| Biomass is a renewable and carbon-neutral energy resource. The exploitation of bio-energy is compatible with the development of low-carbon economy and society. Biomass can be converted into liquid fuel called bio-oil by fast pyrolysis technology, a frontier technology in the renewable energy field. However, bio-oil refining is needed before its use for a transportation fuel is possible, due to its poor fuel properties such as complex composition, low thermal stability, and strong corrosiveness and immiscible with fossil fuel. An alternative to refining bio-oil to hydrocarbons is the partial conversion to a less acidic, less hydrophilic and higher heating value fuel mixture which retains substantial oxygen. Therefore, we have tried to investigate the modification of bio-oil using acid catalyzed reactions of olefins and olefin mixtures with bio-oil. Fuel production by partial upgrading of fast pyrolysis oil with olefins is our goal. Nevertheless, almost all bio-oil upgradings are still in laboratory, so there must be a long time before a practical result on bio-oil upgrading appears. But the calcium-enriched bio-oil(CEB), which combines the functions of fuel, desulfurizer and denitrifizer all in one, can convert the bio-oil's disadvantage of high acid content into the advantage by reacting bio-oil with calcium hydroxide to form calcium salts of organic acids. The application of CEB will be a frontier technology for coal clear combustion. More importantly, CEB can realize the direct application of crude bio-oil in boilers in large-scale.Model liquid phase reactions of 1-octene with phenol in the presence of water, acetic acid, methanol and 2-hydroxymethylfuran, respectively, were carried out over acid catalysts for bio-oil upgrading, including 30 wt.%acidic salt CS2.5H0.5PW12O40 supported on K-10 clay (30%Cs2.5/K-10) and Amberlyst 15. Both catalysts had a high activity and selectivity for O-alkylation of phenol with 1-octene but not with 2,4,4-trimethylpentene. The presence of water, acetic acid and methanol lowered the yield of alkylated phenols by the competitive formation of octanols and dioctyl ethers, octyl acetates and methyl ethers, respectively.30%Cs2.5/K-10 is an excellent water-tolerant catalyst while Amberlyst 15 decomposed at higher temperatures and higher water concentrations.2-Hydroxymethylfuran and hydroxyacetone deactivated catalysts significantly. The two catalysts showed a low catalytic activity in the III reactions of bio-oil simulants with 1-octene,1-octene hydration and esterification of acetic acid by methanol were the two main reactions.Only water in bio-oil reacted with the olefins to form combustible alcohols during crude bio-oil upgrading.1-Octene hydration coupled with condensation and polymerization reactions which resulted in a increase of water content of the bio-oil upgraded in the bio-oil/1-octene two liquid phases. The bio-oil upgraded in one liquid phase with diethyl carbonate (DEC) as solvent was better than that in two liquid phases with no solvent, e.g. After the one liquid phase upgrading at 100℃over 30%Cs2.5/K-10, water content of bio-oil fractions decreased by 73.2% under the actions of octenes and DEC, the calorific value increased by 8.3%. Elevated temperature is good for bio-oil upgrading via the addition of olefins. The bio-oil upgraded in one liquid phase can be used as fuel directly or to replace pure DEC as an oxygen-containing fuel additive. DEC extracting of crude bio-oil can realize the combination of energy utilization and chemical production. The macroporous Amberlyst 15 cation resin was destroyed totally during the upgrading process even at 55℃though Amberlyst 15 had a higher catalytic activity than 30%Cs2.5/K-10 by swelling.30% Cs2.5/K-10 deactivated rapidly in a complex bio-oil system.The calcium-enriched bio-oils (CEBs) were produced by reacting bio-oil with calcium hydroxide, which combined the functions of desulfurization/denitrification and providing heat during the decomposition and calcination processes. CEB8 and CEB10 were homogeneous liquid before dried at 110℃and could be sprayed into combustors for application like CA solution. The characteristics of thermal decomposition of CEB, to a great extend, are quite similar to that of calcium acetate (CA). The decomposition processes can be divided into four stages:the loss of volatile materials, devolatilization and degradation of pyrolytic lignin, decomposition of organic calcium salts and residual carbon, decomposition of CaCO3 to CaO. The CaCO3 from amorphous CEBs exhibits the higher calcination rate than that from CA. The actual mechanisms of the second and the third stages obey the nucleation and growth model (A1) mechanism. The high porosity of calcined CEBs should be the further evidence of the mechanism. Correspondingly, the mechanism of the fourth stage obeys 3-dimentional phase boundary reaction (R3) mechanism but CEB 12, which obeys the nucleation and growth model (Al) mechanism at the stage due to high Ca(OH)2 content. The alkali metal migrated from bio-oil might accelerate the calcination rate of CEB-derived CaCO3 and sintering rate of CaO. The porosities of CEB-derived CaO particles were higher than that from CA but the BET surface areas were lower. The porosities and surface areas of CEB-derived CaO particles decreased with the increase of calcium content in CEB.
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