Development of new catalytic systems for upgraded bio-fuels production from bio-crude-oil and biodiesel

The investigation of upgraded bio-fuels production processes was carried out via the development of efficient catalysts for oxy-organic hydrodeoxygenation (HDO) processes. It was found that Ni–Cu catalysts are more attractive than single Ni catalysts in HDO under mild conditions. Copper facilitates the nickel oxide reduction at temperatures lower than 300 °C. Moreover, copper prevents methanization of oxy-organics at 280–350 °C. The catalyst supports play also a key role in hydrotreatment of oxygen-containing compounds. Screening of catalyst supports showed that CeO₂ and ZrO₂ are most effective in the target processes because of possible additional activation of oxy-compounds on the support surface. The prepared catalysts have non-sulfided nature and can be used for upgrading of bioliquids with a low sulfur content.     

生物油加氢脱氧研究进展

生物油是潜在的可再生能源,但由于含氧量高、低热值、化学性能不稳定和耐腐蚀性差等缺陷,影响其广泛应用,需进一步进行加氢脱氧处理。综述了近年来对生物油的模型化合物及实际油品的催化加氢脱氧的研究进展。     

合成油品加氢脱氧催化剂的研究进展

介绍了近年来国内外合成油品加氢脱氧催化剂在载体及其改性、活性组分及助剂等方面的研究进展,阐述了开发新型加氢脱氧催化剂的不同途径及意义。     

Hydrotreatment of pyrolysis oils from biomass: reactivity of the various categories of oxygenated compounds and preliminary techno-economical study

This paper describes essential aspects of the hydrotreatment of pyrolytic oils in the light of results obtained until now at the Université Catholique de Louvain. Stability of pyrolysis oils necessitates a two-step processing. A low temperature hydrotreatment enables stabilization through reactions like olefin, carbonyl and carboxylic groups reduction. Further hydrotreatment aims at hydrodeoxygenation of phenols and hydrocracking of larger molecules. Results about catalysts, reaction conditions and parameters enabling or influencing the control of the reaction are summarized. Based on these laboratory data, a preliminary techno-economical evaluation is made. 50 wt.-% yields in hydrocarbons for deep hydrorefining of pyrolysis oils can be expected. Nevertheless, a moderate hydroconversion with partial elimination of oxygen would be, economically, more advantageous.     

植物油加氢脱氧催化剂的研究进展

综述了近年来植物油加氢脱氧催化剂的研究进展,包括植物油加氢脱氧反应机理、催化剂活性组分和载体的选择与改性、本体型催化剂的开发以及加氢脱氧催化剂的稳定性等研究进展;指出目前存在的主要问题为催化剂的活性低和水热稳定性差,因此开发具有适宜酸性质和孔结构的高活性和良好水热稳定性的加氢脱氧催化剂是今后研究的重点。     

小球藻热解油在Ni-Cu/ZrO2催化剂上的加氢脱氧

在小型固定床反应器中以Ni-Cu/ZrO₂为催化剂,对小球藻热解油进行催化加氢脱氧,以改善生物油性能。利用XRD、H₂-TPR、TG、NH₃-TPD等技术对催化剂进行了结构表征。结果表明,Cu的加入有效促进了Ni-Cu/ZrO₂催化剂活性相的表面分散,提高了该催化剂对小球藻热解油加氢脱氧反应的催化活性。在2 MPa、350 ℃反应条件下,随Cu/Ni的增大,Ni-Cu/ZrO₂的催化活性先升高后降低,Cu/Ni质量比为0.40时的催化性能最好,连续运行3 h后所得精制生物油脱氧率达82.0%。Ni-Cu/ZrO₂催化剂在反应过程中,表面结焦少,活性粒子及催化剂性能稳定,连续运行24 h后所得精制生物油脱氧率依然维持在77.0%以上。小球藻热解油经催化加氢脱氧所得的精制生物油,低位热值由31.5 MJ·kg^-1提高至35.0 MJ·kg^-1,40℃运动黏度由20.5 mm²·s^-1降至9.5 mm²·s^-1,且油品中水分更易于脱除。精制生物油中高级脂肪酸的含量减少,油品稳定性大幅提高。     

