scholarly journals Pembuatan Bioetanol dari Pati Umbi Uwi (Discorea alata) melalui Proses Fermentasi dan Distilasi

METANA ◽  
2020 ◽  
Vol 16 (2) ◽  
Author(s):  
Hargono Hargono

Bioetanol adalah nama lain etanol yang dapat dibuat dari  bahan baku biomasa. Tanaman Uwi (Discorea alata) mudah tumbuh di lereng-lereng gunung, hutan sebagai tanaman liar, namun tanaman ini ada yang sengaja ditanam orang. Tanaman Uwi mengandung karbohidrat cukup tinggi (32,64%) sehingga dapat dimanfaatkan sebagai bahan baku pembuatan  bioetanol. Pada penelitian ini umbi Uwi  terlebih dulu dibuat pati agar  memudahkan terjadinya proses hidrolisis dan fermentasi. Proses pembuatan pati Uwi adalah dengan mengekstrak bubur  (hasil parutan)  Uwi menggunakan air. Proses  hidrolisis dan fermentasi dilakukan secara serentak atau Simultaneous Saccharification and Fermentation (SSF). Konsentrasi pati  Uwi 200 g/L, konsentrasi enzim (Stargen TM 002) 1,5% (w/w), konsentrasi yeast 1,10% (w/w) dan  pada suhu 30°C. Hasil proses SSF adalah konsentrasi bioetanol kadar rendah, sehingga agar kemurnian bioetanol meningkat perlu dilakukan distilasi. Proses distilasi menggunakan distilasi 2 tahap, terdiri dari 2 kolom, meliputi kolom 1 tanpa bahan isian dilengkapi pipa pendingin yang berbentuk spiral, sedangkan kolom 2 berisi bahan isian yaitu packing. Proses distilasi 2  tahap masing-masing  ini dioperasikan pada suhu 78°C. Tujuan penelitian ini adalah mempelajari pengaruh waktu SSF terhadap konsentrasi bioetanol dan  mempelajari waktu distilasi tahap 1 dan 2 terhadap konsentrasi bioetanol.  Proses SSF dilakukan selama 90 jam. Hasil terbaik proses SSF dicapai selama 72 jam yang menghasilkan konsentrasi bioetanol 12,30%. Proses distilasi 1 dan 2 dilakukan masing-masing selama 105 menit. Hasil terbaik dari distilasi tahap 1 dan tahap 2dicapai selama waktu masing-masing 90 menit, yaitu konsentrasi bioetanol  27,93% dan 85,30%. Perancangan alat distilasi 2 tahap ini layak digunakan sebagai alat pemunian bioetanol  hasil SSF.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Shannon M. Hoffman ◽  
Maria Alvarez ◽  
Gilad Alfassi ◽  
Dmitry M. Rein ◽  
Sergio Garcia-Echauri ◽  
...  

Abstract Background Future expansion of corn-derived ethanol raises concerns of sustainability and competition with the food industry. Therefore, cellulosic biofuels derived from agricultural waste and dedicated energy crops are necessary. To date, slow and incomplete saccharification as well as high enzyme costs have hindered the economic viability of cellulosic biofuels, and while approaches like simultaneous saccharification and fermentation (SSF) and the use of thermotolerant microorganisms can enhance production, further improvements are needed. Cellulosic emulsions have been shown to enhance saccharification by increasing enzyme contact with cellulose fibers. In this study, we use these emulsions to develop an emulsified SSF (eSSF) process for rapid and efficient cellulosic biofuel production and make a direct three-way comparison of ethanol production between S. cerevisiae, O. polymorpha, and K. marxianus in glucose and cellulosic media at different temperatures. Results In this work, we show that cellulosic emulsions hydrolyze rapidly at temperatures tolerable to yeast, reaching up to 40-fold higher conversion in the first hour compared to microcrystalline cellulose (MCC). To evaluate suitable conditions for the eSSF process, we explored the upper temperature limits for the thermotolerant yeasts Kluyveromyces marxianus and Ogataea polymorpha, as well as Saccharomyces cerevisiae, and observed robust fermentation at up to 46, 50, and 42 °C for each yeast, respectively. We show that the eSSF process reaches high ethanol titers in short processing times, and produces close to theoretical yields at temperatures as low as 30 °C. Finally, we demonstrate the transferability of the eSSF technology to other products by producing the advanced biofuel isobutanol in a light-controlled eSSF using optogenetic regulators, resulting in up to fourfold higher titers relative to MCC SSF. Conclusions The eSSF process addresses the main challenges of cellulosic biofuel production by increasing saccharification rate at temperatures tolerable to yeast. The rapid hydrolysis of these emulsions at low temperatures permits fermentation using non-thermotolerant yeasts, short processing times, low enzyme loads, and makes it possible to extend the process to chemicals other than ethanol, such as isobutanol. This transferability establishes the eSSF process as a platform for the sustainable production of biofuels and chemicals as a whole.


2016 ◽  
Vol 27 (1) ◽  
pp. 22-35 ◽  
Author(s):  
Elsa Cherian ◽  
M. Dharmendira Kumar ◽  
G. Baskar

Purpose – The purpose of this paper is to optimize production of cellulase enzyme from agricultural waste by using Aspergillus fumigatus JCF. The study also aims at the production of bioethanol using cellulase and yeast. Design/methodology/approach – Cellulase production was carried out using modified Mandel’s medium. The optimization of the cellulase production was carried out using Plackett-Burman and Response surface methodology. Bioethanol production was carried out using simultaneous saccharification and fermentation. Findings – Maximum cellulase production at optimized conditions was found to be 2.08 IU/ml. Cellulase was used for the saccharification of three different feed stocks, i.e. sugar cane leaves, corn cob and water hyacinth. Highest amount of reducing sugar was released was 29.1 gm/l from sugarcane leaves. Sugarcane leaves produced maximum bioethanol concentration of 9.43 g/l out of the three substrates studied for bioethanol production. Originality/value – The present study reveals that by using the agricultural wastes, cellulase production can be economically increased thereby bioethanol production.


2010 ◽  
Vol 171-172 ◽  
pp. 261-265
Author(s):  
Zhuang Zuo ◽  
Xiu Shan Yang

Corn stover was pretreated using different soaking conditions at mild temperature. Among the tested conditions, the best was 1% NaOH+8% NH4OH,50°C,48 h, Solid-to-liquid ratio 1:10. The results showed that soaking pretreatment achieved 63.6% delignification, retained the xylan and glucan. After enzymatic hydrolysis, conversion rates of xylan and glucan were 70.9% and 78.5%, respectively. The pretreated filtration re-soaking cause 52.7% xylan and 65.0% glucan conversion. NaOH+NH4OH treatment can be performed under mild conditions, gives a good buffering effect, low carbohydates degradation and extensive removal of lignin. Additionally, simultaneous saccharification and fermentation was conducted with pretreated corn stover to assess the ethanol production. For the whole process, 0.15g ethanol /g corn stover was achieved using Saccharomyces cerevisiae Y5, and 0.19g ethanol /g corn stover when using Pichia stipitis.


Sign in / Sign up

Export Citation Format

Share Document