Crop residues

Nearly every food crop has some parts that are too fibrous for people to eat. These are called crop residues, also known as biomass waste.

Examples

• banana leaves
• peanut shells
• coconut shells
• empty corn cobs with no kernels
• rice husks
• sunflower seed husks
• straw

Uses

1. All biomass waste can be burned for energy.
2. Some kinds of biomass waste can be converted into packaging.
3. Some kinds of biomass waste can be fed to ruminants (cows).
4. Some kinds of biomass waste can be used for cultivating mushrooms.
5. If there's no other use, biomass waste can be composted back into the soil.

3 and 4 are both ways to convert fiber into human-edible protein & calories. Help figure out which of these processes is more efficient overall. This page doesn't have enough information yet - join the discussion.

Supply

Major limitation

Global fossil fuel consumption far exceeds what can be produced by crops.

Mass

crop_residues

1.7 billion tonnes/year

Dry mass of all crop residues, byproducts, and oilseed cakes except for soybean

This should be, in principle, all the human-inedible parts of food crops (inedible due to being too fibrous; ruminants can digest the fiber and get calories from it).
Soybean meal is not counted here, because it can be turned into human food (soy flour).

Source:
Breewood, H. & Garnett, T. (2020). What is feed-food competition? (Foodsource: building blocks). Food Climate Research Network, University of Oxford.
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References primary source:
Mottet, A., de Haan, C., Falcucci, A., Tempio, G., Opio, C., & Gerber, P. (2017). Livestock: On our plates or eating at our table? A new analysis of the feed/food debate. Global Food Security.

world.population

8 billion

kalorie

kcal

A food calorie

fiber.energy_by_mass

4 kalorie/gram

power_plant.efficiency

33%

How much of the fuel combustion heat becomes electricity

This applies to any power plant that runs on biomass, coal, nuclear fission, or in some cases natural gas. The fuel heats water which generates steam to drive a turbine that generates electricity.

How much does the world produce: crop_residues / world.population grams/day per capita dry_mass (calculation loading)

If this could be converted into packaging, it would probably be more than enough to replace all disposable plastic.

Energy

If all of it was burned for energy, it would be equivalent to burning: dry_mass * fiber.energy_by_mass cups gasoline/day per capita (calculation loading)

If it was burned in a power plant, the electricity generated would be: dry_mass * fiber.energy_by_mass * power_plant.efficiency watts per capita (calculation loading)

Biomass energy is nowhere near enough to power the world.

See also

Other energy sources:

• Solar
• Wind
• Hydro
• Nuclear