The amount of acid catalyst used in the process also
affects the conversion efficiency of the process. The catalyst
amount is varied in the range of 0.25–2% for five different
values (0.25, 0.5, 1, 1.5 and 2% of sulphuric acid). These
percentages are volume fractions of the oil supplied for this
reaction. The effect of the catalyst amount on the conversion
efficiency is shown in Fig. 2. The acid-catalyst process
attains the maximum conversion efficiency at 0.5% of
sulphuric acid. Also, it is noted during the present
experiments, that excess addition of sulphuric acid, darken
Fig. 1. Effect of molar ratio on conversion efficiency (step 1).
A.S. Ramadhas et al. / Fuel 84 (2005) 335–340 337
the color of the product. Lower amount of sulphuric acid
addition affects the yield of the second step.