Fly ash based Ni catalyst for conversion of sorbitol into glycols

Shanthi, R. Vijaya; Sankaranarayanan, T. M.; Mahalakshmy, R.; Sivasanker, S.

doi:10.1016/j.jece.2015.06.024

Cited by 16 publications

(8 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The selective catalytic hydrogenolysis of sorbitol and xylitol into glycols has been studied intensively in the last two decades with various supported metal catalysts. Typically, the reaction requires a noble or transition metal (Ru, Ni, or Cu) for the dehydrogenation/hydrogenation steps and a base to catalyze C−C cleavage.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, alkaline additives favor the formation of lactate (LA) as a byproduct from glyceraldehyde, at the expense of PG, which limits the selectivity to glycols . To address these issues, recent studies have demonstrated the use of bifunctional catalysts with basic properties . The conversion of sorbitol was studied over a coprecipitated Ni‐MgO catalyst without alkaline additives in the aqueous phase (200 °C, 40 bar of H 2 ).…”

Section: Introductionmentioning

confidence: 99%

“…A Ni‐Mg‐Al catalyst derived from hydrotalcite‐like compounds and coprecipitated Cu/CaO‐Al 2 O 3 catalysts were stable for the conversion of sorbitol at 200 °C/20 bar and 230 °C/76 bar, respectively; the former exhibited a selectivity to glycols of 45 % and the latter 61 % at high conversions. A 6 %Ni supported on fly ash catalyst composed mostly of SiO 2 , Al 2 O 3 , and Fe 2 O 3 was tested four times for the hydrogenolysis of sorbitol in the absence of base. The catalyst remained stable, and high selectivities to glycols (38 %) were reported at 200 °C and 40 % conversion.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Xylitol Hydrogenolysis over Ruthenium‐Based Catalysts: Effect of Alkaline Promoters and Basic Oxide‐Modified Catalysts

et al. 2017

View full text Add to dashboard Cite

The aqueous‐phase hydrogenolysis of xylitol into glycols over Ru/C was performed in the presence and absence of a wide range of concentrations of Ca(OH)2 to investigate the reaction pathway. Without base, epimerization and cascade decarbonylation were the predominant reactions with high selectivities to C5 and C4 alditols and light alkanes at full conversion. Glycol production was obtained by the addition of Ca(OH)2 to promote the retro‐aldol reaction. It competed with reactions without base and became the main reaction for a OH−/ xylitol molar ratio Rmol(OH/xylitol) of 0.13, and high selectivities to glycols (56 %) and glycerol (16 %) were observed. However, lactate was a byproduct at up to 27 % with a high base amount (Rmol(OH/xylitol)=0.68). Bifunctional Ru/metal oxide/C catalysts (metal: Zn, Sn, Mn, Sr, W) were synthesized and were able to cleave the C−C bond into glycols without a base promoter. The 3.1 wt %Ru/MnO(4.5 %)/C catalyst was the most active (220 h−1) with reasonable selectivity to glycols (22 %) and glycerol (10 %) and a low production of lactate (<1 %). Nevertheless, metal oxide leaching of the catalyst was observed likely because of the production of traces of lactate.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Xylitol Hydrogenolysis over Ruthenium‐Based Catalysts: Effect of Alkaline Promoters and Basic Oxide‐Modified Catalysts

et al. 2017

View full text Add to dashboard Cite

show abstract

“…This selectivity was 41% from sorbitol over Ru/Ca(OH) 2 [22] and 32% from xylitol over Ru/MnO/C [10]. The selectivity of Ru-(Mn-Al)O X is equal to that of a few Ni-based catalysts, such as Ni-(Mg-Al)O X [24] or Ni/fly ash [20]. It is close to the one of the best catalytic systems, such as Ni-CaO/C [39] and Cu/CaO-Al 2 O 3 [21], which displayed a selectivity to GLY and glycols of 69% and 73%, respectively; however, the latter Ni catalysts were less active in the hydrogenolysis under similar reaction conditions of alditols with values of 20 and 0.4 h −1 respectively, compared to Ru-(Mn-Al)O X (57 h −1 ).…”

