Suitability of anaerobic digestion effluent as process water for corn fuel ethanol fermentation

A corn fuel ethanol plant integrated with anaerobic digestion treatment of thin stillage increases the net energy balance. Furthermore, the anaerobic digestion effluent (ADE) can be reused as a potential substitute for process water in the ethanol fermentation. In this study, the suitability of ADE as process water for corn ethanol fermentation was investigated by analyzing the potential inhibitory components in the ADE. It was found that ammonium influenced the growth and metabolism of Saccharomyces cerevisiae. Maximum ethanol production was obtained when the concentration of ammonium nitrogen was 200 mg/L, and ammonium could replace urea as the nitrogen source for S. cerevisiae under this concentration. In the ethanol fermentation with a higher concentration of ammonium, more glycerol was produced, thereby resulting in the decrease of ethanol production. In addition, components except ammonium in the ADE caused no inhibition to ethanol production. These results suggest that ADE could be reused as process water for corn ethanol fermentation without negative effect when ammonium concentration is well controlled.

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Blocking mitophagy does not improve fuel ethanol production in Saccharomyces cerevisiae

10.1101/2021.06.29.450456 ◽

2021 ◽

Author(s):

Kevy Pontes Eliodório ◽

Gabriel Caetano de Gois e Cunha ◽

Brianna A White ◽

Demisha HM Patel ◽

Fangyi Zhang ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Viability ◽

Ethanol Production ◽

Ethanol Fermentation ◽

Synthetic Medium ◽

Fuel Ethanol ◽

Specific Gene ◽

Fermentation Performance ◽

Cell Recycling

Ethanol fermentation is frequently performed under conditions of low nitrogen. In Saccharomyces cerevisiae, nitrogen limitation induces macroautophagy, including the selective removal of mitochondria, also called mitophagy. Shiroma and co-workers (2014) showed that blocking mitophagy by deletion of the mitophagy specific gene ATG32 increased the fermentation performance during the brewing of Ginjo sake. In this study, we tested if a similar strategy could enhance alcoholic fermentation in the context of fuel ethanol production from sugarcane in Brazilian biorefineries. Conditions that mimic the industrial fermentation process indeed induce Atg32-dependent mitophagy in cells of S. cerevisiae PE-2, a strain frequently used in the industry. However, after blocking mitophagy, no differences in CO2production, final ethanol titres or cell viability were observed after five rounds of ethanol fermentation, cell recycling and acid treatment, as commonly performed in sugarcane biorefineries. To test if S. cerevisiae's strain background influences this outcome, cultivations were carried out in a synthetic medium with strains PE-2, Ethanol Red (industrial) and BY (laboratory), with and without a functional ATG32 gene, under oxic and oxygen restricted conditions. Despite the clear differences in sugar consumption, cell viability and ethanol titres, among the three strains, we could not observe any improvement in fermentation performance related to the blocking of mitophagy. We conclude with caution that results obtained with Ginjo sake yeast is an exception and cannot be extrapolated to other yeast strains and that more research is needed to ascertain the role of autophagic processes during fermentation.

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Anaerobic digestion of thin stillage of corn ethanol plant in a novel anaerobic baffled reactor

Waste Management ◽

10.1016/j.wasman.2018.06.015 ◽

2018 ◽

Vol 78 ◽

pp. 541-552 ◽

Cited By ~ 11

Author(s):

Farid Sayedin ◽

Azadeh Kermanshahi-pour ◽

Sophia (Quan) He

Keyword(s):

Anaerobic Digestion ◽

Corn Ethanol ◽

Thin Stillage ◽

Anaerobic Baffled Reactor ◽

Ethanol Plant

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Assessing the Impact of Corn-Ethanol Production on Global Corn Price Based on a VAR Model

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.616-618.1358 ◽

2012 ◽

Vol 616-618 ◽

pp. 1358-1362

Author(s):

Ling Xiao Wu ◽

Jun Ping Ji ◽

Xiao Ming Ma

Keyword(s):

