PERTANIKA JOURNAL OF SCIENCE AND TECHNOLOGY

 

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Home / Regular Issue / JST Vol. 31 (6) Oct. 2023 / JST-4076-2022

 

Novel Pre-treatment for Lignocellulosic Biomass Delignification Using Alkaline-Assisted Ohmic Heating

Izzah Farhana Ab Aziz, Hasfalina Che Man, Muhammad Hazwan Hamzah, Nur Syakina Jamali and Rozita Omar

Pertanika Journal of Science & Technology, Volume 31, Issue 6, October 2023

DOI: https://doi.org/10.47836/pjst.31.6.22

Keywords: Biogas, empty fruit bunch (EFB), lignocellulosic, ohmic heating, pre-treatment, recalcitrant

Published on: 12 October 2023

Lignocellulosic biomass (LCB) is a common substrate for biogas and bioethanol production due to its significant properties and abundance. However, it has a unique recalcitrant structure that can inhibit the production of biogas, which necessitates pre-treatment of the substrate to obtain higher cellulose or sugars ready for microbial hydrolysis in producing biogas. In this study, a novel approach for empty fruit bunch (EFB) pre-treatment has been made: ohmic heating pre-treatment. This method is conventionally used in the food industry for pasteurization and extraction. It involves electric current and resistance inside the material that releases heat (Joule effect). A preliminary study has been done to figure out the potential of alkaline assisted with ohmic heating (AA-OH) pre-treatment for EFB. Lignin reduction for AA-OH EFB is higher than EFB that undergoes only size reduction (SR) pre-treatment, which are 15.54% and 11.51%, respectively. After confirming the potential of ohmic heating as one of the pre-treatment methods for EFB, three parameters were investigated (reaction time, temperature, and solvent concentration) by one factor at a time (OFAT) testing to obtain the optimum condition for AA-OH pre-treatment. The optimal condition for achieving a high reduction in lignin (86.9%) and hemicellulose (75%) while also showing a significant increase in cellulose (63.2%), which is desirable for the fermentation process, is achieved by using 4% w/v of NaOH, ohmic-heated at a temperature of 120°C for 25 minutes. To sum up, this developed ohmic heating pre-treatment technique can be applied to LCB prior to biogas or bioethanol production.

  • Akhtar, J., Teo, C. L., Lai, L. W., Hassan, N., Idris, A., & Aziz, R. A. (2015). Factors affecting delignification of oil palm empty fruit bunch by microwave-assisted dilute acid/alkali pretreatment. BioResources, 10(1), 588-596.

  • Alexander, R. A., Innasimuthu, G. M., Rajaram, S. K., Jeganathan, P. M., & Somasundarar, S. C. (2020). Process optimization of microwave-assisted alkali pretreatment for enhanced delignification of Prosopis juliflora biomass. Environmental Progress and Sustainable Energy, 39(1), Article 13289. https://doi.org/10.1002/ep.13289

  • Alkanan, Z. T., Altemimi, A. B., Al-Hilphy, A. R. S., Watson, D. G., & Pratap-Singh, A. (2021). Ohmic heating in the food industry: Developments in concepts and applications during 2013-2020. Applied Sciences, 11(6), Article 2507. https://doi.org/10.3390/app11062507

  • Alvira, P., Tomás-Pejó, E., Ballesteros, M., & Negro, M. J. (2010). Pretreatment technologies for an efficient bioethanol production process based on enzymatic hydrolysis: A review. Bioresource Technology, 101(13), 4851-4861. https://doi.org/10.1016/j.biortech.2009.11.093

  • Aurina, K., & Sari, A. (2022). Ohmic heating: A review and application in food industry. Advances in Biological Sciences Research, 19, 107-113.

