Fifty years of CCR platforming
Professionals in the oil and gas industry today may not remember when gasoline was sold in multiple grades that included fuels containing tetraethyl lead.
Edward R. Morgan
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Now relegated to the historical curriculum in petroleum engineering, we take for granted that millions of automobiles once emitted lead particles from their exhaust, where it entered the food chain through accumulation in waterways and soils.
The use of lead as a fuel additive was necessary to raise the octane number of gasoline by as many as five points, thus reducing pre-ignition, or “engine knock.” As late as the early 1990s, some gasoline produced around the world contained up to 3 grams per gallon of tetraethyl lead, a conspicuous air pollutant and a heavy metal neurotoxin. Lead was tolerated in vehicle emissions as a necessary, but environmentally harmful, consequence to improve engine performance. In addition, there was simply no economically viable way to produce fuels without it.
As a result, emissions from gasoline-powered vehicles became the primary source of photochemical smog in many large cities, a problem amplified in areas such as Los Angeles and Mexico City, where air masses are slow to clear. This all changed in 1970, when the U.S. Clean Air Act regulated components of air pollution including carbon monoxide, lead, and nitrous and sulfur oxides.
It was possible to reduce the oxides in vehicle exhaust by channeling it through an automobile catalytic converter, but lead in the exhaust would quickly deactivate the catalyst.
The barrier to the economic viability of unleaded fuels was broken in 1971 with the introduction of CCR Platforming, a technology that substantially raised the gasoline pool octane number. By making it possible to exclude lead from gasoline, automobile exhaust now could be run through a catalytic converter, attacking the full range of pollutants identified in the Clean Air Act and removing millions of tons of pollutants from the air.
The first CCR Platforming unit entered service on Jan. 3, 1971 at the Coastal States refinery in Corpus Christi, Texas. It was a milestone for the refining industry, ushering in the global transition to lead-free gasoline production. Today, virtually every gasoline-fueled vehicle in the world uses unleaded fuel and a catalytical converter. Most importantly, it has accommodated a five-fold increase in personal mobility while improving the health and living standard of billions of people worldwide.
CCR Platforming Defined
CCR Platforming is a catalytic reforming process for upgrading naphtha feedstocks into high octane gasoline blending components, or into the petrochemical feedstocks used to produce plastic resins, films and fibers.
While Platforming had been a proven process since 1949, the breakthrough for the technology came with the introduction of a dedicated continuous catalyst regeneration (“CCR”) section. This made it technically superior to semi-regenerative reforming, which had been the mainstay for upgrading naphtha, but which was limited by coke production caused by the reforming reactions.
As coke accumulated on the catalyst, the reformate octane number and yield performance decreased until a critical point when the unit would need to be removed from service to regenerate the catalyst.
The CCR section allowed refiners to continuously remove coke accumulating on the catalyst. This allowed lower reforming reaction pressures to increase reformate and hydrogen yields, higher reaction temperatures to achieve higher octane levels for gasoline blending, thereby enabling lead-free gasoline, and increased production of aromatics for use as petrochemical feedstocks.
The technological breakthrough brought by CCR Platforming solved a growing environmental problem and greatly improved the economics of refining. Today, more than 380 CCR Platforming units have been licensed worldwide.
Redefining Refinery and Petrochemical Plant Economics
The relative operating profit margin for naphtha processing using CCR Platforming can be from 1.5 to 2 times the margin of semi-regenerative reforming, due to the increased yields of reformate and hydrogen.
CCR Platforming provided operators more flexibility to reliably process cost-advantaged highly paraffinic or cracked naphtha feedstocks that were difficult for semi-regenerative reforming units due to their higher coke production, shorter operating cycles, and lower reformate and hydrogen yields. It also provided predictable reformate and hydrogen yields, simplifying blending operations and refinery turnarounds. CCR Platforming units typically have on-stream availability of in excess of 97%, higher than the 90-92% performance of semi-regenerative reforming units.
In the 50 years since the first CCR Platforming unit entered service, UOP has continuously improved the technology. New catalyst designs have increased reforming yields and extended catalyst life. A new Platforming catalyst was introduced in 2020, further closing the gap with the theoretical maximum of reforming yield efficiency. New regenerator designs and reactor internals further improve reforming yields and process reliability.
In addition, a new chloride treatment process recycles effluent chlorides in the CCR regeneration vent gas, significantly reducing the quantity of chloride used by the process and marking an improvement on conventional caustic treating. Today, more than 75 CCR Platforming units have been commissioned with this system.
Because the coke barrier has been addressed, the size of a catalytic reforming units has increased, substantially improving economies of scale for catalytic reforming. Several CCR Platforming units now are operating at feed rates exceeding 90,000 barrels per day.
Gasoline remains the world’s most common transportation fuel, and it will continue to be the primary motor fuel for many years, thanks in large part to the elimination of lead from the gasoline pool and superior economics made possible by CCR Platforming.
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