Plant design and economic analysis for solar coal gasification

The advantage of the solar coal gasification (SCG) method, compared to a similar Lurgi plant, is conservation of coal; 40% more product can be produced from a given amount of coal. The primary detriment of SCG is an 8 h/day operation; which leads to a higher plant investment for a given annual production. This higher plant investment is twice as important as the cost of the heliostat field. Providing excess heliostat capacity to maximize the output of the processing units probably is economically justified. Operating costs are lower for SCG, but capital costs are higher. In the future, as coal costs increase relative to investment costs, the SCG plant will become more economical than the Lurgi plant.