  • Azelee, N. I. W., Jahim, J. M., Rabu, A., Murad, A. M. A., Bakar, F. D. A., & Illias, R. M. (2014). Efficient removal of lignin with the maintenance of hemicellulose from kenaf by two-stage pretreatment process. Carbohydrate Polymers, 99, 447-453. https://doi.org/10.1016/j.carbpol.2013.08.043

  • Baruah, J., Nath, B. K., Sharma, R., Kumar, S., Deka, R. C., Baruah, D. C., & Kalita, E. (2018). Recent trends in the pretreatment of lignocellulosic biomass for value-added products. Frontiers in Energy Research, 6, Article 141. https://doi.org/10.3389/fenrg.2018.00141

  • Behera, S., Arora, R., Nandhagopal, N., & Kumar, S. (2014). Importance of chemical pretreatment for bioconversion of lignocellulosic biomass. Renewable and Sustainable Energy Reviews, 36, 91-106. https://doi.org/10.1016/j.rser.2014.04.047

  • Bhagwan, J., Kumar, N., & Sharma, Y. (2019). Fabrication, characterization, and optimization of MnxOy nanofibers for improved supercapacitive properties. In Y. B. Pottathara, S. Thomas, N. Kalarikkal, Y. Grohens & V. Kokol (Eds.), Nanomaterials Synthesis: Design, Fabrication and Applications (pp. 451-481). Elsevier. https://doi.org/10.1016/B978-0-12-815751-0.00013-4

  • Cappato, L. P., Ferreira, M. V. S., Guimaraes, J. T., Portela, J. B., Costa, A. L. R., Freitas, M. Q., Cunha, R. L., Oliveira, C. A. F., Mercali, G. D., Marzack, L. D. F., & Cruz, A. G. (2017). Ohmic heating in dairy processing: Relevant aspects for safety and quality. Trends in Food Science and Technology, 62, 104-112. https://doi.org/10.1016/j.tifs.2017.01.010

  • Cardona, E., Llano, B., Peñuela, M., Peña, J., & Rios, L. A. (2018). Liquid-hot-water pretreatment of palm-oil residues for ethanol production: An economic approach to the selection of the processing conditions. Energy, 160, 441-451. https://doi.org/10.1016/j.energy.2018.07.045

  • Chang, S. H. (2014). An overview of empty fruit bunch from oil palm as feedstock for bio-oil production. Biomass and Bioenergy, 62, 174-181. https://doi.org/10.1016/j.biombioe.2014.01.002

  • Conde-Mejía, C., Jiménez-Gutiérrez, A., & El-Halwagi, M. (2012). A comparison of pretreatment methods for bioethanol production from lignocellulosic materials. Process Safety and Environmental Protection, 90(3), 189-202. https://doi.org/10.1016/j.psep.2011.08.004

  • Diyanilla, R., Hamidon, T. S., Suryanegara, L., & Hussin, M. H. (2020). Overview of pretreatment methods employed on oil palm biomass in producing value-added products: A review. BioResources, 15(4), 9935-9997. https://doi.org/10.15376/biores.15.4.diyanilla

  • Ezechi, E. H., & Muda, K. (2019). Overview of trends in crude palm oil production and economic impact in Malaysia. Sriwijaya Journal of Environment, 4(1), 19-26. https://doi.org/10.22135/sje.2019.4.1.19-26

  • Fatriasari, W., Anita, S. H., & Risanto, L. (2017). Microwave assisted acid pretreatment of oil palm empty fruit bunches (EFB) to enhance its fermentable sugar production. Waste and Biomass Valorization, 8(2), 379-391. https://doi.org/10.1007/s12649-016-9573-6

  • Gavahian, M., Farhoosh, R., Farahnaky, A., Javidna, K., & Shahidi, F. (2015). Ohmic-assisted hydrodistillation of essential oils from Mentha piperita. Iranian Food Science and Technology Research Journal, 11(3), 236-246.

