Reducing Greenhouse Gas Emissions and Improving Air Quality
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12.4 Renewable Fuels
Some renewable fuels are produced from crops and crop waste materials.
Perhaps most notably, ethanol is produced in significant quantities in several countries. The most common substrates for ethanol fermentation in the
United States are corn and grain sorghum. Sugarcane is a common substrate
in Brazil, which produces ethanol in significant quantities. Cellulose has
been investigated as a substrate, but the economics are not very good at the
present time (2019). Waste carbohydrate sources, such as grain dust cereal
wastes, can also potentially be used to produce ethanol.
Another renewable fuel option from agriculture is through anaerobic
digestion of agricultural wastes to produce methane. Waste products with
this potential include dairy manure, food manufacturing waste, feed waste,
and food waste. The economics of methane production depend on the
alternatives that are available, but where methane from natural gas is expensive, the process of anaerobic digestion can provide gas that has value as a
renewable fuel.
12.5 Air Quality
Finally, the issue of good air quality can centrally include agricultural
concerns. The burning of crop residues and pastures impacts air quality significantly where it is allowed. The use of solid fuels and fires for cooking
and heating, common in underdeveloped rural areas that often overlap with
agricultural areas, causes air pollution and impacts health.
Larger domesticated animal operations have a different set of air quality
issues that can arise. Dust from large cattle (and other animal) feeding
operations is an issue when the feedlot soil is dry. There are odors from
animal feeding operations in many cases. Where animal feeding takes place
inside buildings, indoor air quality may be a problem. There can also be an
issue with microbial pathogens that may move through the air to contaminate other organisms.
References
Esguerra, E.B. (2018). Case studies on managing quality, assuring safety and reducing postharvest losses in fruit and vegetable supply chains in South Asian Countries. UN Food
and Agriculture Organization; www.fao.org/ publications
116
1 1 6
12.4 Renewable Fuels
Some renewable fuels are produced from crops and crop waste materials.
Perhaps most notably, ethanol is produced in significant quantities in several countries. The most common substrates for ethanol fermentation in the
United States are corn and grain sorghum. Sugarcane is a common substrate
in Brazil, which produces ethanol in significant quantities. Cellulose has
been investigated as a substrate, but the economics are not very good at the
present time (2019). Waste carbohydrate sources, such as grain dust cereal
wastes, can also potentially be used to produce ethanol.
Another renewable fuel option from agriculture is through anaerobic
digestion of agricultural wastes to produce methane. Waste products with
this potential include dairy manure, food manufacturing waste, feed waste,
and food waste. The economics of methane production depend on the
alternatives that are available, but where methane from natural gas is expensive, the process of anaerobic digestion can provide gas that has value as a
renewable fuel.
12.5 Air Quality
Finally, the issue of good air quality can centrally include agricultural
concerns. The burning of crop residues and pastures impacts air quality significantly where it is allowed. The use of solid fuels and fires for cooking
and heating, common in underdeveloped rural areas that often overlap with
agricultural areas, causes air pollution and impacts health.
Larger domesticated animal operations have a different set of air quality
issues that can arise. Dust from large cattle (and other animal) feeding
operations is an issue when the feedlot soil is dry. There are odors from
animal feeding operations in many cases. Where animal feeding takes place
inside buildings, indoor air quality may be a problem. There can also be an
issue with microbial pathogens that may move through the air to contaminate other organisms.
References
Esguerra, E.B. (2018). Case studies on managing quality, assuring safety and reducing postharvest losses in fruit and vegetable supply chains in South Asian Countries. UN Food
and Agriculture Organization; www.fao.org/ publications