Comparative study of different catalysts for the direct conversion of cellulose to sorbitol

2015 ◽  
Vol 4 (2) ◽  
Author(s):  
Lucília S. Ribeiro ◽  
José J.M. Órfão ◽  
Manuel Fernando R. Pereira
Keyword(s):  
Direct Conversion ◽  
Single Step ◽  
Raw Material ◽  
Added Value ◽  
Supported Metal Catalysts ◽  
One Pot ◽  
Hydrolytic Hydrogenation ◽  
Renewable Raw Material ◽  
Pre Treatment ◽  
The One

AbstractThe catalytic conversion of lignocellulosic biomass to obtain high added value compounds and fuels is a rapidly developing field. Given the abundance of this renewable raw material and its reduced impact on the food chain, it is an attractive source for obtaining chemicals or fuels in the context of a sustainable economy. In this work, bi-functional catalysts were developed that were capable of performing in a single step the hydrolysis and hydrogenation of cellulose to produce compounds that may be used in the production of fine chemicals or easily converted into fuels (e.g., sorbitol). Different activated carbon (AC) supported metal catalysts were examined for the one-pot hydrolytic hydrogenation of cellulose. Among the prepared catalysts, 0.4% Ru/AC was shown to be the most active and selective for the conversion of cellulose into sorbitol. When microcrystalline cellulose was used, a conversion of 32% was reached after 5 h of reaction, with a selectivity to sorbitol of 30%. Moreover, ball-milled cellulose allowed attaining conversions over 50%, with selectivities to sorbitol of 45%. The results obtained showed that Ru/AC is effective for the hydrolytic hydrogenation of cellulose to sugar alcohols and that the conversion can be greatly improved by using the substrate after pre-treatment by ball-milling.

Screening of catalysts and reaction conditions for the direct conversion of corncob xylan to xylitol

2017 ◽  
Vol 6 (3) ◽  
Author(s):  
Lucília S. Ribeiro ◽  
José J.M. Órfão ◽  
Manuel F.R. Pereira
Keyword(s):  
Direct Conversion ◽  
Supported Metal Catalysts ◽  
Reaction Conditions ◽  
One Pot ◽  
Metal Loading ◽  
Catalytic Support ◽  
Metal Metal ◽  
Repeated Use ◽  
Loading Amount ◽  
The One

AbstractDifferent supported metal catalysts were tested for the one-pot transformation of corncob xylan to xylitol. The influence of several factors, such as catalytic support, nature of metal, metal loading, amount of catalyst, hydrogen pressure and reaction temperature, was investigated. The results revealed that xylan can be converted into xylitol with a yield close to 80% after 2 h of reaction using Ru supported on carbon nanotubes (CNT, 0.4 wt% metal loading) with excellent stability after repeated use, at a temperature of 170°C and an H

scholarly journals Mesoporous Activated Carbon Supported Ru Catalysts to Efficiently Convert Cellulose into Sorbitol by Hydrolytic Hydrogenation

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4394
Author(s):  
Fatima-Zahra Azar ◽  
M. Ángeles Lillo-Ródenas ◽  
M. Carmen Román-Martínez
Keyword(s):  
Carbon Materials ◽  
Activated Carbons ◽  
One Pot ◽  
Cellulose Conversion ◽  
Hydrolytic Hydrogenation ◽  
Ru Nanoparticles ◽  
Two Samples ◽  
Materials Used ◽  
The One ◽  
By Products

Catalysts consisting of Ru nanoparticles (1 wt%), supported on mesoporous activated carbons (ACs), were prepared and used in the one-pot hydrolytic hydrogenation of cellulose to obtain sorbitol. The carbon materials used as supports are a pristine commercial mesoporous AC (named SA), and two samples derived from it by sulfonation or oxidation treatments (named SASu and SAS, respectively). The catalysts have been thoroughly characterized regarding both surface chemistry and porosity, as well as Ru electronic state and particle size. The amount and type of surface functional groups in the carbon materials becomes modified as a result of the Ru incorporation process, while a high mesopore volume is preserved upon functionalization and Ru incorporation. The prepared catalysts have shown to be very active, with cellulose conversion close to 50% and selectivity to sorbitol above 75%. The support functionalization does not lead to an improvement of the catalysts’ behavior and, in fact, the Ru/SA catalyst is the most effective one, with about 50% yield to sorbitol, and a very low generation of by-products.

