Technical and Economic Analysis of Pemfcs and DMFCs for Material Handling Applications

Abstract

There has been tremendous growth in the material handling industry partially driven by the fast-growing logistics industry. As the major transport equipment, forklift trucks powered by internal combustion engine and petroleum-driven fuels such as gasoline, diesel, or liquefied petroleum gas (propane) historically dominate the forklift industry. Within the 850,000 total forklifts in use across the United States, there are only more than 20,000 forklifts driven by fuel cells. Based on available forklift deployment data between 2004 and 2014, it is estimated that only about 6% of fuel-cell forklifts are driven by DMFC. DMFC-driven forklifts have huge growth potentials due to its low infrastructure cost, low fuel cost, and easy handling of liquid methanol. As a result, the research team will analyze the technical and economic feasibility of DMFCs as the next generation power source for the material handling industry. Preliminary analyses have compared the life cycle cost (LCC) of PEMFC forklifts and DMFC forklifts. The analyses include the cost of fuel cell components, balance of plant (BOP), system assembly, fuel cost, performance of the fuel cell, as well as the average operating conditions of Class I, II, and III forklifts. If the hydrogen price is assumed to be $8/kg, the min LCC ($36,682) of the PEM fuel cell is reached at a moderate current density (533 mA/cm2). Due to the high price of hydrogen, the fuel cost over the lifetime ($26,415 or 72%) is counted for the majority of LCC while the cost of infrastructure and fuel cell installation ($10,267 or 28%) makes up the rest of LCC. The LCC of PEM fuel cell is very sensitive to the hydrogen price. When the hydrogen price varies between $4/kg and $12/kg, the LCC changes between $23,079 and $49,691. The min LCC ($43,308) of the DMFC is reached at a similar current density (591 mA/cm2). Even though DMFC has much lower efficiency (27%) at the min LCC than PEM fuel cell (60%), the fuel cost of DMFC over lifetime ($17,273) is lower than that of the PEM fuel cell because hydrogen price is at least an order of magnitude higher than methanol price per heating value. Since DMFC uses much more PGM catalyst than PEM fuel cell to generate the same amount of power, DMFC’s installation cost accounts for the majority (60%) of DMFC’s LCC. Comparisons between the LCCs of DMFC and PEMFC indicate that DMFC could be a more economic feasible technology than PEMFC for Class I and II forklifts in relatively small warehouses with less than a dozen forklifts and/or if the hydrogen price is high (>$10/kg).