  • Gavahian, M., Tiwari, B. K., Chu, Y. H., Ting, Y., & Farahnaky, A. (2019). Food texture as affected by ohmic heating: Mechanisms involved, recent findings, benefits, and limitations. Trends in Food Science and Technology, 86, 328-339. https://doi.org/10.1016/j.tifs.2019.02.022

  • Głazowska, S., Baldwin, L., Mravec, J., Bukh, C., Hansen, T. H., Jensen, M. M., Fangel, J. U., Willats, W. G. T., Glasius, M., Felby, C., & Schjoerring, J. K. (2018). The impact of silicon on cell wall composition and enzymatic saccharification of Brachypodium distachyon. Biotechnology for Biofuels, 11, Article 171. https://doi.org/10.1186/s13068-018-1166-0

  • Hamzah, F., Idris, A., & Sarif, M. (2020). Effect of microwave-alkali techniques on the morphology and physical changes of treated oil palm empty fruit bunches fiber. Materials Science Forum, 987, 124-128. https://doi.org/10.4028/www.scientific.net/msf.987.124

  • Hamzah, M. H., Sudin, S. S., Mutalib, T. N. A. T. A., Malek, N. F. H. A., Yusof, N., Jamaludin, H., Man, H. C., & Abidin, Z. Z. (2011). Preliminary study of ohmic heated hydro distillation for essential oil’s plant extraction Malaysia. In 2011 IEEE Student Conference on Research and Development (pp. 211-214). IEEE Publishing. https://doi.org/10.1109/SCOReD.2011.6148737

  • Hassan, N., Tan, L. W., Anwar, N. A. K., & Idris, A. (2021). Ionic solution pretreatment of oil palm empty fruit bunch to produce sugars. BioResources, 16(1), 1816-1824.

  • Hassan, S. S., Williams, G. A., & Jaiswal, A. K. (2018). Emerging technologies for the pretreatment of lignocellulosic biomass. Bioresource Technology, 262, 310-318. https://doi.org/10.1016/j.biortech.2018.04.099

  • Hoekstra, A. Y., & Wiedmann, T. O. (2014). Humanity’s unsustainable environmental footprint. Science, 344(6188), 1114-1117. https://doi.org/10.1126/science.1248365

  • Hu, F., & Ragauskas, A. (2012). Pretreatment and lignocellulosic chemistry. Bioenergy Research, 5(4), 1043-1066. https://doi.org/10.1007/s12155-012-9208-0

  • Hu, Y., Qin, H., Zhan, Z., Dun, Y., Zhou, Y., Peng, N., Ling, H., Liang, Y., & Zhao, S. (2016). Optimization of Saccharomyces boulardii production in solid-state fermentation with response surface methodology. Biotechnology & Biotechnological Equipment, 30, 173-179. https://doi.org/10.1080/13102818.2015.1086689

  • Iberahim, N. I., Jahim, J. M., Harun, S., Nor, M. T. M., & Hassan, O. (2013). Sodium hydroxide pretreatment and enzymatic hydrolysis of oil palm mesocarp fiber. International Journal of Chemical Engineering and Applications, 4(3), 101-105. https://doi.org/10.7763/ijcea.2013.v4.272

  • Indiarto, R., & Rezaharsamto, B. (2020). A review on ohmic heating and its use in food. International Journal of Scientific & Technology Research, 9(2), 485-490.

  • Irmak, S., Meryemoglu, B., Sandip, A., Subbiah, J., Mitchell, R. B., & Sarath, G. (2018). Microwave pretreatment effects on switchgrass and miscanthus solubilization in subcritical water and hydrolysate utilization for hydrogen production. Biomass and Bioenergy, 108, 48-54. https://doi.org/10.1016/J.BIOMBIOE.2017.10.039

  • Karunakaran, V., Abd-Talib, N., & Yong, T. L. K. (2020). Lignin from oil palm empty fruit bunches (EFB) under subcritical phenol conditions as a precursor for carbon fiber production. Materials Today: Proceedings, 31, 100-105. https://doi.org/10.1016/j.matpr.2020.01.252

  • Karunanithi, S. (2019). Optimization of process parameters of ohmic heating for improving yield and quality of tomato seed oil. International Journal of Pure & Applied Bioscience, 7(3), 104-114. https://doi.org/10.18782/2320-7051.7477

