Optimasi Pretreatment melalui Metode Hydrothermal Pressure dan Pelarut Alkali pada Produksi Bioetanol dari Lemna minor
Authors: Arif Abdur Rahman , Erviani Andi Evi , Natsir Hasnah , Haidir Ilham , Affandy Maudy Audina 
Published: February 2018

<p>Produk bioetanol dengan bahan dasar biomassa lignoselulosa perlahan banyak dikembangkan sebagai sumber energi alternatif. Tantangan utama dalam produksi lignoselulosa etanol berada pada tahap <em>pretreatment</em>. <em>Pretreatment</em> merupakan tahap yang memegang peranan penting dalam mendegradasi lignoselulosa menjadi selulosa. Pada penelitian ini digunakan <em>Lemna minor</em> yang merupakan gulma perairan dengan kombinasi dua tahap <em>pretreatmen</em> untuk melihat efektivitas degradasi lignoselulosa dalam sampel. Tahap pertama dengan metode <em>hydrothermal pressure</em> pada suhu pemanasan uap 121 °C dan tekanan 15-20 psi dengan variasi waktu proses selama 5, 15, 30, 45, dan 60 menit. Tahap kedua <em>pretreatment</em> dengan metode kimiawi menggunakan NaOH dengan variasi konsentrasi 0,5; 1; 1,5; 2; dan 2,5 M. Hasil penelitian menunjukkan 60 menit merupakan waktu optimum dari metode <em>hydrothermal pressure </em>pada sampel <em>L</em><em>. minor</em> dengan kadar lignin 11,32%, kadar selulosa 17,39%, kadar hemiselulosa 16,73% dan kadar gula total 0,82%. Untuk tahapan <em>pretreatment</em> dengan pelarut alkali (NaOH) kandungan kadar lignin <em>L</em><em>. minor</em> setelah <em>pretreatment</em> dengan NaOH 2,0 M sebesar 5,36%, kadar.  Kandungan kadar selulosa, hemiselulosa dan gula total optimum diperoleh pada konsentrasi 2,5 M dengan nilai kadar 31,03%; 5,57% dan 1,74%. Efektivitas penurunan kadar lignin pada <em>pretreatment</em> <em>hydrothermal pressure</em> sebesar 37,04% sedangkan <em>pretreatment</em> dengan NaOH sebesar 70,18%. Kombinasi proses <em>pretreatment</em> memberikan hasil yang cukup baik terhadap proses degradasi lignin yang terkandung dalam sampel <em>Lemna minor </em>sehingga sangat efektif digunakan dalam proses pembuatan bioetanol dengan bahan dasar biomassa.  </p><p><strong>Optimization Pretreatment through Hidrothermal Preassure and Alkaline Solvent Methods in Bioethanol Production from <em>Lemna minor</em></strong>. Bioethanol products with lignocellulosic biomass feedstock have been developed as an alternative energy source. The main challenge in the production of lignocellulosic ethanol is on the pretreatment stage. Pretreatment is a stage that plays an important role in degrading lignocellulose into cellulose. In this study, we used a <em>Lemna minor</em> which is a water weed with a combination of two stages of pretreatmentt to see the effectiveness of lignocellulosic degradation in the sample. The first stage is hydrothermal pressure method of steam heating temperature 121 °C and pressure 15-20 psi with variation of processing time for 5, 15, 30, 45, and 60 minutes. The second stage of pretreatment with chemical methods using NaOH with a concentration variation of 0.5; 1; 1.5; 2 and 2.5 M. The results showed that 60 minutes was the optimum time of the hydrothermal pressure method in the <em>L.</em><em> </em><em>minor</em> sample with the lignin content of 11.32%, the cellulose 17.39%, the hemicellulose 16.73% and the total sugar 0.82%. For the pretreatment stage with alkaline solvent (NaOH) the content of <em>L. minor</em> lignin after pretreatment with 2.0 M NaOH was 5.36%. The content of cellulose, hemicellulose and total sugars was obtained at a concentration of 2.5 M with a grade value of 31.03%, 5.57%, and 1.74%. The effectiveness of lignin decrease in pretreatment hydrothermal pressure was 37.04% while pretreatmentt with NaOH was 70.18%. The combination of pretreatment process gives a good result to the lignin degradation process contained in the <em>L</em><em>.</em><em> minor</em> sample in order that it is very effective in the process of making bioethanol with biomass feedstock.</p>