Q & A > Question Details
I am asking about the idea of mixing paraxylene with gasoline to increase its RON .
From an economic perspective, is mixing Px with gasoline considered beneficial?
22/01/2020 A: Joel Kaye, Retired from UOP & Tesoro, kaye13@gmail.com
The price of paraxylene is typically significantly higher than the gasoline price. Economics would say it is much better to blend heavy reformate (from which the PX is derived).
17/12/2019 A: Sridhar Balakrishnan, Bharat Oman Refineries Limited , laksrid@yahoo.com
Yes , blending paraxylene with gasoline will surely increase the RON of gasoline pool. Paraxylene is produced through BTX Reforming process. Paraxylene is aromatic , which has a very high octane value. Aromatics have the highest octane numbers. But from economic perspective , mixing Paraxylene with gasoline needs to be reconsidered. Paraxylene price is higher than gasoline price. Paraxylene is widely used as a feed stock to manufacture industrial chemicals, terephthalic acid (TPA), purified terephthalic acid (PTA) and dimethyl-terephthalate (DMT). Modern refineries uses FCC gasoline streams and other ethers for gasoline blending.

16/12/2019 A: keith bowers, B and B Consulting, kebowers47@gmail.com
"Economic attractiveness' is something a good (high fidelity) LP analysis can solve easily. However, the precision of data inputs is critical. The 'prediction' and actual measurement of RON's is not nearly as precise as we often presume. That said, The manufacture of PX is an energy and Entropy intensive process compared to incremental naphtha reforming severity. Market pricing values often do not reflect the real 'cost of manufacture' at any particular time. "Long term' economics are usually a better indicator of reality at the particular location and market characteristics, while 'spot' values can present temporary economic opportunities.

Generally, the ENTROPY Expenditure is a good measure of true 'cost of manufacture' of gasoline blending components. The 'process' of manufacturing gasoline is already so highly optimized there is little probability of 'discovering' a new general path. Any calculated 'improvement' is likely to be a 'local optimum' driven by imprecision and hysteresis in the data. The 'blending recipe' for the next blend must consider at least two 'time periods' --today, this week, and this month--as appropriate for your specific environment.
Thus, a 'General Answer' must be: It Depends