Biochar composites for sustainable thermal packaging applications

Biochar materials are derived from pyrolysis of organic biomass, often for the purpose of producing soil amendments. However, there is also significant potential for utilizing biochar in developing sustainable insulation materials, because it is known that certain types of biochar combined with biomass-based substrates can generate composites with high porosity and low thermal conductivity. In this study, we have explored combinations of biochar materials with a sustainable bio-based binder as a potential alternative to expanded polystyrene (EPS) for temperature sensitive products that require cold-chain packaging (i.e., medical products, vaccines, fresh meats). EPS is known to have negative environmental impacts and few options exist for re-use or recycling, and thus there is a market need for new materials that reduce greenhouse gas (GHG) emissions and other impacts while simplifying end-of-life handling. Our research has focused on understanding the impacts of different types of biochar, produced using various feedstocks over a range of temperatures, on key properties of composite insulation panels, including density, compressive strength, thermal conductivity and R-value. We have identified several combinations of biochar and organic binder that provide performance comparable to EPS, and in one case achieved about a 10% lower thermal conductivity than that measured for EPS, in close agreement with values reported in literature (0.036 W/mK). Through application of in-house characterization methods including scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), we have identified structural properties of the biochar-binder matrix that enhance thermal insulation properties.

Keywords: insulationthermal conductivityR-valueexpanded polystyrenecold-chain packaging

Madan Manipati - Rochester Institute of Technology, Rochester, NY, United States
Carlos Diaz - Rochester Institute of Technology, Rochester, NY, United States
Kathleen Draper - Cinterest LLC, East Rochester, NY, United States
Thomas Trabold - Cinterest LLC, East Rochester, NY, United States