Valorisation of technical lignin in rigid polyurethane foam: a critical evaluation on trends, guidelines and future perspectives

Abstract

Lignin is one of the most abundant natural polymers. Produced as a by-product from the biomass refinery industries, lignin remains largely underutilised in high-value industrial applications. The incorporation of lignin...

Hydrothermal Treatment of Biomass Feedstocks for Sustainable Production of Chemicals, Fuels, and Materials: Progress and Perspectives

“…Model compounds represent the main components of biomass feedstocks, which play a key role in hydrothermal transformation of biomass to chemicals, fuels, and materials. ,,, In comparison to raw biomass feedstocks, model compounds are usually extracted and purified with a homogeneous structure, making it feasible to individually observe the hydrothermal transformation with a mechanistic insight. ,,, Additionally, the yield and quality of products derived from model compounds is higher than those of raw biomass. ,,, Thus, the pioneering research studies ,,,,,,− on hydrothermal transformation of model compounds to high-quality products promote the development of biobased production to substitute the fossil fuel-based production. Nowadays, model compounds used in research laboratory and industries are usually commercially available. − There are numerous studies conducted on hydrothermal transformation of model compounds in lab or commercial scales. − This section involves the typical model compounds of lignocellulosic biomass (i.e., cellulose, hemicellulose, and lignin) and nonlignocellulosic biomass (e.g., saccharide, chitin, chitosan, lipids, protein, and amino acids). The products (i.e., biochemicals, biofuels, and biomaterials) involved in the hydrothermal transformation of bomass are summarized in Table .…”

A Review of Rigid Polymeric Cellular Foams and Their Greener Tannin-Based Alternatives

“…Thus, the polymer network gains flexibility and exhibits a more elastic behavior. Conversely, the rigidity of the foam can be enhanced by supplementing the formulation with a filler such as hexamine [ 235 , 247 ], or recent more environmentally friendly alternatives, such as biochar [ 248 , 249 ] or lignin [ 250 ]. The addition of isocyanates to create urethane bridges can also be carried out to serve this purpose [ 180 , 220 , 251 ].…”

Mystifications and misconceptions of lignin: revisiting understandings

“…The conservative definition supported by many lignin chemists takes the technical lignin as a byproduct of the pulping industry. [19][20][21][22][23] Nevertheless, it is not rare for technical lignin to generically be defined as a derivative product from a delignification process, 14,24 leading to interpretations of any isolation procedure. For example, the isolated material may be obtained on the laboratory scale, which does not correspond to industrial conditions and thus cannot be characterised as technical.…”