Patent Analysis of Light Naphtha Isomerization from Statistical and Process Perspective

The light naphtha isomerization patents were technically categorized into 5 groups of process, catalyst, isolation, reactor and pre-treatment. The largest number of patents is in the process and catalyst fields mainly filed by UOP and Shell companies. The highest number of patents were registered in the 1960s. The patents published by UOP are the most widely cited. Largest number of patents are filed in the United States which reveals that US is the main target market for isomerization process. Three groups of aluminum chloride, zeolite and metal oxide catalysts such as platinum, palladium and rhodium have been used on chlorine alumina support, which is chosen as the optimal catalyst according to the feed, operating conditions and product. There are two main separation techniques for fractionation of normal paraffin from isoparaffin; namely, molecular sieve towers or DIH towers (Deisohexanizer) and DIP (Deisopentanizer) which are placed before or after the reactor.