Features Bioenergy Biomass
Biomass feedstocks for the emerging bioeconomy

April 5, 2010 – Biomass! Feedstocks! We are hearing these words everywhere as people and businesses look for ways to participate in the emerging bioeconomy. Biomass feedstocks are organic materials that supply some processing/refining process to produce a wide variety of end products, including energy (biogas, ethanol, heat, electricity), biomaterials (bioplastics, bioresins), biochemicals (organic replacements of almost any conventionally derived chemicals), and many others.

Biomass feedstocks include a wide range of materials such as crop residues, dedicated biocrops (Miscanthus, switchgrass, big bluestem, prairie cord grass, sweet sorghum, reed canary grass, and many others), manure, used vegetable oils and food processing byproducts, dedicated forestry resources, forestry residues, organic wastes from municipalities, and even sewage treatment wastes. The feedstock product of choice will depend on the process/refining step(s) and the end product sought.

How much is available?

One fact that continues to surprise me is the estimation of potential biomass volumes from the agricultural sector that have been identified in several studies conducted by researchers and environmental and industry associations such as the Suzuki Foundation and Biocap. The contribution from agriculture in these studies far exceeds that from forestry despite the vast acreage of forestry resource in Canada. It seems that the availability from agriculture is because of its proximity to markets, expected ease of access, robustness of the agricultural landscape, gross volumes that exist, and assumed logistics associated with accessing it.

A significant issue around feedstocks that must be addressed is how much is realistically available in the Canadian landscape. This is important; every week we see new businesses announcing they are going to produce new products in the bioeconomy. We need to understand the potential of these businesses to be successful compared to the amount of biomass feedstock they suggest they require and compare this to the realistically available resources from the various sources. Does the amount of feedstock required from these expectations have any correlation to the actual amount of biomass feedstock that may be available to meet all these demands? If not, how will we decide what products get access to the available biomass resources across the country?
{mospagebreak}
Agricultural residues

If we consider crop residues, what volumes are out there? There are three major questions that have to be answered with respect to the biomass resources available in Canada. First, how much can be removed sustainably without damaging the long-term productivity potential of the precious soil resource? This comes down to sustainability questions about the volume that can be removed verses the concern for increased erosion, reductions in soil organic matter and other soil constituents, and how the soil texture, cropping practices, soil types, and other factors affect the fragility of each landscape.

Second, how much is practically available? Cereal straw and even soybean stubble can be laid out in a nice neat windrow that is easily harvested by a baler or forage harvester. It is even relatively simple to engineer the combine to collect the residue out of the back right into a wagon. Corn harvest is different because only the ear goes through the combine while the stalk and leaf material is pulled under the corn header and deposited on the ground. This stover then likely has to be windrowed and harvested in some manner. Especially with corn stover, but also with soybean stubble, we are up against tight timelines. With soybean, any residue has to be removed quickly, as we are often planting winter wheat between mid-September and mid-October in Ontario. With corn, we are up against the arrival of snow and cool, damp conditions that are not conducive to getting clean, dry stover out of the field.

Third, how much is the crop residue worth financially? The answer must consider the value of the crop residue remaining in the fields, the logistics of its removal and storage, and what would be reasonable payment to the owner of the biomass resource.

In Ontario, we have historically removed cereal straw from many acres. This feedstock has a ready market in a wide range of areas, including feed, livestock bedding, mushroom production, mulches in other crops, and even in building and other industrial uses. Traditionally, we have not taken the soybean stubble or corn stover from the landscape. In a normal Ontario three-crop rotation sequence of corn, soybeans, and wheat, two of the three crops have traditionally had their crop residues left in the field. Now we are potentially talking about removing the crop residue from all three crops.

We have a lot of work ahead of us to determine how sustainable a practice this might be. Because we have not experienced the removal of soybean and corn residues from the field in any significant amount, we do not have good research or even knowledge of what the implications of this practice might be. The changes that increased crop residue removal could bring may be positive or negative. Moving to a system of crop residue removal may require other changes in crop production systems to offset this loss of organic matter.

There is a lot of work to do and many people to educate as we explore this exciting new era of the bioeconomy.

Ian McDonald is the applied research coordinator for the Field Crops Unit, Agriculture Development Branch, Ontario Ministry of Agriculture, Food, and Rural Affairs. He works from the Plant Agriculture Department of the University of Guelph and is involved in a wide range of research activities exploring new technologies in field crop agriculture. He is exploring the implications for field crop agriculture of the emerging bioeconomy as it pertains to the use of crop residues and dedicated feedstocks.