Mathematical Modelling and Simulation of Hydrotropic Delignification

Indah Hartati(1*), Wahyudi Budi Sediawan(2), Hary Sulistyo(3), Muhammad Mufti Azis(4), Moh Fahrurrozi(5)

(1) Department of Chemical Engineering, Faculty of Engineering, Universitas Wahid Hasyim Jl. Menorah Tengah X No 22, 50236 Semarang
(2) Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada Jl Grafika No. 2 Kampus UGM, 55281 Yogyakarta
(3) Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada Jl Grafika No. 2 Kampus UGM, 55281 Yogyakarta
(4) Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada Jl Grafika No. 2 Kampus UGM, 55281 Yogyakarta
(5) Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada Jl Grafika No. 2 Kampus UGM, 55281 Yogyakarta
(*) Corresponding Author



Delignification is a fundamental step in bio-refinery for lignocellulose feedstock processing. Hydrotropic delignification is considered as a promising alternative compared to other conventional delignification processes due to the use of mild chemicals. In this paper, a quantitative description of hydrotropic delignification for a cylindrical biomass particle is presented by using fundamental concepts of chemical kinetics and transport processes. The development of hydrotropic delignification model was based on following assumptions: i) lignin in the biomass is immobile, ii) delignification is considered as a simultaneous process which involves intra-particle diffusion of hydrotropic agent followed by second order reaction for lignin and hydrotropic chemical, as well as intra-particle product diffusion. Finite difference approximation was applied to solve the resulting partial and ordinary differential equations. The simulation results of the proposed model may describe the concentration profiles of lignin, hydrotropic agent and soluble product distributions in a cylindrical solid particle as a function of radial position and time. In addition, the model could also predict the concentration of hydrotropic agent and soluble product in the liquid phase as well as the yield and conversion as a function of time. A local sensitivity analysis method using one factor at a time (OFAT), has been applied to investigate the influence of particle size and hydrotropic agent concentration to the yield and conversion of the hydrotropic delignification model. Validation of the proposed model was conducted by comparing the numerical results with an analytical solution for a simple case diffusion in cylinder with constant surface concentration and in the absence of chemical reaction. The validation result showed that the hydrotropic delignification model was in good agreement with the analytical solution.

Keywords: cylindrical particle; delignification; hydrotropic; modelling; simulation



Delignifikasi merupakan tahap penting dalam proses biorefineri biomassa berlignoselulosa. Delignifikasi hidrotropi adalah salah satu alternative proses yang memiliki beberapa kelebihan dibandingkan proses-proses delignifikasi konvensional karena tidak menggunakan bahan kimia berbahaya. Dalam artikel ini disajikan deskripsi kuantitatif proses delignifikasi hidrotropi untuk partikel berbentuk silinder dengan menggunakan konsep fundamental kinetika reaksi dan proses-proses perpindahan. Penyusunan model proses delignifikasi hidrotropi dilakukan berdasarkan asumsi-asumsi bahwa i) lignin pada biomassa bersifat immobile, ii) proses delignifikasi dipandang sebagai suatu rangkaian proses simultan yang terdiri atas proses difusi intrapartikel senyawa hidrotrop, reaksi order dua terhadap lignin dan senyawa hidrotrop, serta difusi intrapartikel produk delignifikasi. Finite difference approximation (FDA) digunakan untuk menyelesaikan persamaan simultan berbentuk persamaan diferensial ordiner dan persamaan diferensial parsial dalam tahap pemodelan. Hasil simulasi memberikan gambaran profil distribusi konsentrasi lignin, konsentrasi senyawa hidrotrop dan produk delignifikasi di dalam partikel padatan yang berbentuk silinder sebagai fungsi posisi dan waktu. Model yang dikembangkan juga dapat memprediksi konsentrasi senyawa hidrotropik dan produk di fasa cairan, serta yield dan konversi sebagai fungsi waktu.  Metode analisis sensitivitas lokal, yakni metode one factor at a time (OFAT), digunakan untuk mengkaji pengaruh ukuran partikel dan konsentrasi senyawa hidrotropik terhadap yield dan konversi proses delignifikasi. Validasi model yang diajukan dilakukan dengan membandingkan hasil analisa numerik dengan hasil penyelesaian analitis untuk kasus difusi pada silinder dengan konsentrasi permukaan yang konstan serta tidak melibatkan reaksi kimia. Hasil validasi model menunjukkan bahwa model delignifikasi hidrotropi yang diajukan memiliki kesesuaian yang tinggi dengan hasil penyelesaian analitis.

Kata kunci: delignifikasi; hidrotropi; pemodelan; silinder; simulasi


cylindrical particle; delignification; hydrotropic; modelling; simulation

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Ansari, K.B., and Gaikar, V.G., 2014, Green hydrotropic extraction technology for delignification of sugarcane bagasse by using alkybenzene sulfonates as hydrotropes, Chem. Eng. Sci., 115, 157–166.