  • Khalil, H. P. S. A., Jawaid, M., Hassan, A., Paridah, M. T., & Zaido, A. (2012). Oil palm biomass fibres and recent advancement in oil palm biomass fibres based hybrid biocomposites. In N. Hu (Ed.), Composites and Their Applications (pp. 187-220). InTech. https://doi.org/10.5772/48235

  • Kim, J. S., Lee, Y. Y., & Kim, T. H. (2016). A review on alkaline pretreatment technology for bioconversion of lignocellulosic biomass. Bioresource Technology, 199, 42-48. https://doi.org/10.1016/j.biortech.2015.08.085

  • Krishnan, Y., Bong, C. P. C., Azman, N. F., Zakaria, Z., Othman, N., Abdullah, N., Ho, C. S., Lee, C. T., Hansen, S. B., & Hara, H. (2017). Co-composting of palm empty fruit bunch and palm oil mill effluent: Microbial diversity and potential mitigation of greenhouse gas emission. Journal of Cleaner Production, 146, 94-100. https://doi.org/10.1016/j.jclepro.2016.08.118

  • Kumar, A. K., & Sharma, S. (2017). Recent updates on different methods of pretreatment of lignocellulosic feedstocks: A review. Bioresources and Bioprocessing, 4, Article 7. https://doi.org/10.1186/s40643-017-0137-9

  • Kutlu, N., Isci, A., Sakiyan, O., & Yilmaz, A. E. (2021). Effect of ohmic heating on ultrasound extraction of phenolic compounds from cornelian cherry (Cornus mas). Journal of Food Processing and Preservation, 45(10), Article e15818. https://doi.org/10.1111/jfpp.15818

  • Le, D. M., Sørensen, H. R., Knudsen, N. O., & Meyer, A. S. (2015). Implications of silica on biorefineries - interactions with organic material and mineral elements in grasses. Biofuels, Bioproducts and Biorefining, 9(1), 109-121. https://doi.org/10.1002/bbb.1511

  • Lee, S. H., & Jun, S. (2011). Enhancement of sugar release from taro waste using ohmic heating and microwave heating techniques. Transactions of the ASABE, 54(3), 1041-1047.

  • Lee, S. Y., Ryu, S., & Kang, D. H. (2013). Effect of frequency and waveform on inactivation of Escherichia coli O157:H7 and Salmonella enterica serovar typhimurium in salsa by ohmic heating. Applied and Environmental Microbiology, 79(1), 10-17. https://doi.org/10.1128/AEM.01802-12

  • Lourenço, A., & Pereira, H. (2018). Compositional variability of lignin in biomass. In M. Poletto (Ed.), Lignin - Trends and Applications (pp. 65-98). InTech. https://doi.org/10.5772/intechopen.71208

  • Marçal, F. A., França, L. F., & Fernandes Corrêa, N. C. (2018). Empty fruit bunch treatment. BioResources, 13(3), 6911-6921.

  • Mohammad, I. N., Ongkudon, C. M., & Misson, M. (2020). Physicochemical properties and lignin degradation of thermal-pretreated oil palm empty fruit bunch. Energies, 13(22), Article 5966. https://doi.org/10.3390/en13225966

  • Nabilah-Jansar, K., Roslan, A. M., & Hassan, M. A. (2018). Appropriate hydrothermal pretreatment of oil palm biomass in palm oil mill. Pertanika Journal of Scholarly Research Reviews, 4(1), 31-40. http://pjsrr.upm.edu.my/index.php/pjsrr/article/view/119

  • Nomanbhay, S. M., Hussain, R., & Palanisamy, K. (2013). Microwave-assisted alkaline pretreatment and microwave assisted enzymatic saccharification of oil palm empty fruit bunch fiber for enhanced fermentable sugar yield. Journal of Sustainable Bioenergy Systems, 03(01), 7-17. https://doi.org/10.4236/jsbs.2013.31002

