Base oils 2014: Green lubricants continue progress

Bio-based lubricants continue to make headway in the market, as producers enhance performance by tailoring the properties of the vegetable oils used in their production

Over the last three decades, bio-based vegetable-oil derived lubricants, which are also typically biodegradable, have been introduced to the market and are finding growing use in applications where the grease or oil is lost to the environment.

Turning plant products such as oil palm fruits into lubricants can reduce industry’s carbon footprint Copyright: Rex Features

However, because these products are biodegradable, they have generally been perceived as not able to provide the performance required for applications where the lubricant must perform at high temperature for long periods of time.

The situation is changing, however, as technology for the conversion of bio-based raw materials into lubricants with properties similar to those of high-performing synthetic oils has reached the commercialisation stage.

Bio-based lubricants can offer several environmental benefits for lubricant users, according to Jeffrey A Brown, president and CEO of Novvi. He specifically points to three areas – renewability and a lower carbon footprint, biodegradability (although the two are not synonymous) and low toxicity.

The desire to find renewable raw materials as alternatives for petrochemical-based feedstocks is transcending nearly all chemical markets and lubricants is no exception. Many lubricants derived from renewable raw materials also offer the added benefit of reduced environmental impact, and as a result, products currently on the market – most of which are derived from vegetable oils – find use in environmentally sensitive areas (close to waterways or on water) and in applications where the lubricant (grease or liquid), is lost during use, according to Lou Honary, professor at the University of Northern Iowa and director of the National Ag-Based Lubricants Center (UNI-NABL).

In Europe, adds Chris Donaghy, sales director for polymer additives and lubricants with Croda International, bio-based lubricants are commonly used to meet the criteria for “environmentally aware lubricants”, which are related to bioaccumulation and toxicity.

During the past 20 years, UNI-NABL has been a leader in the commercialisation of ­bio-based lubricants and greases based on vegetable and plant oils, such as soybean oils, for both industrial and consumer applications.

These products (more than 30) are manufactured by Environmental Lubricants Manufacturing, which was formed by Honary and the UNI Research Foundation, and are sold under the UltraLube private label at most major US big box stores like Lowes and Home Depot.

Honary and his colleagues at UNI-NABL have also developed a microwave processing method for the production of bio-based greases that results in improved performance and significantly lower manufacturing costs.

There are limits to the application of vegetable-based lubricants, however, due to the chemical nature of these compounds. Their biodegradability, which makes them attractive, is due to the use of natural oils that, if not treated properly, could lack oxidation stability and freeze at higher temperatures than petroleum oils, preventing their use in high-performance applications that require extended durability and resistance to degradation under extreme conditions.

“Cost and performance requirements have typically dictated where and when the different technologies are used,” notes Donaghy. While vegetable oils do have advantages in the area of lubricity, unless treated properly, they suffer from poor temperature stability and low temperature pourability and inconsistency as the result of crop variability.

BETTER PERFORMANCE AT A PRICE
Bio-based synthetic esters, which are typically vegetable oils that have been separated, refined and put back together in a way that maximises lubricant performance for a given application, offer increased consistency, improved stability and better low-temperature performance, but are priced higher than vegetable oils.

“To make real gains in the marketplace, environmentally friendly lubricants must provide equal or better performance compared to that expected for traditional petrochemical-based products, and do so at a competitive price,” asserts Brown.

Technology is advancing on several fronts with respect to improved performance of bio-based lubricants and greases and many new products are being brought to the market. That includes developments in the natural oil space. “First,” notes Honary, “there are several new and more stable genetically enhanced vegetable oils that promise to improve performance (higher levels of oxidation resistance) and reduce the cost of bio-based liquid lubricants.

Second, there are several non-food industrial crops that will continue to grow due to their potential use in industrial applications, such as camalina, which is currently grown in the western US in dry and arid land and has about 40% oil. Third, there are novel base oils obtained from algae that can be produced in industrial reactors and have properties matching those of petroleum and synthetic base oils,” he explains.

