PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

 

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ISSN 1511-3701

Home / Regular Issue / JTAS 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 Tropical Agricultural Science, 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