The generation of functional materials from biomass waste streams represents an attractive and important topic in the context of developing future biorefineries. This chapter briefly summarizes our recent research on microwave-assisted low-temperature (<200 °C) pyrolysis of three biorenewable waste streams (i.e., spruce wood chips, waste office paper and DIR) for the generation of bio-oil, bio-char (microwave residue) and gas. The potential application of crude organic phase bio-oils as adhesives towards metal bonding was investigated. Furthermore, a model compound study using 5-(hydroxymethyl)-2-furaldehyde (HMF), catechol and levoglucosan was conducted to get further understanding of the adhesion properties of bio-oil towards aluminium bonding. We anticipate that these preliminary results will potentially lead to applications and provide new ideas for generating adhesives from currently underutilized biomass waste streams.