THE ECONOMICS OF GEOLOGICAL STORAGE OF CO2 IN AUSTRALIA

The economics of the storage of CO2 in underground reservoirs in Australia have been analysed as part of the Australian Petroleum Cooperative Research Centre’s GEODISC program. The economic analyses in the paper are based on cost estimates generated by a CO2 storage technical/economic model developed at the beginning of the GEODISC project. The estimates rely on data concerning the characteristics of geological reservoirs in Australia. The uncertainties involved in estimating the costs of such projects are discussed and the economics of storing CO2 for a range of CO2 sources and potential storage sites across Australia are presented.The key elements of the CO2 storage process and the methods involved in estimating the costs of CO2 storage are described and the CO2 storage costs for a hypothetical, but representative storage project in Australia are derived. The effects of uncertainties inherent in estimating the costs of storing CO2 are shown.The analyses show that the costs are particularly sensitive to parameters such as the CO2 flow rate, the distance between the source and the storage site, the physical properties of the reservoir and the market prices of equipment and services. Therefore, variations in any one of these inputs can lead to significant variation in the costs of CO2 storage. Allowing for reasonable variations in all the inputs together in a Monte Carlo simulation of any particular site, then a large range of total CO2 storage costs is possible. The effect of uncertainty for the hypothetical representative storage site is illustrated.The impact of storing other gases together with CO2 is analysed. These gases include methane, hydrogen sulphide, nitrogen, nitrous oxides and oxides of sulphur, all of which potentially could be captured together with CO2. The effect on storage costs when varying quantities of other gases are injected with the CO2 is shown.Based on the CO2 storage cost estimates and the published costs capturing CO2 from industrial processes, the economics are shown of combined capture and storage (that is, the sequestration process as a whole) for the major CO2 generation sites across Australia combined with potential compatible storage sites. Examples are shown of the volumes of CO2 that could be sequestered economically depending on the level of the carbon credit in a hypothetical carbon credit trading regime. Purely as an illustration, assuming hypothetically that a real carbon credit of US$50 per tonne applied and that the cost of capture was US$40 per tonne across the board, then preliminary indications are that, ignoring tax considerations, it would be economic to store about 180 million tonnes per year of CO2. This is equivalent to about 70% of the annual CO2 emissions from stationary sources in Australia in 2000.

Protection against oronasal challenge with virulent feline leukaemia virus lasts for at least 12 months following a primary course of immunisation with Leukocell 2 vaccine

The duration of immunity provided by a feline leukemia virus (FeLV) vaccine, Leukocell 2, was determined. Kittens were vaccinated when 9 and 12 weeks of age and were challenged 12 months later with FeLV-A/Glasgow-1. An oronasal challenge protocol without corticosteroid enhancement was developed in order to induce a persistent viraemia in a high proportion of adult cats. Fourteen of 18 (80%) of the vaccinated cats challenged in this way remained non-viraemic while 9/15 (60%) of age-matched controls became persistently infected, a preventable fraction of 63%. This difference was statistically significant (P=0.038). For comparison, 10 of 12 (83%) 15-17-week-old kittens challenged in the same way became persistently infected, confirming the relative resistance of adult animals to FeLV. Tests for virus neutralising and anti-feline oncornavirus-associated cell membrane antigen (FOCMA) antibodies suggested that the former were more important than the latter in protection. Thus, Leukocell 2 protected a significant proportion of cats from FeLV challenge 1 year after primary vaccination as kittens.

