The Properties of an Optimal Biomass Energy Crop
Biomass energy crops are plants that are grown specifically for use as fuel. These crops can be used to produce electricity, heat, or transport fuels.
There are many different types of biomass energy crops, but not all crops are created equal.
- 1 The Properties of an Optimal Biomass Energy Crop
- 1.1 High yield (maximum dry matter output per hectare)
- 1.2 Low energy demand for cultivation & processing
- 1.3 Drought tolerance/low water demand
- 1.4 Pest resistant
- 1.5 Fast growth
- 1.6 Low input costs
- 1.7 Cleanest composition
- 1.8 Minimal nutrient requirement
- 1.9 The ability to grow on marginal land
- 1.10 Non-invasive
- 1.11 Compatible with existing crops (e.g. can be planted in between rows of food crops)
- 1.12 Flexible management (e.g. can be planted in agroforestry systems, or as a short-rotation coppice)
- 1.13 Able to be harvested mechanically
- 1.14 Can be decomposed easily by enzymes
- 1.15 Non-allergic & non-toxic
Some crops are better suited for specific purposes than others. When choosing a biomass energy crop, it is important to consider the following properties:
High yield (maximum dry matter output per hectare)
We always want more of something for less effort and that’s exactly what a high yield indicates.
A crop that can produce a lot of dry matter per hectare is ideal because it means less land will be required to grow the same amount of biomass. This is important not only from an economic standpoint but also from an environmental perspective.
The selected biomass plant should offer the greatest dry matter per hectare in order to minimize the land footprint of biomass energy production.
Low energy demand for cultivation & processing
The entire point of growing biomass energy crops is to create a fuel source that is renewable and has a lower carbon footprint than fossil fuels.
Therefore, it stands to reason that the chosen crop should not require a lot of energy to grow and process. A crop that takes a lot of energy to cultivate or process defeats the purpose of using it as a biomass fuel.
The selected biomass crop should have a low energy demand for its farming operations, including seed production, planting, fertilizer application, irrigation (if needed), pest and weed control, and harvesting.
Low energy demand for biomass production also means that a greater proportion of the total biomass crop can be used for energy. This is an important criterion since the objective of biomass energy is to replace fossil fuels.
Drought tolerance/low water demand
Water scarcity is a major problem in many parts of the world and it is only getting worse.
A crop that can tolerate drought conditions or doesn’t require a lot of water to grow is ideal. This ensures that the crop can be grown in areas where water is scarce and that less water will be needed to irrigate the crops.
Therefore, the selected biomass crop should be able to withstand periods of drought and have a relatively low water demand. This is important because water availability may become a constraint on biomass production in the future as climate change progresses.
Pests are natural enemies of crops and can cause serious damage. A crop that is resistant to pests is less likely to be damaged and will require less pesticide application.
This is important from an economic standpoint because it reduces the cost of production, but it is also important from an environmental standpoint because it reduces the number of chemical inputs into the ecosystem.
Thus, the selected biomass crop should be resistant to pests and diseases, or at least have low susceptibility.
The faster a crop grows, the sooner it can be harvested. This is important because it allows for more frequent harvests and a longer growing season.
A crop that has a shorter growing season is also less likely to be impacted by adverse weather conditions. Therefore, the selected biomass crop should have a fast growth rate so that it can be harvested quickly and frequently.
This in return reduces the land footprint of biomass energy production. Some of the fastest-growing plants that are being evaluated for commercial energy production include miscanthus, switchgrass, sorghum, and sugarcane.
Low input costs
The cost of growing and processing the crop is an important consideration. A crop that requires a lot of expensive inputs is less likely to be economically viable.
Therefore, the selected biomass crop should have low input costs, including seed cost, fertilizer cost, and pesticide cost. This is important because it makes the overall production of biomass energy more economical.
Contamination of biomass feedstock is a major issue in energy production. The selected biomass crop should have a low ash content (the inorganic matter that is left after the fuel is burned) and low sulfur content. This will minimize the emissions of pollutants when the biomass is combusted.
Certain crops tend to have these characteristics, making them better suited for biomass energy production. However, there is still much research that needs to be done in order to determine the cleanest and most efficient biomass energy crop.
Minimal nutrient requirement
The selected biomass crop should have minimal nutrient requirements in order to minimize the need for fertilizer. This is important because fertilizer production uses fossil fuels and emits greenhouse gases.
In addition, it is important to select a crop that doesn’t deplete the soil of nutrients. This ensures that the land can be used for a longer period of time without the need for replenishment.
The ability to grow on marginal land
The selected biomass crop should be able to grow on land that is not suitable for other crops. This is important because it will minimize the competition between food production and energy production.
By growing on marginal land, biomass energy production will not displace food production and compete for scarce resources. Marginal land includes land that is too steep, too dry or has poor soil quality.
An invasive species is a plant that has been introduced to an ecosystem and has negative impacts on the environment, such as crowding out native plants.
The selected biomass crop should not be invasive in order to minimize the negative environmental impacts of biomass energy production.
Some crops, such as Miscanthus, have been shown to be non-invasive in North America. However, more research is needed to determine the potential invasiveness of other biomass energy crops.
Compatible with existing crops (e.g. can be planted in between rows of food crops)
Compatibility with existing crops is important for two reasons. First, it minimizes the land that is required for biomass energy production. Second, it reduces the competition between food production and energy production.
Miscanthus has been shown to be compatible with a variety of food crops, including corn, soybeans, and wheat. However, more research is needed to determine the compatibility of other biomass energy crops.
Flexible management (e.g. can be planted in agroforestry systems, or as a short-rotation coppice)
The selected biomass crop should be able to be managed in a variety of ways. This is important because it will allow the crop to be adapted to different conditions and maximize the land that is available for biomass energy production.
For example, Miscanthus can be planted in agroforestry systems, or as a short-rotation coppice. This flexibility makes Miscanthus a promising biomass energy crop.
On the other hand, crops that can only be managed in one way are less promising for biomass energy production.
An example of a crop that is less promising for biomass energy production is switchgrass. Switchgrass can only be managed as a monoculture, which limits its flexibility and makes it less adaptable to different conditions.
Able to be harvested mechanically
Harvesting biomass crops manually is time-consuming and labor-intensive. The selected biomass crop should be able to be harvested mechanically in order to minimize the cost of biomass energy production.
Mechanical harvesting includes using machines to cut, collect, and transport biomass crops. The use of machines can significantly reduce the cost of biomass energy production.
Can be decomposed easily by enzymes
Not all biomass plants go through the process of direct combustion. Some biomass plants are converted into biofuels through the process of fermentation.
The selected biomass crop should be able to be decomposed easily by enzymes in order to be used for biofuel production. That way, the crop can be converted into biofuel more efficiently.
Non-allergic & non-toxic
The selected biomass crop should be non-allergic and non-toxic. We don’t want people to have allergic reactions or get sick from exposure to the biomass crop.
Certain crops develop compounds that are toxic to humans and animals when they decompose. The selected biomass crop should not have these compounds in order to be safe for people not only when it is growing, but also when it is being used as a biofuel.