Gideon Kuncoro

PhD Candidate

BE (Chem)

Location: Room N242 Engineering North
Email: gkuncoro@chemeng.adelaide.edu.au
Phone: +61 8 8303 3270
FAX: +61 8 8303 4373

Supervisors

Dr Yung Ngothai, School of Chemical Engineering, The University of Adelaide
A/Prof. Brian O'Neill, School of Chemical Engineering, The University of Adelaide
Prof. Allan Pring, South Australian Museum
Dr. Joel Brugger, South Australian Museum

Research Topic

Geochemistry, Corrosion and Scaling in Hot Dry Rock Energy Extraction Systems

Research Abstract

Hot "dry" rock geothermal energy has a great potential to supply electricity by harnessing stored thermal energy from high temperature granitic rocks in the Cooper Basin and North Flinders Ranges. This route provides opportunities for the generation of electric power without producing greenhouse gas emissions or long-lasting nuclear wastes, at costs competitive with those for energy generated from fossil fuels.
Geothermal power is an established energy source in several countries, for example New Zealand and Iceland. However, the proposed geothermal operation in South Australia, occur at a much greater depth, up to 5000 m, and the heat source is radioactive decay rather than volcanism.
How will the "granites" react when large volumes of water at high pressure move through the rocks? The granites are currently in equilibrium with surrounding ground water. Its composition is likely to differ significantly from the water pumped through the granite to extract energy. The flow of large volumes of water may cause partial chemical dissolution or alteration of some of the mineral granite, which could potentially increase the dissolved solids such as silica, and other metals in the circulating fluid. Also the saturation of metals in fluids is volume dependent, very small volumes of fluid require under-cooling before they will precipitate their metals. The complexity of the system is the high temperature (>>200oC) and possibly the high salinity of the fluid (>>1 wt. %)
A number of issues relating to hydrothermal geochemistry need to be considered and explored to ensure safe, economic energy production from "hot rocks". This initial project will focus on the following two issues:
Corrosion and scaling in pipes: low pH and saline waters at >>200oC are highly corrosive, and it is vital to prevent the generation of scales as the brines are transported to the surface. Specifically, the potential scaling rates due to silica and deposition in pipe lines due to differences in silica solubility as a function of the changes in temperature difference in the system need to be quantified.
Maintaining open pores: clogging of the fracture network that allows the brines to exchange heat with the host rock in the reservoir will result in costly shutdowns. Clogging may occur both by precipitation of minerals or by hydration of pre-existing minerals with associated volume increase. Again, these phenomena need to be understood, quantified and modelled.

Interests

Geochemistry, corrosion and scaling, thermodynamics and modelling in the Hot Dry Rock Energy Extraction Systems

Recent Publications

Masters of Engineering Science Publications

• G. Kuncoro, Y. Ngothai, D. Sweeney, B. O'Neill, U. Kaeding, Investigation of potato starch and sonicated RAS as alternative carbon sources for biological nitrogen removal, International Journal of Environmental and Waste Management (IJEWM), accepted for publication in volume xxx, 2009
• G. Kuncoro, Y. Ngothai, D. Sweeney, B. O'Neill, U. Kaeding, Investigation of potato starch and sonicated RAS as alternative carbon sources for biological nitrogen removal, Proceedings: Chemeca 2006 34th Australasian Chemical Engineering Conference, D. Patterson and B. Young, Eds., The Institution of Engineers, Auckland, New Zealand, 17 - 20 September 2006, Environmental: Biological Treatment Processes II, Paper 248 (ISBN: 0-86869-110-0)