LITMIR.BIZ

Figure 4.8 Glycerol dehydration in the presence of acidic catalyst [55].

      Very few studies have been reported on the carbon-based catalyst for glycerol dehydration. Lili et al. have utilized activated carbon-supported silicotungstic acid catalyst for the glycerol dehydration into acrolein. Activated carbon was selected as support due to its high surface area, superior stability over a wide pH range, and strong interaction with acidic silicotungstic material. The activity of the catalyst depends upon the loading of silicotungstic acid, its dispersion, and the relative amount of acidic sites. The catalyst with 10% loading showed the highest activity and selectivity [56].

       4.4.2.7 Cyclization

      N-heterocyclic carbene–silica nanoparticles have been used for glycerol cyclization into cyclic acetals. The catalyst was prepared by immobilization of 1-Butylimidazole onto rice husk ash by 3-chloropropyltriethoxysilane (CPTES). The chlorine of the catalyst was replaced by the phosphate and sulfate group, and the resulting catalysts were named RHABIm-H₂PO₄ and RHABIm-HSO₄ respectively. The RHABIm-H₂PO₄ catalyst show superior catalytic efficiency and selectivity as compared to RHABIm-HSO₄ owing to the presence of extra free acidic proton. The cyclization reaction followed a pseudo-first-order rate low [57].

Conclusion

      The utilization of glycerol to valuable products has attracted the attention of researchers because glycerol is produced in large quantities as waste during biodiesel production. The effective utilization of this waste will be an important factor that can reduce the cost of biodiesel and promote its commercialization. Since glycerol is a biomass-derived chemical feedstock, research efforts are being made globally for its transformation into marketable chemicals which can be employed as substitutes for chemicals derived from fossil resources. A catalytic route is an efficient approach for its transformation into valuable chemicals.

This chapter explained many catalytic processes for the conversion of glycerol into useful chemicals using carbon-based materials as a catalyst. Carbon-based catalysts have shown the potential to exhibit high glycerol conversions with quite a good selectivity. However, only a small number of studies have been conducted using carbon-based catalysts, and reaction conditions have not yet been completely optimized. A very high selectivity towards the desired product is still difficult because of the multifunctional structure of glycerol with the presence of hydroxyl groups of the same reactivity. Therefore, excellent opportunities are available to find new highly active carbon catalysts with high surface area, functional properties, desirable acidic or basic sites, and high hydrothermal stability for the transformation of glycerol to valuable products.

References

      1. Zhao, G., Huang, X., Wang, X., Wang, X., Progress in catalyst exploration for heterogeneous CO₂ reduction and utilization: A critical review. J. Mater. Chem. A, 5, 21625–21649, 2017.

      2. U.S. Energy Information Administration, EIA projects 48% increase in world energy consumption by 2040, U.S. Energy Information Administration Data available on US Govt. site. (accessed December 2020).

      3. Hammond, C., Lopez-Sanchez, J.A., Rahim, M.H.A., Dimitratos, N., Jenkins, R.L., Carley, A.F., He, Q., Kiely, C.J., Knight, D.W., Hutchings, G.J., Synthesis of glycerol carbonate from glycerol and urea with gold-based catalysts. Dalton Trans., 40, 3927, 2011.

      4. Mishra, V.K. and Goswami, R., A review of production, properties and advantages of biodiesel. Biofuels, 9, 273–289, 2018.

      5. Suresh, M., Jawahar, C.P., Richard, A., A review on biodiesel production, combustion, performance, and emission characteristics of non-edible oils in variable compression ratio diesel engine using biodiesel and its blends. Renew. Sust. Energ. Rev., 92, 38–49, 2018.

      6. Veluturla, S., Archna, N., Rao, D.S., Hezil, N., Indraja, I.S., Spoorthi, S., Catalytic valorization of raw glycerol derived from biodiesel: A review. Biofuels, 9, 305–314, 2018.

      7. He, Q., McNutt, J., Yang, J., Utilization of the residual glycerol from biodiesel production for renewable energy generation. Renew. Sust. Energy Rev., 71, 63–76, 2017.

      8. Lin, Y.C., Catalytic valorization of glycerol to hydrogen and syngas. Int. J. Hydrogen Energy, 38, 2678–2700, 2013.

      9. Zhou, C.-H., Beltramini, J.N., Fan, Y.-X., Lu, G.Q., Chemoselective catalytic conversion of glycerol as a biorenewable source to valuable commodity chemicals. Chem. Soc. Rev., 37, 527–549, 2008.

      10. Global biodiesel production by country, 2019 https://www.statista.com/statistics/271472/bio-diesel-production-in-selected-countries (accessed December 2020).

      11. Len, C. and Luque, R., Continuous flow transformations of glycerol to valuable products: An overview. Sust. Chem. Process., 2, 1–10, 2014.

      12. Kaur, J., Sarma, A.K., Jha, M.K., Gera, P., Valorisation of crude glycerol to value-added products: Perspectives of process technology, economics and environmental issues. Biotechnol. Rep., 27, e00487, 2020.

      13. Veluturla, S., Archna, N., Rao, D.S., Hezil, N., Indraja, I.S., Spoorthi, S., Catalytic valorization of raw glycerol derived from biodiesel: A review. Biofuels, 9, 305–314, 2018.

      14. Checa, M., Delgado, S.N., Montes, V., Encinar, J.M., Recent advances in glycerol catalytic valorization: A review. Catalysts, 10, 1, 2020.

15. Kongjao, S., Damronglerd, S., Hunsom, M., Purification of crude glycerol derived from waste used-oil methyl ester plant. Korean J. Chem. Eng., 27, 944–949, 2010.

      16. Ardi, M.S., Aroua, M.K., Hashim, N.A., Progress, prospect and challenges in glycerol purification process: A review. Renew. Sust. Energy Rev., 42, 1164–1173, 2015.

      17. Isahak, W.N.R.W., Ismail, M., Yarmo, M.A., Jahim, J.M., Salimon, J., Purification of crude glycerol from transesterification RBD palm oil over homogeneous and heterogeneous catalysts for the biolubricant preparation. J. Appl. Sci., 10, 2590–2595, 2010.

      18. Manosak, R., Limpattayanate, S., Hunsom, M., Sequential-refining of crude glycerol derived from waste used-oil methyl ester plant via a combined process of chemical and adsorption. Fuel Process. Technol., 92, 92–99, 2011.

      19. Johnson, D.T. and Taconi, K.A., The glycerin glut: Options for the value-added conversion of crude glycerol resulting from biodiesel production. Environ. Prog., 26, 338–348, 2007.

      20. Kang, S., Ye, J., Chang, J., Recent advances in carbon-based sulfonated catalyst: Preparation and application. Int. Rev. Chem. Eng., 5, 133–144, 2013.

      21. Bagheri, S., Julkapli, N.M., Yehye, W.A., Catalytic conversion of biodiesel

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