Editorial

6 pages, 224 KiB

Open AccessEditorial

Biofuels Production and Processing Technology

by Alessia Tropea

Fermentation 2022, 8(7), 319; https://doi.org/10.3390/fermentation8070319 - 07 Jul 2022

Cited by 9 | Viewed by 4158

The negative global warming impact and global environmental pollution due to fossil fuels mean that the main challenge of modern society is finding alternatives to conventional fuels. In this scenario, biofuels derived from renewable biomass represent the most promising renewable energy sources. Depending [...] Read more.

The negative global warming impact and global environmental pollution due to fossil fuels mean that the main challenge of modern society is finding alternatives to conventional fuels. In this scenario, biofuels derived from renewable biomass represent the most promising renewable energy sources. Depending on the biomass used by the fermentation technologies, it is possible obtain first-generation biofuels produced from food crops, second-generation biofuels produced from non-food feedstock, mainly starting from renewable lignocellulosic biomasses, and third-generation biofuels, represented by algae or food waste biomass. Although biofuels appear to be the closest alternative to fossil fuels, it is necessary for them to be produced in competitive quantities and costs, requiring both improvements to production technologies and diversification of feedstock. This Special Issue is focused on technological innovations, which include but are not limited to the utilization of different feedstock; different biomass pretreatments; fermentation strategies, such as simultaneous saccharification and fermentation (SSF) or separate hydrolysis and fermentation (SHF); different applied microorganisms used as monoculture or co-culture; and different setups for biofuel fermentation processes. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

Research

Jump to: Editorial, Review

27 pages, 2631 KiB

Open AccessArticle

Simultaneous Saccharification and Fermentation of Empty Fruit Bunches of Palm for Bioethanol Production Using a Microbial Consortium of S. cerevisiae and T. harzianum

by Eryati Derman, Rahmath Abdulla, Hartinie Marbawi, Mohd Khalizan Sabullah, Jualang Azlan Gansau and Pogaku Ravindra

Fermentation 2022, 8(7), 295; https://doi.org/10.3390/fermentation8070295 - 23 Jun 2022

Cited by 13 | Viewed by 4218

Abstract

A simultaneous saccharification and fermentation (SSF) optimization process was carried out on pretreated empty fruit bunches (EFBs) by employing the Response Surface Methodology (RSM). EFBs were treated using sequential acid-alkali pretreatment and analyzed physically by a scanning electron microscope (SEM). The findings revealed [...] Read more.

A simultaneous saccharification and fermentation (SSF) optimization process was carried out on pretreated empty fruit bunches (EFBs) by employing the Response Surface Methodology (RSM). EFBs were treated using sequential acid-alkali pretreatment and analyzed physically by a scanning electron microscope (SEM). The findings revealed that the pretreatment had changed the morphology and the EFBs’ structure. Then, the optimum combination of enzymes and microbes for bioethanol production was screened. Results showed that the combination of S. cerevisiae and T. harzianum and enzymes (cellulase and β-glucosidase) produced the highest bioethanol concentration with 11.76 g/L and a bioethanol yield of 0.29 g/g EFB using 4% (w/v) treated EFBs at 30 °C for 72 h. Next, the central composite design (CCD) of RSM was employed to optimize the SSF parameters of fermentation time, temperature, pH, and inoculum concentration for higher yield. The analysis of optimization by CCD predicted that 9.72 g/L of bioethanol (0.46 g/g ethanol yield, 90.63% conversion efficiency) could be obtained at 72 h, 30 °C, pH 4.8, and 6.79% (v/v) of inoculum concentration using 2% (w/v) treated EFBs. Results showed that the fermentation process conducted using the optimized conditions produced 9.65 g/L of bioethanol, 0.46 g/g ethanol yield, and 89.56% conversion efficiency, which was in close proximity to the predicted CCD model. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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19 pages, 4494 KiB

