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Biomass bale & propane hybrid grain drying

Principal Investigator: Evan Krebs

Research Institution: Sole Proprietor (Custom Farming Business)

Timeline: June 2022 – May 2025  


  • Design a hybrid biomass and propane retrofit system specifically for on-farm grain dryers.
  • Test and analyze design performance; develop design feasibility requirements for Ontario farmers.
  • Analyze the life cycle economics and economic feasibility of on-farm grain drying with a biomass-propane hybrid system.


  • Ontario farmers who currently dry grain with propane will be less exposed to risk from volatility in propane price and supply if a practical / reliable biomass and propane hybrid system can be developed.
  • Combusting baled residue for drying grain will create a new market opportunity for crop residue.
  • The retrofit system offers farmers low capital costs and simplicity by adapting existing dryers and using whole unprocessed biomass bales.
  • Compared to energy from propane, the same amount of energy from sustainably removable crop residue is approximately ¼ the cost.

Scientific Summary:

Propane and natural gas are undoubtedly the most common methods for fueling grain driers in the province. Propane is popular in many areas because it has far greater accessibility than natural gas (only 20% of rural Ontario has access to natural gas utilities). However, the consumer price of propane is determined by local distributors, allowing for large price fluctuations. Natural gas prices are more consistent over time as they are regulated by the Ontario Energy Board. Natural gas is also relatively cheap. For example, propane at 45 cents/liter costs four times more per unit of energy than natural gas at 17 cents/cubic meter. For farmers without access to natural gas, development of an alternative to propane is an economic priority.

Crop residue plays an important part in maintaining soil organic matter (SOM) levels, nutrient cycles, and other services for soil life. When removing crop residue, a break-even cost which accounts for the value of nutrients, labour and competing uses of the residue must be accounted for. A second consideration is the amount of residue that must be left in the field to maintain the SOM. It is understood that soil texture and management practises can greatly affect SOM behaviour. For example, planting a cover crop after removing wheat straw could offset the negative impact on soil health. Research at the Elora Research Station suggests that the minimum annual residue required to maintain SOM is 4,502 kg/ac/year. Residue produced in excess of this can be removed from the field without having significant impact on SOM. This is known as sustainably removable crop residue (SRR) and could potentially be used to fuel grain drying. There is now an opportunity to assess the life cycle economics of using crop residue for on-farm grain drying.

In North America there are very few examples of grain dryers fueled with biomass. Market research has shown there are three suppliers in Canada promising biomass furnaces suitable for grain drying: Mabre Air Systems, Säätötuli Canada, and Triple Green Products. These systems are all similar in that each one requires biomass in the form of chips, pellets, or finely shredded material. This is a problem for crop residue as it would require specialized equipment to prepare and store biomass. Since baling crop residue is the most common method of collection in Ontario, burning whole bales would improve feasibility for many Ontario farmers. Presently there is no whole bale burner readily available in the Canadian market.

This project proposes to design a furnace specifically designed for grain drying applications. A retrofit system will be designed that uses readily available baled crop residue and incorporates existing propane-fueled equipment to create a hybrid system capable of continuous and reliable operation. The project will also break new ground by offering a full lifecycle assessment of biomass-fueled grain drying in Ontario.

External Funding Partners: