degree of nitration and the largeris the yield.An excess of acids establishes equilibria that favour a more complete reaction.The surplus must not be too large,however,since nitroglycerine is slighty solible in spent acid and this may consideratly decrease the final product.For this reason it is necessary to formulate the nitrating acid so as to achive as complete a nitration as possible while at the same time mimimizing the loss of product due to its solubility in the spent acis.
shady mutha
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted February 13, 2001 01:13 AM
--------------------------------------------------------------------------------
Nitroglycerine can be obtained if nitric acid alone is used as a nitrating agent.In this case a large excess of acid should be used.One part by weight of glycerine mixed with 10 parts by weight of the strongest nitric acid[99%]below room temperature and afterwards diluted with 30 parts wieght of water ind ice yield 1.765 parts of nitroglycerine.From the separated spent acid a further quanity[0.307 parts by weight]of the subdtance can be extracted by means of chloroform.The total yield therefore amounts to 2.072 parts of nitroglycerine,containing a small admiture of "dinitroglycerine"[glycerol dinitrate},i.e about 84% of throetcal yield.
If a smaller quanity of nitric acid is used in the process,e.g 5 parts of acid with 1 part of glycerine,the yield decreses and the product repersents a mixture if nitroglycerine and dinitroglycerine in the radio of 1;3.Clearly an uneconomic procedure of thid kind cannot have any practacal application.Therfore even in the earliest experiments on nitroglycerine manufacture a mix of nitric and sulphuric acid was used for nitrating the glycerine.It was proved that for 1 part of glycerine a strong mixed acid containing 3 parts of nitric acid 90% and 4.5 parts of concentrated sulphiric acid could be used instead of 10 part of anhydros nitric acid,the yield being significantly higher,namely from 100 parts glycerine 215 parts of nitroglycerine,corresponding to 87% of the throretical yield.Thequanity of water should be below this required for
H2SO4*H2O
Considerable procress in the field of nirating glycerine was achieved by Nathen,Thomas and Rintoul who introduced oleum as a component of the nitrating acid,thus forming an anhydrous mixed acid for the nitration process.Its application gave larger yields than nitration qith acid containing about 5% of water.For example 100 parts of glycerine react with a mixed acid prepared from 280 parts of nitric acid 90% and 360 parts of oleum 20% to yield 225 parts nitroglycerine which corresponds with 91% of the theoretical yield.
At present the most commonly used nitrating agent is the anhydrous mixed acid containing
45-50%HNO3
50-55%H2SO4
shady mutha
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted February 25, 2001 03:12 PM
--------------------------------------------------------------------------------
If decomposition begins in the nitrator with increasing temperature and evolution of brown fumes,it is necessary to make the contents of the nitrator harmless by discharging the whole into a drowning tank.
Decompsition can be caused by the following factors:
(1) insufficent purity of the glycerine,especially if sugurs and fatty acids are present.
(2)defective stirring-insufficent purity of the compressed air.
(3)unadequate cooling or leaks in the cooling coil.
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted February 08, 2001 11:30 PM
--------------------------------------------------------------------------------
OLD PROCESS
The oldest method of manufacturing nitroglycerine was a most primitive process that consisted of dropping small amounts of glycerine into a cast iron pot containing a mixtuer of nitric acid and sulphuric acid.The pot was cooled by standing in a larger,stoneware vessel containing water and ice,and hand stirring was performed with an iron rod.When the nitration was completed{or danger of decomposition arose}the contents of the cast iron pot were turned out inti the water and ice.water was then removed by decantation and the blasting oil washed.In that way a 200% yield of nitroglycerine was obtained.
pete
Frequent Poster
Posts: 56
From: u.k
Registered: JAN 2001
posted February 09, 2001 05:48 PM
--------------------------------------------------------------------------------
A 200% yield?
shady mutha
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted February 10, 2001 01:53 AM
--------------------------------------------------------------------------------
PART 2
The design of apperatus to facilitate rapid and efficent revovel of the heat produced during nitration was not known at that time.Solution of these difficulties was therefore sought in modifacation of the manufacturing process itself,as suggested by Boutmy and Faucher.they divided the nitrating process into two stages.At each stage a certain amount of heat is developed,which is less,off course,than the total heat of nitration.
The stages suggested byBoutmy and Faucher are as follows.
1.Dissolving the glycerine in sulphric acid to form glycerl-sulphuric acid;
2.Adding nitric acid to the solution of glycerine in sulhuric acid.
The greater part of the heat is produced during the relatively save process[1].The amount of heat developed during nitration proper[2]is therefore relatively small and the temperature can be controlled easily even if primitive methods are used.
For several years[untill 1882]the bounty-Faucher method was used in France and Great britain.In completey primitive apparatus,about 680kg nitroglycerine were made at a time.The disadvantage of this method was that thr nitroglycerine obtained by nitrating according to reaction[2]seperated only very slowly from the acid.In the standard method the contents of the nirator were allowed to stand overnight to permit seperation of the nitroglycerine.This lenghy contact between the nitroglycerine and the acid involved the danger of decomposition.Indeed,in factories where this method of nitroglycerine was practices frequent explosions occurred durring the seperation stage.
c0deblue
Frequent Poster
Posts: 229
From:
Registered: JAN 2001
posted February 10, 2001 04:35 AM
--------------------------------------------------------------------------------
In various texts I've come across references to a "Biazzi Nitrator", which by inference I take to be some sort of continuous-process nitration system in which (for safety) the volume of reactants is kept to a minimum during the critical (i.e. heat-producing) phase.
