Development of renewable-based che­micals for rubber manufacture is expanding amid rising prices for petroleum-based rubber chemicals (ICIS Chemical Business).  US synthetic rubber and tire manufacturer Goodyear continues its pursuit in the development of bio-based isoprene in a joint venture (JV) with industrial biotechnology company Genencor, which is part of US chemical firm DuPont following its acquisition of Genencor's parent company  Danisco.  Genencor is exploring the construction of a pilot plant for its bio-isoprene and notes that the pilot project could be built next year, although the future of the project may hinge on the full integration of Danisco and DuPont.

Isoprene is a key material used to make polyisoprene - a synthetic rubber used for tire manufacture - and is traditionally produced as a by-product of the thermal cracking of naphtha or crude oil, as well as a co-product in the production of ethylene. Genencor's collaboration with Goodyear started in 2007 when Goodyear said it was looking for a way to supplement its petroleum-based isoprene supply.

Another company that recently announced its own development of bio-isoprene is US-based Glycos Biotechnologies (GlycosBio). The company says it will commercialize crude glycerin-based isoprene via its subsidiary GlycosBio Asia with a planned 20,000 tonne/year biorefinery located at Bio-Xcell, a dedicated biotechnology park in Johor, Malaysia.

Plant construction is expected to start in the third quarter of this year and commissioning of the plant is estimated to commence in the first quarter of 2013. Production of bio-isoprene for rubber applications is planned for 2014. The facility also will produce industrial ethanol and acetone from crude glycerin.

"The plant will be operated by GlycosBio Asia employees and the subsidiary will directly market bio-isoprene in Asia," says GlycosBio CEO Richard Cilento. "GlycosBio is well positioned to support the Malaysian rubber industry as well as the emerging regional synthetic rubber market as isoprene has a global demand of approximately 850,000 tonnes/year."

The company expects to produce commercial-size samples of bio-isoprene in Malaysia during the 2013 plant commissioning and testing phase. Cilento says the company will be the low-cost producer to the isoprene market.  "Biological processes are generally cost competitive to niche or specialty chemical markets such as isoprene, which is not produced on purpose. Given the fact that isoprene is produced from naphtha and the recent fluctuations in crude oil, the market has been hampered by price volatility and price spikes," Cilento says.

BIO-ISOBUTENE RACE IS ON

France-based Global Bioenergies US bio-isobutanol producer Gevo with its collaboration with German rubber chemical company LANXESS are the major developers for bio-based isobutene (also called isobutylene).  Isobutene, which has an estimated market value of $25bn (€18bn), is the feedstock for production of polybutene or butyl rubber. Synthetic rubber can be made from the polymerization of a large number of monomers including isoprene, butadiene, chloroprene and isobutene, along with a small percentage of isoprene for cross-linking.

Global Bioenergies of business development Thomas Buhl says the company chose bio-isobutene for its first project because not only does it address the very promising rubber market, but the molecule also can be used in fuel applications with the dimerization of isobutene to iso-octane. The company says it achieved a laboratory prototype in producing isobutene from direct fermentation of glucose in October last year and is moving towards industrialization of the process.

"Our next step consists of performing tests in a pilot plant and further optimizing the process through enzyme engineering and strain engineering," says Buhl. "We plan to have industrial pilot plant by 2013, demonstration plant by 2015 and by 2017-2018, we hope to start commercial production."

The company is not yet producing isobutene at quantities usable for commercial applications. Global Bioenergies €6.6m from its initial public offering (IPO) held in June, and most of the funding will be used to industrialize the isobutene process.

In July, the company also received a €475,000 grant from the French innovation agency OSEO to help finance its isobutene project. Buhl says the company is looking for licensing partners in the rubber and tire industry interested in converting its bio-isobutene into butyl rubber or isoprene.

"We are planning to grant application-specific licenses such as bio-isobutene for butyl rubber application," says Buhl. "The production and marketing would then be carried out by those licensees that are already currently producing and [or] consuming isobutene."

Buhl notes that it has already granted its first licensing option on a particular application to a major US company in December 2010. The company's technology also can target other molecules such as isoprene, butadiene or n-butene, Buhl adds.

While Gevo is gearing up its commercial production of bio-isobutanol, its partner and investor LANXESS said it has already been able to successfully convert laboratory-scale isobutanol to isobutene through LANXESS's dehydration process over a period of several months.  "Tests have shown that the process can deliver bio-based butyl rubber that meets the rigorous specifications of the tire industry, which represents roughly 25% of LANXESS's sales," says Daniel-Alexander Smith, LANXESS head of financial and business media relations. "Based on current expectations, commercial bio-based butyl rubber amounting to several tens of thousand of tonnes could be available by the middle of the decade."

