Butanol Concentration Research Articles

Optimization of Butanol Production from Mixed Sugars and Sweet Sorghum Bagasse Hydrolysate Using Clostridium beijerinckii TISTR 1461

This study investigated the capability of Clostridium beijerinckii TISTR 1461 to utilize mixed sugars (glucose and xylose) in synthetic media and sweet sorghum bagasse (SSB) hydrolysate for butanol production. Synthetic media containing 60 g/L of glucose and xylose at various ratios were used for butanol production. C. beijerinckii TISTR 1461 preferentially utilized glucose over xylose for butanol production. The highest butanol concentration (PB, 10.25–10.60 g/L), butanol yield (YB/S, 0.27–0.28 g/g), butanol productivity (QB, 0.22 g/L·h), and sugar consumption (SC, 61–63%) were achieved when the glucose content was at least 75% of the total sugars. When an SSB hydrolysate (produced via enzymatic hydrolysis) containing 60.83 g/L of total sugars (glucose:xylose ratio = 88:12, w/w) was used as a substrate for butanol production, the SSB hydrolysate supplemented with 1 g/L of yeast extract and buffers significantly yielded higher PB (15.10 g/L), YB/S (0.31 g/g), QB (0.31 g/L·h), and SC (82%) values compared to the synthetic media. These results indicate that sweet sorghum bagasse hydrolysates containing glucose and xylose mixtures show promise as cost-effective substrates for sustainable butanol fermentation, demonstrating the potential of agricultural residues in biofuel production.

Adsorption of VOC vapors on ZnPc: sensing and kinetic studies.

Thin film of sensing unit, 2,3,9,10,16,17-hexakis(3-dietylaminophenoxy)-23-etynylphenyl-(2-ferrocenyl-o-carborane)phthalocyaninato zinc(II) (ZnPc), have been deposited by spray pyrolysis technique on the quartz crystal surface with a fundamental resonance frequency of 10MHz. The surfacemorphology of the film has been studied using the contact mode atomic force microscope (AFM) technique and the average surface roughness was determined to be 36.4nm. Then, this film was exposed to the vapors of methanol, ethanol, 2-propanol, and 1-butanol with various concentrations varying between 50 and 400ppm. In addition, studies on response time and repeatability of the sensors have also been carried out. Films exhibit maximum sensing response to methanol vapor while the lowest sensitivity of the film towards 1-butanol has been observed. After an exposure time of 10min, the frequency shift of 415Hz was recorded for 400ppm methanol vapor concentration, while a frequency shift of 215Hz was observed for the same concentration of 1-butanol. The sensor was 1.30 times more sensitive to methanol vapor than ethanol and 2.00 times more sensitive to methanol than to 1-butanol. Variations in the sensitivity of the sensor have been correlated with the number of carbon groups in analyte vapors. The effect of the number of carbon groups in analyte molecule on adsorption kinetics of the film has also been investigated and compared. Adsorption isotherms of four volatile organic compounds on ZnPc were investigated at room temperature and the experimental data obtained were correlated with different existing adsorption isotherm models such as the Langmuir, the Freundlich, and Temkin model. An overall evaluation of the obtained results showed that the sensing performance, adsorption kinetic, and adsorption isotherms are dependent on the molecular size of the analyte molecules.

Developing a separation system to enable real-time recovery of acetone-butanol during fermentation

Methods such as gas stripping and vacuum-assisted gas stripping (VAGS) result in significant removal of water from the bioreactor, thus requiring continuous water replenishment in the bioreactor. In this study, we developed a hydrophobic stainless steel meshes capable of selectively recovering concentrated ABE stream from the bioreactor during VAGS. Three stainless steel meshes with pore sizes of 180 µm, 300 µm, and 425 µm were made hydrophobic and oleophilic with zinc oxide (ZnO) and polydimethylsiloxane (PDMS). Butanol concentrations in the model solutions range from 3 to 10 g/L which mimic concentrations typically produced during batch ABE fermentation. The meshes were integrated in a 5-L bioreactor containing 2.5 L of operational ABE model solution followed by the evaluation of selective extraction of ABE from both cell-free and Clostridium beijerinckii-rich ABE model solutions. The results show that the 180-µm ZnO/PDMS-coated mesh retained 54–64% more water in the bioreactor without C. beijerinckii cells and 61–65% more water with cells compared to the uncoated mesh. Furthermore, the butanol concentration of condensates recovered with 180-µm ZnO-PDMS-coated mesh was up to 10.8-fold greater than that of uncoated counterpart. Our data demonstrate that the developed ZnO-PDMS mesh can recover high concentrations of ABE while selectively retaining water in the bioreactor. Additionally, this technology demonstrates the potential for real-time ABE recovery during the fermentation of lignocellulosic and colloidal materials, without the concern of clogging the separation system.Key points• Hydrophobic mesh enhanced water retention in the bioreactor by up to 1.65-fold.• Butanol concentration in the collected condensate was increased by up to 10.8-fold.• Hydrophobic mesh is compatible with fermentation of lignocellulose.