THE POTENTIAL FOR GEOLOGICAL SEQUESTRATION OF CO2 IN AUSTRALIA: PRELIMINARY FINDINGS AND IMPLICATIONS FOR NEW GAS FIELD DEVELOPMENT

Many industries and researchers have been examining ways of substantially reducing greenhouse gas emissions. No single method is likely to be a panacea, although some options do show considerable promise. Geological sequestration is one option that utilises mature technology and has the potential to sequester large volumes of CO2. This technology may have particular relevance to some of Australia’s major gas resources that are relatively high in CO2. In Australia, geological sequestration has been the subject of research within the Australian Petroleum Cooperative Research Centre’s GEODISC program. A portfolio of potential geological sequestration sites (sinks) has been identified across all sedimentary basins in Australia, and these have been compared with nearby known or potential CO2 emission sources, including natural gas resources. These sources have been identified by incorporating detailed analysis of the national greenhouse gas emission databases with other publicly available data, a process that resulted in recognition of eight regional emission nodes. An earlier generic economic model for geological sequestration in Australia has been updated to accommodate the changes arising from this process of source to sink matching. Preliminary findings have established the relative attractiveness of potential injection sites through a ranking approach. It includes the ability to accommodate the volumes of sequesterable greenhouse gas emissions predicted for the adjacent region, the costs involved in transport, sequestration and ongoing operations, and a variety of technical geological risks. Some nodes with high volumes of emissions and low sequestration costs clearly appear to be suitable, whilst others with technical and economic issues appear to be problematic. This assessment may require further refinement once findings are completed from the GEODISC site-specific research currently underway.

A rapid and facile method for the dereplication of purified natural products

A new approach to the use of commercial databases for the dereplication of purified natural products has been developed. This is based on searching a text file that links each structure with its molecular weight and an exact count of the number of methyl, methylene, and methine groups it contains. Analysis of such a text file, constructed from a database containing more than 126,000 natural product structures, revealed that these data, readily measured using MS and NMR spectroscopy, are highly discriminating. The identification of an alkaloid and a sesquiterpene using this new approach is described.

Prediction of biological activity for high-throughput screening using binary kernel discrimination

High-throughput screening has made a significant impact on drug discovery, but there is an acknowledged need for quantitative methods to analyze screening results and predict the activity of further compounds. In this paper we introduce one such method, binary kernel discrimination, and investigate its performance on two datasets; the first is a set of 1650 monoamine oxidase inhibitors, and the second a set of 101 437 compounds from an in-house enzyme assay. We compare the performance of binary kernel discrimination with a simple procedure which we call "merged similarity search", and also with a feedforward neural network. Binary kernel discrimination is shown to perform robustly with varying quantities of training data and also in the presence of noisy data. We conclude by highlighting the importance of the judicious use of general pattern recognition techniques for compound selection.

Complexity of staff communication and reported level of understanding skills in adults with intellectual disability

Staff reports of the communication acts taking place with 22 adults with intellectual disability were compared with video observations of the communication acts used by staff with 12 of these service users. The interactions were coded in terms of the form of communication used, the function of the act and the level of complexity. The results show that staff tend to underestimate their own use of verbal communication and overestimate their use of non-verbal communication. The findings also indicate a mismatch between the reported level of understanding of the service user and the level of complexity of the language used. Staff appeared unable to adapt their communication to the skills of the service user and an average of 45% of communicative acts were outside the reported understanding skills of the individual. The implications of these findings are discussed and possible explanations for staff behaviour are suggested.

