Pressure and specific energy requirements for densification of compost derived from swine solid fraction

Abstract

Compost derived from swine solid fraction is a low density material (bulk density less than 500 kg m-3). This makes it costly to transport from production sites to areas where it could be effectively utilized for value-added applications such as in soil fertilization. Densification is one possible way to enhance the storage and transportation of the compost. This study therefore investigates the effect of pressure (20-110 MPa) and pressure application time (5-120 s) on the compaction characteristics of compost derived from swine solid fraction. Two different types of material have been used: composted swine solid fraction derived from mechanical separation and compost obtained by mixing the first material with wood chips. Results obtained showed that both the pressure applied and the pressure application time significantly affect the density of the compacted samples; while the specific compression energy is significantly affected only by the pressure. Best predictor equations were developed to predict compact density and the specific compression energy required by the densification process. The specific compression energy values based on the results from this study (6-32 kJ kg-1) were significantly lower than the specific energy required to manufacture pellets from biomass feedstock (typically 19-90 kJ kg-1).

Phytotoxicity and Chemical Characterization of Compost Derived from Pig Slurry Solid Fraction for Organic Pellet Production

“…Pelletising increases the bulk density of SF from an initial value of 400-450 kg m −3 to a final one of more than 1000 kg m −3 [7,8]. This allows better handling and transportation of SF at greater distances (even at hundreds of km as an order of magnitude) in order to move nitrogen (N) from Nitrate Vulnerable Zones to others less prone to pollution.…”

Reuse of Animal Manure: A Case Study on Stakeholders’ Perceptions about Pelletized Compost in Northwestern Italy

“…Pelletizing is a densification process that makes it possible to increase the bulk density of compost from <500 kg m −3 to >1000 kg m −3 [29,30]. The low density of organic fertilizers, notably compost, is recognized as the most important obstacle for its adoption for agricultural use [31] because of the associated increased transport, handling, storage, and application costs [32].…”

Recycling Pig Slurry Solid Fraction Compost as a Sound Absorber

“…Previous studies [8] investigating the characteristics of compacts made from compressed pig slurry solid fraction (SF) highlighted that it is a porous material, permeable to air and, therefore, potentially has acoustical features that can be used as a sound absorber.…”

“…One of the most penalizing SF characteristics is the low density (<500 kg m −3 ) that increases the handling and transportation costs [8]. One possible solution to this problem is the densification of SF.…”