scholarly journals Process Improvements to Biomass Pretreatment of Fuels and Chemicals

2015 ◽  
Author(s):  
Farzaneh Teymouri ◽  
◽  
Keyword(s):  
Biomass Pretreatment ◽  
Process Improvements ◽  
Fuels And Chemicals

scholarly journals Development of Lignocellulosic Biorefinery Technologies: Recent Advances and Current Challenges

2016 ◽  
Vol 69 (11) ◽  
pp. 1201 ◽  
Author(s):  
Antonella Amore ◽  
Peter N. Ciesielski ◽  
Chien-Yuan Lin ◽  
Davinia Salvachúa ◽  
Violeta Sànchez i Nogué
Keyword(s):  
Research And Development ◽  
Recent Progress ◽  
Biomass Pretreatment ◽  
Major Research ◽  
Integrated Production ◽  
Continual Improvement ◽  
The Past ◽  
Biomass Structure ◽  
Recent Developments ◽  
Fuels And Chemicals

Recent developments of the biorefinery concept are described within this review, which focuses on the efforts required to make the lignocellulosic biorefinery a sustainable and economically viable reality. Despite the major research and development endeavours directed towards this goal over the past several decades, the integrated production of biofuel and other bio-based products still needs to be optimized from both technical and economical perspectives. This review will highlight recent progress towards the optimization of the major biorefinery processes, including biomass pretreatment and fractionation, saccharification of sugars, and conversion of sugars and lignin into fuels and chemical precursors. In addition, advances in genetic modification of biomass structure and composition for the purpose of enhancing the efficacy of conversion processes, which is emerging as a powerful tool for tailoring biomass fated for the biorefinery, will be overviewed. The continual improvement of these processes and their integration in the format of a modern biorefinery is paving the way for a sustainable bio-economy which will displace large portions of petroleum-derived fuels and chemicals with renewable substitutes.

In Situ Observation of Catalyzed Gasification of Graphite by Nickel

1981 ◽  
Vol 39 ◽  
pp. 76-77
Author(s):  
R. T. K. Baker ◽  
R. D. Sherwood
Keyword(s):  
Objective Lens ◽  
In Situ Observation ◽  
Gas Flows ◽  
Catalytic Gasification ◽  
Television Camera ◽  
Viewing Screen ◽  
Fuels And Chemicals ◽  
Gasification Of Carbon ◽  
Transmission Microscope

The catalytic gasification of carbon at high temperature by microscopic size metal particles is of fundamental importance to removal of coke deposits and conversion of refractory hydrocarbons into fuels and chemicals. The reaction of metal/carbon/gas systems can be observed by controlled atmosphere electron microscopy (CAEM) in an 100 KV conventional transmission microscope. In the JEOL gas reaction stage model AGl (Fig. 1) the specimen is positioned over a hole, 200μm diameter, in a platinum heater strip, and is interposed between two apertures, 75μm diameter. The control gas flows across the specimen and exits through these apertures into the specimen chamber. The gas is further confined by two apertures, one in the condenser and one in the objective lens pole pieces, and removed by an auxiliary vacuum pump. The reaction zone is <1 mm thick and is maintained at gas pressure up to 400 Torr and temperature up to 1300<C as measured by a Pt-Pt/Rh 13% thermocouple. Reaction events are observed and recorded on videotape by using a Philips phosphor-television camera located below a hole in the center of the viewing screen. The overall resolution is greater than 2.5 nm.

scholarly journals Production of Fuels and Chemicals from a CO2/H2 Mixture

Reactions ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 130-146
Author(s):  
Yali Yao ◽  
Baraka Celestin Sempuga ◽  
Xinying Liu ◽  
Diane Hildebrandt
Keyword(s):  
Co2 Hydrogenation ◽  
Water Gas Shift ◽  
Liquid Fuels ◽  
Saturated Hydrocarbons ◽  
Reverse Water Gas Shift ◽  
Cu Catalyst ◽  
In Series ◽  
Fuels And Chemicals ◽  
Water Gas ◽  
Aspen Simulation