THE SEARCH FOR SITES FOR GEOLOGICAL SEQUESTRATION OF CO2 IN AUSTRALIA: A PROGRESS REPORT ON GEODISC

The APCRC GEODISC research program has encountered many challenges looking for geological sequestration sites for CO2, but has also found some solutions. Challenges already faced have been in effectively searching databases, developing uniform terminology and evaluation methodology, establishing comparative quality assessment of Australia’s sequestration sites against each other and against those from overseas, improving our understanding of the injection and trapping properties of CO2 and predicting its effects on reservoirs/seals, and developing economic and reservoir models.Pilot research projects at the regional and site specific levels have been used to address these issues, as well as developing generic models, before building site specific models. Issues such as storage efficiency and the use of carbonates as CO2 sequesrationt reain challenges for the future.Preliminary conclusions reached from the regional study of Australia suggest that suitable deep saline formations will be widespread, have the largest sequestration volumes, and are likely to be the most economically attractive option currently available. In the future, some depleted oil and gas fields and enhanced coalbed methane production sites may also represent local high-volume options. It is considered unlikely that sequestration into voids/cavities or associated with enhanced oil recovery (EOR) will represent attractive options other than in exceptional circumstances. Despite these limitations, it is expected that many of Australia’s sedimentary basins will have excellent sequestration sites. The GEODISC program will provide an assessment of the critical factors required for success at each site.Several of the highest-ranking saline formations are currently undergoing site-specific study. Early indications are that the petrophysical data required for models of injection, migration, and trapping is of limited availability. Various methods are required to estimate the distribution and likely variability of these parameters across any site.These and other uncertainties in the distribution, quantity and quality of data required for predictive modelling necessitate an innovative and thorough approach to handling both risk and uncertainty. This will also be a challenge to be addressed during the GEODISC program.From the GEODISC work to date, it appears that it will be technically feasible to sequester large quantities of CO2 in geological formations in Australia for long periods of time. What is less clear is whether this can be done at a cost that would not impose an unreasonable economic burden on Australian industry. The future results for GEODISC will be highly relevant to answering this key question.

PUTTING IT BACKWHERE IT CAME FROM: IS GEOLOGICAL DISPOSAL OF CARBON DIOXIDE AN OPTION FOR AUSTRALIA?

Liquefied natural gas projects with a total value of around $20 billion are planned for Australia. Over the next decade or so, they have the potential to generate an increase of approximately 3% in Australia's GDP, and an excess of 50,000 jobs. One of the major risks to this vast investment is uncertainty over how to deal with the major increase in direct carbon dioxide (C02) emissions that will result from these developments. The 1997 Kyoto Protocol has served to focus even more attention on this issue.Potentially, a solution to sustaining Australia's economic development, whilst at the same time meeting emission targets, may lie, in part, in developing suitable methodologies for C02 sequestration. One of the key sequestration options is geological disposal. The method, which involves injection of supercritical C02 into the deep subsurface, is being tested on a commercial scale in only one place in the world at the present time, although several other countries are now developing research programs into the technique.The APCRC research program GEODISC is investigating the applicability of this method in Australia. Whilst the focus of GEODISC is on the application of C02 disposal to the Australian natural gas industry, its outcomes will have implications for other industries such as power generation and minerals processing. It will also be looking at some of the other potential benefits of geological sequestration, such as enhanced oil recovery and enhanced coalbed methane recovery.The program will establish the most viable locations for C02 injection, determine the key areas of technical, social and economic risk, and help define a pilot injection program to address the most critical areas of uncertainty. GEODISC brings together six major petroleum companies, the Australian Greenhouse Office and key Australian research groups. The total cost of GEODISC will be approximately $10 million over four years. The major expected outcome of GEODISC will be to help the Australian gas industry plan the way ahead in terms of C02 emissions in an environmentally acceptable manner, whilst concurrently ensuring that the industry does not incur major cost disadvantages, which may adversely impact upon Australia's international competitiveness.

Implementation of a system for reagent selection and library enumeration, profiling, and design

We describe an integrated suite of computational tools which are used to assist in the selection of compounds for biological assays and the design of combinatorial libraries. These functions are delivered in a platform-independent manner via a corporate intranet and are used by computational experts and nonexperts alike. While the system was primarily designed to be used prior to synthesis, it can also be used to provide structural information for library registration and for decoding beads in tagged libraries. We describe a simple statistical method for monomer selection and compare it to computationally more demanding approaches.

