Background
90% of the rice produced in Bangladesh is parboiled. The small rice parboiling and milling units produce a vast amount of rice-husk and bran mixture as a by-product and rice-husk ash as a waste product. There is very inefficient use and disposal of these materials. This project aimed to increase the efficiency of use of these products. There are three components to this project.

I Improving the rice-husk combustion efficiency
A majority of mills use the rice-husk and bran mixture as fuel to generate steam to parboil rice. The combustion efficiency of the furnace is very low leading to wastage of rice-husk and bran mixture. The mixture is used as animal feed. The growth in the poultry industry and the rising price of this mixture is making it difficult for poor households to afford it.

The First objective
of the project is to improve the furnace design and increase the efficiency by at least 15% to save the rice-husk and bran mixture. To enhance the scope of uptake, the project aimed to keep the costs low and affordable. Increasing the combustion efficiency would increase the profitability of the mills, improve the working conditions for workers and increase the supply of animal feed for poor households.

II Reducing the cost of making briquettes from husk of parboiled rice.
Paddy in Sylhet and Chittagong is dry hulled and the husk made into briquettes, which is a clean and efficient fuel. Poor household and small, street-food retailing units in these districts have shifted to briquettes from firewood. Only a small amount of rice husk from parboiled rice is used for briquetting, This is primarily because the wear and tear of the screw used in the extrusion process is high, giving a screw life of about three hours, which is not cost effective.

The Second Objective
of this project is to improve the screw life so that it is economically feasible to make briquettes with rice-husk from parboiled rice. This would make a clean and affordable fuel more accessible for the poor.

III Assessing alternative uses of Rice Husk Ash (RHA) in low strength construction
Rice mills through out Bangladesh dump the ash on surrounding agricultural land. RHA is being used with Portland cement in many countries. However, the ratio of the mix and the strength will vary with the specific characteristics of the RHA.

The Third Objective
is to assess alternative uses of Rice Husk Ash in construction.