LANXESS did not indicate how much bio-isobutanol it will source from Gevo purely for captive use for its butyl rubber. Smith notes the company's intent to use renewable feedstocks for 50% of the requirements at its 150,000 tonne/year butyl rubber plant in Sarnia, Ontario, Canada, in the near future. "We would only proceed with such a project if it was commercially viable. All investments made by LANXESS must adhere to strict payback criteria," adds Smith.

Gevo president and chief operating officer Christopher Ryan says that its isobutanol is expected to be much lower in cost compared to petroleum-based isobutanol. "The challenge of making isobutene is in the production of low-cost bio-isobutanol. We estimate the bio-isobutene from our isobutanol is competitive with petroleum-based isobutene," says Ryan.  "We expect to supply isobutanol to other companies interested in isobutene production to help meet the demand for C4s, which is a tight market due to natural gas economics. We will also consider converting isobutanol to isobutene as opportunities arise."

Gevo plans to have 110m gal/year of isobutanol capacity online in 2013, and a total of 350m gal/year by 2015. The company is currently retrofitting a 22m gal/year ethanol plant in Luverne, Minnesota, US which will produce 18m gal/year of bio-isobutanol in the first half of 2012. In mid-June, Gevo bought a 50m gal/year ethanol plant in South Carolina that will be retrofitted later this year to produce 38m gal/year bio-isobutanol by the fourth quarter of 2012.

QUEST FOR BIO-BUTADIENE

LANXESS notes several ongoing projects covering all carbon chains. "We will announce these projects when the time is right," says Smith. "We are pioneers in this field of green chemistry and are highlighting how the chemical industry is able to create additional products down the value chain from renewable resources."

At the 6th ICIS World Olefins Conference held in Belgium in March, Christof Krogmann, vice president of petrochemical projects at LANXESS, noted that high prices for C4s, especially butadiene (BD), could make alternative on-purpose routes viable. Butadiene continues to be the major feedstock in synthetic rubber manufacture. Industry sources are forecasting butadiene demand will outstrip supply because of the expected under-utilization of European crackers due to new Middle East capacities, and the preference to crack lighter, more competitive feeds.

"Alternative manufacturing routes to the C4 molecules such as selective dehydrogenation are becoming increasingly attractive," said Krogmann. He illustrated several possible routes to manufacturing bio-based 1,3 butadiene such as the conversion of bioethanol to butadiene via the Lebedev process; the conversion of biobutanol to butenes and then to butadiene using the oxidative dehydrogenation (Oxo-D) process; and conversion of 2,3 butanediol to butadiene using a dehydration process.

In mid-July, Global Bioenergies its partnership with Polish rubber manufacturer Synthos to develop a new process for renewable-based butadiene. Under the deal, Global Bioenergies receive R&D funding, multi-million euro development fees and royalty payments from Synthos on sales of bio-butadiene for rubber manufacturing. Synthos also acquired a 3.6% stake in the company for €1.4m.

Global Bioenergies will retain exclusive rights on non-rubber applications. "About 10m tonnes/year of butadiene are produced worldwide, of which two thirds are used to manufacture synthetic rubber. The rest is used to produce nylon, latices, ABS (acrylonitrile butadiene styrene) plastics and other polymers," said Buhl. He noted spot price of butadiene has recently rocketed to over $3/kg and that the global butadiene market is currently estimated at $30bn.

automotive industry seeks bio

The automotive market, rubber's largest consumer, has become a big proponent in using renewable-based materials - not only for tires, but also for other auto components.

US manufacturer Ford Motor’s biomaterial researchers have applied a patent for soybean oil-based rubber that can be used in automotive parts such as deflector shields and baffles, radiator deflector shields, cupholder inserts, floor mats and even gaskets and seals. The researchers have engineered a formula to use renewable soy oil to improve rubber car parts and make them more environment-friendly, says Cynthia Flanigan, Ford technical leader in elastomeric polymers.

"Ford is focused on finding innovative ways to make our vehicles more eco-friendly. Soy-based rubber has win-win potential as it provides superior stretchability and serves as a renewable resource that helps reduce carbon dioxide emissions from raw materials," says Flanigan. She notes that the automotive sector accounts for more than 50% of worldwide rubber consumption, which exceeded 22m tonnes in 2008.

France-based Hutchinson Worldwide, which provides systems and components for the automotive sector, noted customers' growing requests for renewable-based solutions. The company partnered with US-based Elevance Renewable Sciences in July to develop renewable processing aids for rubber compounds. Primary products in the collaboration include modified triglycerides and specialty difunctional materials that are all based on renewable oil feedstock, says Elevance's Andy Shafer, vice president of sales and development.