Feasibility Study of CO2 Mitigation with Methanol Production through Hydrogenation and Bi-Reforming of Natural Gas

2019 ◽  
Vol 965 ◽  
pp. 117-123
Author(s):  
Igor Lapenda Wiesberg ◽  
José Luiz de Medeiros ◽  
Ofélia de Queiroz Fernandes Araújo
Keyword(s):  
Natural Gas ◽  
Raw Materials ◽  
Chemical Conversion ◽  
Direct Conversion ◽  
Raw Material ◽  
Sensitivity Analyses ◽  
Atmospheric Conditions ◽  
Methanol Production ◽  
Pre Treatment ◽  
Economic Analyses

Chemical conversion of carbon dioxide (CO2) to methanol has the potential to address two relevant sustainability issues: economically feasible replacement of fossil raw materials and avoidance of greenhouse gas emissions. However, chemical stability of CO2 is a challenging impediment to conversion, requiring harsh reaction conditions at the expense of increased energy input, adding capital, operational and environmental costs. This work evaluates two innovative chemical conversion of CO2 to methanol: the indirect conversion, which uses synthesis gas produced by bi-reforming as intermediate, and the direct conversion, via hydrogenation. Process simulations are used to obtain mass and energy balances, needed to support economic analyses. Due to the uncertainties in the raw material prices, including CO2 and hydrogen (H2), its limits for economic viability are estimated and sensitivity analyzes are carried in predetermined prices (base cases). It is considered the scenario of free CO2 available in atmospheric conditions, as in a bioethanol industry, but the sensitivity analyses show the results for other scenarios, as in a CO2 rich natural gas, in which the cost of processing CO2 is zero. The economic analyses show that hydrogenation can be feasible if hydrogen prices are lower than 1000 US$/t, while the indirect route is viable only for cheap sources of natural gas below 3.7 US$/MMBtu. The CO2 pre-treatment costs are not as sensible as the others raw materials.

Single-step formulation of levodopa-based nanotheranostics – strategy for ultra-sensitive high longitudinal relaxivity MRI guided switchable therapeutics

2020 ◽  
Vol 8 (6) ◽  
pp. 1615-1621
Author(s):  
Dan Tian ◽  
Hongxia Xu ◽  
Bing Xiao ◽  
Xiaoxuan Zhou ◽  
Xiangrui Liu ◽  
...  
Keyword(s):  
Photothermal Therapy ◽  
Single Step ◽  
Tumor Ablation ◽  
One Pot ◽  
Mri Contrast ◽  
Longitudinal Relaxivity ◽  
Mri Guided ◽  
The One ◽  
Complete Tumor

The one-pot synthesized nanotheranostic agent T-SWITCH showed high MRI contrast efficiency (r1 = 61.94 mM−1 s−1) and complete tumor ablation after photothermal therapy.

Direct Conversion of Carboxylic Acids to Various Nitrogen-Containing Compounds in the One-Pot Exploiting Curtius Rearrangement

2019 ◽  
Vol 84 (17) ◽  
pp. 11323-11334 ◽  
Author(s):  
Arun Kumar ◽  
Naveen Kumar ◽  
Ritika Sharma ◽  
Gaurav Bhargava ◽  
Dinesh Mahajan
Keyword(s):  
Carboxylic Acids ◽  
Direct Conversion ◽  
One Pot ◽  
Curtius Rearrangement ◽  
The One ◽  
Nitrogen Containing Compounds

scholarly journals Application of Ionic Liquids in the Utilization of the Agricultural Wastes: Towards the One-Step Pre-Treatment and Cellulose Hydrolysis

2015 ◽  
Vol 43 (2) ◽  
pp. 85-89 ◽  
Author(s):  
Gábor Megyeri ◽  
Nándor Nemestóthy ◽  
Milan Polakovic ◽  
Katalin Bélafi-Bakó
Keyword(s):  
Cellulose Hydrolysis ◽  
Agricultural Wastes ◽  
Raw Material ◽  
Biofuel Production ◽  
Human Consumption ◽  
Imidazolium Chloride ◽  
Material Source ◽  
Glucose Content ◽  
Pre Treatment ◽  
The One

Abstract Cheap, renewable lignocellulosic materials are relevant to the future of biofuel production. Wood and agricultural wastes (e.g. straw, corn stover) provide a raw material source that cannot be used for human consumption, thus biofuels from such sources do not threaten the food supply. The aim of the work was to carry out the pre-treatment and hydrolysis of lignocellulosic material in the same ionic liquid solvent (1-n-butyl-3- methyl-imidazolium-chloride, [Bmim]Cl), using ground wheat straw and a mixture of corn (Zea mays) leaf and stover, as substrates. Our measurements show that it is possible to achieve an acceptable glucose content from the cellulose by applying Cellic® CTec2 and Cellic® HTec2 enzyme complexes.