Open AccessArticle

Bioethanol Production Optimization from KOH-Pretreated Bombax ceiba Using Saccharomyces cerevisiae through Response Surface Methodology

by Misbah Ghazanfar, Muhammad Irfan, Muhammad Nadeem, Hafiz Abdullah Shakir, Muhammad Khan, Irfan Ahmad, Shagufta Saeed, Yue Chen and Lijing Chen

Fermentation 2022, 8(4), 148; https://doi.org/10.3390/fermentation8040148 - 28 Mar 2022

Cited by 13 | Viewed by 3160

Abstract

The present study was based on the production of bioethanol from alkali-pretreated seed pods of Bombax ceiba. Pretreatment is necessary to properly utilize seed pods for bioethanol production via fermentation. This process assures the accessibility of cellulase to the cellulose found in seedpods [...] Read more.

The present study was based on the production of bioethanol from alkali-pretreated seed pods of Bombax ceiba. Pretreatment is necessary to properly utilize seed pods for bioethanol production via fermentation. This process assures the accessibility of cellulase to the cellulose found in seedpods by removing lignin. Untreated, KOH-pretreated, and KOH-steam-pretreated substrates were characterized for morphological, thermal, and chemical changes by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Hydrolysis of biomass was performed using both commercial and indigenous cellulase. Two different fermentation approaches were used, i.e., separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). Findings of the study show that the maximum saccharification (58.6% after 24 h) and highest ethanol titer (57.34 g/L after 96 h) were observed in the KOH-steam-treated substrate in SSF. This SSF using the KOH-steam-treated substrate was further optimized for physical and nutritional parameters by one factor at a time (OFAT) and central composite design (CCD). The optimum fermentation parameters for maximum ethanol production (72.0 g/L) were 0.25 g/L yeast extract, 0.1 g/L K₂HPO₄, 0.25 g/L (NH₄)₂SO₄, 0.09 g/L MgSO₄, 8% substrate, 40 IU/g commercial cellulase, 1% Saccharomyces cerevisiae inoculum, and pH 5. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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12 pages, 2247 KiB

Open AccessArticle

Bioethanol Production from Spent Sugar Beet Pulp—Process Modeling and Cost Analysis

by Damjan Vučurović, Bojana Bajić, Vesna Vučurović, Rada Jevtić-Mučibabić and Siniša Dodić

Fermentation 2022, 8(3), 114; https://doi.org/10.3390/fermentation8030114 - 06 Mar 2022

Cited by 5 | Viewed by 3892

Abstract

Global economic development has led to the widespread use of fossil fuels, and their extensive use has resulted in increased environmental pollution. As a result, significantly more attention is being paid to environmental issues and alternative renewable energy sources. Bioethanol production from agro-industrial [...] Read more.

Global economic development has led to the widespread use of fossil fuels, and their extensive use has resulted in increased environmental pollution. As a result, significantly more attention is being paid to environmental issues and alternative renewable energy sources. Bioethanol production from agro-industrial byproducts, residues, and wastes is one example of sustainable energy production. This research aims to develop a process and cost model of bioethanol production from spent sugar beet pulp. The model was developed using SuperPro Designer^® v.11 (Intelligen Inc., Scotch Plains, NJ, USA) software, and determines the capital and production costs for a bioethanol-producing plant processing about 17,000 tons of spent sugar beet pulp per year. In addition, the developed model predicts the process and economic indicators of the analyzed biotechnological process, determines the share of major components in bioethanol production costs, and compares different model scenarios for process co-products. Based on the obtained results, the proposed model is viable and represents a base case for further bioprocess development. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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10 pages, 441 KiB

Open AccessArticle

Pineapple Waste Cell Wall Sugar Fermentation by Saccharomyces cerevisiae for Second Generation Bioethanol Production

by Fabio Salafia, Antonio Ferracane and Alessia Tropea

Fermentation 2022, 8(3), 100; https://doi.org/10.3390/fermentation8030100 - 27 Feb 2022

Cited by 11 | Viewed by 4502

Abstract

Agricultural food waste is rich in cellulosic and non-cellulosic fermentable substance. In this study, we investigated the bioconversion of pineapple waste cell wall sugars into bioethanol by simultaneous saccharification and fermentation using Saccharomyces cerevisiae ATCC 4126. Soluble and insoluble cell wall sugars were [...] Read more.

