Date of Graduation

2012

Document Type

Thesis

Degree Type

MS

Committee Chair

Kaushlendra Singh

Abstract

Coal, red maple, yellow-poplar, torrefied red maple, torrefied yellow-poplar, coalbiomass mixtures and coal-torrefied biomass mixtures were characterized for fuel properties. West Virginia bituminous coal was used and samples of red maple and yellow-poplar were collected from Appalachian logging residues. The samples were torrefied at 300oC for 30 minutes to produce torrefied red maple and torrefied yellowpoplar. Characterization of samples was done for proximate analysis, ultimate analysis, calorific value and thermo gravimetric analysis. The volatiles produced from thermogravimetric analysis were tested for chemical functional groups using Fourier Infrared Spectroscopy (FTIR). Results showed that the torrefied red maple and yellow-poplar samples lost their hemi-cellulose content. Also, the torrefied samples had calorific value, volatile matter, fixed carbon, and carbon contents comparable to coal. Thermogravimetric analysis showed that coal degraded at higher temperature than woody biomass. This gives an indication that radicals formed during biomass pyrolysis may combine with radicals formed during coal pyrolysis. FTIR Analysis of volatiles evolved during thermo-gravimetric analysis of yellow-poplar, torrefied yellow-poplar, coal and mixture of coal and yellow-poplar showed the presence of following functional groups: alcohol, aliphatic ketone, aromatic anhydrides, aromatic esters, aromatic hydrocarbon aliphatic aldehydes, aliphatic anhydrides, aliphatic esters and aliphatic hydrocarbons. In addition, co-liquefaction experiments were performed. A mechanically stirred and electrically heated parr reactor was used for co-liquefaction experiments. A mixture of 10 gm of sample and 100 ml of tetralin was placed inside the reactor.The reactor was pressurized with 600 psi cold hydrogen pressure and then heated up to the 300oC temperature for 30 minutes. After the reaction, the reactor was cooled and the product slurry was fractionated using soxhlet extraction. Soxhlet extraction was performed on dried products using toluene, hexane, and tetrahydrofuran solvents.The soxhlet extraction produced following products: oils (hexane soluble); asphaltenes (hexane insoluble; toluene soluble); preasphaltenes (toluene insoluble, tetrahydrofuran soluble); and residues (tetrahydrofuran insoluble). Attenuated Total Reflectance Infrared Spectroscopy (ATRIR) was used to analyze the fractionated products. The results showed that there was a synergy between coal and torrefied biomass during liquefaction. The oil yields obtained from co-liquefaction of either coal + torrefied wood mixtures were higher than the weighted average yields from coal and wood separately. The ATR-IR spectra for oils, (hexane extracts) showed the presence of compounds that are derivative of naphthalene.

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