Disposing of cattle meat and bone meal, or MBM, has been an environmental problem since the mid-1990s, when its use as animal feed was banned in Europe following outbreaks of Bovine Spongiform Encephalopathy (BSE), better known as mad-cow disease. Infectious and virtually indestructible proteins called prions, which are found in animal brains and spinal cords, cause BSE and its human variant, Creutzfeldt-Jakob Disease (vCJD). The diseases are always fatal but now the unwanted byproduct of the meat-processing industry may face a promising future that could cut energy costs for American cement producers. Domestically, it could also raise unresolved issues concerning waste transport, storage, surface and groundwater contamination and airborne emissions (reports Engineering News Record).
In August 2004, the law firm of Foley & Lardner LLP, Washington, D.C., representing Lafarge North America Inc., wrote a letter to the US Food and Drug Administration about using MBM as kiln fuel. It cited Lafarge’s positive experience in Europe and Japan and noted that "cement kilns destroy organic constituencies with an efficiency of 99.9999%." The letter further noted that "Ruminant byproduct material has a high Btu level, which makes it a potentially useful substitute for a portion of fossil fuel being fed to fire cement kilns."
According to the National Renderers Association, Alexandria, Va, the European Union has over a 400,000-ton MBM disposal backlog. When not used in kilns MBM is either incinerated or landfilled there. Since the US banned MBM from cattle feed in 1997, the 2Mt annually produced here now is used in pet food, aquaculture and chicken feed. "In the US, MBM is ground up and heated into a powder and dried," says Kent J. Swisher, NRA vice president. "We have very low storage capacity because the renderers move it quickly in bulk containers, rail cars or hopper-bottom trailers, which can also carry other products."
Since the mad-cow scare originated in England, there have been only two cases of the disease in the US, which prompted an effective feed ban and high level of surveillance. And the public’s taste for meat remains unabated. "We have all this organic material, which has a huge Btu value so it has potential for fuel and some North American firms are exploring the option," says Andrew T. O’Hare, PCA vice president regulatory affairs. "But before individual cement plants can utilise it, community concerns will have to be addressed, most likely through a state or local process. There are no federal regulations that I am aware of regarding MBM usage at cement plants."
