FREQUENTLY ASKED QUESTIONS
AD plants are 24-hour operations and as such they need to be fed regularly. Pumps and other machinery also need to be maintained to ensure production is not interrupted.
There can be noise, dust, and if there are leaks the potential of smells and environmental contamination. However, these issues are strictly controlled by environmental regulations, so should not occur. The liquid part of the digestate contains nitrates and other chemicals which should not be released to water but which can safely be spread to land or processed for wider use.
The use of biogas also releases CO2, which is a greenhouse gas. However, this is offset because the biogas produced in AD replaces fossil fuels when it is used for heat, power or transport. If the waste were landfilled it would naturally rot and release methane, a potent greenhouse gas.
It turns waste into a resource. Instead of sending waste to landfill, we can use it to produce energy and fertiliser.
It produces fuel. Biogas can be used instead of fossil fuels.
It produces fertiliser. Fertilisers are made from fossil fuels. The digestate from this can replace some synthetic fertilisers.
It reduces our carbon footprint. The methane produced during AD is burned as fuel, and therefore releases CO2 into the atmosphere. Because it comes from biomass, this does not contribute to climate change. However, if the same waste was left to degrade in a landfill site, the methane produced could escape into the atmosphere: methane has a global warming potential 23 times larger than that of CO2. Therefore, harvesting and using methane from biomass can help to prevent climate change.
It can benefit many different people. AD potentially benefits the local community, the environment, industry, farmers and energy entrepreneurs and government.
There is some odour associated with the organic material that goes into a digester. However, AD can actually reduce nuisance odours as waste is delivered in closed vessels and vehicles, received in a closed reception area, and the digestion process takes place in a sealed tank. The digestion of slurry, for example, is significantly less odorous than the common practice of storing slurry
No. Digestate is not compost, although they have some similar properties. Compost is produced by aerobic (with air) decomposition of biological material and digestate is produced by anaerobic (without air) decomposition of biological material. They can both be used as fertiliser under specific regulations.
The amount of energy produced by AD will vary depending on the material that goes into it and the particular type of digester that is used
Anaerobic digestion (AD) processes plant materials (biomass) into gas for heating and power. The gas is called methane or biogas. It is produced by bacteria, which digest biomass and produce methane as a by-product.
What happens to recycled food waste? … During this process, food waste is put into an anaerobic digester where micro-organisms break down food waste in the absence of oxygen. This process produces biogas, a mixture of methane and carbon dioxide which can then be used to produce heat, electricity or transport fuels.
Gather organic food waste and scraps. Collecting compostable material requires little additional work—you simply place organic items, such as food waste and scraps in a collection container separate from your trash can. While you may purchase a designated indoor compost bin, many people collect their food scraps and waste in repurposed plastic food containers, trash cans, or compostable bags. After preparing or eating meals, place your food scraps into a compost collection bin.
• Acceptable items include table scraps, fruit, vegetables, and eggshells. These items are considered “green” waste as opposed to “brown” waste.
• If you are participating in a public or private program, only place approved compostable materials in your bin.
• If you are composting in your backyard, do not save meat and fish products for your compost pile—these items attract rodents and pests.
Organic waste is any material that is biodegradable and comes from either a plant or an animal. … Recycling organic waste will help reduce greenhouse gas emissions.
Food waste that is sent to landfill doesn’t harmlessly breakdown. It has a big impact on the environment as it rots and releases methane – a harmful greenhouse gas that is 25 times more potent than carbon dioxide. However, it’s not all bad news as many of us will be able to recycle our food waste.