Efficient production of isosorbide from sorbitol dehydration over mesoporous carbon-based acid catalyst

2019 ◽  
Vol 575 ◽  
pp. 38-47 ◽  
Author(s):  
Yi Zhang ◽  
Tong Chen ◽  
Gang Zhang ◽  
Gongying Wang ◽  
Hua Zhang
BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 4284-4303
Author(s):  
Junkang Xie ◽  
Qiaoning Han ◽  
Bo Feng ◽  
Zuguang Liu

An amphiphilic mesoporous carbon-based solid acid (LCx-SO3H) with high specific surface area was prepared from kraft lignin that was carbonized using a phosphoric acid treatment. It was found that the specific surface area, pore structure, and amphiphilic nature of the catalyst was effectively controlled through adjusting the phosphoric acid dosage during lignin carbonization. Under optimum preparation conditions, the specific surface area, pore volume, and average pore size of the catalyst were 282.2 m2/g, 0.26 cm3/g, and 6.73 nm, respectively. The performance of this solid acid catalyst for the hydration of α-pinene was characterized via gas chromatography analysis. The conversion of α-pinene and the yield of α-terpineol during hydration reaction were as high as 95.3% and 55.3%, respectively; these results were greater than the results from other hydration methods with sulfuric acid and commercially available solid acid catalysts (e.g., Amberlyst-15). After five recycles of the carbon-based solid acid without regeneration, conversion of α-pinene decreased from 95.3% to 92.6%, and the yield of α-terpineol decreased from 55.3% to 47.6%. These observations indicated that the solid acid catalyst derived from kraft lignin carbonization has high potential as a hydration agent for α-pinene.


2020 ◽  
Vol 16 ◽  
Author(s):  
Anping Wang ◽  
Heng Zhang ◽  
Hu Li ◽  
Song Yang

Background: With the gradual decrease of fossil energy, the development of alternatives to fossil energy has attracted more and more attention. Biodiesel is considered to be the most potent alternative to fossil energy, mainly due to its green, renewable and biodegradable advantages. The stable, efficient and reusable catalysts are undoubtedly the most critical in the preparation of biodiesel. Among them, nanoporous carbon-based acidic materials are very important biodiesel catalysts. Objective: The latest advances of acidic nanoporous carbon catalysts in biodiesel production was reviewed. Methods: Biodiesel is mainly synthesized by esterification and transesterification. Due to the important role of nanoporous carbon-based acidic materials in the catalytic preparation of biodiesel, we focused on the synthesis, physical and chemical properties, catalytic performance and reusability. Results: Acidic catalytic materials have a good catalytic performance for high acid value feedstocks. However, the preparation of biodiesel with acid catalyst requires relatively strict reaction conditions. The application of nanoporous acidic carbon-based materials, due to the support of carbon-based framework, makes the catalyst have good stability and unique pore structure, accelerates the reaction mass transfer speed and accelerates the reaction. Conclusion: Nanoporous carbon-based acidic catalysts have the advantages of suitable pore structure, high active sites, and high stability. In order to make these catalytic processes more efficient, environmentally friendly and low cost, it is an important research direction for the future biodiesel catalysts to develop new catalytic materials with high specific surface area, suitable pore size, high acid density, and excellent performance.


2019 ◽  
Author(s):  
Dung Van Nguyen ◽  
Pinthep Sethapokin ◽  
Harifara Rabemanolontsoa ◽  
Eiji Minami ◽  
Haruo Kawamoto ◽  
...  

To valorize the underutilized nipa sap composed mainly of sucrose, glucose and fructose, acetic acid fermentation by Moorella thermoacetica was explored. Given that M. thermoacetica cannot directly metabolize sucrose, we evaluated various catalysts for the hydrolysis of this material. Oxalic acid and invertase exhibited high levels of activity towards the hydrolysis of the sucrose in nipa sap to glucose and fructose. Although these two methods consumed similar levels of energy for the hydrolysis of sucrose, oxalic acid was found to be more cost-effective. Nipa saps hydrolyzed by these two catalysts were also fermented by M. thermoacetica. The results revealed that the two hydrolyzed sap mixtures gave 10.0 g/L of acetic acid from the 10.2 g/L of substrate sugars in nipa sap. Notably, the results showed that the oxalic acid catalyst was also fermented to acetic acid, which avoided the need to remove the catalyst from the product stream. Taken together, these results show that oxalic acid hydrolysis is superior to enzymatic hydrolysis for the pretreatment of nipa sap. The acetic acid yield achieved in this study corresponds to a conversion efficiency of 98%, which is about 3.6 times higher than that achieved using the traditional methods. The process developed in this study therefore has high potential as a green biorefinery process for the efficient conversion of sucrose-containing nipa sap to bio-derived acetic acid.


2020 ◽  
Vol 10 (3) ◽  
pp. 918 ◽  
Author(s):  
Jack Clohessy ◽  
Witold Kwapinski

In recent years, a new class of superior heterogeneous acid catalyst for biodiesel production has emerged. These catalysts offer advantages over their predecessors such as high surface area, elevated acid site density, enhanced catalyst activity, good operation stability and relevant economic affordability in an environmentally friendly frame. This review was concerned with carbon-based solid acid (CBAS) catalysts derived from both carbohydrate and pyrolysis products. A series of CBASs with various origins such as D-glucose, sucrose, starch, cellulose and vegetable oil asphalt, converted to char and sulphonated, have been explored as potential heterogeneous catalysts. Catalyst preparation and synthesis methods were briefly summarized. Catalyst characterization and performance for biofuels related reactions were elucidated, identifying potential research applications. Three catalysts in particular were identified as having potential for industrial application and requiring further research.


Sign in / Sign up

Export Citation Format

Share Document