Catalytically upgraded landfill gas as a cost-effective alternative for fuel cells

Fuel quality issues in stationary fuel cell systems.

“…Upon oxygen depletion, anaerobic decomposition takes place where the final phase is characterized by a steady production of LFG. This gas is typically saturated with water vapor, and it contains mainly methane (40-60%) and carbon dioxide (35-50%), with smaller amounts of oxygen <1% and nitrogen (3-5%) [3,4]. Generally, one million tons of MSW produce approximately 430,000 standard cubic feet (scf) per day of LFG for 20-30 years after being deposited in the landfill.…”

“…The contaminant 4 Thermal Power calculated (LHV) (MW th ) >200 15 5,147 3,783 50 159 100 -200 26 3,885 2,652 53 84 75 -100 27 2,321 1,350 44 52 50 -75 30 1,847 1,125 28 56 20 -50 178 5,375 2,573 29 132 10 -20 286 3,883 2,039 13 125 5 -10 504 3, [7]. matrix can be rather complex, containing several hundred species that can potentially damage the fuel cell anode 6 or other unit operations and processes that precede the fuel cell stack.…”

“…The activated carbon used was Calgon BPL with a micro pore volume of 0.42 cm 3 /g, BET surface area of 1050 m 2 /g, and a bulk density of 450 kg/m 3 . In addition to the trace contaminants, the adsorption effects for CH 4 and CO 2 on activated carbon were also included, based on their Langmuir isotherms [86]. Figure 15 shows the breakthrough time (days) for some of the species that are adsorbed strongly in the bed for However, some halogenated species (e.g., dichlorobenzene) and linear siloxanes (e.g., L2) appear to have a strong adsorption affinity on carbon.…”

“…Activated carbon is used in pressure swing adsorption (PSA) to separate those species for hydrogen purification [87]. While CO 2 and CH 4 do not adsorb on carbon as strongly as VOC, the combination of high concentrations and high pressure will favor their adsorption on the carbon and, thus, reduce the ability of the bed to trap D4.…”

“…While the trace contaminants in the fuel greatly affect the performance and degradation of the fuel cell system, variations in the main components of the gas, i.e., CH 4 and CO 2 , impact the systems significantly since they determine the calorific value of the gas [20]. Such variations can cause irregular problems and lead to a shut-down of the fuel cell system.…”