The rising cost of energy has caused many people to look for ways to reduce their reliance on fossil fuels. One option is to turn waste into energy. This process is called waste-to-energy or thermal treatment, and it can be used to produce electricity, heat, or chemicals.
Waste material consists of everything disposed of because of its uselessness or toxicity. It is often generated from human activity and it is considered undesirable hence its desposal. For instance, human waste is generated as a result of digestion of nutrients, factory waste generated as a consequency of production. Much as waste is considered undesirable, it can be put to good use by converting it to useful energy.
There are a number of methods that can be used to covert waste into useful energy among which include: Incineration, Anerobic digestion, gasification, pyrolysis, and land fill gas recovery. Each of these methods requires the use of different tools and a different approach. Most of these approaches harness the energy from the waste through either directly tapping the heat generated, or through using the heat to produce electricity. Energy generated from this waste can be used for mainly cooking, lighting, and charging.
Incineration; This involves the mass combustion of waste. Most waste is flammable thus setting it on fire generates even more energy in form of heat. The heat energy produced is channeled towards heating up water in a boiler to produce steam. The steam is chaneled to turbines that are connected to a generator. The energy from the spinning turbines thus generate electricity. The process of turning waste to energy using this approach is as follows:
Waste is transported and dumped in one large pit where it is all to be collected. The transportation is done using large garbage trucks.In the pit, the waste goes through a drying and dorting process.
From there, the waste is mechanically transported from the pit into a combustion chamble. Insight the combustion chamber the waste is set abalze and left to burn in an enclosed but aerated chamber.
The heat produced is channeled towards a boiler containing water. The steam is then channeled towward a set of turbines connected to a generator. The spinning of the generates electricity.
Gasification; this process invloves the conversion of waste matter into gaseous fuels. It involves reacting the waste material at high temperatures without combustion. This converts waste material into gases like: Nitrogen, hydrogen, carbonmonoxide and carbondioxide. Energy from this waste is harnessed by combustion of the resultant gas. This methos produces more energy than direct incineration.
Pyrolysis; This involves the thermo decomposition of waste, at high temperatures in an inert atmosphere. The waste material in this case undergoes chemical changes that converts it into a flammable fuel. This process involves a particial decomposition of the waste. It is the process before gasification. An example of this process is the charring of wood to form a carbon rich residue called char, commonly known as charcoal.
Anerobic digestion; This involves the decomposition of waste by microorganisms in an enclosed oxygen deprived environment. It is a process similar to alcohol fermentation which is also a form of anaerobic digestion. The microorganisms break down waste like sugars and amino acids into biogas consisting of methane and carbon dioxide dioxide. Biogas is directly used to produce energy through its combustion. The process of conversion involves collecting biomass into one big enclosed pit deprived of air and leaving it for a while. After some time, the resultant gas is tapped using a pipe system to a combustion point.
Land fill gas recovery; Land fill gas is the gas collected from a land fill. A land fill is a site where waste material is damped. The decomposition of this waste materioal produces a gas which can be used as a fuel. The gas produced consists of mainly methane which is combustible. The gas can be tapped by digging a hole in a land fill site, then channeling the gas to a collection point.
Pros and cons
Pros
Converting waste to energy cuts down expenditures on waste desposal because it reduces the need to depsose of waste.
These processes also add value to otherwise useless waste making it valuable and useful. The energy from these processes can be used for cooking, lighting electricity generation among others.
Some methods are cheap and can easily be done at home. For instance, anerobic digestion simply needs an airtight container to store the waste for sometime as it decomposes.
By making use of waste, these processes clean up the environment previuosly littered with this previously useless waste.
Cons
Waste can still pollute the environment even after conversion into energy. For example, Char from wood burns releasing pisonous gases like carbonmonoxide whic still pollute the environment.
If mishandled, waste can be hazardous and cause illness. For example, careless exposure to human waste van cause serious illnesses like cholera. It’s for this reason that it should be handled by an expert with protective equipment like gloves and face masks.
Conclusion;
The potential for waste to energy as a solution is clear. With the right technology and infrastructure in place, there is no doubt that this could be a major contributing factor to reducing our carbon footprint. With the ever-growing population and the need for more energy, it is important that we explore all possible options for reducing our impact on the environment. Waste to energy should be one of those options.