Additives

The Notorious PIBs

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While polyisobutene commands respect for its versatility across a slew of global industries, including lubricants, it rarely grabs headlines. It pops up occasionally to assert its place as the heir apparent to bright stock when supplies seem to be under threat, but has otherwise kept a steady beat in the market.

A recent rise in capacity points to increasing demand for PIB-not from blenders searching for a bright stock replacement, but from a growing thirst for lubricant additives, according to Kline & Co.

The Parsippany, New Jersey-based consultancy forecasts that PIB capacity will reach 1.3 million metric tons per year by 2028, an increase of about 8 percent. But demand may not grow as quickly as supply, resulting in lower utilization rates in the short- and mid-term, Klines Hareesh Nalam said during a webinar.

According to LubesnGreases 2018 Nonconventional Base Stocks Guide, global PIB capacity is about 1.2 million t/y. Thats a 30 percent increase from 2012, the first year LubesnGreases began tracking such data. But the road has included a few bumps.

A wave of new capacity from Texas Petrochemical Corp. in Houston, Ineos Oligomers in northern Indiana and France, Polibutenos Industrias in Brazil and South Koreas Daelim Industries rolled onto the market in the late 2000s, just as the Great Recession caused an ebb in demand. In 2012, Ineos threw in the towel for its 88,000 t/y plant in Whiting, Indiana, which helped bring the market back toward balance.

But producers dove in to replace that capacity almost immediately. Additions from BASF in multiple locations, Braskem in Brazil, Gujarat Polybutenes in India, CNPC in China and YPF in Argentina added back 13 percent of supply. Capacity has been slowly picking up steam since then, with a 6 percent jump from 2017 to 2018, mostly due to BASF and Petronas Chemicals addition of 50,000 t/y of highly reactive PIB at their joint venture petrochemical complex in Kuantan, Malaysia.

The bulk of Klines predicted increase over the next decade will come from Lubrizols addition of HR PIB capacity at its Deer Park, Texas, facility, where it already makes conventional PIB. The size of the project has not been reported, but output should begin in 2020.

Early this year, Saudi Aramco, Total and Daelim announced plans to team up on an 80,000 t/y PIB plant in Jubail, Saudi Arabia, set to open by 2024. The new plant is not included in Klines prediction, and would put global capacity closer to 1.4 million t/y in 2028-a 15 percent increase from 2018.

There has been no announcement on the split of PIB types to be produced in Jubail, but it is natural to expect that there will be a greater focus on HR PIBs than conventional, given the demand from its biggest application, which is lubricant additives, observed Nalam, who is a senior consultant.

Klines estimate also accounts for JXTG in Japan to increase its capacity by 5,000 t/y to a total of 12,000 t/y by the end of this year, with a focus on very high molecular weight material (30,000 grams per mole and higher). However, the company told LubesnGreases in June that construction has not yet begun.

Kline views the current PIB market as mostly balanced but with some spare capacity. New capacity creation will increase the supply, which may make this market a buyers market in the short- to mid-term, said Anuj Kumar, project manager in Klines energy practice, also speaking during the webinar.

Whats the 411?

Polyisobutenes used in lubricant applications are thick, clear liquid polymers made from hydrocarbon chains with four carbon atoms produced in naphtha crackers, according to supplier Kemat. The feedstock can be sourced from crude refineries or from natural gas plants.

Lubricants account for about 60 percent of PIB demand, according to Kline. The chemicals are also used in fuel additives; food, medical and personal care; agriculture; plastics and rubber; adhesives, sealants and coatings.

PIBs have two main roles in the lubes industry: In their stable form, they serve as base oils and thickeners, and in their more reactive form they are used to create additives. While the two forms can be used for both applications, producing polyisobutenyl succinic anhydrides is easier with highly reactive PIBs, which have an olefinic group on the tail end of the polymer. PIBSA is used to make the succinimides and succinic acids that go into lube additives, explained Kumar.

By the same token, HR PIB can be used as a base fluid, but it comes at a higher cost without providing additional benefit in the application.

