NATCHEZ &8212; According to a top Environmental Protection Agency air quality official in Washington, the type of plant Rentech&8217;s proposed for Natchez is among the cleanest of fuel processes.

When it comes to environmental controls on such a coal gasification plant, said Bob Wayland, &8220;the (plant) itself is pretty much the control.&8221;

Wayland is the leader of the Combustion Group of the EPA&8217; Air Quality Planning Division.

The coal gasification process is more like oil refining than coal combustion, Wayland explained, adding, &8220;it&8217;s a controlled chemical reaction.&8221;

As a substance taken from the earth, coal &8220;contains almost every element on the periodic table,&8221; Wayland said. But the vast majority of such elements, including mercury, fall out of the coal during the extreme heat of the gasification process as black, glassy pellets.

Those pellets don&8217;t leach substances into the environment and, in fact, are commonly used as material in roadbeds, Wayland said.

Sulfur left over from the process, meanwhile, can be sold to other industries, as will be the case with the Rentech plant proposed for Natchez. Fly ash removed from such plants can be used by other industries to produce such materials as concrete and wallboard.

The process also &8220;uses 30 percent less water than a coal combustion plant,&8221; Wayland said.

Such plants are still subject to the EPA&8217;s clean air rule, passed in March of this year.

On the whole, however, &8220;EPA is very aggressive in pushing (this technology),&8221; Wayland said. &8220;It&8217;s environmentally friendly.&8221;

Denver-based Rentech has proposed building a 200-employee coal gasification plant at the site of the old Belwood Country Club in Natchez. The plant, which would turn coal into a clear diesel fuel, would be one of Rentech&8217;s first commercial ventures. Rentech is also in the process of converting a nitrogen plant in East Dubuque, Ill., into a coal gasification facility.

Rentech has said the Natchez plant would represent up to a $750 million investment in Adams County.