In this research we are following the thermo-chemical degradation of wood in the absence of oxygen. The objectives are to evaluate the influence of heating rates on pyrolysis products obtained from wood pyrolysis and to evaluate the influence of acid pre-treatment on pyrolysis products. Depending on the wood heating rates, pyrolysis can be categorized as Flash pyrolysis, Fast pyrolysis, and Slow pyrolysis. We have evaluated the volatile products obtained at different heating rates and the volatile products obtained from sulfuric acid pre-treatment by using gas chromatography- mass spectrometry (GC-MS). We have also performed thermo-gravimetric analysis (TGA) of raw wood samples and sulfuric acid pre-treated wood samples of Yellow Pine to determine the changes in weight in relation to change in temperature.
Our results indicated that by using the Flash, Fast, and Slow heating rates, the overall volatile products obtained from wood pyrolysis (i.e. the overall list of all the compounds obtained from different temperature ranges in wood pyrolysis by using different heating rates) were the same, but the volatile products obtained at different temperature ranges like Room temperature-300°C, 300°C - 400°C, and 400°C -500°C in Flash, Fast, and Slow pyrolysis were different. Most of the volatile products obtained from the pyrolysis of untreated wood were phenols. Our results also indicated that the pretreatment of wood with sulfuric acid alters the charcoal properties and releases gaseous products including furan derivatives that are useful as fuels or fuel additives. The sulfuric acid (10%) pretreatment of wood followed by slow pyrolysis produced maximum yield of charcoal, indicated by the lowest mass % decrease of 58.234. The production of furan derivatives increased by using sulfuric acid pre-treatment, which is a good improvement for the production of Furanics, the furan based biofuels. The furan based biofuels are of increasing research interest because of their significant advantages over the first generation biofuels. The thermogravimetric analysis (TGA) results indicated that the acid pre-treatment altered the decomposition rate of pyrolysis and lowered the onset of temperature for decomposition.
The use of thermal degradation of plants for creating chemicals and fuels is seeing renewed interest across the globe as it is considered carbon-neutral and it uses a renewable feedstock. The information obtained from this research work will also be valued by industries, such as charcoal and activated carbon producers, which currently perform biomass pyrolysis, by allowing them to form approaches that optimize their energy use and minimize waste.
| Identifer | oai:union.ndltd.org:WKU/oai:digitalcommons.wku.edu:theses-2080 |
| Date | 01 December 2010 |
| Creators | Gade, Prabhavathi |
| Publisher | TopSCHOLAR® |
| Source Sets | Western Kentucky University Theses |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Masters Theses & Specialist Projects |
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