Agricultural food waste is rich in cellulosic and non-cellulosic fermentable substance. In this study, we investigated the bioconversion of pineapple waste cell wall sugars into bioethanol by simultaneous saccharification and fermentation using Saccharomyces cerevisiae ATCC 4126. Soluble and insoluble cell wall sugars were investigated during the fermentation process. Moreover, the fermentation medium was investigated for protein, moisture, ash, lignin and glycerol determinations with a particular focus on the increase in single cell protein due to yeast growth, allowing a total valorization of the resulting fermentation medium, with no further waste production, with respect to environmental sustainability. Soluble and insoluble sugars in the starting material were 32.12% and 26.33% respectively. The main insoluble sugars resulting from the cell wall hydrolysis detected at the beginning of the fermentation, were glucose, xylose and uronic acid. Glucose and mannose were the most prevalent sugars in the soluble sugars fraction. The ethanol theoretical yield, calculated according to dry matter lost, reached up to 85% (3.9% EtOH). The final fermentation substrate was mainly represented by pentose sugars. The protein content increased from 4.45% up to 20.1% during the process. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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17 pages, 3015 KiB

Open AccessArticle

Performance Evaluation of Pressurized Anaerobic Digestion (PDA) of Raw Compost Leachate

by Alessio Siciliano, Carlo Limonti and Giulia Maria Curcio

Fermentation 2022, 8(1), 15; https://doi.org/10.3390/fermentation8010015 - 30 Dec 2021

Cited by 12 | Viewed by 2188

Abstract

Anaerobic digestion (AD) represents an advantageous solution for the treatment and valorization of organic waste and wastewater. To be suitable for energy purposes, biogas generated in AD must be subjected to proper upgrading treatments aimed at the removal of carbon dioxide and other [...] Read more.

Anaerobic digestion (AD) represents an advantageous solution for the treatment and valorization of organic waste and wastewater. To be suitable for energy purposes, biogas generated in AD must be subjected to proper upgrading treatments aimed at the removal of carbon dioxide and other undesirable gases. Pressurized anaerobic digestion (PDA) has gained increasing interest in recent years, as it allows the generation of a high-quality biogas with a low CO₂ content. However, high pressures can cause some negative impacts on the AD process, which could be accentuated by feedstock characteristics. Until now, few studies have focused on the application of PAD to the treatment of real waste. The present work investigated, for the first time, the performance of the pressurized anaerobic digestion of raw compost leachate. The study was conducted in a lab-scale pressurized CSTR reactor, working in semi-continuous mode. Operating pressures from the atmospheric value to 4 bar were tested at organic loading rate (OLR) values of 20 and 30 kg_COD/m³d. In response to the rise in operating pressure, for both OLR values tested, a decrease of CO₂ content in biogas was observed, whereas the CH₄ fraction increased to values around 75% at 4 bar. Despite this positive effect, the pressure growth caused a decline in COD removal from 88 to 62% in tests with OLR = 20 kg_COD/m³d. At OLR = 30 kg_COD/m³d, an overload condition was observed, which induced abatements of about 56%, regardless of the applied pressure. With both OLR values, biogas productions and specific methane yields decreased largely when the pressure was brought from atmospheric value to just 1 bar. The values went from 0.33 to 0.27 L_CH4/g_CODremoved at 20 kg_COD/m³d, and from 0.27 to 0.18 L_CH4/g_CODremoved at 30 kg_COD/m³d. Therefore, as the pressure increased, although there was an enhanced biogas quality, the overall amount of methane was lowered. The pressured conditions did not cause substantial modification in the characteristics of digestates. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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12 pages, 1245 KiB

Open AccessArticle

Enhanced Energy Recovery from Food Waste by Co-Production of Bioethanol and Biomethane Process

by Teeraya Jarunglumlert, Akarasingh Bampenrat, Hussanai Sukkathanyawat and Chattip Prommuak

Fermentation 2021, 7(4), 265; https://doi.org/10.3390/fermentation7040265 - 16 Nov 2021

Cited by 13 | Viewed by 3263

Abstract

The primary objective of this research is to study ways to increase the potential of energy production from food waste by co-production of bioethanol and biomethane. In the first step, the food waste was hydrolysed with an enzyme at different concentrations. By increasing [...] Read more.

