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All Journal Eksergi: Jurnal Teknik Energi JTPG (Jurnal Teknologi Pertanian Gorontalo)
Riski Gunawan Nasution
Program Studi Teknologi Rekayasa Bioproses Energi Terbarukan, Politeknik ATI Padang
Chemical Engineering, Chemistry & Bioengineering Electrical & Electronics Engineering Energy Engineering Mechanical Engineering

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Modification of a Double Adsorber Series Type with Multiple Stages Installed on Biodigester for Biogas Purification Riski Gunawan Nasution; Rehan Aditya Nugraha; Desniorita Desniorita; Dyah Nirmala; Riski Gunawan Nasution
Eksergi Vol. 22 No. 02 (2026): MAY 2026
Publisher : Politeknik Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32497/eksergi.v22i02.7558

Abstract

Biogas produced from conventional biodigesters typically still contains impurities such as H₂S and CO, which can damage equipment and reduce combustion efficiency. This study aims to modify the adsorber into a series-type double adsorber integrated directly into the biodigester and evaluate its performance in purifying biogas. The study used a 200 L biodigester with 40 kg of cow rumen and 120 L of water. The fermentation process lasted 14 days with feed circulation. Purification was carried out using activated carbon as an adsorbent with a contact time of 60 minutes. Tested parameters included CH₄, H₂S, CO, O₂ levels, flame test, and FTIR characterization. The results showed that the double adsorber increased methane content from 69% to 91% and reduced H₂S to 0.7 ppm and CO to 0 ppm. The tool efficiency averaged above 90% for H₂S and CO absorption. The flame test showed an increased burning duration from 55 seconds to 1 minute 54 seconds. FTIR characterization confirmed the presence of O-H and C=O groups involved in the adsorption process. In conclusion, the series-type double adsorber modification is effective in improving biogas quality according to SNI 8019:2014.
Rancang Bangun Fermentor Berbahan Akrilik dengan Pompa Peristaltik sebagai Sistem Sirkulasi pada Produksi Bioetanol dari Molases Kerisna Darmawan Syahputra; Farhan Johansyah Putra; Desniorita Desniorita; Rosalina Rosalina; Riski Gunawan Nasution
JTPG (Jurnal Teknologi Pertanian Gorontalo) Vol 10 No 2 (2025): Jurnal JTPG (November)
Publisher : PROGRAM STUDI MESIN DAN PERALATAN PERTANIAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30869/jtpg.v10i2.1583

Abstract

Penelitian ini bertujuan untuk merancang, membangun, dan menguji kinerja fermentor berbahan akrilik yang diintegrasikan dengan sistem sirkulasi pompa peristaltik untuk produksi bioetanol dari molase. Fermentor berkapasitas 7 liter dirancang menggunakan material akrilik yang transparan dan mudah difabrikasi. Sistem sirkulasi pompa peristaltik diterapkan untuk menjaga homogenitas substrat, distribusi nutrisi, dan stabilitas suhu selama proses fermentasi berlangsung. Penelitian dilakukan dengan membandingkan dua kondisi operasi, yaitu fermentasi menggunakan sirkulasi dan tanpa sirkulasi, dengan memanfaatkan ragi Saccharomyces cerevisiae. Parameter yang diamati meliputi suhu, pH, penurunan nilai Brix (kadar gula), dan densitas selama fermenasi 5 hari. Hasil penelitian menunjukkan bahwa sistem sirkulasi berhasil mempertahankan suhu yang lebih stabil pada kisaran 30–31°C serta pH yang konstan. Fermentasi dengan sirkulasi juga mempercepat fase eksponensial pertumbuhan ragi, meskipun durasinya lebih singkat akibat konsumsi gula yang lebih cepat. Penurunan nilai Brix pada sistem bersirkulasi lebih signifikan, yang mengindikasikan efisiensi konversi substrat yang lebih baik. Disimpulkan bahwa fermentor akrilik dengan sistem sirkulasi pompa peristaltik efektif dalam meningkatkan homogenitas dan stabilitas kondisi fermentasi. Untuk pengembangan selanjutnya, diperlukan penambahan sistem kontrol otomatis dan optimasi kecepatan sirkulasi guna memaksimalkan produktivitas bioethanol.
Purification of Lipase Enzyme from Oil Palm Mesocarp by Ammonium Sulfate Fractionation: Activity and Storage Stability Ririn Arsy Gunawan; Nurfajrina Husna Rahimi; Rita Youfa; Addin Akbar; Riski Gunawan Nasution
JTPG (Jurnal Teknologi Pertanian Gorontalo) Vol 11 No 1 (2026): JTPG (May)
Publisher : PROGRAM STUDI MESIN DAN PERALATAN PERTANIAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30869/jtpg.v11i1.1639

Abstract

This study examines the isolation and salting-out fractionation of lipase enzyme from oil palm mesocarp as a preliminary step toward preparing a biocatalyst for enzymatic biodiesel production, aimed at overcoming the limitations of conventional acid and base catalysts such as soap formation, corrosiveness, and difficulty of separation and reuse. Lipase was isolated from oil palm mesocarp through extraction using phosphate buffer, then fractionated by salting-out with ammonium sulfate at four saturation ranges (0-20%, 20-40%, 40-60%, and 60-75%). Volumetric enzyme activity (U/mL) was determined by acid-base titration, while storage stability was evaluated by comparing the activity of fresh enzyme with that of enzyme stored for 2 weeks at 18 oC. The crude extract obtained from isolation had a moisture content of 69.19%, indicating that the enzyme was in a fresh condition prior to fractionation. Enzyme activity increased consistently from the crude extract (4.16 U/mL) to Fraction IV (53.59 U/mL), an increase of about 12.9-fold; because protein concentration was not determined, this increase reflects volumetric activity rather than specific activity or purification fold, and is consistent with, but does not by itself confirm, separation of lipase from co-precipitating, less active proteins. After 2 weeks of storage, all fractions showed a decline in activity, but to different degrees: the crude extract lost 53.85% of its activity, whereas Fraction IV lost only 4.37%. These findings, based on single measurements, suggest that ammonium sulfate fractionation not only increases the volumetric activity of lipase but may also improve its short-term storage stability. Fraction IV is accordingly proposed as a promising biocatalyst candidate for further application in enzymatic biodiesel production from high-FFA feedstocks; confirmation through replicated measurements, protein/purity characterization, and direct catalytic testing is recommended before firmer conclusions are drawn, and further work on immobilization and stabilizing additives is suggested to extend its storage life.
Co-Authors Addin Akbar Desniorita Desniorita Desniorita Desniorita Dyah Nirmala Farhan Johansyah Putra Kerisna Darmawan Syahputra Nurfajrina Husna Rahimi Rehan Aditya Nugraha Ririn Arsy Gunawan Riski Gunawan Nasution Rita Youfa Rosalina Rosalina