This Is AuburnElectronic Theses and Dissertations

Economic Analysis of Various Reforming Techniques and Fuel Sources for Hydrogen Production

Date

2006-12-15

Author

McGlocklin, Kristin

Type of Degree

Thesis

Department

Chemical Engineering

Abstract

Hydrogen is emerging as a future replacement fuel for the traditional fossil fuels that will be capable of satisfying our energy needs. Hydrogen may enable future energy systems to be cleaner, more reliable, and much more efficient; thus possibly ensuring our energy security and environmental viability. One of the many major challenges of a future hydrogen energy economy is the reduction in the cost of production, storage, and transportation of hydrogen. A generic, robust optimization framework has been developed that enables the identification of economically optimal hydrogen production schemes. Inclusion of constraints on capacity, fuel complexity, and capital investment has been successfully tested for linear and non-linear functions. In this work a total of 16 rigorous process simulation models have been developed for multiple reformation strategies; steam reformation (SR), partial oxidation (POX), auto thermal reformation (ATR), supercritical methanol reformation (SC), and dry methane reformation (DR). The various hydrogen production schemes were investigated for three different fuels: natural gas (approximated by methane), diesel (approximated by dodecane), and methanol. The models included all the feed pretreatment steps along with the reforming reactors and effluent treatment including the water gas shift reactors. Using process integration techniques and advanced computer-aided tools, the systems have been optimized and the economic potential of the technologies evaluated. This work provides a comparison of reformation strategies based on their utility requirements, effects of fuel complexity, energy integration potential, size constraints, electricity production capabilities, and economics; challenging previous ideas on how to compare the efficiency and economic feasibility of each reformation strategy. The results obtained in this work indicate that for industrial scale production of hydrogen, only dry reforming (DR) of natural gas shows any promise for competing with the traditional reforming strategies like steam reforming (SR), partial oxidation (POX) and autothermal reforming (ATR). For size-constrained systems, e.g. onboard vehicular fuel processing systems, partial oxidation appears to provide the best trade-off between power production and system size.