The primary objective of this research is to study ways to increase the potential of energy production from food waste by co-production of bioethanol and biomethane. In the first step, the food waste was hydrolysed with an enzyme at different concentrations. By increasing the concentration of enzyme, the amount of reducing sugar produced increased, reaching a maximum amount of 0.49 g/g food waste. After 120 h of fermentation with Saccharomyces cerevisiae, nearly all reducing sugars in the hydrolysate were converted to ethanol, yielding 0.43–0.50 g ethanol/g reducing sugar, or 84.3–99.6% of theoretical yield. The solid residue from fermentation was subsequently subjected to anaerobic digestion, allowing the production of biomethane, which reached a maximum yield of 264.53 ± 2.3 mL/g VS. This results in a gross energy output of 9.57 GJ, which is considered a nearly 58% increase in total energy obtained, compared to ethanol production alone. This study shows that food waste is a raw material with high energy production potential that could be further developed into a promising energy source. Not only does this benefit energy production, but it also lowers the cost of food waste disposal, reduces greenhouse gas emissions, and is a sustainable energy production approach. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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10 pages, 1241 KiB

Open AccessArticle

Preparation of Porous Biochar from Soapberry Pericarp at Severe Carbonization Conditions

by Wen-Tien Tsai, Tasi-Jung Jiang, Yu-Quan Lin, Hsuan-Lun Chang and Chi-Hung Tsai

Fermentation 2021, 7(4), 228; https://doi.org/10.3390/fermentation7040228 - 11 Oct 2021

Cited by 7 | Viewed by 1661

Abstract

The residue remaining after the water extraction of soapberry pericarp from a biotechnology plant was used to produce a series of biochar products at pyrolytic temperatures (i.e., 400, 500, 600, 700 and 800 °C) for 20 min plant was used to produce a [...] Read more.

The residue remaining after the water extraction of soapberry pericarp from a biotechnology plant was used to produce a series of biochar products at pyrolytic temperatures (i.e., 400, 500, 600, 700 and 800 °C) for 20 min plant was used to produce a series of biochar products. The effects of the carbonization temperature on the pore and chemical properties were investigated by using N₂ adsorption–desorption isotherms, energy dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FTIR). The pore properties of the resulting biochar products significantly increased as the carbonization temperature increased from 700 to 800 °C. The biochar prepared at 800 °C yielded the maximal BET surface area of 277 m²/g and total pore volume of 0.153 cm³/g, showing that the percentages of micropores and mesopores were 78% and 22%, respectively. Based on the findings of the EDS and the FTIR, the resulting biochar product may be more hydrophilic because it is rich in functional oxygen-containing groups on the surface. These results suggest that soapberry pericarp can be reused as an excellent precursor for preparing micro-mesoporous biochar products in severe carbonization conditions. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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18 pages, 6629 KiB

Open AccessArticle

Multi-Objective Sustainability Optimization of Biomass Residues to Ethanol via Gasification and Syngas Fermentation: Trade-Offs between Profitability, Energy Efficiency, and Carbon Emissions

by Elisa M. de Medeiros, Henk Noorman, Rubens Maciel Filho and John A. Posada

Fermentation 2021, 7(4), 201; https://doi.org/10.3390/fermentation7040201 - 23 Sep 2021

Cited by 5 | Viewed by 2335

Abstract

This work presents a strategy for optimizing the production process of ethanol via integrated gasification and syngas fermentation, a conversion platform of growing interest for its contribution to carbon recycling. The objective functions (minimum ethanol selling price (MESP), energy efficiency, and carbon footprint) [...] Read more.