Honary also points to the commercialisation of estolide chemistry by Biosynthetic Technologies. Estolides, a type of synthetic ester originally developed by Steve Cermak of the US Department of Agriculture, are prepared from vegetable oils, but offer high oxidation stability, low cold temperature performance, low volatility, high viscosity indices and consistency.

Croda, meanwhile, has been offering lubricant oils with around 70% renewable content for many years. “We consider product performance to be as critical as renewability and offer a range of synthetic esters that deliver high end performance and high renewable content,” states Donaghy.

Most recently, Croda launched Perfad 5000, a 100% renewable, 100% biodegradable, low toxicity product for use as a seal swell additive to replace phthalate esters. In the first quarter of 2014, the company is launching three new HX-1 approved food-grade esters for use in chain oils that are largely derived from renewable resources and have a focus on performance.

Elevance Renewable Sciences is also using vegetable feedstocks (such as canola and soybean oils), but with metathesis technology using a proprietary catalyst, to design Inherent novel building blocks with the right chain length and appropriate difunctionality that enable engineering of performance of its renewable lubricant oils, according to Robin Weitkamp, Elevance senior vice president for lubricants and additives.

“With our technology, we are actually synthesising materials from renewable feedstocks that have properties comparable to synthetic high-performance materials and we are doing so using low energy intensity process. Thus our products offer a low carbon footprint,” adds Greg Gerhardt, market development manager with Elevance.

“In fact,” adds Weitkamp, “renewability is almost an added benefit, because our focus in on engineering performance and creating polyalpha-olefin (PAO)-type molecules with ester functionality and differentiated properties of interest to the market.”

BIOREFINERY UP AND RUNNING
In 2013, Elevance commercialised its Inherent C18 diacid, which can be used as a feedstock for base oil manufacturing, started up its 180,000 tonne/year joint venture biorefinery with Wilmar International in Gresik, Indonesia, rolled out its GC350 complex grease formulation for high-temperature applications and, most recently, launched its Aria WTP 40 ­high-viscosity lubricant base stock that ­covalently combines PAO-type molecules with ester functionality.

The latter product, according to Gerhardt, offers balanced additive solvency, lower friction, excellent wear resistance, increased deposit control and cleanliness, a high viscosity index and improved shear stability, and is designed for use in engine and gear lubricants, metalworking applications, industrial and hydraulic fluids and greases.

Much of the lubricant development efforts at Elevance are pursued through collaborations with strategic partners, including lubricant manufacturers and other participants in the lubricant marketplace that are targeting high-performance and are committed to the development and commercialisation of innovative products, according to Weitkamp.

Those efforts have been successful enough to lead the company to move forward with plans to convert an existing biodiesel facility in Natchez, Mississippi, into its second world-scale biorefinery and derivatives facility. This will have a capacity of 280,000 tonnes/year and be operational in 2016, 
according to Gerhardt.

The biorefinery approach is beneficial for Elevance as it allows production of the company’s Inherent renewable building blocks, including renewable C10+ alpha- and internal olefins and high-value, difunctional specialty chemicals, including 9-decenoic acid methyl ester. The triglycerides and fatty acids found in natural oils (plant, vegetable and animal oils) are converted to the building blocks via metathesis, trans-esterification and hydrogenation reactions.

“Olefin metathesis, pioneered by Nobel Laureates Robert H Grubbs and Richard Schrock, enables the rearrangement of the structures of the oils in an efficient, stable and predictable manner using widely available industrial equipment,” Gerhardt explains. He adds that while multiple different feedstock oils are suitable (palm, mustard, soybean, canola and, when commercially available, jatropha or algal oils), the company prefers to use those with a high degree of mono-unsaturation.

The Gresik biorefinery currently uses palm oil and the Natchez biorefinery is expected to use canola or soybean oil. “The ability to produce a mix of high-value performance specialty chemicals, olefins and oleochemicals makes it possible to reach commercial scale volume and achieve competitive pricing for the various products,” notes Weitkamp.

