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A facile approach was developed to directly synthesize carbon-supported metal nanoparticles with pomelo peel as the carbon source and metal nitrate solution as the metal source. Fe/C, Co/C, Ni/C, a...

In this paper, we study the production of aromatic hydrocarbons by co-feeding furans and methanol in a continuous flow fixed-bed reactor over HZSM-5 at 400–600 °C. The effects of reaction temperature, weight hourly space velocity (WHSV), furan to methanol molar ratio and time on stream on the product distribution were investigated. Maximum aromatics yield of 42.0% was obtained over HZSM-5 (Si/Al = 25) with 2-methylfuran (MF) to methanol molar ratio of 1:5 at 500 °C. With the methanol to MF molar ratio increasing from 0 to 5, the conversion of MF increased from 64.7% to 100.0% and the yield of coke decreased from 22.3% to 11.4%. In this process, dimethyl ether derived from methanol dehydration could promote the conversion of MF to aromatic hydrocarbons via Diels-Alder reaction. HZSM-5 with Si/Al ratio of 25 exhibited superior catalytic activity, indicating that strong acidity was necessary for the coupling conversion of MF and methanol. Additionally, the coupling conversions of 2,5-dimethylfuran (DMF), furfural (FF) and furfuryl alcohol (FA) and methanol were investigated. Functional groups of furan rings did not change the formation pathway of aromatic hydrocarbons but they have different constraints on the Diels-Alder reaction of furan ring with olefins.

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-base catalysts are promising candidate for the hydrogenation of furfural (FAL) to high-value chemicals. However, slow intermediate desorption and low selectivity limit its implementation. Identifying the catalytic performance of each active sites is vital to design hydrogenation catalyst, and tuning the geometrical sites at molecule level in PtNi could lead to the modification of electronic structure, and thus the selectity for the hydrogenation of FAL was modulated. Herein, PtNi hollow nanoframes (PtNi HNFs) with three dimensional (3D) molecular accessibility were synthesized, EDX results suggested that Ni was evenly distributed inside of the hollow nanoframes, whereas Pt was relatively concentrated at the edges. DFT calculation demonstrated that PtNi significant decrease the desorption energy of the intermediates. This strategy could not only enhance the desorption of intermediates to improve the catalytic performance, but also transfer the adsorption mode of FAL on catalyst surface to selective hydrogenation of FAL to FOL or THFA. The PtNi HNFs catalyst afforded excellent catalytic performance for selective hydrogenation of a broad range of biomass-derived platform chemicals under mild conditions, especially of FAL to furfuryl alcohol (FOL), in quantitative FOL yields (99%) with a high TOF of 2.56 h−1. It is found that the superior performance of PtNi HNFs is attributed to its 3D hierarchical structure and synergistic electronic effects between Pt and Ni. Besides, the kinetic study demonstrated that the activation energy for hydrogenation of FAL was as low as 54.95 kJ mol−1.

In this paper, jet fuel range alkanes were produced by aldol condensation of furfural and levulinic acid over modified chitosan catalyst and subsequent hydrodeoxygenation. NaOH modified chitosan was developed and used as a solid catalyst in the aldol condensation of furfural and levulinic acid to produce long carbon chain compounds. At room temperature, the total yield of condensation products reached 94.4% over NaOH/CT-4 catalyst. The amine of chitosan plays an important role in the aldol condensation, which reacted with the aldehyde group of the furfural, producing an intermediate Schiff base and promoting the formation of condensation products. This new route avoided the occurrence of side reactions caused by NaOH. Therefore, the yield of the products was greatly increased. Moreover, kinetic analysis of the condensation reaction and the test of catalyst repeatability were also conducted with NaOH/CT-4. The condensation products were further converted to long-chain branched alkanes by hydrodeoxygenation over the 5 wt% Pd/NbOPO4 catalyst. As a potential application, these alkanes could be mixed with and used as the components of jet fuels.