Selecting national items for the WHOQOL: conceptual and psychometric considerations

The WHOQOL is a new measure designed to assess quality of life cross-culturally in health and health care. An international core of 276 items covering 29 facets of quality of life organised into 6 domains has been established conceptually and then assessed in psychometric terms. The method also allowed for the inclusion of extra national items to enable the concept of quality of life to be complete for each language and culture and to achieve conceptual equivalence between different language versions in participating centres. The present study investigates the properties of these national items using data obtained from 3740 participants world-wide, who completed the instrument in 10 of 16 original WHOQOL centres. Five statistical criteria were applied to 144 national items to examine their performance in competition with internationally agreed core items from the same facet, using data obtained from within that centre. Multi-dimensional scaling and cluster analysis was used to examine the structural relationship of national items within their own facet and directed their inclusion. Forty (29%) national items were selected and detailed examples demonstrate the selection methods used. They show how entirely new facets as well as individual items can be assessed for appending to the core WHOQOL-100. They also enable ambiguity to be resolved where there may be doubt about whether proposed items constitute part of an existing facet or justify a new one. Where national items are similar in more than one centre, a mechanism is provided whereby these items can be re-evaluated as candidates for inclusion in any future revision of the international core. Lastly, a case is identified that may provide justification for the establishment of national facets.

Middle cranial fossa arachnoid cysts: not always a benign entity

Arachnoid cysts are often discovered as incidental findings on cranial imaging. A rare manifestation is described in a child presenting acutely with symptoms and signs of raised intracranial pressure.

Identification of biological activity profiles using substructural analysis and genetic algorithms

A substructural analysis approach is used to calculate biological activity profiles, which contain weights that describe the differential occurrences of generic features (specifically, the numbers of hydrogen-bond donors and acceptors, the numbers of rotatable bonds and aromatic rings, the molecular weights, and the 2 kappa alpha descriptors) in active molecules taken from the World Drug Index and in (presumed) inactive molecules taken from the SPRESI database. Even with such simple structural descriptors, the profiles discriminate effectively between active and inactive compounds. The effectiveness of the approach is further increased by using a genetic algorithm for the calculation of the weights comprising a profile. The methods have been successfully applied to a number of different data sets.

ASSESSMENT—TRANSLATING THE FUTURE INTO NUMBERS

Geological risk assessment is a comprehensive method used to compare different exploration opportunities at the prospect and play scale. Though common place in the petroleum exploration industry for decades, the assessment method can be updated and made more powerful when integrated with recent advances in geological concepts and technology, such as petroleum systems, relational databases and Geographical Information Systems (GIS). Empirical analysis of field size distributions and discovery histories is another traditional method for estimating undiscovered hydrocarbon potential for sedimentary basins or particular play types rather than for individual prospects. New mathematical descriptions of natural populations are available to further refine this approach; and the natural population of hydrocarbon fields is now seen as the petroleum system, rather than the basin or play. A key development has been the realisation that the methods of risk assessment can be applied to other complex decision making situations including environmental and resource planning.

Deleted in colorectal carcinoma (DCC) binds heparin via its fifth fibronectin type III domain

DCC (deleted in colorectal carcinoma) is a broadly expressed cell-surface receptor. Netrin-1 was recently identified as a DCC ligand in brain, but the possibility of other DCC ligands was suggested by the finding that an anti-DCC antibody (clone AF5) neutralized netrin-1-dependent commissural axon outgrowth without blocking DCC/netrin-1 interactions. Here we have searched for alternative cell-surface DCC ligands. A DCC-Ig fusion protein bound to neural and epithelial derived cell lines, indicating that these lines express ligand(s) for DCC. The cell-surface binding activity was mediated by the loop between beta-strands F and G of the fifth fibronectin type III repeat FNIII-D5. The loop included the sequence KNRR, which resembles heparin-binding motifs in other proteins. Heparinase and heparitinase treatment of cells reduced binding of DCC-Ig, suggesting that heparan sulfate proteoglycans are cell-surface DCC ligand(s). This was further supported by heparin blocking experiments and by binding of DCC-Ig to immobilized heparan sulfate. The interaction between DCC-Ig and heparan sulfate/heparin, both on the surface of cells and immobilized on plastic, was blocked by the same anti-DCC antibody that blocks netrin-1-dependent commissural axon outgrowth. Taken together, these findings suggest that the DCC-Ig/heparin interaction may contribute to the biological activity of DCC.