A company is considering converting a gas burner currently using R fuel to S fuel. The fuel properties are given below;

Molar composition; R Fuel : 20 vol% M, 80 vol% E

S Fuel ; 80 vol% M, 10 vol% E and 10 vol% I

Specific gravity (SG); SGM = 0.55

SGE = 1.05

SGI = 1.53

Calorific Value (CV); CVM = 9500 kcal/m³

CVE = 16600 kcal/m³

1. It can be proven that the conversion is not possible without either nozzle modification or pressure adjustment. One alternative method that can be applied to enable the same burner system to be used without any modification or adjustment is by fuel enrichment,i.e. adding a supplementary fuel to S fuel. Two possible types of supplementary fuels ( P and B) are being considered with the following properties

Two available options are available

Option 1 : Add pure Fuel P to fuel S

Option 2 : Add pure Fuel B to fuel S

In order to avoid replacing the existing pressure regulator, the pressure increase ratio of (S+P) or (S+B) fuel mixture to R fuel (i.e. (DP(S+P or S+B)/DPR) ) should not be more than1.5 times. In addition, for economic and safety reasons, the molar composition of the (S+P) or (S+B) fuel mixture should not contain more than 12.5 mol % of the P or B fuels. On the basis of 1 mol of S fuel used which option is preferred? Support your answer with necessary calculations. (18 Marks)