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Process design and techno-economic analysis of a pilot bio-jet fuel production facility were investigated using Aspen plus software and net present value method (NPV). This process include two-step hydrothermal decomposition of corncob to furfural (steam stripping of hemicellulose) and Levulinic acid (LA, acidic hydrolysis of cellulose), oxygenated precursor production via aldol condensation reaction of furfural and LA, and the subsequent hydro-processing for oxygen removal. Lab experiments on the major area of the process were carried out. The yields of furfural, LA, oxygenated precursor and bio-jet fuel-range hydrocarbons (C 8 –C 15 ) were 59.5% (based on hemicellulose), 34.4% (based on cellulose), 75% (based on furfural and LA input) and 51 wt% (based on precursor) respectively. These values were used as the input information for the process simulation of a first-of-a-kind pilot facility for 1.3 ML/a bio-jet fuel production using this pioneering technology. The mass and energy analysis from Aspen plus model shows that the bio-jet fuel yield was 0.125 tonne/tonne dried corncob. 31.0% of carbon atoms and 47.6% of potential energy from carbohydrate compounds of corncob leave as bio-jet fuel. The estimated consumption of water, steam and electricity is relatively high of 12.3 kg, 63.7 kg and 1.22 KW h respectively due to small simulation scale and lack of process optimization. The total capital cost was ca. $3.96 MM for the 1.3 ML/a facility, of which 28% of equipment investment is spent for oxygenated precursor production. The total operation expense (OPEX) is $1.18/L bio-jet fuel, including variable and fixed costs. Expenses on corncob, catalytic catalyst and H 2 contribute 23%, 19% and 16% respectively. Single point sensitivity analysis of the major breakdown of OPEX shows that catalyst lifetime is the priority factor. Economy of scale of minimum selling price of bio-jet fuel (MSPB) for different capacity facilities (1.3 ML/a, 6.5 ML/a and 13 ML/a) was investigated using different discount and tax rates, of which the lowest MSPB was $0.74/L with a subsidy of $0.31/L at 10% discount rate.

Ni-based catalysts supported on γ-Al 2 O 3 and SiO 2 were prepared by impregnation. Catalyst characterization was performed using XRD, NH 3 -TPD, H 2 -TPR and chemisorption. Effects of supports on catalytic performance were tested using the hydrodeoxygenation (HDO) of phenolic compounds as a model reaction. Experiment result shows that single phenolic compounds can be converted via HDO reaction over Ni/SiO 2 and Ni/γ-Al 2 O 3 catalysts at 300 °C. The hydrocarbon yields are in the range of 60–90%. The effect of supports on the reaction mechanism was also explored. It is found that hydrogenation of the aromatic ring preferentially occurs over Ni/SiO 2 catalyst while the cleavage of C AR O bond preferentially occurs over Ni/γ-Al 2 O 3 catalyst in the HDO of phenol. Compared to Ni/γ-Al 2 O 3 catalyst, Ni/SiO 2 catalyst exhibits better repeatability and higher catalytic activity for hydrocarbon yield when mixed phenolic compounds were used as feedstock in the HDO reaction, and the carbon deposited on the surface of Ni/SiO 2 catalyst is lower.

Direct HDO process for difurfurylidene acetone dimer (F2A) conversion to liquid alkanes (C8 C14) at 260 °C in a batch reactor was investigated over different material supported 1 wt%Pt catalysts, including SAPO-11, HZSM-5, SiO2 Al2O3, MCM-22, and home-made SiO2 ZrO2. C8 C14 alkanes of 55.8% was obtained over the optimized 1 wt%Pt/SiO2 ZrO2 due to its proper pore size of 9.0 nm and moderate acidic centers, together with more than 10% carbon yield of the oxygenated hydrocarbons, including C11 C13 chain alcohols & ketones and the hydrogenated F2A dimers with furan ring (H-F2A dimers). To improve the liquid alkane yield, a two-step process for F2A conversion was also investigated, which included low-temperature hydrogenation at 50 °C over Raney Ni catalyst in a batch reactor and the subsequent high-temperature hydrodeoxygenation (HDO) at 280 °C over 1 wt%Pt/SiO2 ZrO2 in a fixed-bed reactor. The selectivity of 1,5-di(tetrahydro-2-furanyl)-3-pentanol (II-c) was the highest of 83.0% among the hydrogenated intermediates of H-F2A dimers due to the protonation effect of methanol as the solvent and the hydrogenation of C C bonds by Ni active centers. In the same time, the high content of this saturated alcohol H-dimer of II-C increased the solubility and stability of the intermediates in methanol solvent. High carbon yield of C8 C14 alkanes of 82.9%(mol) was obtained after oxygen atom removal from H-F2A dimers via. the second-step HDO reaction. Long time operation showed the stability of 1 wt%Pt/SiO2 ZrO2 as HDO catalyst, deduced from the steady phase structure, acidity of SiO2 ZrO2 support and Pt active centers by catalyst characterization.