This work presents a strategy for optimizing the production process of ethanol via integrated gasification and syngas fermentation, a conversion platform of growing interest for its contribution to carbon recycling. The objective functions (minimum ethanol selling price (MESP), energy efficiency, and carbon footprint) were evaluated for the combinations of different input variables in models of biomass gasification, energy production from syngas, fermentation, and ethanol distillation, and a multi-objective genetic algorithm was employed for the optimization of the integrated process. Two types of waste feedstocks were considered, wood residues and sugarcane bagasse, with the former leading to lower MESP and a carbon footprint of 0.93 USD/L and 3 g CO₂eq/MJ compared to 1.00 USD/L and 10 g CO₂eq/MJ for sugarcane bagasse. The energy efficiency was found to be 32% in both cases. An uncertainty analysis was conducted to determine critical decision variables, which were found to be the gasification zone temperature, the split fraction of the unreformed syngas sent to the combustion chamber, the dilution rate, and the gas residence time in the bioreactor. Apart from the abovementioned objectives, other aspects such as water footprint, ethanol yield, and energy self-sufficiency were also discussed. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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13 pages, 1165 KiB

Open AccessArticle

Residual Gas for Ethanol Production by Clostridium carboxidivorans in a Dual Impeller Stirred Tank Bioreactor (STBR)

by Carolina Benevenuti, Marcelle Branco, Mariana do Nascimento-Correa, Alanna Botelho, Tatiana Ferreira and Priscilla Amaral

Fermentation 2021, 7(3), 199; https://doi.org/10.3390/fermentation7030199 - 21 Sep 2021

Cited by 6 | Viewed by 2865

Abstract

Recycling residual industrial gases and residual biomass as substrates to biofuel production by fermentation is an important alternative to reduce organic wastes and greenhouse gases emission. Clostridium carboxidivorans can metabolize gaseous substrates as CO and CO₂ to produce ethanol and higher alcohols [...] Read more.

Recycling residual industrial gases and residual biomass as substrates to biofuel production by fermentation is an important alternative to reduce organic wastes and greenhouse gases emission. Clostridium carboxidivorans can metabolize gaseous substrates as CO and CO₂ to produce ethanol and higher alcohols through the Wood-Ljungdahl pathway. However, the syngas fermentation is limited by low mass transfer rates. In this work, a syngas fermentation was carried out in serum glass bottles adding different concentrations of Tween® 80 in ATCC® 2713 culture medium to improve gas-liquid mass transfer. We observed a 200% increase in ethanol production by adding 0.15% (v/v) of the surfactant in the culture medium and a 15% increase in biomass production by adding 0.3% (v/v) of the surfactant in the culture medium. The process was reproduced in stirred tank bioreactor with continuous syngas low flow, and a maximum ethanol productivity of 0.050 g/L.h was achieved. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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13 pages, 2705 KiB

Open AccessArticle

Comparison of Water-Removal Efficiency of Molecular Sieves Vibrating by Rotary Shaking and Electromagnetic Stirring from Feedstock Oil for Biofuel Production

by Cherng-Yuan Lin and Lei Ma

Fermentation 2021, 7(3), 132; https://doi.org/10.3390/fermentation7030132 - 26 Jul 2021

Cited by 2 | Viewed by 4580

Abstract

Adequate water-removal techniques are requisite to remain superior biofuel quality. The effects of vibrating types and operating time on the water-removal efficiency of molecular sieves were experimentally studied. Molecular sieves of 3 Å pore size own excellent hydrophilic characteristics and hardly absorb molecules [...] Read more.

