Process for the preparation of thermally cracked products and application of the process for reducing the coking of heat exchange surfaces

摘要

Tubular reactors or heat exchangers in processing plants for hydrocarbons and other organic compounds at high temperatures in the gaseous phase are to be protected against coke formation. The problem in such plants is that the usual steam/air cleaning process for removing coke deposits causes an increase in the catalytic activity of the material surfaces, which shortens the service life of the plant. The object of the invention is to substantially reduce coking and to maintain the long term passivity of steels for long working periods. The disclosed process for producing thermally cracked products from hydrocarbons and for reducing at the same time coke formation on heat exchanger surfaces is characterised in that 20 to 1000 ppm of an additive composition containing organically bound silicon and sulphur are added to the feed to be cracked, and the mixture is brought into contact with the heat exchange surfaces at temperatures in a range from 400 to 1000 DEG C.