Sweet Deal in Polymer and Plastic Production

Mitsui and Dow will be making sugarcane-based plastics and polymers.
Mitsui and Dow will be making sugarcane-based plastics and polymers.

The Japanese company Mitsui & Co. is partnering with the American chemical giant Dow Chemical to build a biopolymers complex in Brazil, reports Senior Editor Alex Tullo for Chemical & Engineering News. The complex will oversee the entire process, starting from sugarcane cultivation and going all the way to producing plastics for home electronics, food packages, and for the motor industry.

Dow has been thinking about establishing a complex since 2007. It had announced plans for a 350,000-metric-ton-per-year linear, low-density polyethylene plant based on sugarcane, but the Brazilian sugar processor Crystalsev that was supposed to join in on the venture had dropped out.

Mitsui will put in an initial investment of $200 million and buy a 50% stake in Santa Vitória Açúcar e Álcool, a Dow subsidiary. The subsidiary is growing 17,000 hectares of sugarcane in the Brazilian state of Minas Gerais.

Tullo reports:

Later this year, the pair will start building a 240 million-L ethanol plant that will start up in the second quarter of 2013.

Eventually, the companies plan to build a plant that will dehydrate the ethanol into ethylene and a polyolefins plant of undetermined size and product slate. Luis Cirihal, Dow’s director of renewable alternatives and business development for Latin America, says the partners may also expand into other biobased materials. ‘What we are pursuing today is the first step in many,’ he says.

According to a press release by Mitsui, the production process will begin with sugars derived from sugarcane. Those sugars will be converted into ethanol. Then the ethanol will be made into ethylene.

Ethylene is the most produced organic compound in the world. In 2005, global production of ethylene exceeded 107 million tonnes. Ethylene is used to make polyethylenes of various types. Polyethylene, also called polythene, is the world’s most widely used plastic. It shows up in packaging, carrier bags, and trash liners. Other chemicals from ethylene go on to become detergents, synthetic lubricants, and other products.

Mitsui and Dow will definitely be making polyethylene with their sugarcane-based ethylene but they will also be making other chemicals, such as biodegradable plastics.

A press release from Dow Chemical says:

Once fully operational, this platform will be back-integrated into renewable sugar cane, enabling environmentally sustainable production of high performance plastics with a reduced carbon footprint. Biopolymers produced at this facility will be a green alternative and drop-in replacement for the high-performance flexible packaging, hygiene and medical markets, offering customers the same performance attributes with a more sustainable environmental profile.

Kevin Bullis, energy editor at Technology Review (published by MIT), points out that bio-based chemicals production has recently shot up, but still represents only 7.7% of the overall chemicals market. Dow Chemical now claims chemicals made from plant feedstocks may be ready to take on petrochemicals which are made in large volumes.

But high oil prices have made petrochemicals more expensive to make. Brazil, where long-standing government support for sugarcane ethanol production has let the industry blossom, makes ethanol competitive with fossil fuels. Making polyethylene from sugar makes sense in Brazil.

Bullis quotes Luis Cirihal, Dow’s director of renewable alternatives and business development for Latin America:

The technology for converting ethanol into ethylene, the precursor for polyethylene, is not new. ‘The dehydration process for converting ethanol to ethylene has been known since the 1920s. The only thing that’s really new here is the scale,’ Cirihal says. The new plant will have a polyethylene production capacity comparable to production at a petrochemical plant. Though the exact production levels aren’t yet settled, they will be on the order of ‘what you have heard before,’ he says, referring to a proposed Dow project that would have made 350,000 metric tons of polyethylene from sugarcane. (That proposal relied on a partnership that ended as a result of the recession.) It will be bigger than a 200,000-ton sugarcane-to-polyethylene plant operated by Brazil-based Braskem.

Source: “Biopolymers: Dow and Mitsui forge ahead on joint polyolefins project in Brazil,” Chemical & Engineering News, 07/25/11
Source: “Cheap Plastic Made from Sugarcane,” MIT’s Technology Review, 07/25/11
Image by 91RS (Phil), used under its Creative Commons license.

Rajendrani "Raj" Mukhopadhyay is a science writer and editor who contributes news stories and feature articles on scientific advances to a variety of magazines. Raj holds Ph.D. in biophysics from Johns Hopkins University.