  • Ozkan, G., Guldiken, B., & Capanoglu, E. (2019). Effect of novel food processing technologies on beverage antioxidants. In A. M. Grumezescu & A. M. Holban (Eds.), Processing and Sustainability of Beverages (pp. 413-449). Elsevier. https://doi.org/10.1016/b978-0-12-815259-1.00012-4

  • Palamae, S., Dechatiwongse, P., Choorit, W., Chisti, Y., & Prasertsan, P. (2017). Cellulose and hemicellulose recovery from oil palm empty fruit bunch (EFB) fibers and production of sugars from the fibers. Carbohydrate Polymers, 155, 491-497. https://doi.org/10.1016/j.carbpol.2016.09.004

  • Panigrahi, S., & Dubey, B. K. (2019). Electrochemical pretreatment of yard waste to improve biogas production: Understanding the mechanism of delignification, and energy balance. Bioresource Technology, 292, Article 121958. https://doi.org/10.1016/j.biortech.2019.121958

  • Panigrahi, S., Sharma, H. B., Tiwari, B. R., Krishna, N. V., Ghangrekar, M. M., & Dubey, B. K. (2021). Insight into understanding the performance of electrochemical pretreatment on improving anaerobic biodegradability of yard waste. Renewable Energy, 180, 1166-1178. https://doi.org/10.1016/j.renene.2021.08.123

  • Pare, A., Nema, A., Singh, V. K., & Mandhyan, B. L. (2014). Combined effect of ohmic heating and enzyme assisted aqueous extraction process on soy oil recovery. Journal of Food Science and Technology, 51(8), 1606-1611. https://doi.org/10.1007/s13197-012-0685-0

  • Perasiriyan, V., Priya, S., Gowri, A. M., Ramasamy, D., & Sivakumar, T. (2016). Design and evaluation of electrical resistance unit (ohmic heating) for food processing. International Research Journal of Engineering and Technology, 3, 1357-1361.

  • Pereira, R. N., Rodrigues, R. M., Genisheva, Z., Oliveira, H., de Freitas, V., Teixeira, J. A., & Vicente, A. A. (2016). Effects of ohmic heating on extraction of food-grade phytochemicals from colored potato. LWT, 74, 493-503. https://doi.org/10.1016/j.lwt.2016.07.074

  • Picart-Palmade, L., Cunault, C., Chevalier-Lucia, D., Belleville, M. P., & Marchesseau, S. (2019). Potentialities and limits of some non-thermal technologies to improve sustainability of food processing. Frontiers in Nutrition, 5, Article 130. https://doi.org/10.3389/fnut.2018.00130

  • Pires, R. P. S., Cappato, L. P., Guimarães, J. T., Rocha, R. S., Silva, R., Balthazar, C. F., Freitas, M. Q., Silva, P. H. F., Neto, R. P. C., Tavares, M. I. B., Granato, D., Raices, R. S. L., Silva, M. C., & Cruz, A. G. (2020). Ohmic heating for infant formula processing: Evaluating the effect of different voltage gradient. Journal of Food Engineering, 280, Article 109989. https://doi.org/10.1016/j.jfoodeng.2020.109989

  • Rinaldi, M., Littardi, P., Paciulli, M., Ganino, T., Cocconi, E., Barbanti, D., Rodolfi, M., Aldini, A., & Chiavaro, E. (2020). Impact of ohmic heating and high pressure processing on qualitative attributes of ohmic treated peach cubes in syrup. Foods, 9(8), Article 1093. https://doi.org/10.3390/foods9081093

  • Ríos-Ríos, K. L., Gaytán-Martínez, M., Rivera-Pastrana, D. M., Morales-Sánchez, E., Villamiel, M., Montilla, A., Mercado-Silva, E. M., & Vázquez-Barrios, M. E. (2021). Ohmic heating pretreatment accelerates black garlic processing. LWT, 151, Article 112218. https://doi.org/10.1016/j.lwt.2021.112218

