Objective UP TO 1973, THE AVAILABILITY OF VIRGIN NAPHTHA IN EUROPE (LIGHT OR MEDIUM OILS DISTILLED FROM CRUDE OIL) WAS HIGHER THAN THE DEMAND AND ITS PRICE WAS LOWER THAN THAT OF OTHER PETROLEUM PRODUCTS. THEREFORE, ALMOST ALL STEAM CRACKING PLANTS PRODUCING OLEFINIC PRODUCTS WERE BASED ON VIRGIN NAPHTHA AS PRIMARY FEEDSTOCK. MANY OF THE EXISTING CRACKING MONOTUBULAR REACTORS, WHICH ARE THE HEART OF AN ETHYLENE PLANT, NO LONGER COMPLY WITH THE NEW MARKET CONSTRAINTS, I.E. REDUCED VIRGIN NAPHTHA AVAILABILITY AND HIGHER FEEDSTOCK AND ENERGY COSTS. THE AIM OF THIS STUDY IS TO DESIGN A NEW COIL REACTOR WHICH WOULD INCREASE THE YIELD OF OLEFINIC PRODUCTS, REDUCE THE FEEDSTOCK AND THE ENERGY REQUIREMENTS PER UNIT OF PRODUCT AND GIVE MAXIMUM FLEXIBILITY TO THE CHOICE OF FEEDSTOCK. IT IS EXPECTED THAT SUBSTANTIAL COST SAVINGS CAN BE ACHIEVED, ESPECIALLY IN VIEW OF THE RISING COST OF BOTH RAW MATERIALS AND ENERGY. BY USING A COMPUTER SIMULATION PROGRAM ("SPYRO" KINETIC MODEL) SEVERAL COILS, DESIGNED ON THE BASIS OF MONTEDIPE'S EXPERIENCE, HAVE BEEN TESTED. THE COIL SELECTED, CONSISTING OF A MULTIPLE DIAMETER TUBE ARRANGEMENT, IS MORE SELECTIVE IN OLEFINIC PRODUCTS THAN THE EXISTING ONE. DUE TO A HIGHER AVERAGE CRACKING TEMPERATURE, WHICH WAS NOT COMPATIBLE WITH EXISTING ALLOYS, A NEW ALLOY (MARAUNITEXA) WITH HIGHER DESIGN TEMPERATURE RESISTANCE OF ABOUT 100 DEGREES C HAD TO BE USED. THE NEW GEOMETRY WITH THE NEW ALLOY EMPLOYED REDUCE THE FOULING RATE AND ALSO CONSUME LESS DILUTION STEAM, AT CONSTANT OLEFINIC YIELD AND COKING RATE. THE NEW COIL WAS CONSTRUCTED AND PLACED IN THE FURNACE. IN ORDER TO COMPARE THE PERFORMANCE OF THE OLD AND THE NEW COIL, THE FURNACE WAS RUN WITH THE SAME FEEDSTOCK BEFORE AND AFTER THE MODIFICATION. THE ANALYSIS OF THE EFFLUENTS BEFORE AND AFTER THE MODIFICATION CONFIRMED WHAT WAS EXPECTED. THE NEW COIL WAS MORE SELECTIVE IN VALUABLE PRODUCTS AND GAVE MORE ETHYLENE, MORE BUTADIENE, LESS METHANE AND LESS AROMATICS AND FUEL OIL. DUE TO THE HIGHER SELECTIVITY A CONSIDERABLE REDUCTION IN DILUTION STEAM WAS ALSO POSSIBLE. Programme(s) PRE-ENNONUC 2C - Energy research and development programme (EEC), 1979-1983 Topic(s) Data not available Call for proposal Data not available Funding Scheme Data not available Coordinator Riveda Srl EU contribution No data Address 96010 Priolo Siracusa Italy See on map Total cost No data
