The Age of Group II by STEVE HAFFNER

The Age of Group II BY STEVE HAFFNER

1 COPYRIGHT 2020, LUBES’N’GREASES MAGAZINE. REPRODUCED WITH PERMISSION FROM THE 25TH ANNIVERSARY ISSUE When Lubes’n’Greases was in its infancy, the American In 1993, the American Petroleum Institute classified base Petroleum Institute’s base oil groups were just a couple of stocks into five groups, with Group I, II and III paraffinic min- years old, and API Group I was the base stock of choice for eral oils categorized by saturates, sulfur and viscosity index. most lubricants. In the mid-1990s, new refining technology Polyalphaolefins got their own category, Group IV, and Group was being scaled up that could deliver better base stock per- V encompasses all other base stocks, including naphthenics. formance and more efficient production. These advance- Group II was defined as having saturates greater than 90 per- ments would eventually turn Group II oils into the workhorse cent, sulfur less than 0.03 percent and a viscosity index between that they are today, making up 40 percent of the world’s base 80 and 120. API Group III base stocks have a viscosity index oil production capacity. greater than 120.

Chevron’s 25,000-barrels-per-day API Group II base oil plant in Pascagoula, Mississippi (Photo: Chevron)

COPYRIGHT 2020, LUBES’N’GREASES MAGAZINE. REPRODUCED WITH PERMISSION FROM THE 25TH ANNIVERSARY ISSUE 2 Industry veteran Terry Hoffman, for- Chevron began to develop a selective wax the new technology. After it made its merly of Sunoco, remarked that the first isomerization process. Instead of remov- debut, “I participated in an internal study Group II-type oils appeared in 1971 ing wax molecules as in solvent dewaxing team that recommended Chevron license when the first hydrocrackers were or cracking them into light hydrocarbons the technology rather than keep it pro- installed in Japan and at the company’s as in catalytic dewaxing, the Isodewaxing- prietary to advance the overall use of Yabucoa, Puerto Rico, refinery. “These branded catalyst and technology isomer- Group II technology in the marketplace,” initial base oils were introduced using izes the wax molecules—rearranging the Lok recalled. “It has been quite gratifying Gulf Oil technology. The early process to atoms to form new molecules—into low to see the phenomenal market growth of make Group II at Yabucoa used furfural pour point lubricating base oil. Group II and III base oils to where it is solvent extraction to reduce aromatics, Launched in 1993 at Chevron’s today.” then hydrocracking to further reduce Richmond plant, this new process repre- Jirong Xiao, Chevron Oronite’s vice aromatics and increase V.I.,” he sented a breakthrough improvement in president of sales and marketing, was also explained. hydroprocessing technology. “The a young engineer on the Isodewaxing “Another furfural extraction step Isodewaxing catalyst significantly increases project. “No one spoke in terms of [achieved] color stabilization, and finally lubricant base oil yield over competitive Group I or II, as API had not officially vacuum distillation was used to cut the technologies [solvent dewaxing, catalytic classified base stocks back then, but just material into 40, 50, 70, 100, 170 and 300 dewaxing],” said Bharat Srinivasan, how we could transform to higher quality [Saybolt Universal Seconds] viscosity Chevron’s managing director of technolo- base stocks that could extend oil drains base oils.” Hoffman noted the early 100 gy marketing. “It also can significantly and allow for higher quality lubricants,” solvent neutral cut only had a viscosity improve the product’s V.I. due to the iso- he noted. index of 90, which was much lower than merization of wax, which is the highest V.I. Xiao pointed out that lubricant additive the 100 to 110 V.I.—and even higher for component, into the base oil fraction.” companies were also able to take advan- oils marketed as Group II+—that formu- The technology “made it possible for tage of Group II base stocks. Everyone lators see today. refiners to produce large volumes of understood the oils’ improved oxidative Plants with the new technology could higher quality base oil economically,” he properties and their ability to yield prod- also make base stocks from crude that boasted, which “has led to the steady ucts at lower viscosity, lower volatility and could not be used by solvent processing increase of premium base oil production higher V.I., which enabled better fuel refineries. worldwide.” efficiency. But soon the industry found The next Group II plant started up Brent Lok was a green engineer in the other benefits, such as lower additive around 1978 at what is now Petro- mid-1980s when he began working on treat rates to meet sludge and deposit Canada’s refinery in Mississauga, Ontario, followed by Chevron’s Richmond plant in North American Base Oil Capacity Shifts 1984. These early facilities struggled to raise viscosity index in light neutral cuts (SN 100, 150 and 220) without significant reductions in the volumes that the plants could produce. Viscosity index and pour point are two competing property targets for base oils. Normal paraffins, or waxes, have the highest V.I., but their pour points are pro- hibitive for base oil applications. To meet the pour point target, solvent dewaxing removes wax from the base oil fractions. Catalytic dewaxing was also developed in the 1970s to remove wax from oil. It provided an alternative to solvent dewaxing because it separated normal paraffins and waxy side chains from other molecules by catalytically cracking them into light hydrocarbons. In the mid-1980s,