Adequate water-removal techniques are requisite to remain superior biofuel quality. The effects of vibrating types and operating time on the water-removal efficiency of molecular sieves were experimentally studied. Molecular sieves of 3 Å pore size own excellent hydrophilic characteristics and hardly absorb molecules other than water. Molecular sieves of 3 Å accompanied by two different vibrating types, rotary shaking and electromagnetic stirring, were used to remove initial water from the reactant mixture of feedstock oil in order to prevent excessive growth or breeding of microorganisms in the biofuel product. The physical structure of about 66% molecular sieves was significantly damaged due to shattered collision between the magnetic bar and molecular sieves during electromagnetic stirring for 1 h. The molecular sieves vibrated by the rotary shaker appeared to have relatively higher water-removal efficiency than those by the electromagnetic stirrer and by keeping the reactant mixture motionless by 6 and 5 wt.%, respectively. The structure of the molecular sieves vibrated by an electromagnetic stirrer and thereafter being dehydrated appeared much more irregular and damaged, and the weight loss accounted for as high as 19 wt.%. In contrast, the structure of the molecular sieves vibrated by a rotary shaker almost remained original ball-shaped, and the weight loss was much less after regenerative treatment for those molecular sieves. As a consequence, the water-removal process using molecular sieves vibrated by the rotary shaker is considered a competitive method during the biofuel production reaction to achieve a superior quality of biofuels. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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12 pages, 834 KiB

Open AccessArticle

Bottlenecks in the Development of Bioethanol from Lignocellulosic Resources for the Circular Economy in Taiwan

by Yu-Ru Lee and Wen-Tien Tsai

Fermentation 2021, 7(3), 131; https://doi.org/10.3390/fermentation7030131 - 26 Jul 2021

Cited by 5 | Viewed by 2001

Abstract

Strategies and actions for mitigating the emissions of greenhouse gas (GHG) and air pollutants in the transportation sector are becoming more important and urgent due to concerns related to public health and climate change. As a result, the Taiwanese government has promulgated a [...] Read more.

Strategies and actions for mitigating the emissions of greenhouse gas (GHG) and air pollutants in the transportation sector are becoming more important and urgent due to concerns related to public health and climate change. As a result, the Taiwanese government has promulgated a number of regulatory measures and promotion plans (or programs) on bioethanol use, novel fermentation research projects and domestic production since the mid-2000s. The main aim of this paper was to present a trend analysis of the motor gasoline supply/consumption and bioethanol supply, and the regulatory system relevant to bioethanol production and gasohol use since 2007 based on the official database and the statistics. The motor gasoline supply has shown a decreasing trend in the last five years (2016–2020), especially in 2020, corresponding to the impact of the COVID-19 outbreak in 2020. Although the government provided a subsidy of NT$ 1.0–2.0 dollars per liter for refueling E3 gasohol based on the price of 95-unleaded gasoline, the bioethanol supply has shown decreasing demand since 2012. In addition, the plans for domestic bioethanol production from lignocellulosic residues or energy crops were ceased in 2011 due to non-profitability. To examine the obstacles to bioethanol promotion in Taiwan, the bottlenecks to bioethanol production and gasohol use were addressed from the perspectives of the producer (domestic enterprise), the seller (gas station) and the consumer (end user). Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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11 pages, 3139 KiB

Open AccessArticle

Techno-Economic Analysis of Integrating Soybean Biorefinery Products into Corn-Based Ethanol Fermentation Operations

by Kurt A. Rosentrater and Weitao Zhang

Fermentation 2021, 7(2), 82; https://doi.org/10.3390/fermentation7020082 - 25 May 2021

Cited by 1 | Viewed by 2951

Abstract

With the development of agricultural biorefineries and bioprocessing operations, understanding the economic efficiencies and environmental impacts for these have gradually become popular for the deployment of these industrial processes. The corn-based ethanol and soybean oil refining industries have been examined extensively over the [...] Read more.

With the development of agricultural biorefineries and bioprocessing operations, understanding the economic efficiencies and environmental impacts for these have gradually become popular for the deployment of these industrial processes. The corn-based ethanol and soybean oil refining industries have been examined extensively over the years, especially details of processing technologies, including materials, reaction controls, equipment, and industrial applications. The study focused on examining the production efficiency changes and economic impacts of integrating products from the enzyme-assisted aqueous extraction processing (EAEP) of soybeans into corn-based ethanol fermentation processing. Using SuperPro Designer to simulate production of corn-based ethanol at either 40 million gallons per year (MGY) or 120 MGY, with either oil separation or no oil removal, we found that indeed integrating soy products into corn ethanol fermentation may be slightly more expensive in terms of production costs, but economic returns justify this integration due to substantially greater quantities of ethanol, distillers corn oil, and distillers dried grains with solubles being produced. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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Review

