Controlled Release Studies
Greenhouse Gas Controlled Release Facility
Geoscience Australia and the CO2CRC have installed a greenhouse gas (GHG) controlled release facility at the CSIRO Plant Industry Ginninderra Experiment Station in Canberra. It is one of few similar facilities internationally that enables researchers to study emissions of carbon dioxide (CO2) (and other GHG gases) from the soil into the atmosphere under controlled conditions. The design is modelled on the Zero Emission Research and Technology Centre (ZERT) controlled release facility in Montana, USA.
Description of the Facility
The facility is equipped with a 2.5t liquid CO2 storage vessel, vaporiser and mass flow controller unit with a capacity for 6 individual metered CO2 gas streams (up to 600kg/d capacity in total). Injection of CO2 into the soil is via a 120m long slotted HDPE pipe installed horizontally 2m underground. This is fitted with a straddle packer system to partition the well into six CO2 injection chambers.
Shallow Sub-surface Release Experiment (March – May 2012)
The first sub-surface CO2 experiment was held from March – May 2012. The purpose of the release experiment was to evaluate different CO2 monitoring technologies and track the CO2 as is moved through the soil and into the atmosphere. The total daily CO2 release rate was 100 kg/d. Monitoring techniques trialled at the site during the release include:
- eddy covariance
- atmospheric tomography using a wireless networked array of solar powered CO2 stations
- soil flux surveys
- soil gas measurements
- frequency-domain electromagnetics (FDEM)
- soil community DNA analysis, and
- krypton gas tracer studies (soil gas and air).
Organisations contributing to the experiment include Geoscience Australia, CSIRO , the CO2CRC and the University of Adelaide . A summary of the experiment was recently presented at the IEAGHG Environmental Impacts of CO2 Storage Workshop in Montana (to be published by the IEAGHG in 2012-13).
Above Ground Release Experiment (July – October 2010)
A surface release experiment was conducted at the site in conjunction with CSIRO Marine and Atmospheric Research , the CO2CRC and University of Wollongong Centre for Atmospheric Chemistry to explore the application of an atmospheric tomography technique to simultaneously determine the location and emission rate of a leak when both are unknown. Determination of emission rate was possible to within 3% accuracy for CO2 and within 5% for nitrous oxide (N2O). Localisation occurred within 0.5 m (2% error) of the known location for both release species. This very successful technique is now being applied on a larger scale.