Fermentation Of Biomass Research Articles

Fed-batch fermentation of sugarcane biomass applied for biomolecules production in fluidized bed reactor

A production of xylitol and ethanol from a mixture of sugarcane straw and bagasse (biomass composed of 50 % m/m of both) hydrolysates was evaluated in a batch-fed column reactor. The biomass underwent acid hydrolysis, and the xylitol production process from hemicellulosic hydrolysate was assessed to determine the feasibility of operating four batches, showing conversions (YP/S of 0.28, 0.46, 0.57 and 0.47 g/g). Afterwards, alkaline pretreatment was performed, followed by enzymatic saccharification of the remaining biomass to obtain fermentable sugars for ethanol production. This involved operating five cycles, showing YP/S values of 0.14, 0.18, 0.24, 0.38 and 0.37 g/g, respectively. Additionally, the utilization of the black liquor generated from alkaline pretreatment was studied for reuse in subsequent pretreatments, demonstrating the feasibility of 4 cycles and thus, reducing the need for chemical preparation. The potential for maximizing the use of the main fractions of sugarcane biomass was confirmed.

Bio-Polyethylene and Polyethylene Biocomposites: An Alternative toward a Sustainable Future.

Polyethylene (PE), a highly prevalent non-biodegradable polymer in the field of plastics, presents a waste management issue. To alleviate this issue, bio-based PE (bio-PE), derived from renewable resources like corn and sugarcane, offers an environmentally friendly alternative. This review discusses various production methods of bio-PE, including fermentation, gasification, and catalytic conversion of biomass. Interestingly, the bio-PE production volumes and market are expanding due to the growing environmental concerns and regulatory pressures. Additionally, the production of PE and bio-PE biocomposites using agricultural waste as filler materials, highlights the growing demand for sustainable alternatives to conventional plastics. According to previous studies, addition of ≈50% defibrillated corn and abaca fibers into bio-PE matrix and a compatibilizer, results in the highest Young's modulus of 4.61 and 5.81GPa, respectively. These biocomposites have potential applications in automotive, building construction, and furniture industries. Moreover, the advancement made in abiotic and biotic degradation of PE and PE biocomposites is elucidated to address their environmental impacts. Finally, the paper concludes with insights into the opportunities, challenges, and future perspectives in the sustainable production and utilization of PE and bio-PE biocomposites. In summary, production of PE and bio-PE biocomposites can contribute to a cleaner and sustainable future.

Production of Bio-Ethanol from Agricultural Waste Using Microbes: An Overview

Ethanol produced through the fermentation of plant biomass is considered an environment friendly alternate to fossil fuels. Bioethanol and biodiesel, commonly known as second-generation biofuels, are produced through biological processes using agro-industrial waste and are considered sustainable, safe, and ecofriendly. These biofuels can minimize the emission of carbon dioxide and reduced the world’s dependence on fossil fuel. This review article focuses on three generations of biofuels, particularly the production of biofuel using fungal biocatalysts specifically Aspergillus niger and Saccharomyces cerevisiae and the mechanism by which they convert biomass into biofuel. A. niger is known for releasing cellulolytic and pectolytic enzymes to hydrolyze biomass and survive against toxins, while S. cerevisiae produces invertase and zymase enzymes to convert sucrose into fructose and glucose sugars, and then further convert fructose and glucose into ethanol. The main purpose of this review is to explore alternative techniques for generating biofuels, using as few harmful chemicals as possible and reducing time consumption.

A virtuous cycle for thermal treatment of polyvinyl chloride and fermentation of lignocellulosic biomass

