Drying of high moisture grains in humid tropical climates

This project follows on from an earlier one entitled "The drying in bulk storage of high moisture grains in humid tropical climates", and will fulfil the need for further research to develop complete drying strategies for rice and other grains. The review undertaken of the ACIAR Grain Storage Research Program in March 1986 identified drying as the most critical process in preventing losses and maintaining quality of high-moisture grains, especially paddy and maize, in the grain-producing countries of Southeast Asia.

Project scientists will undertake a range of different research initiatives, covering studies of mill-level drying, short-term quality maintenance of wet paddy after harvest, first stage drying of paddy and drying of other grains such as maize and peanuts. Selected aspects of these studies will take place in Australia, Malaysia, the Philippines and Thailand as in the earlier project, and will also extend to Indonesia.

The scientists will investigate ways to maintain quality of wet paddy in the period between harvest and drying, with particular reference to cooling both in transit and after delivery to handling complexes. They will study mill-level drying using rice-hull fuelled furnaces, and evaluate the options available for first-stage drying where a two-stage drying process is needed.

Other studies will gather data on the relative efficiency of different drying systems and facilities for grain drying. The project team will use these data to develop pilot drying plants, which they will test for their capacities to dry different grains. A separate study will monitor the effects of the various aeration, cooling and drying processes on the quality of maize, peanuts and other grains and legumes.

Economic studies undertaken through the ACIAR Grain Storage Research Program will assist in the development of the drying processes to a stage of readiness for adoption by the grain industries. Further developments beyond this stage would be appropriate for commercial interests.

Benefits anticipated from the studies include the reduction of losses and improvement in quality of stored high-moisture grains. Better knowledge of the characteristics of grain bulks, the movement of moisture within the mass and the temperature profiles through grain while drying will enable better drying/storage practices in all tropical countries. Streamlining of drying and storage procedures will enable multiple use of a facility for a range of different grains throughout the year.
New drying techniques utilising freely available heating sources such as rice hulls or solar energy will make these drying processes feasible for developing countries. The overriding benefits will be derived from the introduction of superior drying strategies for high-moisture grains in humid tropical climates and improved management of the drying processes.