No abstract

Fractional catalytic pyrolysis is a selective in situ conversion of biopolymers into desired products. Fractional catalytic pyrolysis was used to convert the lignin fraction of hybrid poplar wood into high yields of cresols and phenols while the carbohydrate fraction was selectively converted into gaseous products. Ground air-dried biomass was fractionally pyrolyzed at 450−500 °C in a 2-in fluidized bed reactor. The total liquid, gas, and char/coke yields were 33%, 53%, and 12.5%, respectively. The low viscosity liquid products consisted of almost pure phenolics with minor carbohydrate decomposition products. The major liquid components were phenol, cresols, methyl substituted phenols, and small fractions of indene and substituted naphthalenes. The carbon and oxygen contents and high heating value (HHV) of the oil were 71%, 21%, and 30.5 MJ/kg, respectively. About 90 wt % of the gaseous products was carbon monoxide and carbon dioxide, and the rest was a mixture of hydrocarbons.

No abstract

(51) Int. Cl' Methods for fractional catalytic pyrolysis which allow for C013 3/36 (200601) conversion ofbiomass into a slate ofdesired products without C013 60" (200601) the need for post-pyrolysis separation are described. The C101 1/207 (200601) methods involve use of a fluid catalytic bed which is main-C1013/00 (200601) tained at a suitable pyrolysis temperature. Biomass is added (52) us C1' to the catalytic bed, preferably while entrained in a non-USPC """""""" 48/197 R; 48/2013 48/2093 48/2103 reactive gas such as nitrogen, causing the biomass to become _ _ _ 423/644 pyrolyzed and forming the desired products in vapor and gas (58) Fleld 0f Class1ficatlon Search forms, allowing the desired products to be easily separated.

Effects of equivalence ratio (ER = 0.15, 0.25, and 0.35 at 934 °C) and temperature (790, 934, and 1078 °C at 0.25 ER) were investigated in air gasification of pine for primary gases and contaminants. CO and H 2 increased while CO 2 and CH 4 decreased from 790 to 1078 °C. Opposite trends were observed for ER. Based on overall contaminant weight, tar was highest at all temperatures (7.81, 8.24, and 8.93 g/kg dry biomass) and ERs (13.08, 8.24, and 2.51 g/kg dry biomass). NH 3 varied from 1.63 to 1.00 g/kg dry biomass between 790 and 1078 °C and from 1.76 to 1.47 g/kg dry biomass between 0.15 and 0.35 ER. H 2 S ranged between 0.13 and 0.17 g/kg dry biomass from 790 to 1078 °C and between 0.154 and 0.18 g/kg dry biomass from 0.15 to 0.35 ER. Finally, HCl yields ranged from 13.63 to 0 mg/kg dry biomass and from 11.51 to 0.28 mg/kg dry biomass over the range of temperature and ER, respectively.

Biomass is among the most promising renewable resources to provide a sustainable solution to meet the world's increasing usage of it in biochemical and thermochemical conversion technologies. Thermochemical conversion processes (pyrolysis, gasification, and combustion) thermally convert biomass into energy-dense intermediates that can be, in turn, converted to power, liquid fuels, and chemicals. The performance of the processes and quality of the intermediates are strongly affected by endogenic and technogenic inorganics. This review highlights investigations on the effect and the fate of inorganics during pyrolysis, gasification, and combustion of lignocellulosic biomass and critically and comprehensively presents pretreatment and post-treatment approaches for inorganic removal. During pyrolysis process, the inorganic contents can have significant catalytic effects and change the thermal degradation rate, chemical pathway, and bio-oil yield. During combustion process, the inorganic contents can bring various technological problems, environmental risks, and health concerns. During gasification process, the inorganic contents cause diversified downstream hazards. In recent years, several pre-treatment (mechanical, thermal, and chemical pre-treatment) and post-treatment (gas product and liquid product post-treatment) approaches have been employed to control and diminish the impact of inorganics during thermochemical conversion. Effective pre-treatment technologies exist to remove inorganic contaminants to lower concentration limits. However, the main drawbacks of these pre-treatments are that they (i) reduce the overall efficiency due to the need of further drying process of wet biomass after pre-treatment and (ii) increase chemicals, facilities, and drying costs. Post-treatment technologies are utilized to meet the strict levels of cleanup demands for the downstream applications. A great number of technologies exist to purify the raw synthesis gas stream that is produced by thermochemical conversion of biomass.

The ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([EMIM]Acetate) has been widely used for biomass processing, i.e., to pretreat, activate, or fractionate lignocellulosic biomass to produce soluble sugars and lignin. However, this IL does not achieve high biomass solubility, therefore minimizing the efficiency of biomass processing. In this study, [EMIM]Acetate and three other ILs composed of different 3-methylimidazolium cations and carboxylate anions ([EMIM]Formate, 1-allyl-3-methylimidazolium ([AMIM]) formate, and [AMIM]Acetate) were analyzed to relate their physicochemical properties to their biomass solubility performance. While all four ILs are able to dissolve hybrid poplar under fairly mild process conditions (80 °C and 100 RPM stirring), [AMIM]Formate and [AMIM]Acetate have particularly increased biomass solubility of 40 and 32%, respectively, relative to [EMIM]Acetate. Molecular dynamics simulations suggest that strong interactions between IL and specific plant biopolymers may contribute to this enhanced solubilization, as the calculated second virial coefficients between ILs and hemicellullose are most favorable for [AMIM]Formate, matching the trend of the experimental solubility measurements. The simulations also reveal that the interactions between the ILs and hemicellulose are an important factor in determining the overall biomass solubility, whereas lignin-IL interactions were not found to vary significantly, consistent with literature. The combined experimental and simulation studies identify [AMIM]Formate as an efficient biomass solvent and explain its efficacy, suggesting a new approach to rationally select ionic liquid solvents for lignocellulosic deconstruction.

No abstract