Ethanol Production ◽

Rapid Development ◽

Decomposition Analysis ◽

Fuel Ethanol ◽

External Factors ◽

Var Model ◽

Corn Ethanol ◽

Corn Production ◽

The Us ◽

The Impact

The fuel ethanol industry has been in rapid development in recent years with the US as a leading force, which consumes large amount of corn. In order to assess the impact of corn-ethanol production on global corn price, a VAR model is used in this paper. By impulse responses analysis and variance decomposition analysis the direct impact of corn-ethanol production on global corn price and its relative importance compared with other external factors are proved. The results show that increasing amount of corn used for US ethanol production leads to rapid increases of global corn price when the corn production is steady. The proportion of corn used for ethanol production among total corn production in the US plays an important role in affecting global corn price among all external factors, and the significance of its impact will enhance in the long run. The fuel ethanol industry should turn to non-grain materials in the future to keep the global corn price steady and guarantee global food security, and it’s necessary for all fuel ethanol producers to take action.

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Anaerobic digestion of corn ethanol thin stillage in batch and by high-rate down-flow fixed film reactors

Water Science & Technology ◽

10.2166/wst.2012.371 ◽

2012 ◽

Vol 66 (9) ◽

pp. 1834-1841 ◽

Cited By ~ 3

Author(s):

A. Wilkinson ◽

K. J. Kennedy

Keyword(s):

Anaerobic Digestion ◽

High Rate ◽

Organic Loading Rate ◽

Clean Water ◽

Corn Ethanol ◽

Thin Stillage ◽

Treated Effluent ◽

Fixed Film ◽

Vs Removal ◽

Removal Efficiencies

Thin stillage (CTS) from a dry-grind corn ethanol plant was evaluated as a carbon source for anaerobic digestion (AD) by batch and high rate semi-continuous down-flow stationary fixed film (DSFF) reactors. Biochemical methane potential (BMP) assays were carried out with CTS concentrations ranging from approximately 2,460–27,172 mg total chemical oxygen demand (TCOD) per litre, achieved by diluting CTS with clean water or a combination of clean water and treated effluent. High TCOD, SCOD and volatile solids (VS) removal efficiencies of 85 ± 2, 94 ± 0 and 82 ± 1% were achieved for CTS diluted with only clean water at an organic concentration of 21,177 mg TCOD per litre, with a methane yield of 0.30 L methane per gram TCODremoved at standard temperature and pressure (STP, 0 °C and 1 atmosphere). Batch studies investigating the use of treated effluent for dilution showed promising results. Continuous studies employed two mesophilic DSFF anaerobic digesters treating thin stillage, operated at hydraulic retention times (HRT) of 20, 14.3, 8.7, 6.3, 5 and 4.2 d. Successful digestion was achieved up to an organic loading rate (OLR) of approximately 7.4 g TCOD L−1d−1 at a 5 d HRT with a yield of 2.05 LCH4 L−1d−1 (at STP) and TCOD and VS removal efficiencies of 89 ± 3 and 85 ± 3%, respectively.

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Industrial symbiosis: Corn ethanol fermentation, hydrothermal carbonization, and anaerobic digestion

Biotechnology and Bioengineering ◽

10.1002/bit.24924 ◽

2013 ◽

Vol 110 (10) ◽

pp. 2624-2632 ◽

Cited By ~ 27

Author(s):

Brandon M. Wood ◽

Lindsey R. Jader ◽

Frederick J. Schendel ◽

Nicholas J. Hahn ◽

Kenneth J. Valentas ◽

...

