Research of animal manure compost fertilizer granulation and determination of granules quality indicators

Abstract

It is important to search the new and more rational ways to use biological waste for new forms of energy. Some of these ways – creating fertilizers, building materials and other products. One direction of biodegradable waste management is pelleting as the processing of recyclable materials into organic products. In recent years in the EU countries only 5-7 % of bio-waste is recycled. For comparison, if more bio-waste will be recycled, it could replace up to 30 % of non-organic fertilizers. Currently, the EU imports about 6 million tons of phosphates a year but could replace up to 30 % of this total by extraction from sewage sludge, biodegradable waste, meat or manure. The EU legal requirements specify, that manure is considered to be waste that the livestock owners have to eliminate it by using as crop fertilizer and by trying to reduce the pollution of the environment. By pelleting the manure compost it is possible to increase the bulk density, to improve the material storability, to reduce the transportation costs and to make these materials easier to handle by using the existing handling and storage equipment. For solving of this actual problem there were investigated the granulation process and the factors affecting the organic granular fertilizer physical-mechanical properties. Research was carried out in Aleksandras Stulginskis University with the cattle and pig manure compost fertilizer, which was granulated by the small capacity 7.5 kW granulator with a horizontal granulator matrix, the diameter of produced pellets was 6 mm. Before the production of manure pellets raw material samples were dried naturally till 35-40 % humidity, and before pellet production the manure samples were dried till 25-30 % humidity. [...]