Date of Defense
Date of Graduation
Chemical and Paper Engineering
Biomass is produced in agriculture and forestry, and can be converted to use as a fuel substitute for petroleum. Direct conversion of biomass to bio-oil is conventionally accomplished with a process called fast pyrolysis, in which the biomass is heated to promote the chemical breakdown of its components. This produces some condensable vapors which, when condensed, yield bio-oil. Such a process was compared to a process that gains heat from companion coal gasification instead of traditional heating media such as heated sand. The conversions were then compared to determine the more cost-effective method for producing bio-oil. Additional parameters investigated include the economic benefits of the fuel which are produced through coal gasification.
Almost half of the United States’ petroleum products were imported in 2011, which is economically dangerous. While this percentage has decreased significantly in recent years, other incentives for increasing bio-oil production have risen. Chief among these is the rise in demand for carbon free or carbon neutral sources of energy. Biomass can provide a carbon neutral source of energy, since biomass removes CO2 from the atmosphere while it is growing. With a rise in demand for such sources of energy, it is therefore a worthwhile endeavor to increase the efficiency and decrease the costs for processes that produce bio-oil.
The proposed process operating with companion coal gasification offers several potential advantages over the traditional fast pyrolysis process that may lead to cost reduction. The first advantage is that for this “married” process, it is not necessary to dry the biomass before heating it to promote pyrolysis. The second advantage is that the energy used to heat the biomass to the necessary reaction temperature is gained from the cooling of the syngas produced from coal gasification, eliminating the need for an intermediate heating medium such as sand. The ability to re-use the heat from coal gasification and elimination of the need for drying allows for a simpler design of the biomass pyrolysis reactor and potentially significant savings in terms of total energy costs.
Hayes, Gabriel, "Bio-mass to Bio-oil: Direct Conversion vs Companion Coal Gasification" (2020). Honors Theses. 3258.
Honors Thesis-Open Access