TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Components: The cover is a rigid cover. It is domed or arched. The rigid cover comprises an inner core sandwiched between two exterior layers, and a cable to hold down the rigid cover. The cover may comprise a geomembrane supported by a structural member. The system includes a pump to circulate fluid through the biomass pile by delivering fluid to the fluid input device and to receive fluid from the drainage device after the fluid from the fluid input device has traveled through the biomass pile, an air distribution device to deliver air to the biomass pile, a first water line in the chamber, a first screen to prevent the biomass from entering a portion of first water line that extends outside of the chamber, a second fluid input device, a second water line in the chamber, a pump to deliver fluid to the second fluid input device and receive fluid from the portion of second water line that extends outside of the chamber, and a second screen to prevent the biomass from entering the portion of second water line that extends outside of the chamber. The retrieval device retrieves a fluid product (carboxylate salt) from the portion of first water line that extends outside the chamber. The retrieval device is a drainage device. The bottom comprises screw conveyor(s) to transport solids out of the chamber. It has V-shaped section(s), and the screw conveyor is disposed in a tip of the V-shaped section. The V-shaped section comprises fluid jets to spray solids toward the screw conveyors. Each screw conveyor transports solids to another conveyor which transports solids out of the chamber. The screw conveyor includes at least two sets of screw conveyors, and the other screw conveyor is located between the two sets of screw conveyors. The screw conveyor transports the solids out through the cover or a side of the chamber. A hole surrounds the bottom. The hole is lined with a geomembrane and filled with a gravel layer and water. The bottom may comprise cone(s) having a tip, and the screw conveyor begins at the tip. The cone has a passage to transport solids to a space below the bottom. The space includes a circulating fluid to carry away the solids as slurry. A check valve or pinch valve covers the passage and selectively allows a flow of solids through the passage to the space. A spray nozzle is disposed adjacent the passage and forces solids through the passage with a sprayed fluid.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Materials: The exterior layers are made of waterproofing material, preferably tar.    TECHNOLOGY FOCUS - TEXTILES AND PAPER - Preferred Materials: The inner core is made of papercrete or papier mache. It comprises greater than or equal to50% paper and less than 30% cement.