Removal of carbonaceous deposits from the surface of cobalt-molybdate catalyst via oxidative regeneration

The oxidative regeneration of cobalt-molybdate catalyst used during the hydrodeoxygenation of a phenol solution and for hydrotreatment of Athabasca bitumen was carried out in a fixed-bed reactor. SO₂, CO and CO₂ were analysed as the major products. The surface area of the spent catalysts was the main factor influencing the initial rate of regeneration, i.e. the greater the surface area the higher the initial rate. A mechanism proposed includes 12 reactions which may play an important role in the overall burn-off of hydrotreatment catalysts.     

Magnesium-containing catalysts for the decarboxylation of bio-oil

At present, one of the most promising methods of processing renewable raw materials is pyrolysis, which allows liquid organic products (bio-oil) to be derived from biomass. For obtaining fuel products from bio-oil, the latter needs to be preliminarily upgraded. It is appropriate to carry out this process in two stages. The first stage—decarboxylation—is intended to reduce the corrosiveness (acidity) of the feedstock and hydrogen consumption at the second stage. Decarboxylation is usually conducted over noble metal-based catalysts. There are examples of employing cheaper catalysts based on alkaline-earth metals; however, these catalysts suffer from insufficient stability. Here, we report the activity of MgO-based catalysts in the decarboxylation of pentanoic acid, a model compound imitating bio-oil, and the effect of dopants on the stability of the magnesium-containing catalysts. The process has been carried out in an inert atmosphere at a temperature of 350°C and a pressure of 0.50 MPa. Raising the MgO calcination temperature to 1200°C and introducing stabilizing admixtures (Al₂O₃, SiO₂, and ZrO₂) affords catalysts that are mainly deactivated via carbonate formation rather than the formation of soluble magnesium salts and are, therefore, more promising from the standpoint of regenerability.     

Hydrodeoxygenation of vanillin over carbon nanotube-supported Ru catalysts assembled at the interfaces of emulsion droplets

Carbon nanotube supported ruthenium catalysts, assembled at the water/oil interfaces, show excellent activity and selectivity for the hydrodeoxygenation of the bio-oil model compound of vanillin under mild conditions (1 MPa, 150 °C). Based on a direct fluorescence image, the Ru/CNT catalysts are mainly distributed on the surface of the emulsion droplets, forming a Pickering emulsion. Simultaneous reaction and separation of the products are achieved in the constructed emulsions, which have great potential in the simplifications of the isolation and purification stages for bio-oil refining.     

Effect of preparation variables on the activity of Ni-W/Al2O3 hydrotreating catalysts

Studies have been carried out on the influence of preparation parameters on the activity of nickel-tungsten (Ni-W) catalysts, used to promote the hydrotreatment of model compounds representative of nitrogen, sulphur, oxygen and aromatic containing compounds which typically occur in coal derived liquids. The preparation variables considered for optimisation were the pH of the impregnating solution, the impregnation order, the starting Ni salts, the Ni/Ni + W ratio, the drying conditions and the calcination temperature. It was found that changes in pH, within the range where binding of the starting ions to alumina takes place, is not a significant variable influencing the activity. The use of nickel nitrate as a precursor yields better catalysts. If W is impregnated first it is redistributed during subsequent nickel impregnation, and better catalysts are obtained when Ni is impregnated first. The optimum Ni/Ni + W ratio is between 0.3 and 0.4, based on the total active metals present on the catalyst. The hydrodesulphurisation hydrodeoxygenation and hydrogenation activities decrease with increase in the drying temperature; the reverse is true for hydrodenitrogenation. An optimum activity is obtained when drying at 100°C in a closed oven. The optimum calcination temperature was found to be 500°C.     

