Oxidation of Aromatic Hydrocarbons with HBr/H20 Promoters SIR: Lin and Kehat (1969) mention our patent on the oxidation of aromatic hydrocarbons with H B r / H 2 0 promoters, but state that we operate a t 1.5 to 2 atm and that conversions and yields were not reported. I n fact, we clearly state Lhat in all 36 examples, runs were made a t atmospheric pressure. Furthermore, benzene or toluene conversion and efficiency to phenol or cresols are given for each run and yields are directly calculable. Some examples from data in the patent are shown in Table I. Since the authors have exactly the same system described in our patent, except for a lower temperature range, this reference should properly have been cited in the introductory discussion and not in the experimental section,
and the results reported as a continuation and modest variation of someone else’s original findings. literature Cited
Lin, A . , Kehat, E., IND.ENG.CHEM.PROD. RES. DEVELOP. 8, 436 (1969). Selwitz, C. M. (to Gulf Research & Development Co.), U. S. Patent 3,360,572 (Dec. 26, 1967).
C . M . Selwitz
Gulf Research & Development Co. Pittsburgh, Pa. 15230
Table I. Oxidation of Aromatic Hydrocarbons in the Presence of HBr and H?O Reactant Feed Rate, Moles/Hour Run
Hydrocarbon
6 11 17 28 32
Benzene Benzene Benzene Toluene Benzene
Catalyst
1,2-Dibromoethane tert-Butyl bromide
HBr 1.2-Dibromoethane 1,2-Dibromoethane
Hydrocarbon
H,O
Cat.
0 2
1.01 0.47 0.86 0.84 0.92
10.3 5.1 6.2 5.5 6.3
0.0043 0.0027 0.0069 0.0033 0.0037
0.41 0.21 0.45 0.50 0.46
SIR: The work covered by our paper (Lin and Kehat, 1969) was carried out from December 1965 to July 1967. Selwitz’ patent (Selwitz, 1967) was issued December 26, 1967. Therefore, our work cannot be considered a continuation of Selwitz’s work. Our work, and Selwitz’s work, are a direct sequel to the work of Rust and his coworkers (Barnett et al., 1949). which was given due credit. We did not obtain a copy of the Selwitz patent, but our reference to it was based on two sources: A news item in Industrial and Engineering Chemistry (1968), from which we quoted the pressures of 1.5 to 2.5 atm. The patent abstract in the Oficial Gazette of the c‘. S . Patent Ofice, which did not give any figures on conversion and yields, and which led to our erroneous assumption that none were mentioned in the patent. Whether the achievement of comparable yields and conversions at 285°C /run 29, Table I V (Lin and Kehat, 424
Ind. Eng. Chem. Prod. Res. Develop., Vol. 9, No. 3, 1970
Temp., C.
YO
Yo Molar Efficiency
Conversion
Phenol
9.0 25.0 15.4 12.1 20.7
81 36 51.0 12.3 50.0
714 691 679 758 681
Cresols
.. 11.3
..
1969)] to those obtained by Selwitz a t 679°C (run 17, Selwitz, 1967) is a modest variation of Selwitz’ original findings (Selwitz, 1970), is a matter of personal judgment. literature Cited
Barnett, B., Bell, E. R., Dickey, F. W., Rust, F. F., Vaughan, W. E., Znd. Eng. Chem. 41, 2612 (1949). Znd. Eng. Chem. 60 (3), 4 (1968). RES.DEVELOP. Lin, A,, Kehat, E., IND.ENG.CHEM.PROD. 8, 436 (1969). Selwitz, C. M. (to Gulf Research & Development Co.), U. S. Patent 3,360,572 (Dec. 26, 1967). Selwitz, C. M., IND. ENG.CHEM.PROD. RES. DEVELOP. 9,424 (1970).
Israel Institute o f Technolog?) Haifa, Israel
Ephraim Icehat
