Volume 9 Issue 2 ( June 2022 )

Along with population growth and its activities, in business-as-usual approach, the energy needs to support these activities will be even greater. Up to this point, the fulfillment of energy sources is still dominated by fossil fuels. Therefore, innovation and technology development explore all potentials related to, especially, renewable fuel. Hydrogen (H₂ ) is a potential energy carrier with an energy content 2.75 times higher energy than hydrocarbon fuels. Previous research using Palm Oil Mill Effluent (POME) as a raw material has been carried out on 2.5 dm3 and 40 dm3 scales. Based on these results, a scaling-up system was designed as a bio–Continuous Stirred Tank Reactor (CSTR) for the production of H₂ from a capacity of 900 dm3 by modifying the existing reactor. The bio H₂ production system was designed by considering the feed stream will flow from the bottom and stream up through high concentration activated sludge which will decompose the organic content in POME. POME flow up and out through the overflow pipe. Meanwhile, the biogas, H₂ and CO₂ , will flow through the upper pipe and be channeled to the biogas holder. POME feeding is designed to inflow up laminar so that POME decomposition occurs gradually as indicated by the decreasing COD and BOD values at the bottom and overflow. The difference in COD and BOD concentrations in the bio-CSTR shows a positive effect on the 1 m³ bio-CSTR. The bio CSTR was equipped with impellers in 4 different levels to maintain uniformity at each level. Thus the form of POME flow is laminar and non stagnant. The result showed COD decreased between the bottom and the overflow reached 5280 ppm. In addition, the pH only changes to a maximum of 0.1. Both data indicated that biological processes working well and do not influence the operational condition
Novelty: This bio CSTR design for biogas H₂ production is a modification of an existing bio H₂ production system that uses POME as raw material and has a working volume of around 1 m3 (1000 liters). The previous system mixed with the bottom functioning on top by using circulation in the bioreactor. There hasn't been any decent data on H₂ biogas production until recently. Modification of the H₂ biogas production system is carried out by adding a stirring system that works in a laminar flow – non stagnant. Another added feature is the heating system for pretreatment, which can be used both for conditioning the seeding culture consortium biogas H₂ and for the preparation of feeding into bio-CSTR. A diaphragm pump that can work for sludge is also included in the system. Currently, research on the maximum H2 biogas production is being carried out on a 2.5 liter scale ¹⁾. Novelty in this research is to design a bio CSTR on a scale of 1 m³ which can also be utilized to produce H₂ biogas from POME.

Keywords: POME; bio H₂ ; design bio CSTR; renewable fuel; laminar and non-stagnant