scholarly journals Gas Fermentation Enhancement for Chemolithotrophic Growth of Cupriavidus necator on Carbon Dioxide

Fermentation ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 63 ◽  
Author(s):  
Jian Yu ◽  
Pradeep Munasinghe
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Cell Density ◽  
Cell Mass ◽  
Value Added ◽  
Ammonium Nitrogen ◽  
Cupriavidus Necator ◽  
Negative Effects ◽  
Gas Fermentation ◽  
Chemolithotrophic Growth

Cupriavidus necator, a facultative hydrogen-oxidizing bacterium, was grown on carbon dioxide, hydrogen, and oxygen for value-added products. High cell density and productivity were the goal of gas fermentation, but limited by gas substrates because of their low solubility in the aqueous medium solution. Enhancement of gas fermentation was investigated by (i) adding n-hexadecane as a gas vector to increase the volumetric mass transfer coefficient (kLa) and gas solubility, (ii) growing C. necator under a raised gas pressure, and (iii) using cell mass hydrolysates as the nutrients of chemolithotrophic growth. In contrast to previous studies, little positive but negative effects of the gas vector were observed on gas mass transfer and cell growth. The gas fermentation could be significantly enhanced under a raised pressure, resulting in a higher growth rate (0.12 h−1), cell density (18 g L−1), and gas uptake rate (200 mmole L−1 h−1) than a fermentation under atmospheric pressure. The gain, however, was not proportional to the pressure increase as predicted by Henry’s law. The hydrolysates of cell mass were found a good source of nutrients and the organic nitrogen was equivalent to or better than ammonium nitrogen for chemolithotrophic growth of C. necator on carbon dioxide.

scholarly journals Biotransformation of Methane and Carbon Dioxide Into High-Value Products by Methanotrophs: Current State of Art and Future Prospects

2021 ◽  
Vol 12 ◽  
Author(s):  
Krishna Kalyani Sahoo ◽  
Gargi Goswami ◽  
Debasish Das
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Carbon Dioxide Sequestration ◽  
Value Added ◽  
Operating Conditions ◽  
Scale Production ◽  
Liquid Mass ◽  
Liquid Mass Transfer ◽  
Solubility Of Gases ◽  
Low Solubility

Conventional chemical methods to transform methane and carbon dioxide into useful chemicals are plagued by the requirement for extreme operating conditions and expensive catalysts. Exploitation of microorganisms as biocatalysts is an attractive alternative to sequester these C1 compounds and convert them into value-added chemicals through their inherent metabolic pathways. Microbial biocatalysts are advantageous over chemical processes as they require mild-operating conditions and do not release any toxic by-products. Methanotrophs are potential cell-factories for synthesizing a wide range of high-value products via utilizing methane as the sole source of carbon and energy, and hence, serve as excellent candidate for methane sequestration. Besides, methanotrophs are capable of capturing carbon dioxide and enzymatically hydrogenating it into methanol, and hence qualify to be suitable candidates for carbon dioxide sequestration. However, large-scale production of value-added products from methanotrophs still presents an overwhelming challenge, due to gas-liquid mass transfer limitations, low solubility of gases in liquid medium and low titer of products. This requires design and engineering of efficient reactors for scale-up of the process. The present review offers an overview of the metabolic architecture of methanotrophs and the range of product portfolio they can offer. Special emphasis is given on methanol biosynthesis as a potential biofuel molecule, through utilization of methane and alternate pathway of carbon dioxide sequestration. In view of the gas-liquid mass transfer and low solubility of gases, the key rate-limiting step in gas fermentation, emphasis is given toward reactor design consideration essential to achieve better process performance.

Light-driven reduction of carbon dioxide: Altering the reaction pathways and designing photocatalysts toward value-added and renewable fuels

2021 ◽  
Vol 237 ◽  
pp. 116547
Author(s):  
Quyet Van Le ◽  
Van-Huy Nguyen ◽  
Trinh Duy Nguyen ◽  
Ajit Sharma ◽  
Gul Rahman ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Value Added ◽  
Reaction Pathways ◽  
Renewable Fuels

Atomic-level engineering of two-dimensional electrocatalysts for CO2 Reduction

Nanoscale ◽  
2021 ◽  
Author(s):  
Wei Shao ◽  
Xiaodong Zhang
Keyword(s):  
Carbon Dioxide ◽  
Fossil Fuels ◽  
Co2 Reduction ◽  
Value Added ◽  
Atomic Level ◽  
Two Dimensional ◽  
Excessive Consumption

Carbon dioxide (CO2) from the excessive consumption of fossil fuels has exhibited a huge threat to the planet’s ecosystem. Electrocatalytic CO2 reduction into value-added chemicals have been regarded as a...

