California Cement Plant Uses Biomass With Coal In Kilns
Mitsubishi Cement in Lucerne Valley, Calif., has acquired a Rawlings Manufacturing Wood Hog, enabling it to use both coal and biomass in its cement kilns
California Cement Plant Uses Biomass With Coal In Kilns
By Lisa Gibson Posted June 30, 2009
Mitsubishi Cement in Lucerne Valley, Calif., has acquired a Rawlings Manufacturing Wood Hog, enabling it to use both coal and biomass in its cement kilns.
The wood waste recovery system will use construction waste, according to Judi Tyacke, Rawlings Manufacturing, as Mitsubishis location makes other feedstocks difficult to procure. Theyre in the middle of the desert, she said. There isnt a lot of slash, so theyre using construction wood waste. Rawlings has been making and selling the wood hog design for 30 years, according to Tyacke. It can reduce various types and sizes of wood waste to biomass fuel six inches or less in size, she said. Once the wood has been processed through the hog, the metal is removed by an overhead self-cleaning magnet and conveyed to a walking floor stoker storage system, according to Rawlings. To ensure optimal size, the wood is then processed over two vibrating finger screens and transferred to the kilns by a blower system.
Mitsubishis wood will already be ground when its shipped to the company, Tyacke said. Mitsubishi is working toward a 50-50 coal to biomass ratio, according to Scott Smith, plant manager. The system has been operating at the plant for about a month, he said.
Rawlings is developing a railroad tie separator to expand the types biomass feedstocks that can be fed into the system, Tyacke said. Ties would have to be ground before being put into the system.
Were hoping we can do this at quite a few more cement plants, she added. A study conducted by scientists in Spain showed using biomass in cement kilns decreased the carbon dioxide emissions by 144,000 tons between 2003 and 2006, according to a journal article written by the researchers. The study evaluated the effects of using sewage sludge to generate 20 percent of the thermal energy needed in the cement manufacturing process at a plant in Vallcarca. Smith said the system will reduce carbon dioxide emissions at the Mitsubishi plant, but didnt have specific amounts to cite.