The biomass can also be fermented to yield liquid alcohol fuels. If one assumes that 50% biomass is cellulose and all cellulose is converted into fermentable glucose, then with reac­tion C6H12O6 + 3H2O [L] = 3C2H5OH [L] + 3O2 or 1 kg cellulose + 0.3 kg of H2O = 0.77kg

ethanol + 0.53 kg O2, ethanol production per tonne biomass is 125 gallons per tonne of biomass which is close to the reported theoretical value of 124 gallons/dry tonne of corn grain (Ragauskas). With 1 hectare = 10,000 m2, and solar irradiation of 1200 W/m2 and photosynthesis efficiency of 6%, the biomass production is 1460 tonnes per year per hectare assuming a heat value of

2,800,0 kJ/kmole, and with a molecular weight M = 180 kg/kmole. Comparing it with switch grass whose production is 37 tonnes per hectare per year, the maximum ethanol yield is 48.1 m3 (183,000 gallons) per hectare per year with a heating value (HV) of 7.37 kJ/m3 (28,000 kJ/gallon). With a higher heating value (HHV) of gasoline about 32.9kJ/m3 (125,000kJ/gallon), 1 liter of ethanol is equivalent to 0.22 liter of gasoline. Estimation of biomass growth with 6% conversion efficiency and the yield of ethanol from biomass are tabulated in Table 3.2.