Novvi, meanwhile, is a joint venture company between Amyris, an integrated renewable products company, and leading Brazilian sugarcane and biofuel producer Cosan, which also has a strong lubricants relationship with ExxonMobil in South America and Europe. The company was formed in June 2011 to develop, produce and commercialise renewable base oils made from Biofene, Amyris’s renewable farnesene, which is produced from plant-sourced sugars via fermentation using genetically engineered yeast cells.

Croda’s lube ester plant at Atlas Point in Delaware, US Copyright: Croda

TARGETING MARKETS
“Novvi was created to focus on lubricant applications, which was just one of multiple downstream markets that Amyris was looking to launch products for (such as fuels, polymers, personal care, etc). Rather than expand outside of its core area of expertise – biotechnology – Amyris elected to set up different businesses that could establish a position in targeted markets,” Brown explains.

The initial product of the fermentation process developed by Amyris is farnesene, a C15 hydrocarbon with four sites of unsaturation that offer flexibility for chemical transformation, according to Brown, that enables the production of renewable base oils that perform just like traditional Group III+ and IV synthetic oils with the added benefits of biodegradability and toxicity, thus meeting the performance and environmental requirements of lubricant specifications established by original equipment manufacturers (OEMs).

The base oils that Novvi produces from Biofene are fully saturated, branched-chain alkanes (iso-paraffins) with low volatility that, due to their branched structure, also have a good mix of cold flow properties, biodegradability and oxidative and thermal stability, and thus have properties similar to those of PAOs, but with a beneficial carbon footprint, says Brown.

Currently Novvi offers four NovaSpec brand products with different viscosity grades that are suitable for use across all lubricant applications, from engine oils to greases. These products are manufactured for the company in Houston, US. In addition, Novvi is working with a range of partners, including lubricant manufacturers and additive suppliers, to develop formulated lubricants, which it offers under the trade name Evoshield.

“It is important to demonstrate to customers that bio-based products can perform as well as traditional base oils derived from petrochemicals, and offering formulated products is necessary to do that. In addition, many people aren’t knowledgeable about formulating with these new oils. To make it as easy as possible for potential customers to use our renewable base oils, therefore, we are developing example formulated lubricants that are competitive in the marketplace in order to provide formulating possibilities,” Brown observes.

The investments being made by companies such as Biosynthetic Technologies, Elevance and Novvi reflect a positive outlook for the bio-based lubricants market. “In the past, bio-based lubricants were limited by their performance capabilities and production capacities, but that situation is changing rapidly,” notes Weitkamp.

The success on bio-based lubricants will be determined by two factors, according to Brown. “Performance and cost will be the key issues. With the ability to produce bio-based base oils at large scale, renewable alternatives that can compete in terms of both performance and cost will have an impact on the market,” he asserts.

Cynthia Challener is a freelance journalist based in the US with extensive experience of covering specialty chemicals

KODA TO DISTRIBUTE ALGAE-DERIVED LUBRICANTS
US-based Solazyme, which develops renewable oils and bioproducts from algae, has signed Monson Companies, part of the KODA Distribution Group, to distribute its Renewable Tailored high oleic algal oil to the lubricants and metalworking fluids sectors in the US and Canada. The partnership will provide customers with access to the latest and most innovative oil available, supported by Monson’s technical knowledge and dedicated laboratories for formulation and application assistance.

According to Steve Barney, president of Monson, “We have been looking for the right replacement product for quite some time. Our customers depend on us and require products that meet the changing industry and government demands.”

Solazyme’s Renewable Tailored high oleic algal oil is said to deliver key high performance benefits of both natural oils and synthetic oils, including enhanced lubricity, excellent viscosity, high flash point, low toxicity, improved stability and predictable performance.

“Our goal is to accelerate the development and commercialisation of products formulated with Solazyme’s Tailored high oleic algal oil,” says Frank Bergonzi, CEO and president of KODA. “It delivers exactly what we need – a bio-based, algae-produced oil that we believe outperforms the traditional petroleum-based products in lubricants and metalworking fluids.”