The above-described Boutmy-Faucher method of reacting with sulphuric first and dissipating excess heat prior to nitration would seem to lend itself to this process (although the increased separation time could be a problem), but while I can envision a continuous drop-by-drop "conveyor-like" system I've never seen a description of the actual apparatus.
In my mind's eye such a system might involve a controlled (but un-pressurized) flow of reactants through a small-diameter tube - water-jacketed for cooling. The glycerine injection- and reactant flow-rates (these rates would determine the nitration time for the design stage length) would be carefully proportioned and controlled so that correct mix ratio would be maintained and nitration complete at a predetermined point downstream. The flow and injection rates could be precisely controlled using variable-speed peristaltic pumps (assuming one could find reliable acid-resistant pump tubing) or similar metering devices. Intimate mixture of the reactants would be effected by a baffle rod or turbulator within the tube, and process temperature would be maintained by adjusting the flow rate through the water jacket. The reaction tube would be vented to eliminate gaseous byproducts as they were produced, perhaps via a series of vertical Tees in the line.
At the point where reaction is complete, the product would be separated, washed, and neutralized - also in a continuous process - and transferred to a remote collection vessel. The only product subject to catastrophic runaway would be the minimal volume present in the reaction portion of the tube, and such runaway could only occur in the event of coolant flow failure or breakage.
Obviously such a system would be much safer to operate, since only a very limited quantity of product is in "critical phase" at a given time. The only downside to all this is that the variables in the process would need to be determined empirically. However, knowing the time of nitration required for full conversion would allow these to be estimated for the design stage-length/diameter, and initial settings could be made using non-reactant materials and measuring the outflow per unit of time.
OK, lol, having pretty much answered my own question by re-inventing the wheel, does anyone know the details of the so-called Biazzi system or its commercial equivalent?
PS to pete: I believe the "200%" refers to 2X the volume of glycerine processed - which according to the texts is the optimal yield for NG.
[This message has been edited by c0deblue (edited February 10, 2001).]
shady mutha
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted February 11, 2001 10:01 PM
--------------------------------------------------------------------------------
Theoretical calculation based on the quation of nitration shows that when 100 parts of glycerine are added to 205.4 parts of hno3 the yield is 246.7 parts of nitroglycerine.At the same time 58.7 parts of water are formed.In practice this yield cannot be obtained because nitration of glycerine,like every esterification reation,is in principal a reversible one.the yield is partly defined by the number of O-nitro groups introduced into the molecule of glycerol.
The stronger the acid concentration,the higher the degree of nitration and the largeris the yield.An excess of acids establishes equilibria that favour a more complete reaction.The surplus must not be too large,however,since nitroglycerine is slighty solible in spent acid and this may consideratly decrease the final product.For this reason it is necessary to formulate the nitrating acid so as to achive as complete a nitration as possible while at the same time mimimizing the loss of product due to its solubility in the spent acis.
shady mutha
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted February 13, 2001 01:13 AM
--------------------------------------------------------------------------------
Nitroglycerine can be obtained if nitric acid alone is used as a nitrating agent.In this case a large excess of acid should be used.One part by weight of glycerine mixed with 10 parts by weight of the strongest nitric acid[99%]below room temperature and afterwards diluted with 30 parts wieght of water ind ice yield 1.765 parts of nitroglycerine.From the separated spent acid a further quanity[0.307 parts by weight]of the subdtance can be extracted by means of chloroform.The total yield therefore amounts to 2.072 parts of nitroglycerine,containing a small admiture of "dinitroglycerine"[glycerol dinitrate},i.e about 84% of throetcal yield.
If a smaller quanity of nitric acid is used in the process,e.g 5 parts of acid with 1 part of glycerine,the yield decreses and the product repersents a mixture if nitroglycerine and dinitroglycerine in the radio of 1;3.Clearly an uneconomic procedure of thid kind cannot have any practacal application.Therfore even in the earliest experiments on nitroglycerine manufacture a mix of nitric and sulphuric acid was used for nitrating the glycerine.It was proved that for 1 part of glycerine a strong mixed acid containing 3 parts of nitric acid 90% and 4.5 parts of concentrated sulphiric acid could be used instead of 10 part of anhydros nitric acid,the yield being significantly higher,namely from 100 parts glycerine 215 parts of nitroglycerine,corresponding to 87% of the throretical yield.Thequanity of water should be below this required for
H2SO4*H2O
Considerable procress in the field of nirating glycerine was achieved by Nathen,Thomas and Rintoul who introduced oleum as a component of the nitrating acid,thus forming an anhydrous mixed acid for the nitration process.Its application gave larger yields than nitration qith acid containing about 5% of water.For example 100 parts of glycerine react with a mixed acid prepared from 280 parts of nitric acid 90% and 360 parts of oleum 20% to yield 225 parts nitroglycerine which corresponds with 91% of the theoretical yield.
At present the most commonly used nitrating agent is the anhydrous mixed acid containing
45-50%HNO3
50-55%H2SO4
shady mutha
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted February 25, 2001 03:12 PM
--------------------------------------------------------------------------------
If decomposition begins in the nitrator with increasing temperature and evolution of brown fumes,it is necessary to make the contents of the nitrator harmless by discharging the whole into a drowning tank.
Decompsition can be caused by the following factors:
(1) insufficent purity of the glycerine,especially if sugurs and fatty acids are present.
(2)defective stirring-insufficent purity of the compressed air.
(3)unadequate cooling or leaks in the cooling coil.