of biomacromolecules into known and new products. The designed systems must be robust and be easily recoverable for the next catalytic cycle. On the other hand, there remain technological difficulties. New technologies based on native substrates should optimally employ the whole biomass, not individual or refined components. Although this task may be partially solved by catalytic fractionation in lignocellulose refineries, as discussed in the chapter, the use of algal biomass remains less investigated. The separation and recovery of all valuable products in a given biomass, such as lipids, pigments, and proteins, necessarily enhances the value and sustainability of the approach and represents a significant opportunity to maximize value, but this approach embodies significant engineering, technological, and commercial barriers. For the foreseeable future, biorefineries are likely to focus on predictable and (essentially) uniform feedstocks with scale, such as lignocellulose or, possibly, algal biomass.
References
1 1. Corma, A., Iborra, S., and Velty, A. (2007). Chemical routes for the transformation of biomass into chemicals. Chemical Reviews 107 (6): 2411–2502.
2 2. Gallezot, P. (2012). Conversion of biomass to selected chemical products. Chemical Society Reviews 41 (4): 1538–1558.
3 3. Dusselier, M., Mascal, M., and Sels, B.F. (2014). Top chemical opportunities from carbohydrate biomass: a chemist's view of the biorefinery. In: Selective Catalysis for Renewable Feedstocks and Chemicals (ed. K.M. Nicholas), 1–40. Cham: Springer.
4 4. Bodachivskyi, I., Kuzhiumparambil, U., and Williams, D.B.G. (2018). Acid‐catalyzed conversion of carbohydrates into value‐added small molecules in aqueous media and ionic liquids. ChemSusChem 11 (4): 642–660.
5 5. Han, X., Guo, Y., Liu, X. et al. (2019). Catalytic conversion of lignocellulosic biomass into hydrocarbons: a mini review. Catalysis Today 319: 2–13.
6 6. Negahdar, L., Delidovich, I., and Palkovits, R. (2016). Aqueous‐phase hydrolysis of cellulose and hemicelluloses over molecular acidic catalysts: insights into the kinetics and reaction mechanism. Applied Catalysis B: Environmental 184: 285–298.
7 7. Bodachivskyi, I., Kuzhiumparambil, U., and Williams, D.B.G. (2019). A systematic study of metal triflates in catalytic transformations of glucose in water and methanol: identifying the interplay of Brønsted and Lewis acidity. ChemSusChem 12 (14): 3263–3270.
8 8. Galkin, M.V. and Samec, J.S. (2016). Lignin valorization through catalytic lignocellulose fractionation: a fundamental platform for the future biorefinery. ChemSusChem 9 (13): 1544–1558.
9 9. Agarwal, A., Rana, M., and Park, J.H. (2018). Advancement in technologies for the depolymerization of lignin. Fuel Processing Technology 181: 115–132.
10 10. Corma, A., Hamid, S.B., Iborra, S., and Velty, A. (2008). Surfactants from biomass: a two‐step cascade reaction for the synthesis of sorbitol fatty acid esters using solid acid catalysts. ChemSusChem 1 (1–2): 85–90.
11 11. Cermak, S.C., Isbell, T.A., Bredsguard, J.W., and Thompson, T.D. (2017). Estolides: synthesis and applications. In: Fatty Acids (ed. M.U. Ahmad), 431–475. London: AOCS Press.
12 12. Jamil, M.A., Siddiki, S.H., Touchy, A.S. et al. (2019). Selective transformations of triglycerides into fatty amines, amides, and nitriles by using heterogeneous catalysis. ChemSusChem 12 (13): 3115–3125.
13 13. De Schouwer, F., Claes, L., Vandekerkhove, A. et al. (2019). Protein‐rich biomass waste as a resource for future biorefineries: state of the art, challenges, and opportunities. ChemSusChem 12 (7): 1272–1303.
14 14. Hagen, J. (2015). Industrial Catalysis: A Practical Approach, 3e. Weinheim: Wiley‐VCH.