A Green Alternative for Aryl Iodide Preparation from Aromatic Amines

2020 ◽  
Vol 17 (2) ◽  
pp. 131-135
Author(s):  
Zohreh Shahnavaz ◽  
Lia Zaharani ◽  
Mohd Rafie Johan ◽  
Nader Ghaffari Khaligh
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
Raw Material ◽  
Diazonium Salts ◽  
Separation And Purification ◽  
One Pot ◽  
Aryl Iodide ◽  
Aryl Iodides ◽  
The One

Background: In continuation of our previous work and the applications of saccharin, we encouraged to investigate the one-pot synthesis of the aryl iodides by the diazotization of the arene diazonium saccharin salts. Objective: Arene diazonium salts play an important role in organic synthesis as intermediate and a wide variety of aromatic compounds have been prepared using them. A serious drawback of arene diazonium salts is their instability in a dry state; therefore, they must be stored and handled carefully to avoid spontaneous explosion and other hazard events. Methods: The arene diazonium saccharin salts were prepared as active intermediates in situ through the reaction of various aryl amines with tert-butyl nitrite (TBN) in the presence of saccharin (Sac–H). Then, in situ obtained intermediates were used into the diazotization step without separation and purification in the current protocol. Results: A variety of aryl iodides were synthesized at a greener and low-cost method in the presence of TBN, Sac–H, glacial acetic acid, and TEAI. Conclusion: In summary, a telescopic reaction is developed for the synthesis of aryl iodides. The current methodology is safe, cost-effective, broad substrate scope, and metal-free. All used reagents are commercially available and inert to moisture and air. Also, the saccharine and tetraethylammonium cation could be partially recovered from the reaction residue, which reduces waste generation, energy consumption, raw material, and waste disposal costs.

Direct conversion of cellulose into isosorbide over Ni doped NbOPO4 catalysts in water

2020 ◽  
Vol 44 (25) ◽  
pp. 10292-10299
Author(s):  
Minyao He ◽  
Jiaxing Guo ◽  
Xincheng Wang ◽  
Yongji Song ◽  
ShanShan Liu ◽  
...  
Keyword(s):  
Direct Conversion ◽  
One Pot ◽  
The One ◽  
Aqueous Conditions

Ni doped NbOPO4 catalysts were used efficiently for the one-pot conversion of cellulose to isosorbide under aqueous conditions.

scholarly journals Lignin-Based High-Performance Fibers by Textile Spinning Techniques

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3378
Author(s):  
Yanhong Jin ◽  
Jiaxian Lin ◽  
Yu Cheng ◽  
Chunhong Lu
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Mechanical Performance ◽  
Direct Conversion ◽  
Industrial Applications ◽  
Fiber Spinning ◽  
Raw Material ◽  
Spinning Process ◽  
Renewable Raw Material ◽  
Modified Lignin

As a major component of lignocellulosic biomass, lignin is one of the largest natural resources of biopolymers and, thus, an abundant and renewable raw material for products, such as high-performance fibers for industrial applications. Direct conversion of lignin has long been investigated, but the fiber spinning process for lignin is difficult and the obtained fibers exhibit unsatisfactory mechanical performance mainly due to the amorphous chemical structure, low molecular weight of lignin, and broad molecular weight distribution. Therefore, different textile spinning techniques, modifications of lignin, and incorporation of lignin into polymers have been and are being developed to increase lignin’s spinnability and compatibility with existing materials to yield fibers with better mechanical performance. This review presents the latest advances in the textile fabrication techniques, modified lignin-based high-performance fibers, and their potential in the enhancement of the mechanical performance.

scholarly journals Direct conversion of C6 sugars to methyl glycerate and glycolate in methanol

RSC Advances ◽  
2018 ◽  
Vol 8 (53) ◽  
pp. 30163-30170 ◽  
Author(s):  
Lei Feng ◽  
Gang Li ◽  
Yueer Yan ◽  
Wenrong Hou ◽  
Yahong Zhang ◽  
...  
Keyword(s):  
Maximum Yield ◽  
Direct Conversion ◽  
One Pot ◽  
The One ◽  
Methyl Glycolate ◽  
Reaction Routes

Methyl glycerate (MGLY) and methyl glycolate (MG) are directly produced in maximum yield by the one-pot conversion of hexose, and the formation of MGLY and MG experience different reaction routes.

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