Biohydrogen Production in Semi-Continuous System Using Immobilized Cell Membrane

Abstract

Hydrogen is considered to be the fuel of the future because of its high energy content (122 kJ/g), and water is the only byproduct of its use. Moreover, the production of hydrogen via fermentation of organic wastes is carbon neutral. This study was conducted to evaluate the performance of immobilized cells on PVDF membrane for biohydrogen production using a sequencing batch reactor by varying the hydraulic retention times (HRT) of the system and to compare the efficiency between suspended and attached systems on the production of biohydrogen. It was found that the biohydrogen fermentation performance was improved in a semi-continuous system, especially with immobilized cells. The optimum HRT that supports the highest biohydrogen yield was for an HRT of 12 hours, where the performance of hydrogen production was improved and in which the maximum hydrogen yield was achieved at 2.43 mol H2/mol and maximum hydrogen production rate (HPR) of 2.46 L H2/L.d as compared to other HRT for both systems. Therefore, the result of this study can be applied as the benchmark for scaling up the process. ABSTRAK: Hidrogen boleh dianggap sebagai sumber tenaga penting pada masa hadapan kerana kapasiti tenaga yang tinggi (122 kJ/g) dan hanya air terhasil dari tindak balas hidrogen. Tambahan, sisa pengeluaran hidrogen melalui proses fermentasi sisa organik adalah bersifat semula jadi. Kajian ini dijalankan bagi mengkaji prestasi sel tidak bergerak pada membran PVDF bagi penghasilan biohidrogen menggunakan reaktor kelompok turutan dengan mengubah sistem masa pengekalan hidraulik (HRT) dan dengan membuat perbandingan kecekapan antara sistem yang tergantung dan sistem yang bersambung pada penghasilan biohidrogen. Dapatan kajian mendapati prestasi fermentasi diperbaharui di bawah sistem separa turutan terutama dengan sel tidak bergerak. Nilai optimum HRT yang mempunyai hasil biohidrogen tertinggi adalah pada ketika HRT 12 jam di mana prestasi penghasilan hidrogen dapat diperbaharui dan menghasilkan hidrogen tertinggi pada 2.43 mol H2/mol dan kadar penghasilan hidrogen maksimum (HPR) pada 2.46 L H2/L.d berbanding sistem HRT lain pada kedua-dua sistem. Oleh itu, dapatan kajian ini boleh digunakan sebagai penanda aras bagi kenaikan proses.

Keywords

• Biohydrogen
• semi-continuous system
• Immobilization
• membrane