Tannin: a new insight into a key product for the bioeconomy in forest regions

Abstract

Produced by extraction from certain woods and barks with boiling water, tannin is the name given to a mixture of high molecular weight biophenols increasingly used in a number of industries. This study offers a new bioeconomy insight into an old natural product that, we argue in this study, will likely play a crucial role in the development of the bioeconomy of forest regions. After providing an updated picture of selected key economic and production aspects, we show how flourishing research on tannin's biological activity and technological applications has revealed many new properties that are likely to drive significant growth in demand in the near and mid‐term future. The study concludes with two lessons learned and one forecast that will hopefully accelerate progress in the bioeconomy of forest areas based on the circular economy of tannin enabled by new extraction and purification technologies. © 2021 Society of Industrial Chemistry and John Wiley & Sons Ltd.

Bark extractives as sources of carbon-efficient functional precursors and materials

“…A number of agricultural residues are important sources as well (e.g., tea, coffee grounds, persimmon hulls, grape skins, walnut shells, etc.). 121,122 The annual global production is around 200-300 kt, with condensed polyphenols heavily dominating the market (>90%). 120,[123][124][125] However, the potential production capacity is estimated to be in the 1 to 1.5 Mt range.…”

“…For detailed reviews on advanced extraction techniques, the reader is referred to the recent literature. 122,[125][126][127] Finally, saponins are a family of glycosides that naturally occur in a range of plants such as soapwort (Saponaria officinalis), soap bark tree (Quillaja Saponaria), horse-chestnut (Aesculus spp. ), maple trees (Acer spp.…”

Latest Advancements in the Development of High-Performance Lignin- and Tannin-Based Non-Isocyanate Polyurethane Adhesive for Wood Composites

“…Tannins can be classified into two categories: hydrolysable tannins, which include gallotannins and ellagitannins, and condensed molecules known as polyflavonoid tannins, with global tannin production reaching 1.1 million tonnes in 2017 [75]. Hydrolysable tannins refer to derivatives of gallic acid that are classified according to the outcomes of their hydrolysis, as depicted in Figure 4 [76].…”

“…The composition of the bio-PU created during the production process is determined using the 13 C-NMR technique [70,72,73,75]. The 13 C-NMR spectra of tannin-based NIPU exhibited relatively small tannin peaks.…”

Educating the managers of the bioeconomy

“…Tannin is the name given to a mixture of high molecular weight biophenols extracted from certain woods and bark and increasingly used for widely different applications, including as an environmentally friendly agrochemical. 28 Due to an expensive and energy-demanding production process, the current annual production of commercial tannins amounts to about 230,000 tonnes. Tannin, however, has a high-value chemical application as a building block in the preparation of adhesives and resins.…”