Meat and Bone Meal as a Potential Source of Energy

Source: Saskatchewan Agriculture and Food

It would be fair to say that engineers have an eye for finding value in the most unusual sources, and this time is no different. Scientists at the University of Saskatchewan (U of S) are trying to determine the potential for using meat and bone meal to generate electricity. The project is being funded through Saskatchewan Agriculture and Food’s (SAF) Agriculture Development Fund (ADF #20050714).

After BSE hit, meat and bone meal became worthless, says Terry Fonstad, a professor of Agricultural and Bioresource Engineering. The rendering industry, left with a by-product that now cost them money to dispose of safely, is actively exploring new uses of meat and bone meal.

Fonstad believes the energy potential of meat and bone meal is very real. It has about three-quarters of the heating value of coal, although it does have a high ash content because of the bone meal.

"What do we do with coal?" he asks. "We gasify it to produce a syngas—a gas made up of hydrogen, methane and carbon monoxide—which we use as a fuel to turn a turbine to produce hot water and electricity."

Fonstad realized that, if there was a way to add some value to meat and bone meal by turning it into a feed source for a small gasification unit, every rendering facility in Western Canada could acquire one.

He estimates that 50 per cent of the material that escapes from these rendering plants is steam, 25 per cent is tallow and the remaining 25 per cent is bone that has no value. If renderers could reduce the 25 per cent that is bone to three per cent—just the ash—it would solve many problems.

"They wouldn't have to haul the meal to a central location for safe disposal; they could derive a lot of energy—electricity and hot water—from it; and they could reduce the volume of waste that needed disposal from 25 per cent to three per cent."

Fonstad got his group working on some preliminary investigations into a range of different processes. Any kind of biomass has heating value, he explains. General Motors made thousands of little gasifiers during the Second World War. They worked by heating biomass until it turned to char and gave off gas. The gas and char were burned in a high pressure anaerobic chamber that restricted the amount of oxygen, prevented complete combustion and produced methane, carbon monoxide and nitrogen. This gas—the syngas—could then be burned in a generator to produce electricity and hot water, both of which are useful in the rendering process.

One of the potential problems, according to Fonstad, is that gasification processes require biomass to be burned at a low temperature, whereas government regulations require rendering by-products be burned at a high temperature for a long time to eliminate the danger of BSE-causing prions.

“So if we are going to do this, we will have to balance the requirements of the gasification system process with the regulatory requirements for destruction of prion materials. Can we design the process to satisfy the regulatory requirements for destruction of that material and still have an efficient process for gasifying meat and bone meal as an energy source? That is one of the questions we will address.”

Fonstad knows the project is ambitious, but the potential rewards are great, while doing nothing is not really an option.

“If we can put value into the meat and bone meal, that value will be passed on to the farm. It is a service to the industry and the farm. This is why doing something is the best option. If it can be utilized, that is the best way.”

For more information, contact:

Dr. Terry Fonstad
Professor of Agricultural and Bioresource Engineering
University of Saskatchewan
(306) 966-7860