asked the Secretary of State for Energy (1) what secondary upgrading capacity he estimates will be necessary to produce the yield pattern needed to meet national demand for light distillates; how that figure compares with existing capacity; and what schemes have been submitted to his Department for additional plant;(2) what proportion of heavy oils is being catalytically cracked to produce gasoline and naphthas in the United Kingdom.
At the end of 1976 the gross throughput capacity of catalytic, thermal and hydrocracking plants at United Kingdom refineries was about 13 million tons a year. At a normally high rate of utilisation, this level of capacity would correspond to the use as feedstock, or as a source of feedstock, of roughly 40 per cent. of the residual fuel oil produced by crude oil distillation in 1976. My Department is aware of new cracking units planned or under construction at the Shell Haven, Lindsey and Mobil Coryton refineries. Texaco and Gulf have also announced a possible further project at Milford Haven. These schemes would provide additional capacity of 7 million tons a year.It is not possible to provide a simple estimate of the amount of new upgrading capacity needed to balance the national demand position. Different types of cracking plants produce different yields of light distillate at a given throughput level, and there are also important product quality considerations. Changes in the type of crude oil refined and in other secondary refining plant will also affect the position. The schemes now in hand will make a valuable contribution, but further projects will be needed to eliminate the United Kingdom's net deficit of light distillates and cater for future growth in demand.