Reduction short-chain volatile fatty acids and CO2 into alcohols in microbial electrosynthesis system

Microbial electrosynthesis system (MES) is an attractive strategy for converting CO2 into value-added chemicals and biofuels. In this work, it is for the first time demonstrates the feasibility of producing biofuels (eg., ethanol and butanol) from CO2 and volatile fatty acids (eg. acetic acid and butyric acid) by utilizing Clostridium ljungdahlii ERI-2 as biocatalyst in MES. The highest ethanol and butanol concentration of 12.52 ± 0.57 and 5.85 ± 0.78 mM are obtained at −0.9 V (vs Ag/AgCl) cathode potential, respectively. Furthermore, the trace elements content in growing medium is optimized to improve the production rate of ethanol from acetic acid/CO2 and butanol from butyric acid/CO2. Adding suitable Ni2+ and WO42− in the growing medium resulted in the maximum ethanol and butanol production can be increased 43.3 ± 3.2 % and 32.1 ± 3.5 %, respectively. The analysis of redox cofactor concentration indicates that the NADH is the main reducing force for the improvement of alcohols production. Based on these results, strategies for further improvement of CO2 to alcohols conversion can be formulated.

Stirring the hydrogen and butanol production from Enset fiber via simultaneous saccharification and fermentation (SSF) process

Enset fiber is a promising feedstock for biofuel production with the potential to reduce carbon emissions and improve the sustainability of the energy system. This study aimed to maximize hydrogen and butanol production from Enset fiber through simultaneous saccharification and fermentation (SSF) process in bottles as well as in bioreactor. The SSF process in bottles resulted in a higher butanol concentration of 11.36 g/L with a yield of 0.23 g/g and a productivity of 0.16 g/(L h) at the optimal process parameters of 5% (w/v) substrate loading, 16 FPU/g cellulase loading, and 100 rpm agitation speed from pretreated Enset fiber. Moreover, a comparable result to the bottle experiment was observed in the bioreactor with pH-uncontrolled SSF process, although with a decreased in butanol productivity to 0.095 g/(L h). However, using the pre-hydrolysis simultaneous saccharification and fermentation (PSSF) process in the bioreactor with a 7% (w/v) substrate loading led to the highest butanol concentration of 12.84 g/L with a productivity of 0.104 g/(L h). Furthermore, optimizing the SSF process parameters to favor hydrogen resulted in an increased hydrogen yield of 198.27 mL/g-Enset fiber at atmospheric pressure, an initial pH of 8.0, and 37 °C. In general, stirring the SSF process to shift the product ratio to either hydrogen or butanol was possible by adjusting temperature and pressure. At 37 °C and atmospheric pressure, the process resulted in an e-mol yield of 12% for hydrogen and 38% for butanol. Alternatively, at 30 °C and 0.55 bar overpressure, the process achieved a yield of 6% e-mol of hydrogen and 48% e-mol of butanol. This is the first study to produce hydrogen and butanol from Enset fiber using the SSF process and contributes to the development of a circular bioeconomy.Graphical

Efficient butanol production from sweet sorghum stem juice by a co-culture system at an optimum temperature: Insights from oxidation-reduction potential monitoring and pilot scale validation