Electrografting Amines onto Modified Silver Nanoparticle Electrodes for Electroreduction of CO2 at Low Overpotential

2021 ◽  
Author(s):  
Heinz-Bernhard Kraatz ◽  
Maryam Abdinejad ◽  
Iranaldo Santos da Silva
Keyword(s):  
Carbon Dioxide ◽  
Silver Nanoparticle ◽  
Value Added ◽  
Efficient Manner ◽  
Low Overpotential

Reducing carbon dioxide (CO2) to value-added synthons in a selective and efficient manner remains a sizable challenge to CO2 conversion research. Although many electrocatalysts have been reported to date, those...

An overview of flow cell architectures design and optimization for electrochemical CO2 reduction

2021 ◽  
Author(s):  
Dui Ma ◽  
Ting Jin ◽  
Keyu Xie ◽  
Haitao Huang
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Electrochemical Reduction ◽  
Atmospheric Carbon Dioxide ◽  
Co2 Reduction ◽  
Value Added ◽  
Flow Cell ◽  
Design And Optimization ◽  
Electrochemical Co2 Reduction ◽  
Carbon Dioxide Levels

Converting CO2 into value-added fuels or chemical feedstocks through electrochemical reduction is one of the several promising avenues to reduce atmospheric carbon dioxide levels and alleviate global warming. This approach...

scholarly journals Effects of Ultrasound on Fermentation of Glucose to Ethanol by Saccharomyces cerevisiae

Fermentation ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Luis Huezo ◽  
Ajay Shah ◽  
Frederick Michel
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mass Transfer ◽  
Glucose Uptake ◽  
Ethanol Production ◽  
Ethanol Yield ◽  
Biofuel Production ◽  
Inhibitory Effects ◽  
Negative Effects ◽  
Intraparticle Mass Transfer ◽  
Improve Mass Transfer

Previous studies have shown that pretreatment of corn slurries using ultrasound improves starch release and ethanol yield during biofuel production. However, studies on its effects on the mass transfer of substrates and products during fermentation have shown that it can have both beneficial and inhibitory effects. In this study, the effects of ultrasound on mass transfer limitations during fermentation were examined. Calculation of the external and intraparticle observable moduli under a range of conditions indicate that no external or intraparticle mass transfer limitations should exist for the mass transfer of glucose, ethanol, or carbon dioxide. Fermentations of glucose to ethanol using Saccharomyces cerevisiae were conducted at different ultrasound intensities to examine its effects on glucose uptake, ethanol production, and yeast population and viability. Four treatments were compared: direct ultrasound at intensities of 23 and 32 W/L, indirect ultrasound (1.4 W/L), and no-ultrasound. Direct and indirect ultrasound had negative effects on yeast performance and viability, and reduced the rates of glucose uptake and ethanol production. These results indicate that ultrasound during fermentation, at the levels applied, is inhibitory and not expected to improve mass transfer limitations.

Quantitative Effects of Oxygen Supply on Mycelia Growth and Extracellular Polysaccharide of Ganoderma tsugae

2012 ◽  
Vol 217-219 ◽  
pp. 975-978
Author(s):  
Nukrob Narkprasom ◽  
Tzou Chi Huang ◽  
Yuan Kuang Guu
Keyword(s):  
Mass Transfer ◽  
Secondary Metabolite ◽  
Submerged Fermentation ◽  
Oxygen Supply ◽  
Cell Mass ◽  
Extracellular Polysaccharide ◽  
Mycelia Growth ◽  
High Level ◽  
Dry Cell

