Jul-Sept 2002 The Second Solar Lime Experimental Campaign

Oct-Dec 2002 Improving the Reactor Numerical Model

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QualiCal, PSI's High Temperature Solar Technology Laboratory (HTL) and ETH's Institute of Energy Technology are jointly exploring the potential of an Industrial Solar Lime Plant.

HTL will bring its expertise in developing the science and technology of high temperature solar chemical processes. Qualical will bring its expertise in developing technology for the lime industry.

The specific purpose of the project is to determine the economic feasibility of a 0.5 MW thermal input solar calcination plant for the production of lime in a developing world setting.

The project is partially funded by the BFE Swiss Federal Office of Energy.

The question of feasibility will be addressed by first designing, constructing, and then experimentally evaluating the performance of at least a 5-10 kW thermal input solar reactor for effecting the calcination reaction.

Experimental results obtained at the kW scale will be extrapolated to 0.5 MW , in part, with a numerical model. Finally, the combination of experimental and numerical results along with current economic information on solar and lime production technology will be used to estimate the cost of the large scale plant.

The principal motivation behind the project is the conviction that solar technology can contribute as an energy source for producing versatile chemicals like lime. This project will specifically explore the potential of substituting concentrated solar energy in place of carbonaceous fuels as the heat source for the production of lime, a material with multiple uses , one being that of a building material. Lime is formed by the calcination of calcium carbonate. Decreasing the use of fossil fuels as the prime energy resource for calcination is a means to reducing the process's dependence on conventional energy resources, and it is a means to reducing carbon dioxide emissions. Furthermore, in the case of lime plants located in developing countries where the conventional fuel supply can be limited , a solar calcination process could reduce local deforestation problems which will further help to lessen the CO2 burden. It is self evident , however, that only the most cost effective technology will be used by industry. What defines cost effective will be a function of a myriad of complex variables. In a situation like this one, it is deemed appropriate for the scientific and industrial communities to develop a variety of technological options. Concentrated solar energy technology as an energy source for lime production is foreseen as an option worthy of exploration.

Using solar energy for calcination means developing a solar thermal reactor that operates at temperatures over 900 °C. The challenge is to develop cost effective technology that is adapted to a specific location that leads to local development and prosperity. This project represents the first step in attempting to address this challenge.