Performance and cost analysis of future, commercially mature gasification‐based electric power generation from switchgrass

Abstract

AbstractDetailed process designs and mass/energy balances are developed using a consistent modeling framework and input parameter assumptions for biomass‐based power generation at large scale (4536 dry metric tonnes per day switchgrass input), assuming future commercially mature component equipment performance levels. The simulated systems include two gasification‐based gas turbine combined cycles (B‐IGCC) designed around different gasifier technologies, one gasification‐based solid oxide fuel cell cycle (B‐IGSOFC), and a steam‐Rankine cycle. The simulated design‐point efficiency of the B‐IGSOFC is the highest among all systems (51.8%, LHV basis), with modestly lower efficiencies for the B‐IGCC design using a pressurized, oxygen‐blown gasifier (49.5% LHV) and for the B‐IGCC design using a low‐pressure indirectly heated gasifier (48.6%, LHV). The steam‐Rankine system has a simulated efficiency of 33.0% (LHV). Detailed capital costs are estimated assuming commercially mature (‘Nth plant’) technologies for the two B‐IGCC and the steam‐Rankine systems. B‐IGCC systems are more capital‐intensive than the steam‐Rankine system, but discounted cash flow rate of return calculations highlight the total cost advantage of the B‐IGCC systems when biomass prices are higher. Uncertainties regarding prospective mature‐technology costs for solid oxide fuel cells and hot gas sulfur clean‐up technologies assumed for the B‐IGSOFC performance analysis make it difficult to evaluate the prospective electricity generating costs for B‐IGSOFC relative to B‐IGCC. The rough analysis here suggests that B‐IGSOFC will not show improved economics relative to B‐IGCC at the large scale considered here. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd