Waste to energy is the process of producing thermal energy from the rubbish we throw out. Most wastes to energy processes produce electricity or heat energy directly through combustion.
Ever since the industrial revolution, waste has been a huge environmental issue worldwide. It includes any materials that we decide we no longer need and throw out in the trash. Electrical waste alone, consisting of old computer equipment, TV’s, stereos and kitchen appliances equates to almost 50 million tonnes a year. It doesn’t end there, in the UK alone, according to recent statistics we throw out 7.2 million tonnes of food, almost 500 million plastic bags, 83 square kilometers of wrapping paper and each baby gets through enough disposable nappies to weigh the same as a family car – to name just a few.
We generated 202.8 million tonnes of waste in the United Kingdom in 2017, but we can turn that trash into treasure by transforming it into energy.
So, what types of waste can be transformed into energy? Obviously both liquid and solid materials can be used, but some can be hazardous. Water used to clean industries as well as wash water, grease trap cleaning, sewage, triple interceptor (at a service or gas station) and many more are some examples of liquid waste. On the other hand, solid waste is any rubbish we make at our homes, offices or anyplace where we throw away into ´the bin. Examples of this can be cardboard and packaging, used tyres, general garbage, scrap metal, food and plastics.
Hazardous wastes are discarded materials with properties that make them potentially harmful to human health or the environment. Hazardous wastes can include things such as chemicals, heavy metals, or substances generated as by-products during commercial manufacturing processes, as well as discarded household products like paint thinners, cleaning fluids, and old batteries.
Turning Waste into Energy – Methods!
The rubbish we are producing every day can be turned into something good. Such as electricity, heat or fuel. The solids can be converted into gas to produce energy.
Incineration is the most common technology for WTE. After collection the waste is blasted in the incinerator at a high temperature, this is called thermal treatment. The heat generated will then be used to create energy.
Depolymerization also a common process but a little more technical – the human body uses depolymerization when digesting food. For example, processing protein. However, in this case it is referred to as TDP (Thermal Depolymerization) which uses super-heated water to produce fuels. The process of thermal decomposition is also called Hydrous Pyrolysis, using high heat and pressure on waste products such as biomass and plastic, to create light crude oil, which is then used to create energy.
Pyrolysis
This process is widely used in the industrial process to create energy from waste. This is like Hydrous Pyrolysis. Unlike Hydrous Pyrolysis, Pyrolysis process uses organic or agricultural waste from industries.
Gasification
This a developing process to create energy from waste. In this process, carbonaceous substances are converted into carbon dioxide, carbon monoxide and a small amount of hydrogen at a high temperature in the presence of oxygen. In this process, Synthesis gas is generated which is a good means of alternate energy. Synthesis gas is then used to produce electricity and heat.
Plasma arc gasification
In this process, a plasma torch is used to ionize gas which is generated from compressing the waste. Syn-gas or Synthesis gas then used to produce electricity.
The methods of turning waste into energy is an emerging and innovative development of technologies aimed to create a better and sustainable environment. Waste to energy technology is developing day by day and we can save our ecosystem by adopting this technology. It can also solve the energy problem of the world.
Though the scale of energy generation using waste to energy method is still small right now, it can be a great energy solution in the near future.
