In
climate engineering
Climate engineering (also called geoengineering) is a term used for both carbon dioxide removal (CDR) and solar radiation management (SRM), also called solar geoengineering, when applied at a planetary scale.IPCC (2022Chapter 1: Introduction and F ...
, the residue-to-product ratio (RPR) is used to calculate how much unused
crop residue
Crop residues are materials left in an agricultural field after the crop has been harvested. These residues include stalks and stubble (stems), leaves and seed pods. Good management of field residues can increase efficiency of irrigation and c ...
might be left after harvesting a particular crop. Also called the residue yield or straw/grain ratio, the equation takes the mass of residue divided by the mass of crop produced, and the result is dimensionless.
The RPR can be used to project costs and benefits of bio-energy projects, and is crucial in determining financial sustainability. The RPR is particularly important for estimating the production of
biochar
Biochar is the lightweight black residue, made of carbon and Ash (analytical chemistry),
ashes, remaining after the pyrolysis of biomass. Biochar is defined by the International Biochar Initiative as "the solid material obtained from the th ...
, a beneficial farm input obtained from crop residues through
pyrolysis
The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements ''py ...
. However, it is important to note that RPR values are rough estimates taken from broad production statistics, and can vary greatly depending on crop variety, climate, processing, and residual moisture content.
See also
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Carbon sequestration
Carbon sequestration is the process of storing carbon in a carbon pool. Carbon dioxide () is naturally captured from the atmosphere through biological, chemical, and physical processes. These changes can be accelerated through changes in land ...
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Biomass
Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...
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Biochar
Biochar is the lightweight black residue, made of carbon and Ash (analytical chemistry),
ashes, remaining after the pyrolysis of biomass. Biochar is defined by the International Biochar Initiative as "the solid material obtained from the th ...
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Biofuel
Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. According to the United States Energy Information Administration (E ...
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Pyrolysis
The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements ''py ...
References
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Climate engineering
Crops
Biofuels