A two-stage co-culture approach was employed in an acetone-butanol-ethanol (ABE) fermentation. An obligate aerobic bacterium, Arthrobacter sp., was first grown for 6 h at 30 °C to create anaerobic conditions. Subsequently, Clostridium beijerinckii TISTR 1461 was inoculated and a fermentation was performed at 37 °C. To identify an intermediate temperature suitable for both microorganisms, their growth was examined at 30, 34, and 37 °C. C.beijerinckii exhibited the highest specific growth rate at 37 °C, while Arthrobacter sp. displayed similar growth rates at all tested temperatures. Butanol production from a synthetic medium (P2 medium) by C. beijerinckii at different temperatures using oxygen-free nitrogen (OFN) gas flushing as a control treatment revealed that fermentation at 37 °C gave the highest butanol concentration (PB, 9.98 g/L). Consequently, 37 °C was chosen for butanol production from sweet sorghum stem juice (SSJ) by co-culture of these two microorganisms in 1-L screw–capped bottles. Compared to the control treatment, higher PB (11.38 g/L), yield (YB/S, 0.37 g/g) and productivity (QB, 0.24 g/L·h) were achieved using the co-culture system. These results were further confirmed by monitoring the oxidation–reduction potential (ORP) during ABE fermentation in a 2-L stirred-tank bioreactor (STR). Moreover, when the co-culture fermentation at 37 °C was scaled up in a 30-L STR, the PB, YB/S and QB values were comparable to those obtained in the 2-L STR. Therefore, co-culture fermentation of Arthrobacter sp. and C.beijerinckii TISTR 1461 at 37 °C represents a promising method for large-scale butanol production.

Butanol Used as a Potential Alternative Fuel Blend with N-Decane and Diesel in CI Engines for Marine Application

For compression ignition engines, butanol is the most promising alternative fuel, in comparison with other alcoholic fuels. Butanol is superior to other alcoholic fuels because it has excellent physical and chemical properties that make it appropriate for diesel fuel blends. When butanol and diesel are blended, butanol is fully miscible in all proportions. Because butanol is hygroscopic, it does not absorb moisture from the environment. Because acetone-butanol-ethanol (ABE) fermentation may create butanol, it is commonly touted as a possible biofuel. This research is a significant step in gaining a thorough understanding of the effects of butanol on the fuel based on hydrocarbon. The fuel's molecular interactions mixes are studied using infrared (IR) spectroscopy. Binary mixes of butanol and n-decane, are investigated initially. After that, the mixture of butanol and diesel is investigated. When butanol is mixed with diesel, it forms strong bonds including the components of biodiesel that contain groups of esters. Furthermore, the possibility of employing Infrared spectroscopy for numerical mix analysis is assessed. The spectra are provided to enable a highly precise determination of the butanol concentration.

The Effect of Technological Conditions on ABE Fermentation and Butanol Production of Rye Straw and the Composition of Volatile Compounds.

The objective of this study was to evaluate the effect of pretreatment and different technological conditions on the course of ABE fermentation of rye straw (RS) and the composition of volatile compounds in the distillates obtained. The highest concentration of ABE and butanol was obtained from the fermentation of pretreated rye straw by alkaline hydrolysis followed by detoxification and enzymatic hydrolysis. After 72 h of fermentation, the maximum butanol concentration, productivity, and yield from RS were 16.11 g/L, 0.224 g/L/h, and 0.402 g/g, respectively. Three different methods to produce butanol were tested: the two-step process (SHF), the simultaneous process (SSF), and simultaneous saccharification with ABE fermentation (consolidation SHF/SSF). The SHF/SSF process observed that ABE concentration (21.28 g/L) was higher than in the SSF (20.03 g/L) and lower compared with the SHF (22.21 g/L). The effect of the detoxification process and various ABE fermentation technologies on the composition of volatile compounds formed during fermentation and distillation were analyzed.

1-Butanol treatment enhances drought stress tolerance in Arabidopsis thaliana.

