Research Article Optimization of Concentrated Sulphuric Acid Hydrolysis of Gadam Sorghum Stalks Found in Kenya for Fermentable Sugar Production Wiseman Ngigi , 1 Zachary Siagi , 2 Anil Kumar , 1 and Moses Arowo 1 1 Department of Chemical & Process Engineering, Moi University, 3900-30100 Eldoret, Kenya 2 Department of Mechanical, Production & Energy Engineering, Moi University, 3900-30100 Eldoret, Kenya Correspondence should be addressed to Wiseman Ngigi; wisemanngigi@gmail.com Received 4 May 2022; Accepted 20 September 2022; Published  October 2022 Academic Editor: Kavitha S Copyright © 2022 Wiseman Ngigi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Gadam sorghum stalks are agricultural residues which can be hydrolyzed into fermentable sugars that can be used to produce bioethanol which is a renewable source of energy. In order to produce bioethanol from lignocellulosic biomass such as Gadam sorghum stalks, several processes including hydrolysis are involved. However, the use of lignocellulosic biomass for bioethanol production is hindered by the low yield of fermentable sugars obtained during hydrolysis. The lack of sufficient information on optimal conditions governing hydrolysis of lignocellulosic biomass leads to inefficient process which hinders the economic viability of large-scale bioethanol production. The objective of this study was to optimize reaction conditions involved in concentrated sulphuric acid hydrolysis of Gadam sorghum stalks. During hydrolysis, the conditions that were varied included temperature (40 ° C–80 ° C), time (30-90 minutes), and concentration of acid (30%-70%, w/w). Central composite rotatable design was used to optimize and establish optimum level of hydrolysis conditions. Response surface methodology and analysis of variance were used to interprete the results. The results of hydrolysis revealed that the highest yield of glucose was 87.54% (w/w) which was realized at 60 ° C hydrolysis temperature, 60 minutes hydrolysis period, and 50% (w/w) concentration of sulphuric acid. In addition, the lowest glucose yield was 45.59% (w/w) which was realized at 60 ° C hydrolysis temperature, 60 minutes hydrolysis period, and 16.36% (w/w) sulphuric acid concentration. Concentrated sulphuric acid hydrolysis of Gadam sorghum stalks results in high yield of fermentable sugars. These results reveal that Gadam sorghum stalks are viable substrates for the production of fermentable sugars. 1. Introduction Biofuels are increasingly being used as sources of energy as the world economy tends to substitute fossil fuels due to global warming and declining supplies [1]. In Kenya, the consumption of fossil fuels has been on the rise mainly due to an increase in transportation of people and goods, increased industrial activities, and population growth. Bio- fuels such as bioethanol, biodiesel, and biogas are candidate substitute to fossil fuels [1, 2]. Bioethanol is biodegradable, highly oxygenated, and less polluting when compared to fos- sil fuels [3]. It is used in the transportation sector through blending with gasoline to form a combustible mixture such as E10 which is a blend consisting of 90% gasoline and 10% bioethanol, cooking and lighting in rural and urban homesteads, and as industrial solvent [1, 3, 4]. Bioethanol can be produced from starch (corn, wheat)- and sucrose (sugar)-based substrates or lignocellulosic bio- mass (LGB). Bioethanol produced from starch- and sucrose-based substrates is referred to as first-generation bioethanol (1GBE). Materials containing cellulose, hemicel- lulose, and lignin are referred to as LGB. Bioethanol pro- duced from LGB is referred to as second-generation bioethanol (2GBE). Examples of LGB include materials such as agricultural residues (wheat straws, maize cobs, and sor- ghum stalks), perennial grasses, woody biomass, energy Hindawi Journal of Energy Volume 2022, Article ID 2064600, 13 pages https://doi.org/10.1155/2022/2064600