Rice husk, which is mostly a waste product from rice milling, can be used to generate power in rice mills, according to a study by the Affiliated Renewable Energy Center, Central Philippine University (CPU-AREC).
The study on “Rice Husk potential as Energy Source in Panay, Philippines” finds that rice husk can be used to generate energy, which can be alternately used for other purposes like drying in the rice mills. According to Mr. Jeriel G. Militar, Project Director of CPU-AREC, approximately 290 kilograms of rice husk is obtained from a ton of paddy rice milled and it is usually left on paddy fields to be decayed or burned. Most of the mills face difficulty in disposing it. Though the rice husk is used as fuel for cook stoves, pottery kilns, ovens and dyers, its use is by far very limited.
According to the study, rice husk has high calorific value of about 3,000 kcal/kg and it is a renewable source of energy as well as a non-carbon fuel. Mr. Militar and team found that one ton of rice husk can produce approximately 726.46 Kilo watts of energy per hour and 82.93 megawatts of power. They recommend setting up of rice husk fueled power plants in rice mills.
However generating power from rice husk has some disadvantages. Rice husk is difficult to store because of its bulky nature and ash content from rice husk (17 - 26%) is much more than that from wood (0.2 - 2%) and coal (12.2%). The total cost of setting up plant and running it is pretty high. Mr.Militar and his team are identifying rice mills which are ready to invest in rice husk power plants in each municipality in the Panay province of the Philippines. However, the study will be useful in countries such as Pakistan, where power costs are high and supply is inconsistent.
The team is also considering recommendations of earlier studies on the subject. According to previous studies, direct combustion is recommended for most heat applications and gasification is recommended for small to medium scale applications. Already some rice mills in Nueva Ecija province are using 'Flatbed Paddy Dryer' using direct combustion and 'Flatbed Paddy Dryer' using gasifier. Similarly a rice mill in Isabela province has set up 1-MW rice husk fueled Power Plant and another mill in the same province has set up a 2- MW Power Plant.
The study also says that the Philippines government is providing various incentives for energy utilization of rice husk under the Renewable Energy Law.
Courtesy : http://oryza.com/news/research-development/rice-husk-can-fuel-power-plan...