PRODUCTION OF SULPHURIC ACID. 



11 



the absorption bulbs (D, D', D") containing strong nitric acid, 

 which absorbed the sulphur dioxide escaping oxidation in the spiral. 



The quantities of sulphur dioxide converted into sulphuric acid in 

 the tube (A) and the spiral (B), as well as that which escaped oxida- 

 tion and was subsequently absorbed in the bulbs (D, D', D"), were 

 determined by analyses. The results of these analyses are given in 

 Tables II and III. 



When the lead spiral was used (Table II) , the amount of sulphuric 

 acid formed therein had to be determined by difference because of 

 the formation of lead sulphate, which could not be entirely removed 

 from the tube by washing. 



On account of the many joints and rubber connections necessary 

 in the apparatus there was some loss of sulphur dioxide in the sys- 

 tem. Wben the lead spiral was used, the amount of this loss could 

 not be determined, so all the errors occurring in Table II are thrown 

 into column 5, making the figures for the sulphur dioxide oxidized 

 in the lead spiral larger than they actually should be. 



Table II. — Sulphur dioxide oxidized to sulphuric acid in apparatus shown in figure 1. 

 Lead spiral used and steady stream of oxides of nitrogen furnished throughout experiments. 



Number of run. 



Time of 

 run. 



Rate per 



hour of 



S0 2 . 



SO2 oxidized in 



system. 



S0 2 lost 

 in 



system. 1 



S0 2 

 escaping 



In vessel 

 A. 



In lead 

 spiral B. 



from end 

 of spiral. 



5 



Hoitrs. 

 2 

 2 

 2 



Grams. 

 6.2017 

 6.4887 

 7. 6569 



Per cent. 

 32.07 

 26.61 

 23.00 



Per cent. 

 67.92 

 73.39 

 76.99 





Per cent. 

 0.01 



7 







8 





.01 









1 Could not be determined. Included in the figures in column 5. 



An inspection of Table II shows that by passing sulphur dioxide, 

 air, and water vapor through a lead spiral in the presence of an 

 adequate supply of the oxides of nitrogen, the formation of sulphuric 

 acid is practically complete, even when the gases are run at quite a 

 rapid rate. 



In ordinary chamber plants it is considered very good practice if 

 only 10 feet of chamber space is required for every pound of sulphur 

 burned in 24 hours. Figuring the chamber space required in run 

 No. 8, it is seen that for every pound of sulphur burned in 24 hours 

 only 0.139 foot of chamber space was required. 



While it is hardly fair to compare the results obtained in the 

 laboratory with those obtained on a factory scale, still the efficiency 

 of the apparatus can be more readily judged by expressing the results 

 in the conventional way. 



The' well-known characteristic of some metals, as well as metallic 

 oxides and salts, of acting as catalytic agents made it seem possible 