Abiotic stress is a major factor affecting crop productivity. Chemical priming is a promising strategy to enhance tolerance to abiotic stress. In this study, we evaluated the use of 1-butanol as an effectual strategy to enhance drought stress tolerance in Arabidopsis thaliana. We first demonstrated that, among isopropanol, methanol, 1-butanol, and 2-butanol, pretreatment with 1-butanol was the most effective for enhancing drought tolerance. We tested the plants with a range of 1-butanol concentrations (0, 10, 20, 30, 40, and 50mM) and further determined that 20mM was the optimal concentration of 1-butanol that enhanced drought tolerance without compromising plant growth. Physiological tests showed that the enhancement of drought tolerance by 1-butanol pretreatment was associated with its stimulation of stomatal closure and improvement of leaf water retention. RNA-sequencing analysis revealed the differentially expressed genes (DEGs) between water- and 1-butanol-pretreated plants. The DEGs included genes involved in oxidative stress response processes. The DEGs identified here partially overlapped with those of ethanol-treated plants. Taken together, the results show that 1-butanol is a novel chemical priming agent that effectively enhances drought stress tolerance in Arabidopsis plants, and provide insights into the molecular mechanisms of alcohol-mediated abiotic stress tolerance.

Simultaneous recovery of short-chain fatty acids and diverse carbon sources using magnetic cationic surfactant-functionalized materials integrated with membrane contactor in dark syngas fermentation

Syngas fermentation utilizing acetogenic bacteria like Clostridium sp. provides a promising method for transforming CO and CO2-rich waste gases into valuable products such as short-chain fatty acids (SCFAs) and bio-alcohols, aiding in the reduction of greenhouse gas emissions and supporting carbon neutrality objectives. Magnetic nanoparticle-based coagulants, particularly Fe3O4@MIL-100(Fe)@TEOS@DTAB (FMT@DTAB), have recently attracted attention due to their efficient recovery and enhanced cell disruption capabilities enabled by cationic surfactant surface modifications. At a dosage of 60 g/L, FMT@DTAB has proven highly effective in achieving significant concentrations of acetic acid (7.06 g/L), butyric acid (6.27 g/L), ethanol (6.43 g/L), and butanol (5.24 g/L), along with notable harvesting efficiency (99.2 %) and intracellular ATP concentration (2.1 mM). Recent research on supported liquid membrane contactors highlights their cost-effective and environment-friendly properties, with an emphasis on minimal extractant usage. This study investigated the behavior of SCFAs using both virgin and supported liquid membrane contactors, focusing on factors such as organic extractant and membrane pore size. PVDF filled with tridodecylamine notably improved butyric acid recovery to around 60 %, with a mass flux of 14.95 ± 0.28 g/m2/h, outperforming virgin and other extractant-filled PVDF membranes. This study enhances resource efficiency and reduces industrial environmental impacts by optimizing the recovery and production of valuable chemicals from waste gases. It supports sustainable and economically viable biotechnology applications, aligning with global climate change mitigation efforts.

Molecular Markers and Regulatory Networks in Solventogenic Clostridium Species: Metabolic Engineering Conundrum

Solventogenic Clostridium species are important for establishing the sustainable industrial bioproduction of fuels and important chemicals such as acetone and butanol. The inherent versatility of these species in substrate utilization and the range of solvents produced during acetone butanol–ethanol (ABE) fermentation make solventogenic Clostridium an attractive choice for biotechnological applications such as the production of fuels and chemicals. The functional qualities of these microbes have thus been identified to be related to complex regulatory networks that play essential roles in modulating the metabolism of this group of bacteria. Yet, solventogenic Clostridium species still struggle to consistently achieve butanol concentrations exceeding 20 g/L in batch fermentation, primarily due to the toxic effects of butanol on the culture. Genomes of solventogenic Clostridium species have a relatively greater prevalence of genes that are intricately controlled by various regulatory molecules than most other species. Consequently, the use of genetic or metabolic engineering strategies that do not consider the underlying regulatory mechanisms will not be effective. Several regulatory factors involved in substrate uptake/utilization, sporulation, solvent production, and stress responses (Carbon Catabolite Protein A, Spo0A, AbrB, Rex, CsrA) have been identified and characterized. In this review, the focus is on newly identified regulatory factors in solventogenic Clostridium species, the interaction of these factors with previously identified molecules, and potential implications for substrate utilization, solvent production, and resistance/tolerance to lignocellulose-derived microbial inhibitory compounds. Taken together, this review is anticipated to highlight the challenges impeding the re-industrialization of ABE fermentation, and inspire researchers to generate innovative strategies for overcoming these obstacles.