In this study, a highly corrosive substance, hydrogen chloride (HCl), obtained through the dechlorination of polyvinyl chloride (PVC), was utilized for acid pretreatment in the production of lignocellulosic bioethanol. The study determined that the optimal concentration of HCl was 5 wt%, resulting in the highest sugar recovery of 85.98% from oak sawdust when treated at 130 °C for 2 h. The production of bioethanol (BE) by Pichia stipitis using the hydrolysates treated with 5% HCl and enzymes, supplemented with N-sources, demonstrated efficient productivity compared to the control group. To achieve a virtuous cycle, two residues from the dechlorination of PVC and saccharification of oak sawdust were pyrolyzed in a carbon dioxide (CO2) environment. The generation of carbon monoxide (CO) was significantly enhanced by the homogeneous reaction between CO2 and volatiles. This homogeneous reaction led to the modification of the compositional matrix in the oil. The generation of low-molecular-weight hydrocarbons in oil was observed under CO2 conditions. To impart high reactivity to CO2, the catalytic pyrolysis of the residues was performed in the presence of Ni/SiO2. Indeed, the CO2 reactivity was catalytically enhanced, which greatly expedited the redox kinetics underlying the chemical reactions of CO2 with volatiles from PVC. The experimental findings provide a great avenue for hybridizing the thermochemical process of PVC and the biological bioethanol production process of lignocellulosic biomass. Such efforts are promising from the perspective of economic viability in the waste-to-energy and biofuel fields.

Sustainable synthesis of imidazoles using a catalyst-free approach and ethyl lactate as a bio-based green solvent in the Debus-Japp-Radziszewski reaction

A highly substituted family of imidazoles is effectively obtained through the Debus-Japp-Radziszewski reaction. In this process, benzil, ammonium acetate, and various benzaldehydes react in a particularly notable solvent: ethyl lactate (EL). This bio-based solvent, derived from biomass fermentation, stands out not only for its sustainable origin but also for its remarkable properties. Ethyl lactate is biodegradable, health-risk-free, is easily recyclable, and is non-corrosive, categorizing it as an exemplary green solvent. The multicomponent reaction, carried out under these conditions, eliminates the need for a catalyst, resulting in products with good yields. The isolation of the products is very simple, requiring only filtration, as they are insoluble in the solvent. In this way, this methodology aligns with various principles of green chemistry, emphasizing the strategic choice of ethyl lactate. This choice has a positive impact on the synthesis of imidazoles, well-known for their pharmacological properties.

Waste Lignocellulosic Biomass as a Source for Bioethanol Production

Synthetically produced biofuels play a critical role in the energy transition away from fossil fuels. Biofuels could effectively lower greenhouse gas (GHG) emissions and contribute to better air quality. One of these biofuels is bioethanol, which could act as a gasoline replacement. For this purpose, a simulation of bioethanol production through lignocellulosic biomass fermentation, focused on distillation, was carried out in simulation software Aspen Plus. Since the possibility of absolute ethanol production through distillation is limited by the ethanol–water azeotrope, pressure swing distillation (PSD) was used to obtain fuel-grade ethanol (EtOH) with a fraction of 99.60 wt.%. The flowsheet was optimised with NQ analysis, which is a simple optimisation method for distillation columns. We found that the PSD has the potential to concentrate the EtOH to a desired value, while simultaneously removing other unwanted impurities whose presence is a consequence of pretreatment and fermentation processes.

Henna plant biomass enhanced azo dye removal: Operating performance, microbial community and machine learning modeling

The bio-reduction of azo dyes is significantly dependent on the availability of electron donors and external redox mediators. In this study, the natural henna plant biomass was supplemented to promote the biological reduction of an azo dye of Acid Orange 7 (AO7). Besides, the machine learning (ML) approach was applied to decipher the intricate process of henna-assisted azo dye removal. The experimental results indicated that the hydrolysis and fermentation of henna plant biomass provided both electron donors such as volatile fatty acid (VFA) and redox mediator of lawsone to drive the bio-reduction of AO7 to sulfanilic acid (SA). The high henna dosage selectively enriched certain bacteria, such as Firmicutes phylum, Levilinea and Paludibacter genera, functioning in both the henna fermentation and AO7 reduction processes simultaneously. Among the three tested ML algorithms, eXtreme Gradient Boosting (XGBoost) presented exceptional accuracy and generalization ability in predicting the effluent AO7 concentrations with pH, oxidation-reduction potential (ORP), soluble chemical oxygen demand (SCOD), VFA, lawsone, henna dosage, and cumulative henna as input variables. The validating experiments with tailored optimal operating conditions and henna dosage (pH 7.5, henna dosage of 2 g/L, and cumulative henna of 14 g/L) confirmed that XGBoost was an effective ML model to predict the efficient AO7 removal (91.6%), with a negligible calculating error of 3.95%. Overall, henna plant biomass addition was a cost-effective and robust method to improve the bio-reduction of AO7, which had been demonstrated by long-term operation, ML modeling, and experimental validation.

