Lightweight cellulosic insulation panels made from oil palm trunk fibers

Biobased thermal insulation is of relevance as a sustainable substitute for current fossil-based materials. In this regard, oil palm trunk (OPT), which arises in substantial quantities as a by-product of the palm oil industry, is a suitable raw material due to its relatively high content in cellulosic fibers and low cost. The present study focuses on the inner part of OPT, which is light and low in mechanical performance and therefore lacks suitable applications other than fuel wood. OPT was grinded, chemically pre-treated to reduce the content of non-cellulosic constituents and fibrillated. With the partial aid of additives, the fiber suspensions where then mechanically foamed and dried. The light-weight panels produced by this method showed low densities of roughly 50 – 100 kg m −3 and thermal conductivity of 40 – 45 mW m −1 K −1 . With these values, OPT foam panels are well within reach of current non-bio-based insulation materials and perform equally well or even better than other bio-based thermal insulation materials. • Oil palm trunk is a suitable raw material due to its high content in cellulosic fibers, low cost, and substantial quantities. • The light, low-strength inner part of oil palm trunk is promising for bio-based thermal insulation. • Foaming produced an open-porous, low-density material with thermal conductivity comparable to non-bio-based materials. • The compressive performance of oil palm foam panels compares well with wood fiber, jute, flax, and hemp insulation materials. • The foam insulation materials' vapor sorption is unaffected by the addition of gluten.