+ Bagasse in many cases is biodegradable
+ It is a by-product of sugarcane, one of
the world’s most frequently harvested crops and a rapidly renewable resource
+ The material has a greatly reduced composting time
+ As a building and product material, it can handle heat up to 200 degrees Fahrenheit
+ Bagasse can serve as an alternative to everything from paper to plastic to fuel
+ Plant-based building materials offer the potential to create structures that can draw carbon dioxide out of the atmosphere
– Bagasse factories can be harsh working environments—workers have reported bleeding hands and arms and even serious conditions such as pulmonary fibrosis
– Materials such polylactic acid, made from bagasse, can’t be 100% controlled, which makes their use problematic for certain building materials
– Prices for bagasse are rising because it also is now used as a biomass fuel—you’ll pay more for a metric ton of bagasse than you would for a metric ton of stainless steel
Bagasse, the fibrous substance that remains after juice has been extracted from sugarcane stalks, has long been used for roofing material in traditional houses throughout the Philippines, Jamaica, and Ghana, but here in the United States, it most often has been used as a biofuel or in biodegradable plastics—until recently. Architects are now finding new ways of incorporating the material into their work, either as a building material or as art. Gernot Riether, an architect and assistant professor at the Georgia Institute of Technology, has been developing building components from environmentally friendly materials for years.
“We can, for instance, base the production of plastics on bagasse instead of fossil fuel,” Riether says. “In that way, plastic suddenly becomes an environmentally friendly material, which challenges us as architects to develop new techniques and methods to reintroduce plastic as a building material.” Others, such as the firm WallArt, are creating 3-D wall panels out of bagasse, offering a creative and unique paneling option for the green homeowner. Below, gb&d explores bagasse a little deeper, looking at its various uses, sustainable features, and a few recent projects where the sugarcane substance held the spotlight.
Because sugarcane can be harvested up to three times a year, bagasse is one of the world’s most renewable sources. “The total harvest worldwide of sugarcane is more than 1.2 billion metric tons yearly,” WallArt International sales manager Robert Kits says. “And three tons of sugarcane equals one ton of bagasse. That’s a huge number.” Bagasse also can be manufactured anywhere around the globe.
Bagasse has been used for everything from food trays to wallpaper. Because of its direct environmental superiority over paper and nonbiodegradable plastic, the substance is most often found in eco-friendly home products such as plates, cups, and bowls. Bagasse also often is used to make insulated disposable food containers to replace ones made of Styrofoam, and office-supply companies are processing the cane fiber with recycled paper fibers to make office products, including copy paper, envelopes, and card stock. The substance can also be converted into biofuel, animal feed, herbal cigarettes, building materials (e.g. pressed building board, acoustical tile, etc.), and much more.
Bagasse can be used to produce very durable building materials such as polycarbonate and
acrylic. These materials are transparent, have a low U-value, and are 20 times less brittle then glass. “If iPhones were made from high-performance plastics derived from bagasse, they certainly would not break as easily,” Riether says. “Also, curtain walls can be made from high-performance plastics that are based on bagasse instead of glass.”
Home goods such as flatware and dinnerware made from bagasse are safe to be used in the microwave and the freezer and can withstand heat up to 200 degrees Fahrenheit. The substance is equally durable as paneling. “Whenever used as the raw material for indoor wall panels, the durability of bagasse can be compared to the durability of regular wallpaper,” Kits says.
Bagasse as a raw material is not only 100 percent renewable; it is also 100 percent compostable and biodegradable. “At WallArt we say that by reusing the waste of sugarcane production instead of burning it, it becomes a real eco-friendly product,” Kits says. Bagasse is also often used as a primary fuel source in mills, including sugar mills, and when burned in high enough quantities, it produces more than enough heat energy to supply all the mill’s needs. Additionally, Riether says, “If we find ways to develop building components from plants, the production of buildings will also extract carbon dioxide from the atmosphere.”
However, not all that glitters is bagasse. The working conditions in the bagasse-producing factories can be less than prime, with some workers reporting health problems allegedly related to the process. It also won’t be the new wonder material any time soon given the rising cost. Because bagasse can be used in the production of biomass fuel, the price is increasing with demand for alternative fuel.
A recent project that showcased bagasse’s potential was the AIA pavilion in New Orleans, designed by Riether. “In the AIA pavilion … we developed a modular hybrid system from polyethylene [PETG], a material that can be produced from bagasse,” Riether says. “The pavilion’s geometry was developed to allow the combining of structure and envelope in a single material system.” He and his Digital Design Build Studio at Georgia Tech used PETG structurally. The edges of each cell were folded differently based on each individual cell’s location within the overall structure; this provided a fair amount of stiffness within each cell. “We connected all cells to form a complex geodesic system,” Riether says. To minimize the amount of material and to create a lightweight structure, he increased the complexity of the envelope’s geometry by generating wormholes. This increased the surface tension and stabilized the pavilion’s structure.