John R. Phillips's research while affiliated with Oklahoma State University - Stillwater and other places

Publications (10)

Article
Full-text available
Syngas (mixture of CO, H2 and CO2) fermentation suffers from mass transfer limitation due to low solubility of CO and H2 in the liquid medium. Therefore, it is critical to characterize the mass transfer in syngas fermentation reactors to guide in delivery of syngas to the microorganisms. The objective of this study is to measure and predict the ove...
Article
The hybrid gasification-syngas fermentation platform can produce more bioethanol utilizing all biomass components compared to the biochemical conversion technology. Syngas fermentation operates at mild temperatures and pressures and avoids using expensive pretreatment processes and enzymes. This study presents a new process simulation model develop...
Article
Full-text available
Biomass and other carbonaceous materials can be gasified to produce syngas with high concentrations of CO and H2. Feedstock materials include wood, dedicated energy crops, grain wastes, manufacturing or municipal wastes, natural gas, petroleum and chemical wastes, lignin, coal and tires. Syngas fermentation converts CO and H2 to alcohols and organi...
Article
Full-text available
An efficient syngas fermentation bioreactor provides a mass transfer capability that matches the intrinsic kinetics of the microorganism to obtain high gas conversion efficiency and productivity. In this study, mass transfer and gas utilization efficiencies of a trickle bed reactor during syngas fermentation by Clostridium ragsdalei were evaluated...
Conference Paper
Production of renewable energy is part of the overall solution regarding crude oil depletion, release of harmful pollutants to the environment, and energy security. Ethanol can be produced from agricultural and waste materials using the hybrid gasification-syngas fermentation technology described in this work. The hybrid conversion platform has the...
Conference Paper
The hybrid gasification and syngas-fermentation technology can be used in sustainable production of fuels and chemicals from biomass and wastes via gaseous feedstocks. The low solubility of CO and H2 in the liquid medium makes mass transfer a major challenge for this technology. Gas fermentation reactors designed to provide mass transfer capacity t...
Article
The development of a low cost medium for ethanol production is critical for process feasibility. Ten media were formulated for Clostridium ragsdalei by reduction, elimination and replacement of expensive nutrients. Cost analysis and effects of medium components on growth and product formation were investigated. Fermentations were performed in 250mL...
Article
Trickle-bed reactor (TBR), hollow fiber membrane reactor (HFR) and stirred tank reactor (STR) can be used in fermentation of sparingly soluble gasses such as CO and H(2) to produce biofuels and bio-based chemicals. Gas fermenting reactors must provide high mass transfer capabilities that match the kinetic requirements of the microorganisms used. Th...
Conference Paper
Ethanol can be produced from biomass feedstocks or municipal solid wastes (MSW) using a hybrid thermochemical-biochemical conversion process called gasification-fermentation. In the gasification-fermentation process, biomass is gasified and converted to synthesis gas (syngas; primarily CO, CO2 and H2). The advantage of gasification-fermentation ove...

Citations

... Carbon dioxide may be converted directly to methanol by chemical catalysis (Marlin et al., 2018) to grow methylotrophs (Fig. 15). Carbon dioxide mixed with hydrogen may be fermented (syngas fermentation; Phillips et al., 2017) to acetic acid for growing acetotrophic microbes (Saeki et al., 1997) (Fig. 15). Methanogenic archaea may be used to produce methane from a mixture of CO 2 and hydrogen for growing methanotrophic microorganisms (Fig. 15). ...
... A previous study by the same researchers also showed that TBR provided greater mass transfer capabilities compared to a CSTR [133]. Liu et al. (2019) [134] studied the gasliquid mass transfer in a sparged and non-sparged CSTR with potential application in syngas fermentation and developed a model calculating kLa for syngas components CO, CO2 and H2, which could be used in selecting operating conditions in CSTRs. Almeida Benalcázar et al. (2020) [135] worked on a hybrid model for simulating ethanol production inside a 700 m 3 bubble column bioreactor fed with gas of two compositions as pure CO and a 3:1 mixture of H2 and CO2. ...
... The gasification-syngas fermentation process has been modelled in the existing literature. Pardo-Planas et al. [23], using switchgrass as feedstock, studied the impacts of the gas uptake rate and ethanol concentration achieved in the fermentation unit on the volume of the fermenter and the energy requirement of the system, respectively. De Medeiros et al. [24] carried out the modelling and economic analysis of an energy self-sufficient gasification-syngas fermentation process with sugarcane bagasse as feedstock. ...
... Trickle bed reactor (TBR) is widely used in process industry, including biochemical engineering, [1,2] petrochemical process, [3][4][5][6][7] petroleum refining [8][9][10][11][12] and environmental engineering [13][14][15][16] because of its advantages of simple operation and low catalyst attrition. ...
... The lack of solubility of H 2 (0.0355 mg L À1 at 1 atm, 25 C), CO (0.395 mg L À1 at 1 atm, 25 C), and CO 2 (27 mg L À1 at 1 atm, 25 C) is another factor leading to an inefficiency of syngas-to-butanol conversion. As a result, pressure (>2 atm) fermentation has been suggested as a procedure to enhance the solubility of these gases and conversion to butanol (Fern andez-Naveira et al., 2016;Phillips et al., 2015). Depending on types and number of impurities (e.g., acetylene, ethylene O 2 , HCN, H 2 S, NO, NO 2 , HF) in the syngas, the gas mixture may inhibit microbial cell growth (Liew et al., 2016); thus, necessitating purification prior to fermentation to butanol. ...
... Moreover, reactor design is important; for demonstration, often bubble column reactor technology is applied. Also, continuously stirred tank reactor, trickle bed reactor, and hollow fiber reactor are under investigation (Devarapalli et al. 2012;Verma et al. 2016). ...
... For the effective utilization of gases, many studies have been performed to enhance microbial growth and product formation by changing medium components and concentrations [8,9,[14][15][16][17][18]. Meanwhile, a few studies have been conducted to reduce the cost of the medium by changing the buffer solution [19], replacing yeast extract with corn steep liquor, cotton seed extract, trypticase, and biochar [20][21][22][23][24][25]. In addition, agents, such as methyl viologen [17], neutral red [26], viologen dyes [27], and sodium sulfide [28,29], were successfully used to improve the concentration of end-products. ...
... During the syngas biomethanation process, a crucial limiting factor is the slow gasliquid mass transfer since the microbial conversions occur mainly in the aqueous phase and the gas must pass the interface film of gas-liquid [10,25]. The continuous stirred tank reactor (CSTR) is commonly used in chemical industry. ...