15 15. Loque, D., Scheller, H.V., and Pauly, M. (2015). Engineering of plant cell walls for enhanced biofuel production. Current Opinion in Plant Biology 25: 151–161.
16 16. Heinze, T., El Seoud, O.A., and Koschella, A. (2018). Production and characteristics of cellulose from different sources. In: Cellulose Derivatives (eds. T. Heinze, O.A. El Seoud and A. Koschella), 1–38. Cham: Springer.
17 17. Adhikari, S. and Ozarska, B. (2018). Minimizing environmental impacts of timber products through the production process “From Sawmill to Final Products”. Environmental Systems Research 7 (1): 6.
18 18. Cornils, B., Herrmann, W.A., and Zanthoff, H.W. (eds.) (2013). Catalysis from A to Z. New York: Wiley‐VCH.
19 19. Lowry, T.H. and Richardson, K.S. (1987). Mechanism and Theory in Organic Chemistry. New York: Harper & Row.
20 20. Yamamoto, H. and Futatsugi, K. (2005). “Designer acids”: combined acid catalysis for asymmetric synthesis. Angewandte Chemie International Edition 44 (13): 1924–1942.
21 21. Williams, D.B.G. and Lawton, M. (2010). Metal triflates: on the question of Lewis versus Brønsted acidity in retinyl carbocation formation. Journal of Molecular Catalysis A: Chemical 317 (1–2): 68–71.
22 22. Olah, G.A., Prakash, G.S., Sommer, J., and Molnar, A. (2009). Superacid Chemistry. Hoboken: Wiley.
23 23. Onwukamike, K.N., Grelier, S., Grau, E. et al. (2019). Critical review on sustainable homogeneous cellulose modification: why renewability is not enough. ACS Sustainable Chemistry & Engineering 7 (2): 1826–1840.
24 24. Melero, J.A., Iglesias, J., and Garcia, A. (2012). Biomass as renewable feedstock in standard refinery units. Feasibility, opportunities and challenges. Energy & Environmental Science 5: 7393–7420.
25 25. Holkar, C.R., Jain, S.S., Jadhav, A.J., and Pinjari, D.V. (2018). Valorization of keratin based waste. Process Safety and Environmental Protection 115: 85–98.
26 26. Sivasamy, A., Cheah, K.Y., Fornasiero, P. et al. (2009). Catalytic applications in the production of biodiesel from vegetable oils. ChemSusChem 2 (4): 278–300.
27 27. Yaakob, Z., Mohammad, M., Alherbawi, M. et al. (2013). Overview of the production of biodiesel from waste cooking oil. Renewable and Sustainable Energy Reviews 18: 184–193.
28 28. Hess, S.K., Schunck, N.S., Goldbach, V. et al. (2017). Valorization of unconventional lipids from microalgae or tall oil via a selective dual catalysis one‐pot approach. Journal of the American Chemical Society 139 (38): 13487–13491.
29 29. Mlynarski, J. and Gut, B. (2012). Organocatalytic synthesis of carbohydrates. Chemical Society Reviews 41: 587–596.
30 30. Brethauer, S. and Wyman, C.E. (2010). Continuous hydrolysis and fermentation for cellulosic ethanol production. Bioresource Technology 101 (13): 4862–4874.
31 31. Meng, X., Pu, Y., Yoo, C.G. et al. (2017). An in‐depth understanding of biomass recalcitrance using natural poplar variants as the feedstock. ChemSusChem 10 (1): 139–150.
32 32. Renders, T., Van den Bosch, S., Koelewijn, S.F. et al. (2017). Lignin‐first biomass fractionation: the advent of active stabilisation strategies. Energy & Environmental Science 10: 1551–1557.
33 33. Van den Bosch, S., Schutyser, W., Vanholme, R. et al. (2015). Reductive lignocellulose fractionation into soluble lignin‐derived phenolic monomers and dimers and processable carbohydrate pulps. Energy & Environmental Science 8: 1748–1763.
34 34. Binder, J.B. and Raines, R.T. (2010). Fermentable sugars by chemical hydrolysis of biomass. Proceedings of the National Academy of Sciences of the United States of America
