The agricultural and forest industries both produce residues or waste streams that have little or no economic value. The challenge that remains for agricultural and forestry residues is how to best utilize this material for maximum efficiency and economic profit. While at LSU, Dr. Todd Shupe received $250,000 from the USDA to examine the suitability of a rapidly-developing new technology known as continuous microwave-assisted liquefaction to convert this under-utilized material to bio-polyols for the production of spray-foam insulation. Liquefaction is a process that can be used to dissolve biomass in an organic solvent (also called a reagent solvent) at moderate temperatures (120 to 250 ºC) with or without acid catalysts (Hse et al. 2011; Pan 2007; Pan et al. 2012). Liquefied biomass can be concentrated and used as a raw material for other value-added products such as polyurethane foam, epoxy resin or phenolic resin depending on the reagent solvent used in the liquefaction (Pan 2007). “Our application of microwave technology to the liquefaction process has received a U.S. patent (#8,043,399) and has been shown to dramatically improve the liquefaction rate, shorten the reaction time, lower operational temperature, and use less chemical input as compared to traditional liquefaction reactions,” Todd Shupe says, (Hse et al. 2011).
Spray-foam insulation is growing in popularity as a type of insulation for residential and commercial housing. Spray-foam is a substitute for traditional fiberglass insulation. The chemical agent is stored in canisters and sprayed with a special application device; it then expands and dries, forming a barrier. The advantage of foam insulation is that it expands and leaves no gaps as is the case with typical fiberglass insulation. Therefore, there are no pathways for air to escape – thus an efficient vapor barrier is established. The foam also prevents the buildup of moisture, lowering the incidence of mildew and mold problems, and makes it more difficult for insects and other pests to burrow into a building. Says Todd Shupe, “Spray-foam insulation is recognized as an important part of the wall component in ‘green’ buildings, and also is one of the fastest growing areas in building products.” These advantages and the “green” aspect of foam insulation can be rolled into one with the development of spray-foam insulation from liquefied biomass to attain a new renewable and sustainable product.
The higher cost of spray-foam insulation has slowed its advancement in the residential housing market. The low cost of the feedstock and the proposed experimental parameters for this study should help this product gain market share. The development of “green” spray-foam insulation from liquefied biomass will promote economic development and diversification. In addition to substantial energy cost savings, biomass-based spray-foam has much better biodegradability compared to petro-based foam insulation, which will benefit the environment if this material is landfilled. Dow, Oak Ridge National Laboratory (ORNL), and design-build firm, Paramount Metal Systems, have converted a 50-year-old building at ORNL into a state-of-the art, energy-efficient research facility. Initial test results show a 75 percent reduction in heat flow, resulting in a projected 75-80 percent monthly savings in energy costs (Spray Foam 2013).