Dry matter losses and greenhouse gas emissions from outside storage of short rotation coppice willow chip

A - Papers appearing in refereed journals

Whittaker, C., Yates, N. E., Powers, S. J., Misselbrook, T. H. and Shield, I. F. 2016. Dry matter losses and greenhouse gas emissions from outside storage of short rotation coppice willow chip. Bioenergy Research. 9, pp. 288-302.

AuthorsWhittaker, C., Yates, N. E., Powers, S. J., Misselbrook, T. H. and Shield, I. F.
Abstract

Abstract This study examined the dry matter losses and the
greenhouse gas (GHG) concentrations within two short rotation coppice (SRC) willow wood chip storage heaps. One
heap was built on a grassland area (East Midlands) and the
other (Rothamsted) on a concrete hard standing. A series of 1-
and 3-m probes were embedded in the heaps in order to retrieve gas samples for analysis, and pre-weighed net bags were
positioned in the core of the heap to detect dry matter losses.
The bagged samples showed dry matter losses of 18 and 19 %
in the East Midlands and Rothamsted heaps after 210 and
97 days storage, respectively. The Rothamsted heap showed
a whole-heap dry matter loss of 21 %. During this time, the
wood chips dried from 54 to 39 % moisture content in the East
Midlands heap and 50 to 43 % at Rothamsted. The results
from analysing the whole Rothamsted heap indicated an overall loss of 1.5 GJ per tonne stored, although measurements
from bagged samples in the core suggested that the chips dried
sufficiently to have a minimal energy loss from storage. The
process of mixing the heap, however, led to incorporation of
wet outer layers and hence the average moisture content was
higher in an average sample of chip. After establishment of the
heaps, the temperature rose rapidly and this correlated with a
peak in carbon dioxide (CO2) concentration within the heap.
A peak in methane (CH4) concentration was also detected in
both heaps, though more noticeably in the East Midlands heap
after around 55 days. In both instances, the peak CH4 concentration occurred as CO2 concentrations dropped, suggesting
that after an active period of aerobic decomposition in the first
2 months of storage, the conditions in the heap became anaerobic. The results from this study suggest that outside wood
chip storage is not an efficient method of storing biomass,
though this may be location-specific as there are some studies
showing lower dry matter losses. It is necessary to explore
other methods of harvesting SRC to minimise losses and optimise land use efficiency. Further research is required to detect whether there are fugitive emissions of CH4 from wood
chip heaps, as this will compromise the net GHG savings from
utilising the biomass stored in this way

KeywordsBiomass storage; Wood chips ; Short rotation coppice willow ; Dry matter losses
Year of Publication2016
JournalBioenergy Research
Journal citation9, pp. 288-302
Digital Object Identifier (DOI)doi:10.1007/s12155-015-9686-y
Open accessPublished as ‘gold’ (paid) open access
Funder project or codeCropping Carbon (CC) [ISPG]
Publisher's versionWhittaker2016_Article_DryMatterLossesAndGreenhouseGa.pdf
ISSN19391242
PublisherSpringer

Permalink - https://repository.rothamsted.ac.uk/item/8v149/dry-matter-losses-and-greenhouse-gas-emissions-from-outside-storage-of-short-rotation-coppice-willow-chip

Total views: 8

Total downloads: 20

Views this month: 0

Downloads this month: 2