3 COPYRIGHT 2020, LUBES’N’GREASES MAGAZINE. REPRODUCED WITH PERMISSION FROM THE 25TH ANNIVERSARY ISSUE requirements as well as the ability to han- initial cost and provided a technology ILSAC GF-2 was introduced,” he said. dle soot in diesel engines. base that could be readily expanded to Motiva in Port Arthur, Texas, converted Mike McMillan, former manager of the meet increasing demand. one of its Group I trains to Group II in Lubricant Chemistry and Systems Group The Group II upgrade at Baytown was 1998, then converted the other in 2001. in the Chemical & Environmental completed in 1999 in anticipation of the Jackson was working for the producer Systems Laboratory at General Motors rollout of ILSAC GF-3 and its lower volatili- when it streamed its new base oil hydroc- R&D, was one of the first on the automo- ty requirements. According to Walko, “this racker in 2005. “Moving 41,000 barrels per tive side of the lubricants business to led to ExxonMobil’s investment in raffi- day was initially challenging, but with ILSAC notice the opportunities brought by nate hydroconversion technology that GF-3 the industry began taking advantage Group II base stocks. “GM first took leveraged the existing solvent refining of the newer base stocks and the quality advantage in their factory-fill applications processes at Baytown to produce the light advantages they offered. Then we started when we had Sunoco and Petro-Canada neutral base stock required for GF-3.” seeing Group II postings in industry publi- as key suppliers,” he said. Rick Dougherty, ExxonMobil’s cations, and the [price] separation between “SAE 5W-30 [engine oil] was rolling out basestocks & specialties technology Group I and Group II began.” to the marketplace, and Group II base chief, added, “ExxonMobil produces base “The last 25 years have seen remarkable stocks not only facilitated improved fuel stocks through several of its proprietary change for base stock manufacturing, economy for that viscosity grade, they selective catalytic dewaxing processes including the validation of Group II oils, also provided a lubricant that had superi- that offer higher yields, contaminant tol- the rise of Group III because of the avail- or oxidation properties and eventually erance and higher activity, leading to able new technology, as well as the first allowed for a step-change in oil volatility longer life of the catalyst.” world-scale gas-to-liquids plant,” Jackson from 22 percent to 15 percent Noack The company first commercialized its concluded. when ILSAC GF-3 performance require- Mobil Lube DeWaxing process for Over the next 25 years, the drive ments were [proposed] around 1996,” Group I base stocks in 1981 at its toward even lower viscosity oils is expect- McMillan continued. Adelaide, Australia, refinery. Based on ed to spur advances in API Group III and He also noted that further advances the ZSM-5 aluminosilicate zeolite cata- non-conventional base stocks to meet with Group III and Group III+ base lyst, MLDW technology was designed fuel savings targets without negatively stocks later enabled General Motors to for dewaxing raffinate, but was later impacting volatility or low-temperature move to SAE 0W-20 lubricants with even licensed to several Group II base stock performance. more stringent oxidation and volatility producers, Dougherty said. API Group II is poised to be the domi- requirements. “ExxonMobil began development of its nant base stock for the next decade, and ExxonMobil first began producing own isomerization dewaxing technology, with their increasingly higher viscosity Group II base oil in 1997 at its Jurong Mobil Selective DeWaxing, which was first index, these oils will combine with Group refinery in Singapore. Those oils made commercialized at its Jurong refinery. In III to meet much of the world’s lubricant their debut in North America at the 2000, ExxonMobil commercialized the demand. Baytown refinery in 1999. Ted Walko, second generation of its MSDW technolo- Refiners around the world also are base stocks & specialties marketing man- gy at Jurong with industry-leading selec- rethinking their distillate slates in response ager, told Lubes’n’Greases that “the deci- tivity for both light and heavy stocks,” he to the International Maritime sion to invest in Jurong was driven by continued. Over the years, ExxonMobil Organization’s new curbs on burning high- ExxonMobil’s desire to serve the growing has continued to innovate with new and sulfur fuel at sea. “IMO 2020 may also have demand for Group II base stocks in Asia- improved catalysts as well as advances in an impact on some Group I refineries that, Pacific.” hydrocracking technology, most recently in turn, could accelerate the growth of “At the time, most lubricants were for- deployed at its API Group II plant in Group II in lubricants applications,” mulated with Group I base stocks; how- Rotterdam in early 2019. ExxonMobil’s Walko predicted. ever, as the advantages of Group II—par- Gerry Jackson, vice president of busi- “In the future, quality and technical per- ticularly its improved oxidation stability— ness development with Renkert Oil, formance of base stocks will also become became more well-known in the industry, recalled that selling Group II base oil was more prevalent, and … the industry must ExxonMobil anticipated that more and challenging in the beginning. He had adapt to the changes in the base stock more formulators in Asia-Pacific would worked on the 1995 startup of the Excel business. We believe that production consider a switch,” he explained. The Paralubes plant in Westlake, Louisiana. capacity should adjust over time in line producer was able to utilize Jurong’s “Early times were challenging, as the with demand trends—although it is existing structure, which came at a lower value of Group II was not reflected when always difficult to predict the pace.” T