Business
Refinery changes could boost chemicals Refineries will shift to heavy, sour crude oils and coal in 1980s and 1990s; output of related olefins and aromatics could rise sharply Raw materials for U.S. organic chemicals will shift in the next two decades as changes occur in petrole um refining, a major source of raw materials for chemicals. Generally, chemical feedstocks will become heavier hydrocarbons as refineries move toward heavier, sour (highsulfur) crude oil. Coal- or oil-based synthesis gas will become a factor in energy supplies by the year 2000. As raw materials change, demand for chemicals from petroleum will increase faster than will demand for other petroleum products. Chemical demand may reach about 11% of total U.S. demand of 23 million bbl a day for liquid petroleum products in 1990 compared to the present 6%. Changes in refining and chemical feedstocks will result from three basic forces, Axel R. Johnson, vice presi dent of plant-builder Stone & Web ster Engineering, forecast at the an nual meeting of the National Petro leum Refiners Association in San Antonio, Tex. The first is a projected
shortfall in overall crude oil supplies. A second is a trend toward more de pendence on heavy, sour crude oils. The third is institutional, economic, and technical barriers to near-term establishment of a synthetic fuels industry. Large-scale conversion plants will require 10 to 15 years to plan, license, and build, says Johnson. But in a world where large-scale changes occur suddenly in the crude oil supply pic ture (for example, the oil embargo of 1973 or the current Iranian disrup tion), taking such a long-term risk seems questionable. This risk can be handled in a number of ways, suggests Johnson. A first step is to base boilers for petro chemicals plants and refineries on high-sulfur residual oil with a provi sion to shift to coal later. Coal gasifi cation and liquefaction units also could be added later. Demonstration units to gasify or liquefy coal are being operated or being built by sev eral companies now, so technology is developing. With these technologies available, Johnson forecasts possible changes in petrochemical and refining opera tions for the next two decades. His changes are based on a hypothetical complex including two olefins plants, one based on ethane and propane, and the other based on naphtha and gas oil, in 1980. He also assumes two refineries in the complex, one fed
150,000 bbl per day of sweet crude oil, and the other, 200,000 bbl per day of sweet crude and 100,000 bbl per day of sour crude oil. By 1990, a decline in ethane and propane from natural gas will elimi nate use of the olefins plant based on these gas liquids. Offsetting this will be an increase in olefins made directly in refining. Additional olefins will be produced in a new olefins unit, which will be fed vacuum gas oil, a fraction heavier than the gas oil now being fed some olefins-producing steam crackers. Additional aromatics— benzene, toluene, and a mixed xylenes stream including ethylbenzene—also will come from pyrolysis naphtha produced in the new steam cracker. Emphasis on chemicals output from refineries also will increase. Total output of olefins from refining and chemical units will jump. Total ethylene production will double from 1980; propylene and butadiene out put will triple. Aromatics output will nearly triple. A unit for synthesis gas (hydrogen and carbon monoxide) will produce feedstock for methanol and ammonia by the end of the 1990's. Not all of these changes will occur in all refineries and related chemical plants, Johnson adds. His scenario is designed specifically to make a case for an integrated complex with the option of more use of coal during a transition period in crude oil avail ability and type. Π
Refinery-olefins plant complex could greatly push up chemicals output in 1980s 1980 RAW MATERIALS Oil, bbl per day Sweet crude Sour crude, light Sour crude, heavy Fuel oil, high-sulfur Total oil Natural gas, million cu ft per day propane Ethane, million lb per year Coal, tons per day TOTAL, crude oil equivalent, bbl per day
1990
2000
350,000
170,000
100,000 0 0
348,000 50,000
450,000
75,000 643,000
100,000 329,000 100,000 0 529,000
113
0
0
484 0
0 10,700
0 35,300
471,000
687,000
675,000
Yote. Hypothetical complex consists of two refineries and two nearby olefins; plants. Source: Stone & Webster Engineering
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C&EN April 9, 1979
1980
1990
2000
FUEL PRODUCTS SNG, million cu ft per day LPG, bbl per day Gasoline, bbl per day Distillates, bbl per day Residual fuel oil, bbl per day, 1 % sulfur Residual fuel oil, bbl per day, 3 % sulfur Low-sulfur coke, tons per day CHEMICAL PRODUCTS Ethylene, billion lb per year Propylene, billion lb per year Butadiene, billion lb per year Aromatics, million gal per year Methanol, tons per day Ammonia, tons per day
0 19,000 207,000 140,000 19,000
57 17,000 216,000 178,000
212 14,000 156,000 150,000
117,000
48,000
25,000
0
0
640
630
650
1.89 0.54 0.18 55
2.66 1.00 0.38
3.66 1.60 0.59
110
0 0
0 0
146 1,000 700