The quantitative effects of oxygen supply in terms of shaking speed and medium volume on the production of mycelia and extracellular polysaccharide (EPS) using Ganoderma tsugae in submerged fermentation were investigated. Mycelia growth required the proper shaking speed at 134 rpm for breaking a larger pellet into several smaller pellets. Furthermore, high level of medium volume for consumption of abundant nutrient is needed for maximum mycelia growth. For EPS, a high agitation is needed to promote a good mass transfer for achieving high product concentrations recovery. The appropriate medium volume was found to be 150.4 mL for aiding to produce a secondary metabolite by promoting the mass transfer of substrates. The dry cell mass (DCM)-EPS diagram of G. tsugae was created from the both production equations which this diagram is an useful tool for submerge fermentation industry for decision about to control the both productions.

Mass Transfer From a Bubble in a Vertical Pipe

2011 ◽  
Author(s):  
Shogo Hosoda ◽  
Ryosuke Sakata ◽  
Kosuke Hayashi ◽  
Akio Tomiyama
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Bubble Diameter ◽  
Vertical Pipe ◽  
Oblate Spheroidal ◽  
Wide Range ◽  
Bubble Sizes ◽  
Small Bubbles ◽  
Taylor Bubbles

Mass transfer from single carbon dioxide bubbles in a vertical pipe is measured using a stereoscopic image processing method to develop a mass transfer correlation applicable to a wide range of bubble and pipe diameters. The pipe diameters are 12.5, 18.2 and 25.0 mm and the bubble diameter ranges from 5 to 26 mm. The ratio, λ, of bubble diameter to pipe diameter is therefore varied from 0.2 to 1.8, which covers various bubble shapes such as spherical, oblate spheroidal, wobbling, cap, and Taylor bubbles. Measured Sherwood numbers, Sh, strongly depend on bubble shape, i.e., Sh of Taylor bubbles clearly differs from those of spheroidal and wobbling bubbles. Hence two Sherwood number correlations, which are functions of the Peclet number and the diameter ratio λ, are deduced from the experimental data: one is for small bubbles (λ < 0.6) and the other for Taylor bubbles (λ > 0.6). The applicability of the proposed correlations for the prediction of bubble dissolution process is examined through comparisons between measured and predicted long-term bubble dissolution processes. The predictions are carried out by taking into account the presence of all the gas components in the system of concern, i.e. nitrogen, oxygen and carbon dioxide. As a result, good agreements for the dissolution processes for various bubble sizes and pipe diameters are obtained. It is also demonstrated that it is possible to evaluate an equilibrium bubble diameter and instantaneous volume concentration of carbon dioxide in a bubble using a simple model based on a conservation of gas components.

The Effect of Mixing Coal with Biomass in Solid Fuel Briquettes

2013 ◽  
Vol 856 ◽  
pp. 338-342 ◽  
Author(s):  
Chin Yee Sing ◽  
Mohd Shiraz Aris
Keyword(s):  
Mechanical Properties ◽  
Carbon Dioxide ◽  
Power Plants ◽  
Carbon Dioxide Emission ◽  
Palm Kernel ◽  
Value Added ◽  
Calorific Value ◽  
Fuel Properties ◽  
Biomass Fuel ◽  
Palm Kernel Shell

Burning fossil fuel like coal in power plants released carbon dioxide that had been absorbed millions of years ago. Unfortunately, excessive carbon dioxide emission had led to global warming. Malaysia, as one of the major exporters of palm oil, has abundant oil palm mill residues that could be converted into value-added product like biomass fuel briquettes. Fuel briquette with palm kernel shell and palm mesocarp fibre as its main ingredients showed satisfactory fuel characteristics and mechanical properties as a pure biomass fuel briquette. The effects of adding some coal of higher calorific value to the satisfactory biomass fuel briquette were focused in this study. Various coal-biomass fuel blends were used, ranging from 0wt% coal to 50wt% coal. The fuel properties and mechanical properties of pure biomass briquette and briquettes with different amount of coal added were compared experimentally. From the fuel properties tests, it was found that as the coal content in the briquette was increased, the carbon content and calorific value increased. Mechanical property tests on the fuel briquettes showed a mixture of results, with some favored higher portion of coal in the briquette for better handling, transport and storage properties while some favored greater amount of biomass.

Sign in / Sign up

Export Citation Format

Share Document