Major chemical companies are investing in new plants and technologies to produce plastics from annually renewable sources. Over 95% of all plastics are produced or derived from the major non-renewable energy sources, including natural gas, naphtha, crude oil, and coal, which are used as both feedstock material and energy source in plastics manufacturing. For some time, agricultural materials have been considered as an alternate feedstock and source of energy for plastics production. The key factors hindering the use of plastics from agricultural based feedstocks was cost and product functionality limitations, and lack of flexibility in producing specialized plastics materials. However, soaring oil prices, global interest in renewable resources, growing concern regarding greenhouse gas emissions and a new emphasis on waste management has created renewed interest in biopolymers and the efficiency with which they can be produced. New technologies in plant breeding and processing are narrowing the bioplastics-synthetic plastics cost differential, as well as improving material properties.
Some suppliers aim to produce today's conventional plastics from unconventional feedstocks like ethanol fermented from sugar cane. Others will make new monomers using other fermentation chemistries borrowed from life sciences and biochemistry. Cereplast, a maker of starch-based compounds is changing to product mix- from all-renewable, all-compostable compounds, the company has lately moved on to compounds that are 50/50 renewable starch and conventional PP. Laws also encourage degradability for short-lived products like thin-gauge shopping bags. As of Jan. 1, the Belgian government put a 300% tax on nondegradable bags, making degradable ones more economical. The Italian government mandated that by 2010 all two-handle bags in Italy must biodegrade. USA , the world's largest ethanol producer, has a capacity to produce 24.6 mln m3/yr based on corn. But it is heavily subsidized for fuel use, so little if any of that goes into plastics.
Some firms are investing to seed promising R&D. DSM Venturing, for example, participated in a US$6.6 mln investment in Novomer, an R&D spin-off from Cornell University that has developed low-temperature catalysts to polymerize carbon monoxide and CO2. Novomer's room temperature, low-pressure polymerization of carbon monoxide and dioxide is unconventional but not biologically derived. Novomer intends to get its carbon from the relatively pure CO2 emitted as a byproduct from commercial cement production. Novomer is developing two materials: aliphatic polyethylene carbonate (PEC) and polyhydroxyalkanoate (PHA). PEC is a barrier resin potentially useful for packaging. It's made of 50/50 CO2 and ethylene oxide. Novomer is already selling high-purity PEC toll-produced and shipped in solvent as a binder for capacitor production. Its PHA will be similar to bacterially produced PHA (from sources like the Telles joint venture of Metabolix and Archer Daniels Midland), but is based on mineral CO and epoxides. Novomer is considering building its pilot plant nearby a producer of sugar-based epoxide in order to make 100% sustainable polymers.
Brazilian ethanol is a major ingredient in some of the new biopolymer investments. Thanks to its unique combination of climate and available land, Brazil has some 350 ethanol production units making 20 million m3/yr of ethanol from sugar cane. Last year, Braskem, Solvay and Dow Chemical all announced plans to produce ethylene from ethanol in Brazil to make renewable polyethylene and PVC. Ethylene from ethanol is identical to ethylene from naphtha or natural gas, and plastics made from bio-ethylene are indistinguishable from petro-derived polymers. Chemical plants in Brazil first made plastics from ethanol in the 1980s. The Brazilian government subsidized a half-dozen small ethylene plants, including some now belonging to Braskem, Dow & Solvay. Together they produced 160,000 tons of ethylene from ethanol, which was made into PVC and PE. Braskem made bio-PVC from ethanol from 1981 to 1991. When oil prices fell, the subsidies and bioplastic production stopped. Now Braskem plans to invest US$150 mln to build a 450,000 tpa bio-PE plant, expected to start up in 2009. Dow has a joint venture with Crystalsev in Brazil to build an ethanol-based ethylene plant for 350,000 tpa of Dowlex bio-LLDPE, to start up in 2011. Solvay is investing US$135 mln to add 60,000 tpa of ethanol-based ethylene by 2010 to an existing Brazilian plant in order to make bio-PVC.
Governments and large end-users of plastics are rapidly formulating policies on renewability. The Japanese government set a “Biomass Nippon Strategy” in 2002 with a goal that 20% of all plastics consumed in Japan would be renewably sourced by 2020. The Japanese Bioplastics Association says that 20% represents about 6.6 billion lb/yr of plastics. Toyota set the same goal of having 20% of all plastic in its vehicles not come from oil by 2020, an estimated requirement for about 400,000 tpa of renewable plastics, most of which don't exist today. So Toyota has a development plan for using up to 100,000 tpa of PLA to create interior trim parts. Japanese electronics supplier NEC also wants 10% of its plastic to come from renewable sources by 2010. This demand for renewable materials in durables is accelerating R&D to meet higher property requirements. That is resulting in hybrid resins that combine biomaterials with conventional resins.
Bacterial fermentation used to make PHA and variants PHB and PHBV (polyhydroxybutyrate and polyhydroxybutyrate valerate copolymer) is being developed by at least a dozen companies around the world. Metabolix introduced genetically modified designer bacteria that are more efficient in making plastics. Its joint-venture plant in Clinton, Iowa, is expected to start up this year with capacity for 110 million lb/yr of PHA.
Many other producers use natural bacteria and unmodified feedstocks. The world's first commercial producer of PHBV is Tianan Biologic Material Co. in Ningbo, China , which doubled capacity to 2 million lb/yr late last year. The company plans to start up a 20 mln lb plant in 2009.
Tianan's PHBV is being evaluated for injection molding packages for personal-care and cosmetic products, and also for thermoforming and blown film. Some grades are being blended with BASF's EcoFlex biodegradable (but not renewably derived) polyester to make flexible blown film, which is already used commercially for electronics packaging. Prices are expected to come down when the larger plant starts up.
PHB resin made via fermentation by Biomer in Germany is being used in injection molded medical products.