LLDPE capacity

Outside the U.S.A. the pattern varies, with LLDPE capacity continuing to lag behind, despite rapid expansions. In western Europe, LDPE still represents over half and LLDPE only 12% of all polyethylene produced (8.8 Mt per annum in total) vinyl chloride production is about 5Mt per annum (cf. some 6Mt per annum in the U.S.A., despite environmental concern regarding chlorine-containing chemicals). 

February Exxon Chemical announces LLDPE capacity increase at Mont Belvieu, TX about half of the capacity will use metallocenes. Startup of a 120,000 Mt/yr DSM-Exxon joint venture plastomer plant at Geleen, The Netherlands. 

World growthof LLDPE is forecast between 6 and 9% per year to 2005, and LLDPE will continue to make inroads into traditional LDPE markets. Several new plants are being planned in the Middle East, where LLDPE capacity will double between 2000 and 2005, with a resultant significant increase in exports to European and Asian markets. 

Maoming, a Sinopec affiliate, is one of the largest pretrochemical producers in China with 39 000 employees. The company recently completed an expansion to increase ethylene capacity from 380 000 tonnes to 800 000 tonnes at a cost of 4.4 billion yuan (US 530 million). The company will also increase PP capacity from 140 000 tonnes to 200 000 tonnes. Its annual LDPE and LLDPE capacities are 100 000 tonnes and 140 000 tonnes, respectively. The company also has a 10 000 tonnes per annum (tpa) BR facility and a 30 000 tpa SBR plant. Major products include ethylene, PE, propylene, PP, sulphur, neat benzene, toluene, mixed xylene, kerosene, diesel oil, gasoline and other petroleum products. 

The current and projected HDPE capacities are shown in Table 3, and producers of resins in Table 4. In most cases, an accurate estimation of the total HDPE volume is compHcated by the fact that a large number of plants also use the same reactors for manufacture of HDPE or LLDPE. UHMWPE is produced in the United States (Himont and American Hoechst), in Japan (Asahi), and in Germany (Hoechst) worldwide capacity is approximately 45,000 tons. The use of post-consumer (recycled) HDPE is gradually increasing in volume. The growth of recycling programs is driven principally by economics (110,114) it has increased from a mere 60,000 tons in 1989 to 350,000 tons in 1994 and is expected to increase to 1.4 million t in the year 2000 (115). 

Large quantities of pelletized LLDPE are shipped by rail ia hopper cars with a capacity of 80—100 tons. Smaller amounts are shipped ia cormgated cardboard boxes (1.0 x 1.15 x 0.90 m) with a capacity of 450—500 kg of resiu. 

Countries produciug commodity LLDPE and their capacities, as well as production volumes of some U.S. companies, are Hsted iu Table 5. Iu most cases, an accurate estimate of the total LLDPE production capacity is compHcated by the fact that a large number of plants are used, iu turn, for the manufacture of either HDPE or LLDPE iu the same reactors. VLDPE and LLDPE resius with a uniform branching distribution were initially produced in the United States by Exxon Chemical Company and Dow Chemical Company. However, since several other companies around the world have also aimounced their entry into this market, the worldwide capacity of uniformly branched LLDPE resins in 1995 is expected to reach a million tons. Special grades of LLDPE resins with broad MWD are produced by Phillips Petroleum Co. under the trade name Low Density Linear Polyethylenes or LDLPE. 

By the mid-1990s capacity for polyethylene production was about 50 000 000 t.p.a, much greater than for any other type of plastics material. Of this capacity about 40% was for HDPE, 36% for LDPE and about 24% for LLDPE. Since then considerable extra capacity has been or is in the course of being built but at the time of writing financial and economic problems around the world make an accurate assessment of effective capacity both difficult and academic. It is, however, appeirent that the capacity data above is not reflected in consumption of the three main types of material where usage of LLDPE is now of the same order as the other two materials. Some 75% of the HDPE and LLDPE produced is used for film applications and about 60% of HDPE for injection and blow moulding. 

As mentioned in the introduction to the chapter, world capacity to produce polyethylene was of the order of so c. 50 X 10 t.p.a. in the late 1990s although production to that level is not expected until about 2002. By type, this market is shared between LDPE, HOPE and LLDPE approximately in the ratio 40 36 24. 

Coordination copolymerization of ethylene with small amounts of an a-olefin such as 1-butene, 1-hexene, or 1-octene results in the equivalent of the branched, low-density polyethylene produced by radical polymerization. The polyethylene, referred to as linear low-density polyethylene (LLDPE), has controlled amounts of ethyl, n-butyl, and n-hexyl branches, respectively. Copolymerization with propene, 4-methyl-1-pentene, and cycloalk-enes is also practiced. There was little effort to commercialize linear low-density polyethylene (LLDPE) until 1978, when gas-phase technology made the economics of the process very competitive with the high-pressure radical polymerization process [James, 1986]. The expansion of this technology was rapid. The utility of the LLDPE process Emits the need to build new high-pressure plants. New capacity for LDPE has usually involved new plants for the low-pressure gas-phase process, which allows the production of HDPE and LLDPE as well as polypropene. The production of LLDPE in the United States in 2001 was about 8 billion pounds, the same as the production of LDPE. Overall, HDPE and LLDPE, produced by coordination polymerization, comprise two-thirds of all polyethylenes. 

In many cases, the linear low-density polyethylene (LLDPE) produced in low-pressure processes competes for the same market as LDPE. For this reason, in Figure 8.2-7 capital- and operation costs of the high-pressure polymerization are compared with those of a low-pressure solution process having the same capacity. Also, the production costs of the low-pressure process are dominated by the costs of the monomer, but some differences can be noted which are typical for the economics of low- and high-pressure processes. 

HDPE >LDPE LLDPE PP BP data includes capacities of BP/Solvay JV... 

Today, several high pressure and low pressure process technologies have been developed for the production of the different polyethylene grades [4, 8, 9, 10, 11]. In 2001 about 20 million tonnes of the PE capacity used high pressure and about 45 million tonnes used low pressure technology. In 2000, 32% of the worldwide PE capacity was estimated to be for the production of LDPE, 31% for HDPE and 37% for LLDPE [6, 12,13]. 

Today, 20 Alphabutol units have been licensed, having a combined 1-butene capacity of 330000 t per year, the LLDPE 1-butene content is generally on the order of 8-12 wt. %. Nearly 50% of the world s 1-butene incorporated as comonomer in LLDPE is produced using Alphabutol technology. 

LLDPE with 10% and 37.5% PS, respectively. The decrease in ay suggested that PS particles debonded from the LLDPE matrix and lost their load-bearing capacity before the yield point was reached. Debonding probably initiated near the onset of nonlinearity in the stress-strain curve. 

The Unipol process was first introduced by Union Carbide in its Seadrift, Texas, facility in 1968. Other companies such as Amoco and British Petroleum developed the technology further. Today over a 100 reactors are in operation (or in constmction) worldwide with an annual capacity of 19 billion pounds of HOPE or LLDPE resin. 

Table 5 Producers, plants, and capacities by region— LDPE, HOPE, LLDPE, polypropylene (PP) PVC, polystyrene (PS), in the late 1980s...

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