Recent research progress on bio-oil conversion into bio-fuels and raw chemicals: a review

Recent advances in lignocellulosic biomass valorization for producing fuels and commodities (olefins and BTX aromatics) are gathered in this paper, with a focus on the conversion of bio-oil (produced by fast pyrolysis of biomass). The main valorization routes are: (i) conditioning of bio-oil (by esterification, aldol condensation, ketonization, in situ cracking, and mild hydrodeoxygenation) for its use as a fuel or stable raw material for further catalytic processing; (ii) production of fuels by deep hydrodeoxygenation; (iii) ex situ catalytic cracking (in line) of the volatiles produced in biomass pyrolysis, aimed at the selective production of olefins and aromatics; (iv) cracking of raw bio-oil in units designed with specific objectives concerning selectivity; and (v) processing in fluidized bed catalytic cracking (FCC) units. This review deals with the technological evolution of these routes, in terms of catalysts, reaction conditions, reactors, and product yields. A study has been carried out on the current state-of-knowledge of the technological capacity, advantages and disadvantages of the different routes, as well as on the prospects for the implementation of each route within the scope of the Sustainable Refinery. © 2018 Society of Chemical Industry     

生物质油加氢脱氧精制研究进展

随着石油能源渐趋匮乏,生物质高温裂解制备生物质油备受关注。而生物质油中氧含量高达40%,这将影响生物质油的稳定性、极性、热值、粘度和酸性等,应必须对其进行加氢脱氧精制处理。文中介绍了裂解生物质油的组成分布和特点,阐述了裂解生物质油加氢脱氧精制的反应过程和影响因素。     

Guaiacol hydrodeoxygenation in the presence of Ni-containing catalysts

A series of Ni-containing catalysts supported on different materials has been tested in the hydrodeoxygenation of guaiacol, a compound modeling the products of biomass fast pyrolysis. The reaction has been carried out in an autoclave at 320°C and a hydrogen pressure of 17 MPa. The main guaiacol hydrodeoxygenation products are cyclohexane, 1-methylcyclohexane-1,2-diol, and cyclohexanone (which result from aromatic ring reduction). A guaiacol conversion scheme explaining the formation of the main products is suggested. The highest activity is shown by the Ni-containing catalysts on SiO₂ and SiO₂-ZrO₂ supports prepared by the sol-gel method. According to X-ray diffraction and electron microscopic data, the high activity of these catalysts is due to the high concentration of dispersed nickel as reduced films on the surface of the silicate structures. The catalysts offer promise for refining the biomass fast pyrolysis products (bio-oil) into hydrocarbon fuel.     

生物油含氧化合物加氢脱氧反应机理研究进展

分析了不同原料制备的生物油含氧化合物的组成差异,综述了生物油中典型含氧化合物（酚类化合物、呋喃类化合物、醚类化合物、酸类和酯类化合物）的加氢脱氧机理,重点介绍了含氧化合物加氢脱氧动力学数据及反应路径;同时,还对生物油加氢精制过程进行了描述,主要论述了生物油加氢精制过程的机制以及O、S、N等杂原子在不同催化剂下的脱除活性;最后指出生物油加氢精制面临的问题是人们对其反应机理了解不够深入,而模型化合物加氢脱氧无法真实反映生物油的反应过程,今后应重点研究不同类型含氧化合物的相互作用和真实生物油的反应机理。     

生物质溶剂液化及生物油品质提升技术综述

综述了生物质溶剂液化过程中原料、溶剂、催化剂、液固比、温度、反应气氛、压力、反应时间、停留时间、加热速率等因素对液化反应的影响。进一步分析了多种生物油提质改性的方法,主要有催化加氢、催化裂解、催化酯化、添加物质、乳化、重整制氢、萃取等,旨在为生物质液化条件的优化以及生物油的规模化应用提供依据。     

Second row transition metal sulfides for the hydrotreatment of coal-derived naphtha I. Catalyst preparation, characterization and comparison of rate of simultaneous removal of total sulfur, nitrogen and oxygen