Dynamic microbial and metabolic changes during Apulian Caciocavallo cheesemaking and ripening produced according to a standardized protocol

The microbiota of a cheese play a critical role in influencing its sensory and physicochemical properties. In this study, traditional Apulian Caciocavallo cheeses coming from 4 different dairies in the same area and produced following standardized procedures were examined, as well as the different bulk milks and natural whey starter (NWS) cultures used. Moreover, considering the cheese wheels as the blocks of Caciocavallo cheeses as whole, these were characterized at different layers (i.e., core, under-rind, and rind) of the block using a multi-omics approach. In addition to physical-chemical characterization, culturomics, quantitative PCR, metagenomics, and metabolomics analysis were carried out after salting and throughout the ripening time (2 mo) to investigate major shifts in the succession of the microbiota and flavor development. Culture-dependent and 16S rRNA metataxonomics results clearly clustered samples based on microbiota biodiversity related to the production dairy plant as a result of the use of different NWS or the intrinsic conditions of each production site. At the beginning of the ripening, cheeses were dominated by Lactobacillus, and in 2 dairies (Art and SdC), Streptococcus genera were associated with the NWS. The analysis allowed us to show that although the diversity of identified genera did not change significantly between the rind, under-rind, and core fractions of the same samples, there was an evolution in the relative abundance and absolute quantification, modifying and differentiating profiles during ripening. The real-time PCR, also known as quantitative or qPCR, mainly differentiated the temporal adaptation of those species originating from bulk milks and those provided by NWS. The primary starters detected in NWS and cheeses contributed to the high relative concentration of 1-butanol, 2-butanol, 2-heptanol, 2-butanone, acetoin, delta-dodecalactone, hexanoic acid ethyl ester, octanoic acid ethyl ester, and volatile free fatty acids during ripening, whereas cheeses displaying low abundances of Streptococcus and Lactococcus (dairy Del) had a lower total concentration of acetoin compared with Art and SdC. However, the subdominant strains and nonstarter lactic acid bacteria present in cheeses are responsible for the production of secondary metabolites belonging to the chemical classes of ketones, alcohols, and organic acids, reaffirming the importance and relevance of autochthonous strains of each dairy plant although only considering a delimited production area.

Planar non-contact microwave sensor for the detection of aqueous organic and inorganic samples

In this study, a planar microwave sensor was proposed and manufactured with the aim of detecting and categorizing concentrations of various organic substances, including methanol (CH3OH), ethanol (CH3CH2OH), and 1-butanol (CH3CH2CH2CH2OH), as well as inorganic substances such as sodium carbonate (Na2CO3), potassium carbonate (K2CO3), and sodium hydroxide (NaOH). Throughout the sensor's development, a configuration incorporating a microstrip line and a rectangular patch with a central circular aperture was employed. Full-wave electromagnetic simulation software was utilized to analyze the performance of the sensor in terms of reflection coefficients. The sensor was fabricated using a PCB material with defined properties, which included a dielectric constant of 4.3, a loss tangent of 0.025, and a thickness of 1.6 mm. The reflection coefficient (S11) was measured and analyzed using principal component analysis (PCA) to identify correlations between the classification groups and concentrations of organic and inorganic samples. Additionally, the equivalent circuit has been extracted and modeled to describe the operating mechanism of the microwave sensor. The simulation and measurement results indicate that the sensor is a suitable candidate for the detection and classification of water samples containing CH3OH, CH3CH2OH, CH3CH2CH2CH2OH, Na2CO3, K2CO3, and NaOH. The proposed microwave sensor features a surface area of 29 × 18 mm², leading to a noteworthy reduction in surface utilization compared to other breath biosensors designed for measurement purposes.

