Bifunctional Adsorbent-Catalytic Nanoparticles for the Refining of Renewable Feedstocks

Abstract

A hybrid adsorbent-catalytic nanostructured material consisting of aminopropyl groups and nickel nanoparticles immobilized in mesoporous silica nanoparticles (AP-Ni-MSN) was employed to selectively capture free fatty acids (FFAs) and convert them into saturated hydrocarbons. The working principle of these sorbent-catalytic particles was initially tested in the hydrogenation of oleic acid. Besides providing selectivity for the capture of FFAs, the adsorbent groups also affected the selectivity of the hydrogenation reaction, shifting the chemistry from hydrocracking-based (Ni) to hydrotreating-based and improving the carbon economy of the process. This approach was ultimately evaluated by the selective sequestration of FFAs from crude microalgal oil and their subsequent conversion into liquid hydrocarbons, demonstrating the suitability of this design for the refinery of renewable feedstocks. ABSTRACT: A hybrid adsorbent-catalytic nanostructured material consisting of aminopropyl groups and nickel nanoparticles immobilized in mesoporous silica nanoparticles (APNi-MSN) was employed to selectively capture free fatty acids (FFAs) and convert them into saturated hydrocarbons. The working principle of these sorbent-catalytic particles was initially tested in the hydrogenation of oleic acid. Besides providing selectivity for the capture of FFAs, the adsorbent groups also affected the selectivity of the hydrogenation reaction, shifting the chemistry from hydrocracking-based (Ni) to hydrotreating-based and improving the carbon economy of the process. This approach was ultimately evaluated by the selective sequestration of FFAs from crude microalgal oil and their subsequent conversion into liquid hydrocarbons, demonstrating the suitability of this design for the refinery of renewable feedstocks.

Supported iron nanoparticles for the hydrodeoxygenation of microalgal oil to green diesel

“…2a). In sharp contrast to the hydrogenation of oleic acid using nickel supported on MSN under the same reaction conditions (72% hydrocracking, 25% C17 and 3% C18), [28] the hydrocracking was almost eliminated with Fe-MSN catalyst as it was only observed after 6h reaction (3% yield).…”

“…[35] For instance, Fe forms stronger metal-oxygen bonds than Ni, which favors decarbonylation over hydrodeoxygenation when supported on silica. [18,28] Thus, the capacity to form stronger bonds allows for longer retention times of the oxygenated intermediates, which prevents the reaction from stopping at the carbonyl stage and lead to higher hydrodeoxygenation products.…”

Mesoporous Silica-Supported Amidozirconium-Catalyzed Carbonyl Hydroboration

“…The silica support, in the form of SBA-15 type MSN characterized by a hexagonal array (p6mm) of 9.7 nm diameter pores and a surface area of 385 m 2 /g, was produced by hydrolysis−condensation of tetramethylorthosilicate using the Pluronic P104 template, calcined at 550°C, washed with water, then heated at 550°C under vacuum, and subsequently stored in a glovebox away from ambient air and moisture. 44 The SiOH group surface concentration of 1.7 mmol/g was determined by measuring the concentration of toluene produced in a titration with Mg(CH 2 Ph) 2 (O 2 C 4 H 8 ) 2 53 and by spin counting of Q 3 -sites with 29 Si DPMAS NMR spectroscopy (1.6 mmol/g). Thusprepared MSN and Zr(NMe 2 ) 4 react in benzene at room temperature for 20 h producing Zr(NMe 2 ) n @MSN, a grafted material that we will contend is primarily monopodal tris(dimethylamido)zirconium, with smaller amounts of bipodal species bis(dimethylamido)zirconium and bis(dimethylamido) (dimethylamino)zirconium (eq 1).…”

“…Benzene-d 6 was heated to reflux over Na/K alloy and vacuum-transferred. SBA-15 type MSN was synthesized according to the literature, 44 calcined at 550°C, washed with water, and then heated to 550°C under vacuum. The catalytic materials were characterized by 11 B NMR spectra were referenced to an external sample of BF 3 ·Et 2 O. Infrared spectra were recorded on neat MSN samples using a Bruker Vertex 80 spectrometer with a Harrick Praying Mantis Diffuse Reflection Accessory in a reaction chamber with ZnSe windows.…”

Hydroreforming of the LDPE Thermal Cracking Oil over Hierarchical Ni/Beta Catalysts with Different Ni Particle Size Distributions

“…This kind of procedure can also be applied to other feedstocks, such as fatty acids or vegetable oils, to produce high-quality diesel fuels. 15 Different metal/support combinations have been investigated in hydroreforming reactions. 16−19 It is generally accepted that a proper balance between the two components is required.…”