To save energy when reforming

Abstract

Recent improvements in the Rheniforming process enable refiners to conserve petroleum by increasing efficiency for production of gasoline blending stocks, aromatic chemicals and hydrogen. These advances are based upon the development and commercial demonstration of an improved catalyst and new operating procedures. A new, less costly catalyst, Type E, is more active and even more stable and selective than previous Rheniforming catalysts. The high stability of the new catalyst makes its use advantageous for low pressure reforming, which gives high yields of blending stocks, aromatics and hydrogen. Improved catalyst stability allows operation at reduced gas circulation rates and decreased recycle compressor power requirements. The new operating procedures involve optimization of on-stream catalyst chemistry. Effective regeneration can be ensured through the use of catalyst samplers. New procedures have been developed for control of catalyst and recycle gas properties to maximize selectivity and run length. Experimental evidence indicates that long-cycle, semi-regenerative Rheniforming can maintain higher average selectivity than cyclic or continuous reforming processes using platinum-rhenium catalysts. Cyclic and continuous processes were developed in response to the high deactivation rates of platinum catalysts and their decline of selectivity with time on-stream. In contrast, with many feedstocks the far more stable platinum-rhenium catalysts showmore » large, gradual increases in selectivity that continue through an appreciable portion of each cycle. These selectivity increases are particularly large for feedstocks having low to moderate end points, including those used for production of aromatic chemicals. Consequently, platinum-rhenium catalysts can produce higher run-average liquid and hydrogen yields in long-cycle reforming than in processes involving frequent regeneration.« less