Recovery of Isoamyl Alcohol by Graphene Oxide Immobilized Membrane and Air-Sparged Membrane Distillation.

Isoamyl alcohol is an important biomass fermentation product that can be used as a gasoline surrogate, jet fuel precursor, and platform molecule for the synthesis of fine chemicals and pharmaceuticals. This study reports on the use of graphene oxide immobilized membra (GOIMs) for the recovery of isoamyl alcohol from an aqueous matrix. The separation was performed using air-sparged membrane distillation (ASMD). In contrast to a conventional PTFE membrane, which exhibited minimal separation, preferential adsorption on graphene oxide within GOIMs resulted in highly selective isoamyl alcohol separation. The separation factor reached 6.7, along with a flux as high as 1.12 kg/m2 h. Notably, the overall mass transfer coefficients indicated improvements with a GOIM. Optimization via response surfaces showed curvature effects for the separation factor due to the interaction effects. An empirical model was generated based on regression equations to predict the flux and separation factor. This study demonstrates the potential of GOIMs and ASMD for the efficient recovery of higher alcohols from aqueous solutions, highlighting the practical applications of these techniques for the production of biofuels and bioproducts.

Two stage Stochastic Energy Scheduling for Multi Energy Rural Microgrids With Irrigation Systems and Biomass Fermentation

Two stage Stochastic Energy Scheduling for Multi Energy Rural Microgrids With Irrigation Systems and Biomass Fermentation

Renewable Fuel Production

The growing global energy demand and the environmental concerns associated with fossils fuels have sparked a shift towards renewable and sustainable energy sources, such as bioethanol. Bioethanol, a renewable liquid biofuel is a potential solution to address the challenges of energy security and climate changes. Conventionally first-generation biofuels can be produced through fermentation of starch-rich biomass i.e sugars to ethanol. The article provides a comprehensive overview of the bioethanol production process, encompassing pretreatment, enzymatic hydrolysis, fermentation by various microorganisms, and downstream processing. This focuses on the bioethanol production using microorganisms from starch-rich feedstock such as corn, wheat, potato, cassava and agricultural residues. Overall, the review emphasizes the potential of microbial bioethanol production towards a more sustainable energy landscape.

The potential of native and engineered Clostridia for biomass biorefining.

Since their first industrial application in the acetone-butanol-ethanol (ABE) fermentation in the early 1900s, Clostridia have found large application in biomass biorefining. Overall, their fermentation products include organic acids (e.g., acetate, butyrate, lactate), short chain alcohols (e.g., ethanol, n-butanol, isobutanol), diols (e.g., 1,2-propanediol, 1,3-propanediol) and H2 which have several applications such as fuels, building block chemicals, solvents, food and cosmetic additives. Advantageously, several clostridial strains are able to use cheap feedstocks such as lignocellulosic biomass, food waste, glycerol or C1-gases (CO2, CO) which confer them additional potential as key players for the development of processes less dependent from fossil fuels and with reduced greenhouse gas emissions. The present review aims to provide a survey of research progress aimed at developing Clostridium-mediated biomass fermentation processes, especially as regards strain improvement by metabolic engineering.

Ultra-low temperature direct reconstruction of biomass fermentation of ethanol to higher alcohols in water over thermostable hcp-Ni

Near-ambient temperature direct reconstruction of biomass fermentation of ethanol to higher alcohols in water over thermostable hcp-Ni.

Effective adsorptive removal of a cationic dye from aqueous solutions using a biosorbent derived from Sargassum sp.

Abstract The present research evaluated the potential use of the macroalga Sargassum sp., which was modified with filamentous fungus Cunninghamella echinulata for the biosorption of methylene blue (MB) dye. The modified fungal biomass (FERsarg) was obtained through solid-state fermentation of enzyme (alginate lyase). The FERsarg showed a pHPZC of 7.9, a low mass loss, material micro/mesoporous, and the presence of hydroxyl, carboxylic, phenolic, and carbonyl functional groups. The influence of biomass dosage, solution pH, contact time, initial concentration, and temperature were evaluated for MB biosorption, and the best results were obtained at 2 g L-1 and pH 6. The kinetic study revealed a better fit for the pseudo-second-order model, while the Sips model best described the equilibrium experimental data. The equilibrium was reached within 180 min and showed qmax yielding of 115.49 mg g-1 at 323 K. The thermodynamic understanding of the present research revealed that the biosorbent exhibited spontaneous, exothermic, and physical nature for MB removal. The adsorptive mechanism shows that the process was controlled by electrostatic attraction. Also the feasibility of using residual fermented biomass as a potential adsorbent was applied and discussed, contributing to the concept of minimum waste generation, and supporting the concept of circular bioeconomy.

