fluidized bed

To sift out precious minerals, engineers often blow air bubbles through the material in a setup called a bubbling fluidized bed—and a new twist could make this costly process more efficient.

Mr. Broadbent cited supercritical and ultra-supercritical combustion, high-efficiency, low-emission generation, coal-fired combined cycle generation. fluidized bed combustion. and other technological advances — some of which are being funded by Energy Department money — as more proven, practical ways to reduce emissions and make the burning of coal more efficient.

In fact, the company first implemented their fluidized bed combustion chamber units in the United Kingdom in 2003, and today run eight different units on six different farms there.

Adding limestone to the waste coal in fluidized bed boilers reduces sulfur emissions and reduces acid rain.

They’re called fluidized bed boilers, but contain no fluid.