ABSTRACT

The olefins market is quite energetic and mobile. Polyethylene and polypropylene demands continue to grow. The relative growth rates of PE and PP result in regional mismatch in the ethylene/propylene requirements. The Olefins Conversion Technology (OCT) licensed by ABB Lummus Global provides the feedstock and product flexibility needed to face the ever-changing demand for light olefins. The Olefins Conversion Technology is a family of proprietary processes utilizing a simple fixed bed catalyst system to inter-convert olefins to maximize plant profitability. The catalyst is highly selective and flexible to operate over a broad range of temperatures and pressures. This paper will discuss Olefins Conversion Technology and illustrate specific industry applications.

OCT strategically varies the production rates of ethylene, propylene and butenes. When integrated with an ethylene plant, OCT provides flexibility to save feedstocks while varying light olefins production rates.

The typical ethylene plant production range of 0.4 to 0.6 propylene to ethylene ratio can be extended to greater than 1. OCT achieves these goals at reduced capital and operating costs when compared to conventional ethylene plants.

In refinery applications, OCT coupled with ABB's patented Low Pressure Recovery (LPR) process allows refiners to recover and upgrade fuel gas to propylene. Numerous industry sources of C4 feedstock can be refined with OCT to improve plant propylene production margins. The low cost applications provide refining flexibility to strategically optimize feed/product balances to meet varying market demands and maximize profits.

OCT is the lowest capital and operating cost production route commercially available.

Olefins Conversion Demand for the light olefins ethylene and propylene are forecasted to increase over the next Technology Applications decade. However, the demand for these light olefins will increase at different rates. Global propylene demand is forecasted to increase 6 to 8% per year, which exceeds the global ethylene demand growth forecast of 4 to 6% per year. Due to numerous upstream and downstream market factors - such as NGL and crude prices, downstream product prices (particularly polyethylene and polypropylene), butadiene demand, gasoline prices and plant operating rates - the relative demands and prices are constantly fluctuating and quite dynamic throughout the various regions of the world.

The four commercially proven routes to propylene production are:

  • Steam cracking

  • Fluid catalytic cracking (FCC)

  • Propane dehydrogenation

  • Metathesis of ethylene and butylene

As shown in Figure 1, the majority of propylene is currently produced in steam crackers and FCC units. In these processes, propylene is produced as a byproduct of ethylene production or transportation fuels. Historically, FCC units balanced the propylene demand fluctuations by varying

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