Keyword(s):

Anaerobic Digestion ◽

Ethanol Fermentation ◽

Hydrothermal Carbonization ◽

Industrial Symbiosis ◽

Corn Ethanol

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Anaerobic digestion of thin stillage for energy recovery and water reuse in corn-ethanol plants

Bioresource Technology ◽

10.1016/j.biortech.2011.08.028 ◽

2011 ◽

Vol 102 (21) ◽

pp. 9891-9896 ◽

Cited By ~ 47

Author(s):

A. Alkan-Ozkaynak ◽

K.G. Karthikeyan

Keyword(s):

Anaerobic Digestion ◽

Water Reuse ◽

Energy Recovery ◽

Corn Ethanol ◽

Thin Stillage

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Net Energy Gain and Water Footprint of Corn Ethanol Production in Thailand

Energy Procedia ◽

10.1016/j.egypro.2017.07.003 ◽

2017 ◽

Vol 118 ◽

pp. 15-20 ◽

Cited By ~ 3

Author(s):

Nichanan Cheroennet ◽

Unchalee Suwanmanee

Keyword(s):

Ethanol Production ◽

Water Footprint ◽

Energy Gain ◽

Net Energy ◽

Corn Ethanol ◽

Net Energy Gain

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Very High Gravity Fermentation Using Sweet Potato for Fuel Ethanol Production

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.59 ◽

2011 ◽

Vol 236-238 ◽

pp. 59-62 ◽

Cited By ~ 1

Author(s):

Yu Shen ◽

Hai Dong Zhang ◽

Xu Xu Zheng ◽

Xian Ming Zhang ◽

Jin Song Guo ◽

...

Keyword(s):

Ethanol Production ◽

Sweet Potato ◽

Ethanol Fermentation ◽

Fuel Ethanol ◽

High Rate ◽

Polluted Water ◽

High Gravity ◽

Very High Gravity ◽

Very High Gravity Fermentation ◽

Very High

Sweet potato (Ipomoea batatas) was a wildely planted root crop in most area of China and considered as a good feedstock for fuel ethanol production. Very high gravity ethanol fermentation technology exhibited promising industrial application for advantages including productivity improvement, polluted water output reduction and energy consumption saving. In this study very high gravity liquefied sweet potato mash containing 260 g/kg glucose (after fully saccharified) was used for fuel ethanol fermentation. 0.8 g/kg (dry matter weight) was proved as the optimum glucoamylase adding dosage in simultaneous saccharification and fermentation. Datas analysis indicated that the osmotic pressure was controlled strictly exhibited by high growth rate of yeast and high rate of ethanol formation comparing with other dosages, and 119.78 g/kg (15.07 %, v/v) ethanol equivalent to 90.16 % of theoretical yield was achieved in 64 hours.

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The effect of sulfide and ammonia on cassava fermentation for ethanol production in an ethanol–methane coupled system

Water Science & Technology ◽

10.2166/wst.2011.668 ◽

2011 ◽

Vol 64 (10) ◽

pp. 2066-2071 ◽

Cited By ~ 2

Author(s):

Ke Wang ◽

Li Jiang ◽

ZhongGui Mao ◽

ChengMing Zhang ◽

JianHua Zhang ◽

...

Keyword(s):

Anaerobic Digestion ◽

Ethanol Production ◽

Ethanol Fermentation ◽

Coupled System ◽

Total Sugar ◽

Fermentation Performance ◽

Two Stage ◽

Total Consumption ◽

Wastewater Pollution ◽

Final Ethanol Concentration

An ethanol–methane coupled system was proposed to resolve wastewater pollution in cassava ethanol production. The wastewater originated from ethanol distillation is treated with two-stage anaerobic digestion and then recycled for medium preparation for the next batch ethanol fermentation, thus eliminating wastewater discharge and saving fresh water. The constituents of the two-stage anaerobic digestion effluent were complex which influenced the ethanol fermentation performance. This paper aimed to study the effect of two constituents in the effluent, i.e. sulfide and ammonia, on cassava-based ethanol fermentation performance. It was found that sulfide reduced the consumption rate of total sugar by significantly inhibiting the growth of Saccharomyces cerevisiae, but the total consumption amount of total sugar at the end of fermentation was not influenced. S. cerevisiae produced more glycerol and less ethanol at the end of fermentation containing higher concentration of sodium sulfide. Ethanol fermentation performance could be hardly influenced by the sulfide in the two-stage effluent because of the very low concentration. More glycerol was produced while final ethanol concentration was reduced when the level of ammonia in the two-stage effluent was higher.

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