Kemats conventional PIB product line spans viscosities from 2 to 13,000 centistokes and molecular weights from 280 to 4,200 g/mol. The company also sells highly reactive PIBs, as well as higher molecular weight products than what would be used in lubricants. Most lubricant additives are made from 1,000 to 2,300 g/mol PIBs. As base stocks, 300 to 500 g/mol material is typically used in heavy-duty applications and high-temperature greases. When standing in for bright stock, 1,000 to 2,300 g/mol PIBs are the norm.

Belgium-based Kemat seems to be benefiting from the PIB bump. The company opened a new sales office in Hong Kong in June 2018 and will open another in Shanghai this year to help serve growing demand in Asia. A Canadian office will also open in 2019, according to EMEA Sales and Marketing Representative Suzy Jarman.

Mo Additives, Mo PIBs

Kline expects that the growth rate for HR PIB will be twice that of conventional PIB over the next 10 years, with a rapid shift coinciding with the debut of the ILSAC GF-6 passenger car engine oil specification in 2020. The announcement of ILSAC GF-5 in 2010 led to a surge in demand for HR PIB for making dispersants that would allow oils meet the new standards, Kumar pointed out.

PIBs are the building blocks of dispersants, viscosity index improvers and anti-mist agents for metalworking fluids, but dispersants account for the lions share at 90 to 95 percent, he noted.

The ILSAC GF-6 category is designed to be an upgrade from GF-5, including many new engine tests with more stringent pass/fail limits, explained Ewan Delbridge, global technology manager for consumer engine lubricants at Lubrizol. The Sequence IIIH is an oxidation engine test, which is part of the ILSAC GF-6 specification, superseding the ILSAC GF-5 Sequence IIIG test. Both oxidation tests have a strong appetite for a number of additives, including dispersants.The Sequence IIIH engine test limits on an equivalency basis are higher for ILSAC GF-6 vs. GF-5 and therefore require higher levels of dispersant and other additives. Consequently, demand for many raw materials such as PIB, which makes up a large portion of dispersants, will likely increase for ILSAC GF-6 vs. GF-5.

Additive manufacturing is the biggest application of PIBs, which is attested to by the fact that PIB capacity is concentrated around key additive manufacturing sites globally, said Nalam. Three of the four big additive companies have an in-house supply. Lubrizol and Infineum produce the conventional type, and Chevron Oronite produces highly reactive molecules.

However, only a third of global capacity is owned or operated by these additive companies and their joint ventures, he said. Additive producers, including ones with their own capacity, buy from merchant sellers to meet their demand.

Europe, Asia-Pacific and North America all have about one third of global capacity, with a small share scattered around the rest of the world. Shipping PIB comes with logistical challenges because it must be heated during transit to maintain fluidity. But interregional trade has grown recently, indicating that despite a small surplus of capacity, regional supply-demand imbalances exist, said Nalam.

Not all plants run at optimum rates, he continued. Even though Asia-Pacific has the largest capacity, its output is less than that of North America and Europe. This is because a major portion of regional supply is in China, where producers are solely focused on catering to the domestic market and where supply outstrips demand. Chinese producers are also in competition with other suppliers in the region such as Daelim and BASF.

Further, HR PIB seems to be winning the feud for market share and constraining conventional plants to lower utilization rates.

Ready to Sub

As high-viscosity base stocks, conventional PIBs are most often used in industrial gear oils, greases, marine oils and two-stroke engine oils, in which they burn cleanly without producing so-called blue smoke. However, demand for two-stroke oils is down as the motorcycle market shifts toward four-stroke engines instead. As a result, the overall demand for PIB as a base stock will remain mostly flat, Kumar stated.

PIBs promise as a bright stock replacement-at least in competition with other potential substitutes such as polyalphaolefin and polyalkylene glycol-stems from its solubility in mineral oil, ready availability and relative economy. PIB can substitute for bright stock at a three-to-five ratio, which saves volume, said Kumar. It is also less expensive than PAO and PAG, though it still costs more than bright stock.

Although the search for cost-effective alternatives has intensified, polyisobutene is by far the most popular, constituting around 80 percent of substitution volumes, said Vista Energies commercial director Majid Safdari, speaking at the AMEA Bitumen and Base Oil conference in Dubai earlier this year.

Supply of bright stock has fallen by 15 percent since 2005, and is expected to continue its decline with the erosion of API Group I base oil production. Global bright stock capacity was 3.6 million metric tons in 2018, Safdari said, being used at a rate of 80 percent.