Vapour liquid equilibria data for a range of new carbon dioxide absorbents

Abstract

Carbon dioxide (CO2) is now recognised as the greenhouse gas contributing most to global warming and implicated in climate change model predictions. Electricity generation from fossil fuel combustion is a major source of CO2 emissions both internationally (32% of total CO2 emissions) and nationally (50% of total CO2 emissions). To effectively reduce CO2 emissions in the short to medium term requires CO2 capture and storage from these and other point sources as a part of the solution. The CSIRO Division of Energy Technology has undertaken a major CO2 capture research program covering many aspects of the technology. On the laboratory scale, the chemical reactions involved in CO2 capture and release by chemical absorption are being investigated and modelled to identify where and how improvements in efficiency can be made. A large scale screening study in which the CO2 absorption capacity of over 100 30% w/w amine solutions at 40 ∘C and ∼13 kPa CO2 partial pressure has been carried out. This study has identified a number of novel amines as having outstanding CO2 carrying capacity. An apparatus has been developed used a stirred glass batch reactor, capable of withstanding pressures up to 1100 kPa, coupled to a pressure controller and gas delivery system from a high pressure reservoir. The apparatus has been used to collect vapour liquid equilibria (VLE) data by measurement of CO2 consumption from the high pressure reservoir. VLE data has been collected for three amines identified in the screening study at 1 mol L−1 and 40 ∘C over the pressure range ∼0.3 to 900 kPa. The VLE results will be presented along with a comparison with MEA and an interpretation of the behaviour of the amines.