Rice husk is a byproduct during rice milling. This is the outer covering of rice and you will usually see this kind of waste at the back of rice mills or sometimes near irrigation areas where milling is sometimes done by travelling cono. The Appropriate Technology Center (Approtech), under the College of Agriculture, Resources and Environmental Sciences (CARES) of Central Philippine University were able to look for a way on how to utilize these wastes. Hence, they developed the technology and this technology is a stove fuelled by rice husks.
The stove is a device developed for cooking, utilizing the rice husks as fuel. The stove utilizes the direct combustion method wherein it was designed to make use of the available air in the surroundings in order to sustain the operation. No electricity is needed to use this stove.
“The stove is a device wherein the fuel is used. The fuel is burned first for a purpose. This is not open burning because open burning is burning a fuel without a purpose. For the stove, you are actually burning it to provide heat. In this case, we are burning rice husk in which we place it in a stove as a fuel specifically designed for rice husk only because other ordinary stoves like the charcoal stove cannot be utilize as a rice husk stove. Hence, we have this technology. Therefore, rice husk stove is a stove intended purely for rice husk fuel for cooking or for industrial heat or for other application.” says Engr. Aries Roda D. Romallosa, Project Director of the Approtech.
The technology was started by Engr. Alexis T. Belonio and it was a joint effort together with the Agricultural Engineering students of the college and its faculty. The technology was developed as an answer to the volume of rice husk generated in Iloilo and Panay. Western Visayas specifically for this are rice producing region and Iloilo is a rice producing province. Having so many of this waste the CPU CARES look for a way on how to utilize it rather than letting it decay for many years since rice husk has silica and its quite difficult to decompose. “Rice husk has a good heating value meaning. It is really appropriate to utilize it for burning. It is really an appropriate waste of fuel for burning that’s the main reason why we invented the stove because there are so many of this type of waste in the region so of course if you are into technology development you look for the problem or an issue in the area and one issue here is many generation of rice husk. We look for science and technology that would utilize that waste.” said Engr. Romallosa.
The regular availability of the fuel is one of the greatest benefits for the people or for the users in utilizing the stove. Since, we are not buying rice husk here, except for those who are into bigger production in which rice millers will usually sell rice husk for them, it is really a great benefit for an ordinary household unit in which they could have it for free. The availability of the fuel is very cheap and the rice husk is very abundance in the area, you just have to invest a little for the stove. After that, you don’t have to worry about the price of the fuel because it’s just here, nothing is being done with those wastes and all we need to do is to make use of it. It is a good replacement for LPG stove which of course contributes a lot on environmental pollution but particularly in terms of fuel savings, utilization of rice husk stove will significantly reduce the cost of household spending.
The advantage of the stove is the availability of the fuel found in the local area. Fuel is really available especially here in Iloilo because every municipality has a rice field. So, if there is a rice field there is a rice production and if there is a rice production there is a rice husk. Rice Husk Stove will help minimize the problem on rice husk disposal. Rice husks can be converted into char which is a good material as soil conditioner due to its high water holding capacity. Like with the others, it has also disadvantages. Since rice husk stove is not comparable with the charcoal stove for it would cost only sixty pesos (P60.00). In the case here, the rice husk stove would usually range from one thousand three hundred (P1,300.00) up. However, that one thousand three hundred up would mean no more buying of fuel unlike in the case of LPG tank with 11 kg that would cost at around five hundred (P500.00) to seven hundred pesos (P700.00). So, you will spend seven hundred pesos in buying an LPG every month. For three months, that is more than one thousand three hundred but in the case of rice husk stove you would only buy once and you will not buy for fuel anymore. There is economic benefit in the stove. It would compensate whatever amount you invested and it will be covered later on because the fuel is free.
The operator of the stove has to be familiar also with its operation. According to Engr. Romallosa you would have to learn, in a way, the technique first in using the stove. According to her, others would put the fuel and will unload it hastily, so there is a possibility that the fire would die right away. She said that it’s more of one or two practice, after that, you would have to learn the operation of the stove and it was not really difficult to learn.
So, it is just a matter on when to load or unload the char. Char is the black burned fuel of rice husk.
Rice husk stove pertains to stoves that are operated by direct combustion. Meaning it does not use any other devices like fan or blower to continue the operation. There are three models of rice husk stoves : Conic, Side-in and, Super-Turbo Rice Husk Stove.
Conic Rice Husk Stove is the pioneering stove upon the three and the most common conical stove we have in the country. The stove has a conical shape. It is like a cone but it has no steam.
The Side-in Rice Husk Stove and Super-Turbo Rice Husk Stove is both stove that uses steam injection. The inculcation of steam and fire enhances its operation. The movement of the fire and the heat is different compared to the Conic Rice Husk Stove.
The Side-in Rice Husk Stove is called Side-in Rice Husk because the steam injection is done on the side. Once the water is heated or boils then the water is converted into steam and then the steam would mix into the fire. On the other hand, the Super Turbo Rice Husk Stove is a kind of super turbo because in terms of volume it was bigger and its fire is more or less powerful. Thus, it was seldom recommended for household use. The flame quality is very fine but it is more complicated to the households.
In terms of the stove’s lifespan, assuming that you will use it every day for morning, lunch and dinner; it will lasts for about 12 to 15 months. It depends on how you take care of the stove. So it should be maintained. The Stove is made up of 18 GI Sheet.
Rice Husk Stove used and sold not only in various parts of the country, but also overseas, such as Thailand, Cambodia, U.S. and India.
If more households will adopt this technology, more rice husks will be disposed as fuel. Thus, problem on rice husk disposal would then be minimized.
For details on the Rice Husk Stove, Engr. Aries Roda D. Romallosa can be reached at the Department of Agricultural Engineering and Environmental Sciences, College of Agriculture, Resources and Environmental Sciences of CPU, Jaro, Iloilo City at (033) 329 1971 local 1071.
The video below shows the actual operation of the Rice Husk Stove
CPUCA Side-In Rice Husk Stove
Step-by-Step Operation of the Stove
- Remove the steam box from the stove and fill it with water. Fill it with water at about half of its height. Do not fill the steam bow fully with water because it will not emit steam, instead it will quench firing of fuel in the stove.
- Fill the hopper of the stove with RH. The hopper should be evenly filled with fuel.
- Insert the steam box into the combustion chamber of the stove. At the start, the total length of the steam box must totally expose to the burning gases. Once the steam is produce, gradually pull the box to control the flow of combustible gases from the stove burner.
- Drop 1 to 2 pieces of burning paper into the combustion chamber of the stove. Additional pieces of paper may be added if necessary. Observe the firing of the fuel. If burning of fuel indicate poor ignition, add pieces of paper until the stove shows good burning of fuel.
- Keep the fuel hopper with RH to attain continuous combustion. If the flame dies out, tap the grate or Push RH with a rod. Always keep the combustion area filled with burning RH to minimize smoke and rekindling of fuel.
- Remove the char by swinging the discharge lever. This is to replace the burnt fuel with fresh RH. Do not remove all the char in order to sustain combustion of fuel.
- If there is no more water in the steam box, refill it with water. It would take at about 4 minutes before steam is generated from the steam box during operation. Make sure steam box is totally closed during operation.
- Dispose char from the pan when it is fully filled. Char can be stored in a metal can and it can be used later as soil conditioner in the farm.
- Clean the stove after use.
Department of Agricultural Engineering and Environmental Sciences, College of Agriculture, Resources and Environmental Sciences, Central Philippine University, Jaro, Iloilo City
Engr. Aries Roda D. Romallosa.,Project Leader, Appropriate Technology Center.