Comparative analysis of SOFC–GT freight locomotive fueled by natural gas and diesel with onboard reformation

Abstract

h i g h l i g h t sDynamic simulation model of an SOFC-GT-powered locomotive with onboard reformation. A diesel-powered SOFC-GT locomotive is predicted with 52.2% efficiency. A natural gas-powered SOFC-GT locomotive is predicted with 60% efficiency. The saving in CO 2 /NO x is 30.3%/97.7% and 53.8%/97.7% respectively. The natural gas-powered SOFC-GT locomotive has distinctive advantages. a r t i c l e i n f o t r a c tDue to increasing awareness of the deleterious environmental and health effects of diesel combustion emissions, major regulatory action and policy measures are focused on reducing emissions from diesel engines. Freight operations, including rail-based freight transportation, have received special attention as an industry where major change can be affected, especially in neighborhoods located near operations centers. A FORTRAN-based dynamic simulation model of an SOFC-GT (Solid Oxide Fuel Cell-Gas Turbine) system from a prior feasibility study has been adapted to analyze system operation along a representative but demanding route in southern California. In previous simulations with the model, the basic operational feasibility of the system has been demonstrated as well as the in-service operation for pre-reformed fuels. In the current study, the analysis is extended to include reformation of two fuels (diesel and natural gas) onboard the locomotive and analyses of system efficiency, fuel consumption, CO 2 emission, and NO x emission that can be attained through careful thermal integration of the reformer unit. Route-averaged fuel-to-wheels system efficiencies of 60% and 52% are predicted for natural gas and diesel fuel, respectively. Additionally, SOFC-GT operation could provide (1) a reduction approaching 98% in NO x for both fuels; (2) a 54% savings in CO 2 for operation on natural gas; and (3) a 30% CO 2 reduction for operation on diesel fuel compared to state-of-the-art locomotive technology. These gains may be offset by design challenges, especially for the diesel case, due to the requirement for large volumes of water to support the reformation process even for medium-length freight hauling trips.

Coupling effects of fuel reforming process and fuel utilization on the system performance of a natural gas solid oxide fuel cell/gas turbine hybrid system

“…Ambient air (1) was pressurized to 400 kPa by a two-stage compressor (Comp1 & 2) with an intercooler. Part of the preheated air (3) was bypassed to turbine inlet directly by hot-air bypass (3a) without going through the SOFC, while the rest (3b) was further heated by a pre-combustor and a manifold heat-exchanger (represented by SOFC manifold HX in Figure 1) to reach the required temperature at cathode inlet (5). The SOFC manifold HX was a cybercomponent and was used to simulate the heat transfer between cathode inlet air (5) and post-combustor exhaust (7).…”

Diesel autothermal reforming with hydrogen peroxide for low-oxygen environments

“…ATR has been considered the most appropriate method for diesel reforming because the steam supply suppresses coke formation over the catalyst and aromatic compounds in the diesel fuel can be effectively decomposed by oxygen [24][25][26][27][28][29]. Yoon et al successfully suppressed carbon deposition by controlling SCR and OCR and successfully tested long-term operation of ATR for 2500 h by considering the fuel delivery method [30,31].…”

Performance and economic investigation of a combined phosphoric acid fuel cell/organic Rankine cycle/electrolyzer system for sulfuric acid production; Energy‐based organic fluid selection

“…1 FCs can operate at different temperatures; solid oxide fuel cell (SOFC), phosphoric acid fuel cell (PAFC), molten carbonate fuel cell (MCFC), direct methanol fuel cell (DMFC), alkaline fuel cell (AFC), and polymer electrolyte membrane fuel cell (PEMFC). 2 The operating temperatures of the first and second types range from 600 to 1000 C ( [3][4][5] ). Whereas, the AFC, DMFC, PAFC, and PEMFC operate at temperature ranges of less than 80, 90 to 120, 150 to 200, and 50 to 100 C, respectively.…”