"Run No. 29, recycle delayed coking of crude shale oil, was made primarily to produce a light gas oil fraction for treating to Diesel fuel. During the first part of the run, it was intended to produce a high melting point pitch instead of coke, and during the last part of the run to alter operating conditions sufficiently to produce coke. Two different charge stocks were employed; the first being a mixed crude of N-T-U, G3.s-Flow, and Gas-Combustion oil, the second a typical N-T-U shale oil. The desired high melting point pitch was not obtained; instead it was found that coke had formed during both test periods. It was concluded that the high water content of the mixed crude and the relatively long residence time of the material in the coke chamber contributed to the formation of the coke. The N-T-U crude was used for the coking step of the run, and the results obtained were consistent with those of previous coking rune on the same type crude."