After paddy rice is processed, a large amount of biomass with a relatively high energy content (18 GJ/ton - higher heating value) is left over in the form of rice husks. According to the IEA's Bioenergy Task 33 on thermal biomass gasification, for each ton of processed rice, roughly 280kg of hulls are left over, worth around 120 kWh.
Now consider that Thailand as a whole produced some 29.4 million tons of rice in 2004. At a residue-to-product ratio for hulls of 0.20 to 0.35 (meaning that for each ton of rice produced, some 200 to 350 kilogram of husks are left over, with an average of 280kg/ton), and at a lower heating value of between 13 to 19 MJ/kilogram (with an average higher heating value of 18MJ/kg) then it is not difficult to see the energy potential contained in the resource: if all rice hulls were used in gasification or combustion systems with an overall efficiency of 33 per cent, the country's technical energy potential from rice husks alone can be estimated be around 49.5 TJ of energy.
From Checkbiotech