Chen, L., Dou, J., Ma, Q., Li, N., Wu, R., Bian, H., Yelle, DJ., Vuorinen, T., Fu S., Pan, X., and Zhu, J., 2017, Rapid and near complete dissolution of wood lignin at 80 °C by a recyclable acid hydrotrop, Applied Sciences and Engineering, 3 (9), 1-11.

Cherubini, F., Jungmeier, G., Wellisch, M., Willke, T., Skiadas, I., Van Ree, R., and de Jong, E., 2009, Toward a common classification approach for biorefinery systems, Biofuels Bioprod. Bioref., 3, 534–546.

Charzyzka, A., Nałęcz, A., Rybinski, M., and Gambin, A., 2012, Sensitivity analysis of mathematical models of signaling pathways, Journal of Biotechnology, Computational Biology and Bionanotechnology, 93 (3), 291-308.

Chimenez, T. A., Gehlen, M. H., Marabezi, K., and Curvelo, A. A. S., 2013, Characterization of sugarcane bagasse by autofluorescence microscopy, Cellulose, 21 (1), 653–664.

Crank J., 1975, The Mathematics of Diffusion, Clarendon Press, Oxford, UK, pp. 69-73.

Dang, V. Q., and Nguyen, K.L., 2007, A universal kinetic equation for characterizing the fractal nature of delignification of lignocellulosic materials, Cellulose, 14, 153 –160.

Devendra, L.P., and Pandey, A., 2016, Hydrotropic pretreatment on rice straw for bioethanol production, Renewable Energy, 98, 2-8.

De Bhowmick, G., Sarmah, A.K., and Sen, R., 2017, Lignocellulosic biorefinery as a model for sustainable development of biofuels and value-added products, Bioresour. Technol., 247, 1144-1154.

Dhapte, V., and Mehta, P., 2016, Advances in hydrotropic solutions: An updated review, St. Petersburg Polytechnical University Journal: Physics and Mathematics, 1, 424–435.

Gabov, K., Fadim, P., and Da Silva Junior, F.G., 2013, Hydrotropic fractionation of birch wood into cellulose and lignin: a new step towards green biorefinery, Bioresources, 8 (3), 3518-3531.

Gabov, K., 2018, Hydrotropic process for green biorefinery applications, Ph.D. Thesis, Abo Akademi University, p. 58.

Grenmann, H., Warna, J., Mikkola, J.P., Sifontes, V., Fardim, P., Murzin, D.Y., and Salmi, T., 2010, Modeling the influence of wood anisotropy and internal diffusion on delignification kinetics, Ind. Eng. Chem. Res, 49, 9703–9711.

Hassan, S.S., Williams, G.A., and Jaiswal, A.K., 2018, Emerging technologies for the pretreatment of lignocellulosic biomass, Bioresour. Technol., 262, 310-318

Hodgdon, T.K., and Kaler, E.W., 2007, Hydrotropic solutions, Curr. Opin. Colloid Interface Sci., 12, 121–128.

Kunz, W., Holmberg, K., and Zemb, T., 2016, Hydrotropes, Curr. Opin. Colloid Interface Sci., 22, 99-107.

Li, M., Pu, Y., and Ragauskas, A.J., 2016, Current understanding of the correlation of lignin structure with biomass recalcitrance, Front. Chem. 4(45), 1-8.

Mou, H., Fardim, P., and Wu, S., 2016, A novel green biomass fractionation technology: Hydrotropic pretreatment, in Musatto, S.I., (Ed), Biomass Fractionation Technologies for a Lignocellulosic Feedstock Based Biorefinery, Elsevier., Cambridge, pp. 281-311.

Özdenkçi, K., De Blasio, C., Muddassar, H. R., Melin, K., Oinas, P., Koskinen, J., Sarwar, G., and Järvinen, M., 2017, Novel biorefinery integration concept for lignocellulosic biomass, Energy Convers. Manage., 149, 974–987.

Pande, H., and Roy, D.H., 2006, Delignification kinetics of soda pulping of kenaf, J. Wood Chem. Technol., 16 (3), 311-325.

Ranjbar, S., and Gaemi, A., 2014, Mathematical modeling for volatile organic compounds removal in a biofilter: model validation and sensitivity analysis, Iran. J. Chem. Eng., 10 (3), 76-87.  

Zhao, X., Wu, R., and Liu, D., 2018, Evaluation of the mass transfer effects on delignification kinetics of atmospheric acetic acid fractionation of sugarcane bagasse with a shrinking layer model, Bioresour. Technol., 261, 52–61.


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