Building with Bioplastics - Part 3

July 11, 2012 – Vol.17 No.17

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 3.

Building big things for significant carbon sequestration.

by Bruce Mulliken, Green Energy News

I built a small shed out of plastic boards and decorative plastic shutters to protect and “beautify” the well pump and above ground piping for my home's irrigation system. Bioplastic lumber wasn’t available at the home improvement store. If it had been I would have used it and now would be sequestering a small amount of atmospheric carbon dioxide in the boards of my little pump house. As a small project it’s not doing much to fix the Earth’s warming atmosphere. Yet if there were millions of bioplastic pump houses, and lots of other relatively small building projects like it, maybe there’d be a difference in global atmospheric carbon content. Who knows?

For bioplastics to do a significant and measurable job of sequestering carbon dioxide bigger things than my little house will have to be built. Things with some heft need to built. Things with some mass. Large durable things with a lot of bioplastic and thus considerable carbon content are what’s needed. Individual projects built of carbon sequestering bioplastic need to be measured in tons, not pounds, and there’d have to be lots of those projects too.

Further there will have to be new innovative uses of bioplastics too. There will have to be things built of bioplastic aren't commonly built of plastic or plastic composites now. Fortunately those already in the plastics business are quite adept at inventing new products. Bioplastics that would sequester carbon would just be another challenge for them, and by the way, give them new business that isn’t there now.

Much of our built environment is already physically large things – roads, bridges, commercial and industrial buildings, and the largely unseen underground infrastructure of pipes, wires and holding tanks. The first place to look where bioplastics could be used is simply to look where ordinary petroleum plastics are now in use. There’s a surprising use of petro-plastics already where there was once concrete, steel and wood:

--- docks and piers

--- small bridges

--- water pipes

--- sewage pipes

--- bridge decks

--- culvert pipe

--- buildings

--- sidewalks

--- retaining walls

--- a wide variety tanks

Some bioplastics are available now that be substituted. Lumber, culvert pipe and holding tanks now made of high-density polyethylene (HDPE) could be made of bio-HDPE.

The sequestering of carbon dioxide, as well as the avoidance of carbon dioxide from the manufacture of petroleum HDPE, would be significant. Brazilian chemicals group Braskem claims that its method of using sugar cane-based ethanol to produce bio-HDPE, one metric ton (tonne) of bio-HDPE produced will remove from the atmosphere 2.5 tonnes of carbon dioxide, while making traditional petrochemical HDPE results in emissions of close to 3.5 tonnes.

In 2007, in the most recent study by German market intelligence company Ceresana, the global petro-HDPE market reached a volume of more than 30 million tonnes. (An updated study should be available soon.)

More could be built with bioplastics and bioplastic composites yet to be developed.

--- Plastic composite sidewalk tiles are already available. These certainly could be made of bioplastics. Aside from sequestering carbon and being more durable than concrete, pipes or electrical cables could be buried beneath these bioplastic sidewalks. Need to repair an underground power line? Remove the sidewalk tiles, fix the wire and replace the tiles.

--- Bridges are built with concrete and steel needing regular maintenance and eventual replacement, all at considerable expense to state and local governments. Large, complex and durable goods like yachts and now airliners are built out of composites of glass, carbon fiber and plastic. Why can’t bridges? If so, why can’t bioplastic composites be developed to build the same structures?

--- Anything that comes in contact with the ground. Rot resistant, termite and moisture proof, bioplastic products could protect structures from natural decay. Why not develop whole building foundations made of watertight, lock-together bioplastic composite panels that are ready to build on from the moment they’re installed?

Already there’s a buyer for bioplastic building materials: The US Government.

The Department of Agriculture is currently managing the BioPreferred (R) program. Created by the Farm Security and Rural Investment Act of 2002 (2002 Farm Bill), and expanded by the Food, Conservation, and Energy Act of 2008 (2008 Farm Bill), the purpose of the BioPreferred (R) program is to increase the purchase and use of biobased products. The United States Department of Agriculture manages the program.

The BioPreferred website states that BioPreferred includes:

--- a preferred procurement program for Federal agencies and their contractors,

--- and a voluntary labeling program for the broad scale consumer marketing of biobased products.

Under the procurement program, BioPreferred designates categories of biobased products that are required for purchase by Federal agencies and their contractors. As a part of this process, the minimum biobased content is specified. Going forward, biobased intermediate ingredients and feedstocks will be included in the designation process.

“We’re very excited about the BioPreferred program and feel it will benefit any organization that produces biobased products, from pens made from bioplastics to bioplastics used in building materials,” said Richard Eno, president and CEO of Metabolix, Inc., an innovation-driven bioscience company that delivers sustainable solutions to the plastics, chemicals and energy industries. “The Biopreferred program requires that biobased products undergo rigorous testing to safeguard consumers from false or misleading claims.”

Metabolix currently markets biopolymer resins under the Mirel (tm) and Mvera (tm) brands. The resins are used to make bioplastic products such as plantable flower containers that biodegrade in natural soil, and biobased bags suitable for composting food waste or use in anaerobic digestion.

Although Metabolix is not currently focusing its biopolymers efforts on the building materials sector, opting instead for single use, disposable applications, Metabolix is following the development of this market closely. “Our immediate focus to meet the demand for carbon sequestration in the construction segment is through the development of renewable chemicals,” added Eno. “By converting the current petroleum-based monomers to renewable materials, construction products such as paints, coatings and high performance plastics can be made more sustainable, thus meeting the green materials need.”

Under the voluntary labeling program, biobased products that meet the BioPreferred program requirements carry a distinctive label for easier identification by the consumer.

The program is geared to build the biobased industry. Carbon dioxide sequestration is not mentioned, but should be for certain products. One product category stands out on the BioPreferred list as a good carbon storing building material:

Composite Panels - Structural Wall Panels

Engineered products designed for use in structural walls, curtain walls, floors and flat roofs in commercial buildings. A 94 percent - Minimum Biobased Content is required.

Links.

Metabolix

USDA BioPreferred Program

Ceresana - Polyethylene Study

Braskem

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 1. Introduction to a concept industry.

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 2.
Residential bioplastic building materials when managed and recycled could sequester carbon dioxide for centuries.

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 3.
Building big things for significant carbon sequestration.

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 4.
Renewable energy plays a significant role.

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 5.
Which plants for feedstock?

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 6.
Man-made systems to capture carbon dioxide for plastics and other chemicals.

BUILDING WITH BIOPLASTICS:
ATMOSPHERIC CARBON STORAGE IN CONSTRUCTION MATERIALS - PART 7.
The need for a regulated industry.