RSM approach to pre-treatment of lignocellulosic waste and a statistical methodology for optimizing bioethanol production

A potential substitute for a sustainable and long-term energy source is bioethanol. Although converting lignocellulose to bioethanol may be more economical, eco-friendly, and effective, it would still require extensive process-development and improvement to make biofuel economically feasible. An essential stage in the production of bioethanol is the pre-treatment of biomass to dissolve lignin and recover holocellulose. In this study, waste biomass from agro-forestry was converted into bioethanol by using various pre-treatments and selecting the one that produced the best results to optimize the process using the Classical One Factor at a Time approach (COFAT). The saccharification of selected biomass was done using in-house cultures of hyper-cellulase (Bacillus stratosphericus N12) and hyper-xylanase (B. altitudinus Kd1) producers, while the yeast cultures for fermentation of biomass i.e. Streptomyces cerevisiae and Pichia stiptis were purchased as sterile cultures. COFAT used inoculum size, fermentation pH, incubation time and temperature as optimization parameters and each of these increased the amount of bioethanol produced. Additionally, the Central Composite Design (CCD) of Response Surface Methodology (RSM) contributed to the 28.44 g/L maximum bioethanol output. The pre-treatments that separated the lignin from the holocellulose allowed it to be used in another investigation for the manufacture of nanoparticles and as a biocontrol agent. Since each component of waste biomass can be used to make useful products such as bioethanol from holocellulose and an anti-fungalbiocontrol agentfrom lignin, a comprehensive approach to bioutilization of lignocellulosic biomass has been undertaken.

Innovating in the production of activated carbon through the reuse of fermented biomass

Innovating in the production of activated carbon through the reuse of fermented biomass

Response surface methodology optimisation enhancing lactic acid production from Prosopis africana pods by Rhizopus oryzae

Microbial fermentation of lignocellulosic biomass into lactic acid (LA) has received considerable attention because it ensures the valorisation of wastes and reduces dependence on fossil sources. First, the proximate and phytochemical compositions of Prosopis africana pods (PAP) were determined. Previous biologically-pretreated pods of Prosopis africana were then saccharified using dilute acid hydrolysis following a full factorial design. The factors optimized were acid type (HCl and H2SO4), acid concentration (1 %, 3 % and 5 %), solid loading ratio (5 %, 10 % and 20 %) and reaction time (15, 30 and 60 minutes). Several Rhizopus oryzae isolates were screened for LA production and the most prolific was molecularly identified. The factors affecting LA yield from PAP hydrolysate were screened using a half-factorial design. The significant factors were then optimised using Box-Behnken Design of Response Surface Methodology (RSM). The proximate analysis showed high levels of protein, lipid, ash and carbohydrates. The phytochemical analysis of PAP revealed the presence of flavonoids, alkaloids, saponins, phenols, tannins, glycosides and terpenoids. The hydrolysis conditions of 3 % HCl, 20 % solid loading and 15 minutes hydrolysis time yielded the highest reducing sugars of 42.5 g/L. The most promising isolate, identified as R. oryzae strain AK-22, produced 19.7 g/L after RSM optimization, a 38.1 % increase over yields from non-optimised conditions. These findings are on the biotechnological production of LA from the pods of Prosopis africana, an abundant yet under-utilised tree crop.

