Date of Defense
Date of Graduation
Chemical and Paper Engineering
The purpose of this project was to define, design, and optimize the economic feasibility of the production of bio-oil from a direct conversion of biomass to bio-oil using fast pyrolysis and a secondary side reaction of the production of a syngas from coal gasification. In the end, a combined process of these two was created to show the new strengths and more efficient options to produce a desired product within a budget. The main objectives of this project were to research the economic feasibility of the biomass and bio-oil industry, obtain a market survey, design two process flow diagrams showing the two different processes, calculate the material and energy balances for both processes, develop cash flow tables and economic indicators to show the economic analyses for complete summarization, determine operating costs as well as profits and raw material pricing, and conduct a comparison of the two processes in order to obtain and produce an optimal design. Also specified in this report is an incremental investment option, which is an alternative design. The potential for both processes—Direct Pyrolysis and Combined process—to be implemented in an already existing plant negating real estate costs is this alternate scenario. This project is known as a defender-challenger, to see which process is more efficient and more economically feasible. It can be said that using the Coal Gasification process combined with the Direct Pyrolysis was more viable and useful in this case.
To begin this project, the research process was started by reviewing the AIChE National Student Design Competition of 2013 given to the team as a reference of some initial conditions. During this review, process description, and stream identifications were made clear. A further review would have to be made including research into the fast pyrolysis process, coal gasification process, and overall combining the two together. Operating conditions such as temperature and pressure of each process were also assessed during this research time. The goal then became to use this information and to start a basic design of each process, while taking the market survey and economics into account. The resulting process flow diagrams and basic costing information were designed and estimated using Aspen Plus V11 simulator from similar published processes. After the processes were done and material and energy balances were calculated, a complete economic analysis was made and with related conclusions drawn.
The economic analysis for this project includes some important factors such as the bio-oil produced as a final product, the amount of feed rate into each system, installation and equipment costs, expenses, and profitability. The income for the Combined Process has two factors; bio-oil produced, and syngas produced coming in at $274 million/year. The installation and equipment costing for the Direct Pyrolysis is estimated at $5,755,309, while for the side reaction of Coal Gasification is estimated at $5,933,165 with a combined total of $11.7 million. The total expense cost for the overall Combined Process was $101 million. Based on these estimations, the total profit for a plant running this Combined Process design would be $173 million. Also, this process had an IRR of 9.2%, MAR at 0.4, payback period of 0.108 years, and an NPV of 275.2 million. As a result, the combined process of direct conversion using fast pyrolysis and a side reaction of coal gasification proved to be more efficient given the reduced cost of heat and profit margin.
Evans, Luci, "Comparison of Bio-mass to Bio-oil Reactor Systems: Direct Conversion vs. Companion Coal Gasification" (2022). Honors Theses. 3506.
Honors Thesis-Open Access