Jump to: Editorial, Research

14 pages, 2263 KiB

Open AccessReview

Recent Developments in Lignocellulosic Biofuels, a Renewable Source of Bioenergy

by Ashutosh Kumar Rai, Naief Hamoud Al Makishah, Zhiqiang Wen, Govind Gupta, Soumya Pandit and Ram Prasad

Fermentation 2022, 8(4), 161; https://doi.org/10.3390/fermentation8040161 - 03 Apr 2022

Cited by 24 | Viewed by 5406

Abstract

Biofuel consists of non-fossil fuel derived from the organic biomass of renewable resources, including plants, animals, microorganisms, and waste. Energy derived from biofuel is known as bioenergy. The reserve of fossil fuels is now limited and continuing to decrease, while at the same [...] Read more.

Biofuel consists of non-fossil fuel derived from the organic biomass of renewable resources, including plants, animals, microorganisms, and waste. Energy derived from biofuel is known as bioenergy. The reserve of fossil fuels is now limited and continuing to decrease, while at the same time demand for energy is increasing. In order to overcome this scarcity, it is vital for human beings to transfer their dependency on fossil fuels to alternative types of fuel, including biofuels, which are effective methods of fulfilling present and future demands. The current review therefore focusses on second-generation lignocellulosic biofuels obtained from non-edible plant biomass (i.e., cellulose, lignin, hemi-celluloses, non-food material) in a more sustainable manner. The conversion of lignocellulosic feedstock is an important step during biofuel production. It is, however, important to note that, as a result of various technical restrictions, biofuel production is not presently cost efficient, thus leading to the need for improvement in the methods employed. There remain a number of challenges for the process of biofuel production, including cost effectiveness and the limitations of various technologies employed. This leads to a vital need for ongoing and enhanced research and development, to ensure market level availability of lignocellulosic biofuel. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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37 pages, 5095 KiB

Open AccessReview

Valorisation of CO₂ into Value-Added Products via Microbial Electrosynthesis (MES) and Electro-Fermentation Technology

by Marzuqa Quraishi, Kayinath Wani, Soumya Pandit, Piyush Kumar Gupta, Ashutosh Kumar Rai, Dibyajit Lahiri, Dipak A. Jadhav, Rina Rani Ray, Sokhee P. Jung, Vijay Kumar Thakur and Ram Prasad

Fermentation 2021, 7(4), 291; https://doi.org/10.3390/fermentation7040291 - 30 Nov 2021

Cited by 34 | Viewed by 7517

Abstract

Microbial electrocatalysis reckons on microbes as catalysts for reactions occurring at electrodes. Microbial fuel cells and microbial electrolysis cells are well-known in this context; both prefer the oxidation of organic and inorganic matter for producing electricity. Notably, the synthesis of high energy-density chemicals [...] Read more.

Microbial electrocatalysis reckons on microbes as catalysts for reactions occurring at electrodes. Microbial fuel cells and microbial electrolysis cells are well-known in this context; both prefer the oxidation of organic and inorganic matter for producing electricity. Notably, the synthesis of high energy-density chemicals (fuels) or their precursors by microorganisms using bio-cathode to yield electrical energy is called Microbial Electrosynthesis (MES), giving an exceptionally appealing novel way for producing beneficial products from electricity and wastewater. This review accentuates the concept, importance and opportunities of MES, as an emerging discipline at the nexus of microbiology and electrochemistry. Production of organic compounds from MES is considered as an effective technique for the generation of various beneficial reduced end-products (like acetate and butyrate) as well as in reducing the load of CO₂ from the atmosphere to mitigate the harmful effect of greenhouse gases in global warming. Although MES is still an emerging technology, this method is not thoroughly known. The authors have focused on MES, as it is the next transformative, viable alternative technology to decrease the repercussions of surplus carbon dioxide in the environment along with conserving energy. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology)

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