  • Rochefort, D., Leech, D., & Bourbonnais, R. (2004). Electron transfer mediator systems for bleaching of paper pulp. Green Chemistry, 6(1), 14-24. https://doi.org/10.1039/b311898n

  • Rodríguez, L. M. N., Arias, R., Soteras, T., Sancho, A., Pesquero, N., Rossetti, L., Tacca, H., Aimaretti, N., Cervantes, M. L. R., & Szerman, N. (2021). Comparison of the quality attributes of carrot juice pasteurized by ohmic heating and conventional heat treatment. LWT, 145, Article 111255. https://doi.org/10.1016/j.lwt.2021.111255

  • Sakr, M., & Liu, S. (2014). A comprehensive review on applications of ohmic heating (OH). Renewable and Sustainable Energy Reviews, 39, 262-269. https://doi.org/10.1016/j.rser.2014.07.061

  • Sastry, S. (2008). Ohmic heating and moderate electric field processing. Food Science and Technology International, 14(5), 419-422. https://doi.org/10.1177/1082013208098813

  • Sengun, I. Y., Yildiz Turp, G., Icier, F., Kendirci, P., & Kor, G. (2014). Effects of ohmic heating for pre-cooking of meatballs on some quality and safety attributes. LWT, 55(1), 232-239. https://doi.org/10.1016/j.lwt.2013.08.005

  • Shim, J. Y., Lee, S. H., & Jun, S. (2010). Modeling of ohmic heating patterns of multiphase food products using computational fluid dynamics codes. Journal of Food Engineering, 99(2), 136-141. https://doi.org/10.1016/j.jfoodeng.2010.02.009

  • Simanungkalit, S. P., Mansur, D., Nurhakim, B., Agustin, A., Rinaldi, N., Muryanto, & Fitriady, M. A. (2017). Hydrothermal pretreatment of palm oil empty fruit bunch. AIP Conference Proceedings, 1803(1), Article 020011. https://doi.org/10.1063/1.4973138

  • Sofi’I, I., Arifin, Z., & Oktafrina. (2021). Energy Consumption for Patchouli Oil Extraction Using Ohmic Heating. IOP Conference Series: Earth and Environmental Science, 1012(1), Article 012062. https://doi.org/10.1088/1755-1315/1012/1/012062

  • Sun, S., Sun, S., Cao, X., & Sun, R. (2016). The role of pretreatment in improving the enzymatic hydrolysis of lignocellulosic materials. Bioresource Technology, 199, 49-58. Elsevier Ltd. https://doi.org/10.1016/j.biortech.2015.08.061

  • Sun, W., Greaves, T. L., & Othman, M. Z. (2020). Electro-assisted pretreatment of lignocellulosic materials in ionic liquid-promoted organic solvents. ACS Sustainable Chemistry and Engineering, 8(49), 18177-18186. https://doi.org/10.1021/acssuschemeng.0c06537

  • Tamburini, E., Bernardi, T., Castaldelli, G., Tumiatti, G., & Ferro, S. (2011). Green electrochemical approach for delignification of wheat straw in second-generation bioethanol production. Energy and Environmental Science, 4(2), 551-557. https://doi.org/10.1039/c0ee00226g

  • TAPPI. (1950). T.A.P.P.I. Standards: Testing Methods, Recommended Practices, Specifications of the Technical Association of the Pulp and Paper Industry. Technical Association of the Pulp and Paper Industry.