In order to explore co-production alternatives, a once-through process for CO2 hydrogenation to chemicals and liquid fuels was investigated experimentally. In this approach, two different catalysts were considered; the first was a Cu-based catalyst that hydrogenates CO2 to methanol and CO and the second a Fisher–Tropsch (FT) Co-based catalyst. The two catalysts were loaded into different reactors and were initially operated separately. The experimental results show that: (1) the Cu catalyst was very active in both the methanol synthesis and reverse-water gas shift (R-WGS) reactions and these two reactions were restricted by thermodynamic equilibrium; this was also supported by an Aspen plus simulation of an (equilibrium) Gibbs reactor. The Aspen simulation results also indicated that the reactor can be operated adiabatically under certain conditions, given that the methanol reaction is exothermic and R-WGS is endothermic. (2) the FT catalyst produced mainly CH4 and short chain saturated hydrocarbons when the feed was CO2/H2. When the two reactors were coupled in series and the presence of CO in the tail gas from the first reactor (loaded with Cu catalyst) significantly improves the FT product selectivity toward higher carbon hydrocarbons in the second reactor compared to the standalone FT reactor with only CO2/H2 in the feed.

scholarly journals Further engineering of R. toruloides for the production of terpenes from lignocellulosic biomass

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
James Kirby ◽  
Gina M. Geiselman ◽  
Junko Yaegashi ◽  
Joonhoon Kim ◽  
Xun Zhuang ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Copy Number ◽  
Mevalonate Pathway ◽  
Mevalonate Kinase ◽  
Metabolite Analysis ◽  
Lignocellulosic Hydrolysate ◽  
Microbial Conversion ◽  
Lignocellulosic Hydrolysates ◽  
Lignocellulosic Feedstocks ◽  
Fuels And Chemicals

Abstract Background Mitigation of climate change requires that new routes for the production of fuels and chemicals be as oil-independent as possible. The microbial conversion of lignocellulosic feedstocks into terpene-based biofuels and bioproducts represents one such route. This work builds upon previous demonstrations that the single-celled carotenogenic basidiomycete, Rhodosporidium toruloides, is a promising host for the production of terpenes from lignocellulosic hydrolysates. Results This study focuses on the optimization of production of the monoterpene 1,8-cineole and the sesquiterpene α-bisabolene in R. toruloides. The α-bisabolene titer attained in R. toruloides was found to be proportional to the copy number of the bisabolene synthase (BIS) expression cassette, which in turn influenced the expression level of several native mevalonate pathway genes. The addition of more copies of BIS under a stronger promoter resulted in production of α-bisabolene at 2.2 g/L from lignocellulosic hydrolysate in a 2-L fermenter. Production of 1,8-cineole was found to be limited by availability of the precursor geranylgeranyl pyrophosphate (GPP) and expression of an appropriate GPP synthase increased the monoterpene titer fourfold to 143 mg/L at bench scale. Targeted mevalonate pathway metabolite analysis suggested that 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR), mevalonate kinase (MK) and phosphomevalonate kinase (PMK) may be pathway bottlenecks are were therefore selected as targets for overexpression. Expression of HMGR, MK, and PMK orthologs and growth in an optimized lignocellulosic hydrolysate medium increased the 1,8-cineole titer an additional tenfold to 1.4 g/L. Expression of the same mevalonate pathway genes did not have as large an impact on α-bisabolene production, although the final titer was higher at 2.6 g/L. Furthermore, mevalonate pathway intermediates accumulated in the mevalonate-engineered strains, suggesting room for further improvement. Conclusions This work brings R. toruloides closer to being able to make industrially relevant quantities of terpene from lignocellulosic biomass.