Production of renewable mesitylene as jet-fuel additive: Reaction kinetics of acetone self-condensation over basic (TiO2) and acid (Al-MCM-41) catalysts

Sustainable production of jet fuel additives plays an essential role to decrease greenhouse gas emissions in the aviation industry. Acetone obtained from biomass fermentation is one of the platform molecules of the bio-refinery that can be used as raw material of newly developed sustainable processes. Mesitylene jet fuel additive can be obtained by acetone self-condensation reaction catalyzed by porous solids. In the present work, TiO2 and Al-MCM-41 have been chosen, respectively, as basic and acid catalysts, because of having some tolerance to deactivation. The reaction was studied in a continuous fixed-bed reactor operated in the gas phase at space velocities of 7900 mol/kg h for TiO2 and 5000 mol/kg h for Al-MCM-41. The influence of feed concentration (5–20% acetone and 0–5% mesityl oxide) and temperature (200–350 °C) was studied. First, the reaction scheme was assessed based on the product distribution. It was found that the acid catalyst Al-MCM-41 favors mesityl oxide decomposition to undesired isobutylene and acetic acid. Then, a mechanistic kinetic model of the different steps of the reaction scheme was developed and fitted the experimental results of each catalyst. This model constitutes a valuable tool for the scale-up of this process.

Review on Membrane Materials for Ethanol/Water Separation by Pervaporation

Bioethanol is produced through the fermentation of biomass. It has garnered significant research attention due to its potential as the next generation of sustainable energy. The fermentation broth must be purified before it can be used. This article reviews membrane materials for the separation of ethanol and water using pervaporation membranes. It covers the pervaporation mechanism, membranes for ethanol dehydration, membranes for ethanol recovery, and the prospects of using membranes in this application.

The phase behavior of Isopropanol/Water/NaCl mixtures at atmospheric pressure and temperatures from 294.15 K up to the boiling point

Branched-chain higher alcohols (BCHAs) have potential applications in the preparation of biofuels as they have properties similar to those of gasoline. Isopropanol is the simplest member of the BCHA family and is produced by either a catalytic process or fermentation of biomass. Regardless of the process, the isopropanol is produced as a component of a mixture with water content as high as 80%; therefore, purification is needed to produce fuel-grade isopropanol. Azeotropic and heteroazeotropic distillation are currently used to purify the isopropanol but they are carbon-intensive and costly. The addition of NaCl to an isopropanol/water mixture has two effects: could trigger a liquid–liquid phase split; and increases the relative volatility of the alcohol. These effects could potentially be used as the departure for the design of low-carbon and less expensive purification operations.The phase behavior of isopropanol/water/NaCl mixtures was experimentally mapped at temperatures up to the boiling point at atmospheric pressure. The liquid–solid, liquid–liquid, liquid–liquid–solid, liquid–vapor, liquid–liquid–vapor, liquid–liquid–solid–vapor and liquid–solid–vapor regions were experimentally detected and located in the phase diagram. The equilibrium compositions within the liquid–liquid, liquid–vapor and liquid–liquid–solid–vapor regions were measured. Three well-known methods were employed to assess the reliability of the measured liquid–liquid phase compositions. The temperatures and the composition of the vapor phase in the liquid–liquid–vapor region were also experimentally measured. The collected experimental data was used to construct the phase diagram of isopropanol/water/NaCl mixtures at 5, 10 and 20 wt% NaCl content, at atmospheric pressure, and temperatures from 294.15 K to the boiling point.

Study on combustion characteristics of fully premixed water-cooled biogas burner

Biogas is a renewable gas produced by the fermentation of biomass and is an environmentally friendly alternative to traditional fossil fuels. To overcome the problems of traditional biogas burner, such as unstable combustion, easy flameout and backfire, and low thermal intensity, a new water-cooled biogas burner based on fully premixed combustion technology was designed and developed. Then, numerical simulations and experimental investigations were conducted to explore the effects of CO2 content, excess air coefficient, heat load, and cooling water temperature on the combustion characteristics of the burner. The results revealed that the designed burner exhibited good adaptability to simulated biogas with methane concentrations ranging from 55 % to 80 %. Increasing CO2 content resulted in decreased combustion temperatures and reduced NOx and CO emissions concentration at the burner outlet. In addition, reducing the excess air coefficient enhanced the combustion heat intensity and reduced combustion heat loss. Nevertheless, excessively low excess air coefficients yielded elevated levels of NOx and CO in the flue gas. The results showed that the designed burner demonstrated stable operation at a minimum heat load of 35 %, exhibited a favorable load regulation ratio, and had low emissions. It is a promising solution for utilizing biogas as a clean and sustainable energy source.