Efficient conversion of lignin depolymerization products to more stable chemicals has attracted increasing attention during last few years. Here, we reported a novel and efficient method for lignin depolymerization products valorization on the simple and economic catalyst NixMg1−xO. In which, the unsaturated ingredients were converted to thermal and chemical stable products, resulting in the obvious decreasing of the unsaturated degree of the products and the repolymerization of the phenolic oligomer. The results showed that more than 98% of phenol, a model chemical of lignin depolymerization products, could be converted to cyclohexanol with 100% selectivity. Further investigation demonstrated that it was also efficient for the real lignin depolymerization products, where a significant decrease on the oxygen content and the average molecular weight were shown. Moreover, the NixMg1−xO catalyst was recyclable, and no significant loss of the catalytic activity was exhibited even after 5 runs.

The main products of lignin degradation are phenolic compounds. It is meaningful to study the processes by which cyclohexane is produced from phenolic compounds via hydrodeoxygenation (HDO), because it could be used as fuel additives, chemical feedstock and solvent. In this work, support material ZrO 2 –SiO 2 mixed oxides with different Si/Zr ratio were synthesized, and a series of Ni/SiO 2 –ZrO 2 catalysts with different Ni loading were prepared by impregnation method. The exploration of HDO process was carried out using phenol and guaiacol as model compounds. Effects of Si/Zr ratio, Ni loading and reaction temperature on conversion of phenol and guaiacol as well as distribution of HDO products were systematically investigated. The results showed that almost all of phenol and guaiacol could be effectively converted into O-free products. And the selectivity of cyclohexane was in excess of 90%.

Conference Name:3rd International Conference on Applied Energy (ICAE). Conference Address: Perugia, ITALY. Time:MAY 16-18, 2011.

Pt/HZSM-5 and Ni/HZSM-5 catalysts were prepared and evaluated for aqueous-phase reforming (APR) reaction of xylitol. Effects of reaction temperature, pressure and metal loading on xylitol conversion and pentane selectivity were studied. Experiments over 4 wt% Pt/HZSM-5 catalysts showed that high temperature increased the xylitol conversion while high pressure led to the decrease of pentane selectivity. The xylitol conversion and pentane selectivity increased with the metal loading in the range of 0–3 wt%, but the values decreased as further increasing the metal loading to 5 wt% over both Ni/HZSM-5 and Pt/HZSM-5, indicating that higher metal loading would increase the rate of C–C bond cleavage compared to hydrogenation. Under the condition of 240 °C and 4 MPa, Ni/HZSM-5 and Pt/HZSM-5 with the same metal loading of 2 wt% showed similar xylitol conversion, while the primary had higher pentane selectivity of 95% than 58% of the latter. Ni has higher activity for pentane production than Pt during the APR reaction of xylitol, while Pt has stronger effect of C–C bond cleavage to produce lighter alkanes of C1–C4. In order to investigate catalyst recyclability, 2 wt% Ni/HZSM-5 was reused and analyzed by TG characterization. It was found that considerable amount of coke and heavy hydrocarbons were formed on the catalyst surface, which could cover the active sites and cause catalyst deactivation.

The effect of Ni/Mg mole ratio of Ni–MgO/γ-Al2O3 cordierite monolithic catalysts on dry reforming of model biomass fuel gas(H2/CO/C2H4/CH4/CO2/N2 = 16.0/12.1/2.5/15.1/22.0/32.3, vol.%) was investigated in a lab-scale stainless steel tubular reactor. The results showed that CH4 and CO2 conversions, H2 and CO yields and H2/CO ratio in the tail gas was 87.2%, 54.4%, 65.2%, 43.0%, and 1.17 respectively at 750 °C over the optimized MCNi0.51Mg0.49O (the ratio was 0.51:0.49 with 8.3 wt% NiO loading amount) during 60 h of time on stream (TOS). And the formation of NiO–MgO solid solution structure would restrain the active Ni0 centers from agglomeration and decrease carbon deposition. Cold test of the vertical-placed tubular reformers (packed by monolith of 7 mm cell spacing) indicated that the pressure drop was as low as 850 Pa at 1.57 m/s of gas velocity with 330 g/m3 fly ash added. The reforming of real biomass fuel gas (H2/CO/C2H4/CH4/CO2/N2 = 10.2/16.8/0.5/6.4/15.2/51.0, vol.%, from air gasification of 200–250 kg/h pine sawdust in the pilot plant) in the multi-tube reformer packed with MCP (larger in size than MCNi0.51Mg0.49O) exhibits the pressure drop of less than 700 Pa, CH4 and CO2 conversions of about 84% and 38.5% and the decrease of tar content from 4.8–5.3 g/m3 to 0.12–0.14 g/m3 during 60 h TOS at 670 °C. The characterization of the spent catalysts by TG, XRD and ICP-AES proved the anti-sintering and anti-carbon deposition properties of NiO–MgO solid solution monolithic catalyst.