Ni-Based Catalysts for the Hydrotreatment of Fast Pyrolysis Oil

Catalytic hydrotreatment is an attractive technology to convert fast pyrolysis oil to stabilized oil products for co processing in conventional crude oil refinery units. We report here the use of novel bimetallic NiCu- and NiPd-based (Picula) catalysts characterized by a high Ni content (29-58 wt %) and prepared using a sol gel method with SiO2, La2O3, kaolin, ZrO2, and combinations thereof as the support, for the catalytic hydrotreatment of fast pyrolysis oil. The experiments were performed in a batch autoclave (1 h at 150 degrees C, 3 h at 350 degrees C, and 200 bar initial pressure at 350 degrees C). The catalyst with the highest nickel loading (58 wt % Ni) promoted with Pd (0.7 wt %) was the most active, yielding oil products with improved properties compared to the crude pyrolysis oil (lower oxygen content, higher solubility in hydrocarbons, and less tendency for coke formation). For all Picula catalysts, except the ZrO2-based catalysts, methane formation was considerably lower than for Ru/C, the benchmark catalyst in catalytic hydrotreatment of fast pyrolysis oil. To anticipate possible catalyst deactivation at very long times on stream, catalyst regeneration studies were performed using thermogravimetric analysis. Analyses of the regenerated catalysts (X-ray diffraction, high-resolution transmission electron microscopy, and Brunauer Emmett Teller surface area) showed the occurrence of active metal agglomeration.</p

Reaction Chemistry and Kinetics of Corn Stalk Pyrolysis without and with Ga/HZSM-5

The bifunctional Ga/HZSM-5 catalyst has been proven having the capability to increase the selectivity of aromatics production during catalytic pyrolysis of furan and woody biomass. However, the reaction chemistry and kinetics of pyrolysis of herbaceous biomass promoted by Ga/HZSM-5 is rarely reported. Pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) analysis and non-isothermal thermogravimetric analysis at four heating rates were carried out to investigate the decomposition behavior and pyrolysis kinetics of corn stalk without and with Ga/HZSM-5. The effective activation energies for corn stalk pyrolysis were calculated by using the Friedman isoconversional method. The Py–GC/MS analysis results indicated that the Ga/HZSM-5 catalyst had a high selectivity toward producing the aromatic chemicals of xylene, toluene and benzene, whereas the major products from non-catalytic pyrolysis of corn stalk were oxygenated compounds. The presence of Ga/HZSM-5 could significantly reduce the effective activation energies of corn stalk pyrolysis from 159.9–352.4 kJ mol−1 to 41.6–99.8 kJ mol−1 in the conversion range of 0.10–0.85

Mono-, bi-, and tri-metallic Ni-based catalysts for the catalytic hydrotreatment of pyrolysis liquids

Catalytic hydrotreatment is a promising technology to convert pyrolysis liquids into intermediates with improved properties. Here, we report a catalyst screening study on the catalytic hydrotreatment of pyrolysis liquids using bi- and tri-metallic nickel-based catalysts in a batch autoclave (initial hydrogen pressure of 140 bar, 350 A degrees C, 4 h). The catalysts are characterized by a high nickel metal loading (41 to 57 wt%), promoted by Cu, Pd, Mo, and/or combination thereof, in a SiO2, SiO2-ZrO2, or SiO2-Al2O3 matrix. The hydrotreatment results were compared with a benchmark Ru/C catalyst. The results revealed that the monometallic Ni catalyst is the least active and that particularly the use of Mo as the promoter is favored when considering activity and product properties. For Mo promotion, a product oil with improved properties viz. the highest H/C molar ratio and the lowest coking tendency was obtained. A drawback when using Mo as the promoter is the relatively high methane yield, which is close to that for Ru/C. H-1, C-13-NMR, heteronuclear single quantum coherence (HSQC), and two-dimensional gas chromatography (GC x GC) of the product oils reveal that representative component classes of the sugar fraction of pyrolysis liquids like carbonyl compounds (aldehydes and ketones and carbohydrates) are converted to a large extent. The pyrolytic lignin fraction is less reactive, though some degree of hydrocracking is observed

8 - Recent developments in the catalytic hydrotreatment of pyrolysis liquids

Fast pyrolysis is a promising technology to convert lignocellulosic biomass to a liquid energy carrier. The product, known as fast pyrolysis liquid (PL), has a higher energy density than solid biomass and is more easily transported and stored. The applications of PLs are limited due to a high water and oxygen content and limited storage stability. As such, upgrading technologies have been developed to broaden the application range of PLs. Catalytic hydrotreatment is such an attractive upgrading technology for PLs and leads to improved product properties like, among others, a higher thermal stability and energy density and, reduced oxygen and water content, etc. Catalytic hydrotreatment is typically carried out at elevated temperatures (250-400°C) and hydrogen pressures (100-200. bar) in the presence of heterogeneous catalysts. This chapter starts with a short overview of fast pyrolysis technology followed by the properties and molecular composition of PLs. The core of the chapter is dedicated to a description of the state of the art regarding the catalytic hydrotreatment of the PLS to improve the product properties and to make the products suitable as a transportation fuel or as a co-feed in existing oil refineries. Various length scales are considered, ranging from molecular aspects to process studies in a dedicated continuous set-up. Catalyst screening studies are provided and will be discussed in detail, both in the presence and absence of external solvents. Proposed molecular transformations are summarised, and their implications on both process and product properties will be discussed

PII: 0010-4361(90)90425-V

Damage tolerance and impact resistance have become key parameters for composite materials in structural applications. In this paper a toughening concept for structural composites based on the hybridization of carbon fibres with high performance polyethylene (HP-PE) fibres is presented. Impact behaviour of hybrid HP-PE/carbon laminates was studied using a falling weight impact test. The effect of the addition of HP-PE fibres as well as the effect of the adhesion level of these fibres on the impact resistance of hybrid HP-PE/carbon structures was investigated. Hybridization results in structural composites exhibiting a significantly better resistance to impact damage than all-carbon laminates due to a change in energy absorption mode. After hybridization more energy is stored in the HP-PE component and consequently less energy is available for damage in the structural carbon component, resulting in a reduction in impact damage and improved post-impact properties