hr the expected u03b4p l si and weight ratio with str case tube od 39 s of 2 u2033 id of 1 83 u2033 are also plotted as a function of bed length fig3 c shows that various xcsa designs are expected to be advantageous over an str design with u03c6 str 86 l m for different coolant temperatures and hence different production rates fig3 c also shows that the u03c6 of an xcsa design concept is always lower than or equal to u03c6 str of 86 l m when bed length is equal to or larger than 6 2 m and this is valid for all coolant tubes od of 0 75 u2033 to 1 5 u2033 and at various coolant temperatures fig3 c also demonstrates that an xcsa design concept is expected to have lower weight stability and u03b4p up to a bed length of about 9 5 m as compared to an str design as shown above both the predicted reactor u03b4p and stability are also advantageous over an str design up to 9 5 m bed length fig3 d is a plot showing a prediction of heat transfer area to catalyst volume ratio as function of reactor bed length for an xcsa.