The possibility of using flue gases as a medium for straw drying

Abstract

The paper presents the possibility of drying straw in dedicated and innovative straw dryers with a modified drying system. The basic problem behind the use of bales of straw as a fuel is their moisture content. The moisture content is mostly dependent on the time of harvest and the conditions of storage. The humidity level of dry straw may be as low as 10%, however harvesting the straw during unfavourable weather conditions may cause the moisture level to increase up to 60–70% of the relative humidity, a value often observed for fresh biomass. Experimental studies were conducted to examine the effectiveness of drying and heat transfer in the straw bale. The studies have shown that the inner layers of the bale heat up much faster and achieve significantly higher temperatures than the outer ones. With the application of dedicated straw dryers, a homogenous field of moisture content in the straw bale is achieved in a very cost effective way.