BIMTECH joins hands with Industry in pursuit of Sustainability
Sub: Solving perennial industry problem and environmental sustainability: Waste to Wealth:
Date of visit: 29th and 30th July 2017
About the demonstration work:
Uttar Pradesh state in India is predominantly a Wheat and Rice Growing state. While the entire state has many different crop growing patterns based on the geographic region, this case is especially dedicated to the Pilibhit district of the state.
Out of the about 4000 rice mills in the state of UP, there are 45 such mills in the Pilibhit district alone. The milling capacity of these mills ranges between 2 MT per hour to 12 MT per hour. On an average these mills work for 12 to 14 hrs. per day.
The husk is primarily sold to the larger industries who use it as basic fuel in furnaces, boilers and in power generation plants.
A part of the husk is also used by the mill owners for their own internal consumption for generating hot gases for drying operations or in boilers for making parboiled rice.
In general, it looks like a case of captive availability of the fuel. However, the process of burning the rice husk in the furnaces and boilers generates a side effect of generation of large volumes of Rice Husk Ash.
Problems in disposal of ash: Social and environmental issues.
The ash being an inert material needs disposal. As there are no known usages of this ash, it is treated as a process waste and needs handling and disposal. The industry is also facing problems with disposal of ash. Over a period of time, the ash was being dumped in open fields nearby. However, the local farmers have been raising objections to such dumpings as it would render the area non productive. The rice mill owners have been facing a problem of availability of space for such disposal. The process of disposal is also an added cost to the mill owners as they have to pay for such disposal.
The dimension of the problem:
On an average, the rice milling process has an over all productivity of about 70%, which means that for every 100 Kgs. Of paddy, the useful products recovery, viz: rice and bran is about 70 Kgs. (65 Kgs, rice and 5 Kgs. Bran). While the rice is a readily saleable product, the Bran is purchased by the oil extraction industries who make Rice Bran Oil.
It is the remaining 30% which is Rice Husk, which needs to be addressed.
As there have been no known usages of this ash, it used to be dumped in nearby fields, which resulted in to the objections and resistance by local farmers. Also, the land filling process has been rendering the dumped sites as non productive.
A team of faculty and students at BIMTECH have been working on finding out productive uses of rice husk ash. Based on some experiments and testing, the team found out that a major part of the ash is Amorphous Reactive Silica. In a properly but commercially burnt in industry, the content of this material is between 85 to 90%. However, in controlled burning in laboratory, this can reach as high as 96%.
Silica being the major constituent of normal sand, was considered to be a good replacement of natural river sand, which is becoming a rare commodity.
With India’s paddy production at the level of 100 Million Tonnes annually, and considering the usage pattern of rice husk as a fuel, it is estimated that about 5.5 Million Tonnes of ash is produced in India annually.
With this in mind, the BIMTECH team embarked upon demonstrating it in real life situation.
With the very active help and involvement of Mr. Pradeep Kumar Jaiswal, the Chairman of the Municipal Council of Puranpur town in Pilibhit district of state of Uttar Pradesh, the team visited M/s. Agarwal Rice Mills in Puranpur.
Mr. Rajeev Agarwal, Owner of the mill was very enthusiastic about the initiative as he was facing serious problems with the disposal of the ash.
The exercise started with collection of a sample of the rice husk ash available in the mill.
Prof. K. R. Chari, with the help of Prateek Jaiswal, demonstrated that when stirred in water, the heavier particles of the ash settle down on the bottom and only the unburnt carbon particles, which are black in colour get settled on the surface of the water as they are much lighter and have very low density.
The major part of the ash, which has high density and has settled down on the bottom, is in fact Silica, the major ingredient of common sand.
With the help of the mason in the factory, a plastering mass was prepared with cement and settled down ash in the ratio of 1:5::Cement:Ash and a small patch of brick wall was plastered in the factory.
The mason, who was experienced for years and skilled in the work expressed that the experiment was successful and the material can be used as a replacement of sand.
This experiment opens up many avenues to address a national level problem in more ways than one, as below:
1: Eliminating a major waste from getting in to the system and converting fertile land as barren.
2: The ash, which is very low in density flies in air even with a gentle breeze and impacts the environment and air quality, resulting in to breathing related health issues. This will be eliminated.
3: The national problem of availability of natural river sand can be addressed as this material can be a partial replacement of sand.
4: The rice mills and all industries which use this rice husk as a fuel will be benefitted in the way that they will not have to spend money for disposal of ash and instead can use it themselves or make money by selling it as a useful product and play a direct role in Circular Economy.
BIMTECH is happy that it could play a constructive role in addressing a serious environmental problem and has shown and paved a way towards sustainability.