Naphtha derived from an Illinois No. 6 coal contains appreciable quantities of sulfur-, nitrogen- and oxygen-containing compounds. The hydrotreatment of this naphtha has been evaluated over unsupported transition metal sulfide catalysts of the second row in the Periodic Table. The catalysts were prepared by a room temperature precipitation reaction. Surface areas, crystalline phase and particle size distributions were determined by Brunauer-Emmet-Teller (BET), X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. A comparison of average particle sizes calculated from these three techniques has enabled the understanding of the morphology of the transition metal sulfides. The catalysts exhibit a so-called volcano plot for the HDS of dibenzothiophene. Similar so-called volcano plots are also exhibited for the simultaneous hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and the hydrodeoxygenation (HDO) of the coal-derived naphtha containing a mixture of heteroatoms. The order of reactivity of the transition metal catalysts is the same for all three of the processes. Ruthenium sulfide (RuS₂) is the most active catalyst for HDS, HDN and HDO of the coal-derived naphtha.     

渣油加氢催化剂的研究和应用

渣油加氢处理技术是近年发展最快的技术领域。渣油加氢处理催化剂是此技术的关键。多种固定床渣油加氢处理催化剂在国外已进行了开发和工业应用。我国也开发了多种固定床渣油加氢处理催化剂，实践表明这种催化剂具有良好的活性和稳定性，产品质量良好，收率高，可为RFCC提供优质的原料。悬浮床渣油加氢处理催化剂也在开发之中，中试试验取得了良好的结果。     

PHR系列固定床渣油加氢催化剂的研制开发与工业应用

中国石油石油化工研究院通过深入研究渣油原料的结构组成与加氢转化行为特征,成功开发出包括保护剂、脱金属剂、脱硫剂和脱残炭剂4大类共12个牌号的PHR系列固定床渣油加氢催化剂。在保护剂中构建了"毫米-微米-纳米"多级孔体系,其微米级孔（PHR-402、PHR-403催化剂）与纳米级孔（PHR-404催化剂）均为双峰分布,微米级孔（PHR-402、PHR-403催化剂）主要分布在1μm附近区域和30~200μm的较宽泛区域,纳米级孔（PHR-404催化剂）的集中孔径则分别约为13nm和250nm,纳米级孔中大于100nm的孔比例达到35%。脱金属剂具有双峰分布的孔结构及内高外低的活性金属含量分布,其"扩散孔"孔径达到微米级（2300nm）,大于100nm的孔比例超过20%。工业应用结果表明,PHR系列渣油加氢催化剂具有高而稳定的脱硫、脱氮、脱残炭等活性,催化剂内部孔结构的利用率高,且床层压降更低,有利于延长装置运转周期。     

Hydrodechlorination of tetrachloroethylene over sulfided catalysts: kinetic study

In this work, a commercial sulfided hydrotreatment catalyst (2.8% NiO, 13.5% MoO₃, supported on γ-alumina, supplied by Shell) is compared with different iron sulfide based catalysts. These catalysts were prepared from a by-product (called red mud (RM)) of the bauxite leaching in the Bayer process. Two different activation procedures were tested, both based in dissolving the RM in an acid solution (HCl or HCl+H₃PO₄) followed by a precipitation with ammonia at pH=8 and calcining at 500 °C. All the catalysts were sulfided at 400 °C.

The commercial catalyst was more active than the iron sulfide catalysts in all the range of space times tested. However, considering the low prize of the RM based catalysts, they could be an interesting alternative to the hydrotreatment catalysts. The selectivity for ethane was near 100% for all the catalysts tested.

Kinetics results were successfully modeled with a Langmuir–Hinshelwood model, assuming that the chemisorption of hydrogen (considered as associative) and TTCE occurs over analogous active sites.     

Hydrodeoxygenation of dibenzofuran over noble metal supported on mesoporous zeolite

Hydrodeoxygenation has been considered to be one of the most promising methods for bio-oil upgrading. In this paper, the catalytic performance of noble metal supported on mesoporous zeolite in model bio-oil compound hydrodeoxygenation was examined. Dibenzofuran was chosen here because of its refractory nature and large molecular size. Our results indicate that Pt supported on mesoporous ZSM-5 show better performance in dibenzofuran hydrodeoxygenation than Pt/ZSM-5 and Pt/Al₂O₃. The excellent catalytic performance is attributed to the combination of strong acidity and mesopore structure in mesoporous zeolite.