Modeling and Optimizing Cellulose Extraction from Rice Straw using HCl

Until now, the biggest energy supply has come from fossils. The use of energy sources derived from fossils is increasingly avoided because it causes the greenhouse effect. In addition, the availability of energy from fossil sources is dwindling, even far from being sufficient for needs. This is what causes the need for renewable energy sources. Indonesia has the greatest potential for renewable energy sources, namely biomass. In Indonesia, the biomass with the largest harvested area is rice, so rice straw has the potential to be a source of renewable energy. The process of forming liquid fuel derived from rice straw requires high temperatures. We propose a process of converting rice straw into liquid fuel under mild conditions. This process requires several stages. The first step is to extract cellulose from rice straw. This process uses HCl. Variations of HCl used in this study were 1%, 3%, 5%, 6% and 9%. The temperature variations used are 80⁰C, 90⁰C, 100⁰C, 110⁰C and 120⁰C. From the experiments, it is known that the extracted cellulose content is higher when using higher temperatures. In addition, from the experiment, the result was that the more HCl, the less cellulose content obtained. From this experiment, a model was made, namely cellulose content = 33.001 + 0.03738 x temperature - 0.2639 x HCl content. The model is verified and validated using Hysys and compares the output from Hysys with the experimental output which produces a maximum error of 4.74%. Then to get the maximum cellulose content, optimization is carried out. The optimization methods used are graphical, genetic algorithms, and PSO. These three methods gave corresponding results, namely a maximum 37% cellulose content at 120^0C using 1% HCl.