Section: Hydrogenolysis Of Xylitolmentioning

confidence: 94%

“…Some mixed oxide catalysts were also developed. Ni supported on fly ash (a waste mainly composed of SiO 2 , Al 2 O 3 and Fe 2 O 3 ) showed a high global selectivity to glycols and glycerol (58% at 41% conversion) as well as high hydrothermal stability for four consecutive runs [20]. Catalysts supported on Ca-containing supports or directly on Ca(OH) 2 reached up to 60-70% selectivity to glycols at high conversion under base-free conditions.…”

Section: Introductionmentioning

confidence: 99%

Ru-(Mn-M)OX Solid Base Catalysts for the Upgrading of Xylitol to Glycols in Water

et al. 2018

View full text Add to dashboard Cite

A series of Ru-(Mn-M)O X catalysts (M: Al, Ti, Zr, Zn) prepared by co-precipitation were investigated in the hydrogenolysis of xylitol in water to ethylene glycol, propylene glycol and glycerol at 200 • C and 60 bar of H 2 . The catalyst promoted with Al, Ru-(Mn-Al)O X , showed superior activity (57 h −1 ) and a high global selectivity to glycols and glycerol of 58% at 80% xylitol conversion. In comparison, the catalyst prepared by loading Ru on (Mn-Al)O X , Ru/(Mn-Al)O X was more active (111 h −1 ) but less selective (37%) than Ru-(Mn-Al)O X . Characterization of these catalysts by XRD, BET, CO 2 -TPD, NH 3 -TPD and TEM showed that Ru/(Mn-Al)O X contained highly dispersed and uniformly distributed Ru particles and fewer basic sites, which favored decarbonylation, epimerization and cascade decarbonylation reactions instead of retro-aldol reactions producing glycols. The hydrothermal stability of Ru-(Mn-Al)O X was improved by decreasing the xylitol/catalyst ratio, which decreased the formation of carboxylic acids and enabled recycling of the catalyst, with a very low deactivation.

show abstract

Application of industrial solid wastes in catalytic pyrolysis

Qiu

Deng

Zhang

et al. 2017

Asia-Pacific J Chem Eng

View full text Add to dashboard Cite

The catalytic pyrolysis is one of the thermochemical patterns for producing chemical products consisting of solid char, liquid oil, and pyrolytic gas. A number of parameters affecting the catalytic pyrolysis process, yields, and properties of products such as the temperature, residence time, heating rate, feedstock type, and the use of catalyst were evaluated in details to promote the process of catalytic pyrolysis. Catalytic pyrolysis has emerged with the use of a catalyst such as red mud, fly ash, copper slag, blast furnace slag, coal gangue, and aluminum dross. In this paper, a brief discussion with recent development on industrial solid wastes as a catalyst in catalytic pyrolysis process is presented.In the process, the liquid oil is of higher quality; in addition, process by-products such as solid char can be used as an adsorbent material, while the quality of pyrolysis gases is improved. Despite all the potential advantages with industrial solid wastes as a catalyst, some limitations such as less reuse of catalyst and high parasitic energy demand are still remaining. The recommended measurements for these challenges include exploration of suitable reactor, catalyst regeneration, and catalytic mechanism optimization.

show abstract

Fly ash based Ni catalyst for conversion of sorbitol into glycols

Cited by 16 publications

References 31 publications

Xylitol Hydrogenolysis over Ruthenium‐Based Catalysts: Effect of Alkaline Promoters and Basic Oxide‐Modified Catalysts

Xylitol Hydrogenolysis over Ruthenium‐Based Catalysts: Effect of Alkaline Promoters and Basic Oxide‐Modified Catalysts

Ru-(Mn-M)OX Solid Base Catalysts for the Upgrading of Xylitol to Glycols in Water

Application of industrial solid wastes in catalytic pyrolysis

Contact Info

Product

Resources

About