Critical impacts of energy targeting on the sustainability of advanced biobutanol separation

Biobutanol stands out as an advanced renewable biofuel, yet its production through fermentation yields a low butanol concentration, necessitating expensive and energy-intensive separation methods, particularly by distillation. Alternative approaches, including adsorptive separation, have emerged, with the 2-column zeolite-based process showing promise. This study employed Aspen Plus for simulating adsorptive separation, utilized Pinch technology for heat integration, and analyzed various alternatives using the life cycle assessment (LCA) approach. Compared to the base case, which relied on our previously acquired experimental data and further purification through atmospheric distillation, the adoption of indirect heating/cooling adsorption reduced heating energy demand by 59.5%. Additionally, cooling energy usage was increased notably by 68.9%, and chilling prerequisites were eliminated. The implementation of Pinch technology further reduced heating and cooling energy requirements by approximately 36%. Multi-pressure distillation was also explored, revealing its potential to reduce heating energy consumption by 46.6%, accompanied by a modest 6.2% increase in cooling energy demand. A gate-to-gate LCA framework was used to evaluate the environmental impacts. The results showed that the combination of indirect heating/cooling adsorption, multi-pressure distillation, and energy-efficient practices resulted in over a 98% reduction in damages related to human health, ecosystem well-being, and resource depletion compared to the base case. Prioritization of key performance indicators revealed that human health had the most significant influence, with prominent midpoint effects attributed to human toxicity and global warming. This study underscores the pivotal role of energy targeting in curtailing energy consumption and enhancing the sustainability of adsorptive biobutanol separation.

Novel Batch and Repeated-Batch Butanol Fermentation from Sweet Sorghum Stem Juice by Co-Culture of Arthrobacter and Immobilized Clostridium in Scaled-Up Bioreactors

This research aims to study butanol fermentation from sweet sorghum stem juice (SSJ) by immobilized Clostridium beijerinckii TISTR 1461 cells on bamboo chopsticks using Arthrobacter sp. as an efficient bacterium for creating anaerobic conditions in scaled-up bioreactors. For batch culture in a 1-L screw-capped bottle, a butanol concentration (PB), butanol productivity (QB), and butanol yield (YB/S) were 12.09 g/L, 0.26 g/L·h and 0.28 g/g, respectively. These values were ~8 to 14% higher than those of a single culture using oxygen-free nitrogen (OFN) gas to generate anaerobic conditions. When butanol fermentation by the co-culture was scaled-up to 5-L and 30-L stirred-tank fermenters, the butanol production efficiency was not different from that using the 1-L bottles. Additionally, repeated-batch butanol fermentation in the 1-L bottles by the co-culture was successfully operated for four successive cycles with high butanol production. All results clearly indicate that Arthrobacter sp. is promising for creation of anaerobic conditions for butanol production by immobilized Clostridium in large scale bioreactors.

Characterization of the Volatile Composition of Fermented Ciders Made From Dessert Apple Cultivars With and Without Maceration

Cider is often produced from difficult-to-grow heirloom apple cultivars not commonly produced in North America. As such, the value of widely grown dessert apples for fermented cider was explored, with ciders produced from eleven cultivars analyzed. Additionally, the practice of maceration, or fermentation with pomace, was also investigated. Volatile compounds were analyzed by gas chromatography-mass spectrometry. Raw mass spectrometry (MS) data was then followed by an initial untargeted statistical analysis. Principal component analysis of the MS features demonstrated clear separation between cultivars and between maceration effects, prompting further investigation into the compounds impacting cultivar and maceration discrimination. The aroma-active compounds identified are known to elicit sensorial responses often described as sweet, fruity, and floral. Some compounds have been previously identified as primarily apple-derived. While esters and higher alcohols, originating from yeast metabolic activities, were also identified as contributing factors of the observed differences. Despite these compounds being impacted by yeast metabolism, they were highly influenced by cultivar and treatment, indicating apple-derived precursors were, in part, influencing the yeast-mediated aroma differences. ‘Galaxy Gala’ cider samples had the highest overall intensities of quantified volatiles in both years, driven by high eugenol and 1-butanol concentrations. Extended apple pomace maceration did not induce new aromas but increased the content of some compounds. Maceration impact was cultivar dependent, e.g., ethyl 2-methylbutyrate in the ‘Yataka Fuji’ increased 14-fold with maceration but less in other cultivars. This work demonstrates that dessert apples produce ciders with a diversity of aromas that may be further increased via maceration and are worth consideration by producers.

