Hasbi Priadi, a student of the Chemical Engineering Department Doctoral Program of the Faculty of Engineering (FT) of Universitas Indonesia (UI), successfully defended his dissertation on hydrothermal fractionation experiments and modeling using palm oil by-products for bioethanol production on the FTUI open doctoral promotion session on June 26, 2024. Hasbi passed with a GPA of 3.96 (a very satisfactory predicate). This success brought him to achieve two doctoral degrees from FTUI and Institut Mines-Télécom (IMT) Atlantique, France. He has become the 73rd doctor from the Chemical Engineering Department and the 549th in FTUI.
Hasbi is the first student in the Double Degree Doctoral Program between FTUI and IMT Atlantique, France, with a research focus in the biofuels and biomass valorization field. “I was accepted and started my studies in the FTUI Doctoral Program in 2018. From 2020 to 2022, I continued my doctoral program research in the Department of Energy System Engineering, IMT Atlantique, more precisely in GEPEA (Process Engineering for Environment and Food), research group VERTE (energy/material recovery of residues and treatment of emissions), which is part of CNRS (French National Center for Scientific Research),” said Hasbi.
In his research, using the Analytical Hierarchy Process (AHP), Hasbi found that biomass availability from palm oil production is a deciding factor in bioethanol production. From this process, empty palm oil bunches are identified as the most potential lignocellulose raw material with a factor weight of 39%.
Lignocellulosic biomass, such as wood and agricultural residues, is the most abundant and renewable resource with more than 200 megatons produced each year. Indonesia is one of the countries with a massive lignocellulosic biomass potential. One of the potential lignocellulosic biomass is based on palm oil processing. In 2021, palm oil plantations in Indonesia will reach 47 megatons (Mt), the largest production in the world (Ministry of Agriculture, 2022).
Waste from palm oil mill processing is usually minced for compost and reused as an energy source for power and steam generation, consumed internally in a palm oil factory, or into value-added materials such as activated carbon. The number of by-products from palm oil processing in Indonesia can be processed as renewable energy sources, with the number of solid waste in the form of empty fruit bunch (EFB) as many as 10.4 Mt, 5.15 Mt of fibers, and 2.9 Mt of palm kernels.
Identification results through the AHP method are then simulated using the Aspen Plus™ for factory-scale bioethanol production. The simulation used three different thermochemistry conversion methods: hydrolysis using water in supercritical conditions, supercritical carbon dioxide with a mix of water, and hydrothermal hydrolysis using a catalyst. In addition, environmental analysis was done with the Life Cycle Analysis (LCA) method and economic analysis was also done to determine the best method for the bioethanol production process. A comparison between catalytic hydrothermal hydrolysis and enzymatic hydrolysis shows that catalytic hydrothermal hydrolysis has lower production costs but a higher environmental performance of 50%.
“Process simulation using Aspen Plus™ showed that catalytic hydrothermal hydrolysis is the best method in bioethanol production, bringing in 273 liters of ethanol per ton with an energy ratio of 2.2 and minimum carbon footprint of 61 g CO₂/MJ in a cradle gate scope with the minimum production cost of ethanol being $1.11 per liter. Even though the Capital Expenditure (CAPEX) of catalytic hydrothermal hydrolysis is 1% higher, the variable cost is 23% lower than enzymatic hydrolysis,” said Hasbi. In the closing section of his presentation, Hasbi emphasized the importance of further process optimization to minimize the formation of fermentation inhibitors.
The dean of FTUI, Prof. Dr. Ir. Heri Hermansyah, ST., M.Eng., IPU., conveyed, “Hasbi Priadi’s research results have a great potential to bring real benefits to Indonesian society. By utilizing abundant palm oil waste as the raw material for bioethanol production, Indonesia can reduce its dependency on fossil fuels, reduce greenhouse gas emissions, and increase the economic value of agricultural waste. Additionally, more efficient and eco-friendly bioethanol production can support the country’s efforts in reaching the sustainable energy and environmental continuity targets. This research also opens opportunities for green technology developers to create new job opportunities and encourage local economic growth.”
This Doctoral Promotion session was chaired by Prof. Dr. Ir. Heri Hermansyah, ST., M.Eng., IPU., with Prof. Dr. Ir. Widodo Wahyu Purwanto, DEA., as promoter; Prof. Yves Andres and Sary Awad, Ph.D, as co-promoter I and co-promoter II respectively. The examiner team consists of Prof. Ir. Arief Budiman, MS., D.Eng., IPU.; Prof. Khasayar Saleh; Prof. Ir. Kamarza Mulia, M.Sc., Ph.D.; Prof. Dr.-Ing. Ir. Misri Gozan, M.Tech.; and Audrey Villot, Ph.D.