An eco-friendly biomass pretreatment strategy utilizing reusable enzyme mimicking nanoparticles for lignin depolymerization and biofuel production

2021 ◽  
Author(s):  
Rajiv CHANDRA RAJAK ◽  
Pathikrit Saha ◽  
Mamata S Singhvi ◽  
Darae Kwak ◽  
Danil Kim ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Biofuel Production ◽  
Biomass Pretreatment ◽  
Enzyme Mimicking ◽  
Lignin Depolymerization

Pretreatment of lignocellulosic biomass to specifically depolymerise lignin moieties without loss of carbohydrates as well as to minimize the generation of harmful intermediates during the process is a major challenge...

Effect of pyrolysis temperature on volatile products from hazelnut shells: products characteristics and antioxidant activity assessment of liquid products

2021 ◽  
Vol 19 (4) ◽  
pp. 383-391
Author(s):  
Chenxi Zhao ◽  
Yupeng Xing ◽  
Wei Lv ◽  
Juhui Chen ◽  
Xiaogang Liu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Composition Analysis ◽  
Maximum Output ◽  
Activity Assessment ◽  
Volatile Products ◽  
Liquid Products ◽  
Fuels And Chemicals ◽  
Gas Products ◽  
Combustible Gases ◽  
Hazelnut Shells

Abstract It is being considered to pyrolyze lignin-rich biomass samples (hazelnut shells, HSs) into bio-fuels and chemicals to solve energy shortages and environmental concerns, volatile products (including liquid products and gas products) were produced and characterized from HSs pyrolysis at 400–1000 °C. With the temperature increases, the maximum output of liquid products was up to 35.79% produced at 700 °C, gas products yields increased from 21.82 to 55.46%. Gas chromatography and mass spectrometry (GC–MS) study indicated that liquid products from HSs riched in phenolic compounds, exceed 42% of liquid products and increased as the temperature rises. The application experiment showed that HSs liquid products had a significant role in antioxidant activity, and revealed that not limited to phenols, all compounds containing phenolic hydroxyl structure act as antioxidant. Composition analysis of gas products showed that more combustible gases were produced at the higher temperature, resulted in the significant increase in gas products higher heating value (HHV) from 6.21 to 24.36 MJ/kg.

scholarly journals Decomposition of Rice Chaff Using a Cocultivation System of Thermobifida fusca and Ureibacillus thermosphaericus

Proceedings ◽  
2021 ◽  
Vol 66 (1) ◽  
pp. 31
Author(s):  
Sachiko Nakamura ◽  
Norio Kurosawa
Keyword(s):  
Lignin Peroxidase ◽  
Culture Medium ◽  
Reducing Sugars ◽  
Thermophilic Bacteria ◽  
Thermobifida Fusca ◽  
Bacterial Strains ◽  
Basal Salt Medium ◽  
Moderately Thermophilic ◽  
Fuels And Chemicals ◽  
Ureibacillus Thermosphaericus

Lignocellulosic biomass comprises cellulose, hemicellulose, and lignin and is a potential source of fuels and chemicals. Although this complex biomass is persistent, it can be cooperatively decomposed by a microbial consortium in nature. In this study, a coculture of the moderately thermophilic bacteria Thermobifida fusca and Ureibacillus thermosphaericus was used for biodegradation of rice chaff. The bacterial strains were incubated in modified Brock’s basal salt medium (pH 8.0) supplemented with yeast extract and rice chaff at 50 °C for 7 days. The concentration of reducing sugars and the enzymatic activities of laccase, lignin peroxidase, cellulase, and xylanase in the supernatant of the culture medium were measured every day. The concentrations of reducing sugars in solo cultures of T. fusca and U. thermosphaericus and a mixed culture of the two strains after 7 days of incubation were 0.047, 0.040, and 0.195 mg/mL, respectively, indicating that the decomposition of rice chaff was enhanced in the coculture. Based on the results, it is thought that the lignin surrounding the cellulose was decomposed by laccase and lignin peroxidase secreted from U. thermosphaericus, resulting in cellulose and hemicellulose in the rice chaff being easily decomposed by enzymes from T. fusca.

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