Waste valorization through acetone-butanol-ethanol (ABE) fermentation

BackgroundBiobutanol, produced through acetone-butanol-ethanol (ABE) fermentation, has been proposed for use as a transportation fuel and for the development of butanol-based materials. However, the economic viability of ABE fermentation is heavily dependent on the cost of raw materials. MethodsThis study assesses various carbon and nitrogen sources for ABE fermentation. Carbon sources examined include local molasses (M1), Thai molasses (M2), Taiwan sugar agricultural molasses (M3), and Taiwan sugar edible molasses (M4). Nitrogen sources considered are corn steep liquor (CSL), acid-hydrolyzed black soldier fly larval meal (IA), and enzyme-hydrolyzed black soldier fly larval meal (IE). Significant findingsOur findings reveal that M2CSL, a combination of Thai molasses and corn steep liquor, serves as a cost-effective and efficient medium for ABE fermentation, resulting in a butanol concentration of 7.4 ± 3.5 g/L. Furthermore, our research identifies variations in molasses and their impact on sucrose consumption inhibition. Notably, this study underscores the potential of insect peptone derived from enzyme-hydrolyzed black soldier fly larval meal (IE) as an alternative nitrogen source, while cautioning against the use of insect peptone obtained from acid-hydrolyzed black soldier fly larval meal (IA) due to its inhibitory properties.

Apple pomace as an alternative substrate for butanol production

Butanol-producing strains Clostridium sp. UCM B-7570 and C. acetobutylicum UCM B-7407 were used for research from “Collection of strains of microorganisms and plant lines for food and agricultural biotechnology” of the Institute of Food Biotechnology and Genomics of the National Academy of Sciences of Ukraine, glycerol (BASF, Germany) and apple pomace (total moisture 4%) after apple juice production. The aim of this work was to study the possibility of using apple pomace by domestic butanol-producing strains of Clostridium sp. UCM B-7570 and C. acetobutylicum UCM B-7407 as a substrate. Producers were cultured on medium with different concentrations of apple pomace, glycerol was used for the inoculation. The presence of ethanol, acetone, and butanol in the culture liquid was determined using a gas chromatograph. It was determined that a significant part of the macrocomponent composition of the extracts can be used in bioconversion by producing strains of the genus Clostridium. It was determined that the highest concentration of butanol (10 g/dm3) was at a concentration of 120 g/dm3 in the extracts. The obtained data showed the possibility of using apple pomace as a substrate in biobutanol technology.

Direct injection diesel engine characteristics fuelled with diesel, biodiesel and 1-butanol blends

The current study concentrated on performance, combustion and emission characteristics of a direct injection diesel engine. The experiments were carried out on single cylinder Kirloskar make TV-1 diesel engine test-rig. The blends were made using equal parts of Karanja biodiesel (Pongamia pinnata) and 1-butanol with plain diesel. For the experiment, five mixes were investigated at constant speed of 1500 rpm and varying loading condition from no load to full load in 25 % steps. The properties of the mixtures considered are within the permissible ASTM limits. The study revealed that performance characteristics such as brake thermal efficiency, mechanical efficiency are observed highest for D80K10B10 blend at 100 % BP and BSEC at 25 % BP for D80K20 blend. No appreciable variations are observed in volumetric efficiencies and concentration of 1-Butanol showed greater reduction in EGT amongst others. Highest CO emission reduction to 53 % whereas 31 % CO2 increases and HC, and NOx emissions are observed marginally increased. Long term test and energy-exergy analysis should be required to get more in insights from the research.

Continuous Fermentation Coupled with Online Gas Stripping for Effective Biobutanol Production

The main problems with the butanol fermentation process include high cost of grain raw materials, low product concentration and low butanol productivity caused by butanol cytotoxicity. In this study, cassava, a cheap crop, was used as the raw material. A symbiotic system TSH06, which possesses the capability to synthesize butanol under non-strict anaerobic conditions, was used as the fermentation strain. The fermentation performance of TSH06 in a cassava system was investigated. In order to eliminate product inhibition and promote the concentration and productivity of butanol, a strategy of continuous fermentation coupled with online gas stripping was developed. By using the strategy of two-stage continuous fermentation using immobilized cells coupled with online gas stripping, the butanol productivity reached 0.9 g/(L·h); at the same time, a high butanol concentration was achieved, and the concentration of butanol obtained in the condensate reached 71.2 g/L.