A Mathematical Model to Predict CO2 Emission from Woody Biomass Storage Piles

Abstract

Biomass is promising to substitute petroleum-based products in generating bioenergy due to its potential to release less greenhouse gas (GHG) during processing. However, this opinion has been challenged. Two biomass piles established for bioenergy purpose were studied. Moisture contents for pile 1 and 2 were 51.1% before storage, then increased to 57.6% for pile 1 after 192-day storage; and 56.9% for pile 2 after 114 days. Overall pile densities of pile 1 and 2 were 169.4 and 165.3 kg-od/m3, respectively, with compaction taken into account (9.2% for pile 1 and 10.1% for pile 2). Total dry matter losses were 16.2% and 14.9% for pile 1 and 2, respectively. Consequently, pile 1 released 0.194 grams CO2 per gram dried biomass during storage; while pile 2 produced 0.178 grams CO2 per gram dried biomass. The CO2 emission during storage was found to be much higher than that generated from harvest and transport.