  • Tarasov, D., Leitch, M., & Fatehi, P. (2018). Lignin-carbohydrate complexes: Properties, applications, analyses, and methods of extraction: A review. Biotechnology for Biofuels, 11(1), 1-28. https://doi.org/10.1186/s13068-018-1262-1

  • Timsit, R. S., & Luttgen, A. (2016). Temperature distribution in an ohmic-heated electrical contact at high signal frequencies. Applied Physics Letters, 108(12), Article 121603. https://doi.org/10.1063/1.4944535

  • Tunç, M. T., & Koca, İ. (2021). Optimization of ohmic heating assisted hydrodistillation of cinnamon and bay leaf essential oil. Journal of Food Process Engineering, 44(3), Article e13635. https://doi.org/10.1111/jfpe.13635

  • Ummalyma, S. B., Supriya, R. D., Sindhu, R., Binod, P., Nair, R. B., Pandey, A., & Gnansounou, E. (2019). Biological pretreatment of lignocellulosic biomass-current trends and future perspectives. In A. Basile & F. Dalena (Eds.), Second and Third Generation of Feedstocks: The Evolution of Biofuels (pp. 197-212). Elsevier Inc. https://doi.org/10.1016/B978-0-12-815162-4.00007-0

  • Varga, E., Schmidt, A. S., Réczey, K., & Thomsen, A. B. (2003). Pretreatment of corn stover using wet oxidation to enhance enzymatic digestibility. Applied Biochemistry and Biotechnology - Part A Enzyme Engineering and Biotechnology, 104(1), 37-50. https://doi.org/10.1385/ABAB:104:1:37

  • Wadchasit, P., Siripattana, C., & Nuithitikul, K. (2020). The effect of pretreatment methods for improved biogas production from oil-palm empty fruit bunches (EFB): Experimental and model. IOP Conference Series: Earth and Environmental Science, 463, Article 012126. https://doi.org/10.1088/1755-1315/463/1/012126

  • Wang, C., Llave, Y., Sakai, N., & Fukuoka, M. (2021). Analysis of thermal processing of liquid eggs using a high frequency ohmic heating: Experimental and computer simulation approaches. Innovative Food Science and Emerging Technologies, 73, Article 102792. https://doi.org/10.1016/j.ifset.2021.102792

  • Xu, J., Cheng, J. J., Sharma-Shivappa, R. R., & Burns, J. C. (2010). Sodium hydroxide pretreatment of switchgrass for ethanol production. Energy and Fuels, 24(3), 2113-2119. https://doi.org/10.1021/ef9014718

  • Yaser, A. Z., Jananun, J., Chong, K. P., & Haywood, S. K. (2017). Effect of pre-treatment and inoculant during composting of palm oil empty fruit bunches. ASEAN Journal of Chemical Engineering, 17(2), 1-16. https://doi.org/10.22146/ajche.49551

  • Yimlamai, B., Choorit, W., Chisti, Y., & Prasertsan, P. (2021). Cellulose from oil palm empty fruit bunch fiber and its conversion to carboxymethylcellulose. Journal of Chemical Technology and Biotechnology, 96(6), 1656-1666. https://doi.org/10.1002/jctb.6689

  • Ying, T. Y., Teong, L. K., Abdullah, W. N. W., & Peng, L. C. (2014). The effect of various pretreatment methods on oil palm empty fruit bunch (EFB) and kenaf core fibers for sugar production. Procedia Environmental Sciences, 20, 328-335. https://doi.org/10.1016/j.proenv.2014.03.041

  • Zhai, R., Hu, J., & Saddler, J. N. (2018). Minimizing cellulase inhibition of whole slurry biomass hydrolysis through the addition of carbocation scavengers during acid-catalyzed pretreatment. Bioresource Technology, 258, 12-17. https://doi.org/10.1016/j.biortech.2018.02.124

  • Zhao, Y., Wang, Y., Zhu, J. Y., Ragauskas, A., & Deng, Y. (2008). Enhanced enzymatic hydrolysis of spruce by alkaline pretreatment at low temperature. Biotechnology and Bioengineering, 99(6), 1320-1328. https://doi.org/10.1002/bit.21712

  • Zhuiykov, S. (2018). Semiconductor nano-crystals in environmental sensors. In S. Zhuiykov (Ed.), Nanostructured Semiconductors (pp. 475-538). Elsevier Ltd. https://doi.org/10.1016/b978-0-08-101919-1.00009-x