Naphtha with polyolefins

The results of an interesting study on copyrolysis of naphtha and added polyolefins or their kinetics and degradation products were presented at the Analytical and Applied Pyrolysis meeting at Alicante [12] (Table 1.3). The product yields from cracking (450°C) of LDPE and PP are quite different, with more liquid fraction from PP ... 

The experiments at the University of Hamburg led to the building of three pilot plants by companies. The first was built in 1982 in Ebenhausen, Bavaria by DRP/ABB using a fluidized-bed reactor with a diameter of 1800 mm and a capacity of 800 kg/h of mixed plastics and whole tires. The second plant was built in Grimma, GDR in 1984 for whole tires with a capacity of 5000 t/yr. BP also carried out preliminary experiments 1992 at the University of Hamburg and then built a pilot plant in Grangemouth, Scotland with a capacity of about 5000 t/yr to obtain waxy products from mixed plastics, mainly polyolefins. These waxy products could be used as feedstock for naphtha-crackers. All pilot plants ran for only a few years, mainly because economically operation was not possible due to decreasing crude oil price. 

As shown, it is possible to recover directly high amounts of olefins similar to that of a naphtha crackers from polyolefin wastes. For selling, the olefins have to be cleaned up in distillation plants. To avoid problems with HCl from unexpected PVC fractions, it is safer to produce from polyolefins a waxy material which can be analyzed and, if free from HCl and chloroorganic compounds, mixed with naphtha and used as cracker feed. This was the concept of BP Chemicals. The test runs were made in our Hamburg laboratory plant (LWS3) [15]. Detailed material balances for experiments are provided in Table 17.7... 

In Malaysia, a number of companies both foreign and local, have expressed considerable interests to establish petrochemical operations. The list of such companies include Kellogg-Thyssen which recently announced that it will establish a US 1 billion petrochemical complex producing polyolefines and aromatics from crude oil and/or naphtha. Then there is Himont and C.T. Chao, a Taiwan-US joint venture, proposing to set up a polypropylene plant in Pasir Gudang, Johor in the south of peninsular Malaysia. Petronas, the National Oil Company, itself has formed a joint-venture company with Neste Oy of Finland and Idemitsu Petrochemical Co. Ltd of Japan to establish an MTBE and Polypropylene Project in Kuantan, Pahang on the East Coast of Peninsular Malaysia. 

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