Ni/CMK-3 catalyst, the mesoporous carbon material loading Ni activity, was prepared and used in the in-situ hydrogenation of mixed model compounds (including acetone, acetic acid, furfural, o-cresol, ethanediol and water) of bio-oil (MCB) and actual bio-oil in this paper. The effects of hydrogen donors, solvents and the dosages of catalyst were all investigated in the in-situ hydrogenation process. The results showed that the hydrogen donor of methanol, ethanol and formic acid could all provide hydrogen for the in-situ hydrogenation but the product distributions of bio-oils were different after in-situ hydrogenation. Using alcohols as hydrogen donors, esterification reaction happened between the hydrogen donors and acetic acid. The formic acid could promote the phenols conversion but the conversion of acetic acid was restrained. When the radio of water and methanol was 10:3 and 10:5, most of ketones and aldehydes in the raw bio-oil converted to alcohols and the conversion of acids and phenols was beyond 50%. The contents of alcohols and esters in raw bio-oil increased from 18.52% to 51.14% and 48.21%.

The integrated 1000 tonne/a-scale bio-jet fuel-range hydrocarbon (C8-C15) synthesis system via aqueous phase deconstruction and catalytic conversion process was analyzed for its techno-economics of biomass residue utilization. The operation characterization, mass flow and cost in the system were discussed. A two-step deconstruction of corncob, steam stripping and acidic hydrolysis, was designed for the production of the platform chemicals, furfural and levulinic acid from hemicellulose and cellulose respectively. The oxygenate intermediates with the increased carbon chain length was produced by alkali catalyzed aldol condensation from furfural and levulinic acid. The oxygenate intermediates were catalytically converted to jet fuel-range hydrocarbon (C8-C15) by the tandem steps of low-temperature hydrogenation, high-temperature hydrodeoxygenation and upgrading over noble metal catalysts. The results indicated that bio-jet fuel yield is 139 kg/h or 8 tonne of dried corncob for 1 tonne fuel production. The operation cost of bio-jet fuel is about $1540/tonne and the cost on corncob, catalytic catalyst and H2 contributed 23%, 19% and 16% respectively. The cost sensitivity analysis showed that the catalytic lifetime was one of the main factors that affected the economics of bio-jet fuel production, which could increase bio-jet fuel price to $1820/tonne when its lifetime was reduced to 0.5 year.

Acids, aldehydes, ketones and phenols, which are the main components of bio-oil, have negative effects on the properties. In this paper, the mixture of acetic acid, furfural, hydroxyacetone, ethanediol, phenol and water were chosen as hybrid model compounds of bio-oil (MCB). To convert these compounds into stable and combustible oxygenated organics (alcohols and esters), one step hydrogenation–esterification (OHE) was carried out over Raney Ni catalyst (RN) and Mo, Sn, Fe, Cu modified Raney Ni catalysts (RNs) in the presence of methanol. 100% conversions of furfural and hydroxyacetone were achieved over RNs with high selectivity to desired products. The acetic acid conversion was only 35.1% with no methanol addition, while within 6 g/8 g methanol/MCB addition, the conversion of acetic acid increased to 81.1%. The esterification activity of alcohols was followed by methanol > tetrahydrofurfuryl alcohol (THFA), the hydrogenation product of furfural > ethanediol. Among the RNs, the addition of Fe catalyst restrained the aqueous-phase reforming of methanol and promoted the esterification of methanol and acetic acid. The Mo–RN showed the most favorable performance in the hydrogenation of phenol among the RNs. But the RN modified by both Fe and Mo did not give a good performance. After the OHE of light fraction of raw bio-oil over Mo–RN, there was no ketone & aldehyde detected and the contents of acids and phenols decreased from 49.04% and 7.35% to 8.21% and 3.84%. The conversion of acids could reach to 85.01% which was nearly to the conversion of acetic acid in MCB. The contents of alcohols and esters increased from 5.79% and 4.74% to 53.61% and 33.66%. The content of stable and combustible oxygenated organics reached to 87.27% after OHE of light fraction of raw bio-oil.