WHAT IS WASTE TO ENERGY?
Did you know that in the UK we generate around 290 million tonnes of waste each year? What isn’t recycled or composted will usually end up as landfill. But thanks to new and developing Waste to Energy (WtE) technologies, our unusable residual rubbish doesn’t have to go to waste. By taking a circular economy approach to the management of our waste, it can be converted into a reliable and sustainable form of energy.
Until recently, mass burn incineration has been the main alternative to landfill. However, with the introduction of emerging Waste to Energy technologies such as pyrolysis and gasification, which generate clean, green energy in the form of electricity, heat or fuel, there are now alternative solutions for end of life waste. These solutions are known as waste recovery options.
Harnessing Energy from Waste (EfW) has numerous benefits, from reducing our dependence on expensive energy imports to carbon emissions savings and reducing our waste quantity. Embracing Waste to Energy technologies will also help the UK to meet its renewable energy targets.
HOW IT WORKS
Energy can be generated from waste in different ways, including chipping/shedding waste wood to an appropriate size for biomass chips, or by turning wood/sawdust into fuel pellets or briquettes. Fuel then can be stored ready to be fed into a biomass boiler for heating, or a combined heat and power (CHP) unit to produce heat and electricity.
Wooden pallets are an ideal fuel for biomass boilers. As an added bonus, any metal separated from them during the chipping processes can be sold for scrap.
Pyrolysis and gasification
For non-wood based waste, alternative technologies such as pyrolysis and gasification will be more appropriate. Unlike conventional incineration, advanced conversion/thermal technologies like pyrolysis degrade the waste instead of combusting it.
The gasification process utilises solid waste materials such as paper, plastics, food scraps, crops and general waste, which are shredded to reduce their size if necessary, before being heated in a vessel. Raising the temperature by several hundred degrees, the waste material is exposed to a small amount of oxygen – although not enough for combustion to occur – and broken down into its basic components to create gas, solid and liquid residues. The process produces syngas – a combination of carbon monoxide, carbon dioxide and hydrogen – which can be used as a fuel for heat and electricity production.
Pyrolysis shares similar characteristics, although this process thermally degrades waste without any exposure to oxygen. Commonly used in industrial processes, during pyrolysis waste is heated to produce a combustible gas, oil and solid char which can be used to produce electricity or other fuels.
Organic rankine cycle
An organic rankine cycle (ORC) is a technology used for waste heat recovery. Waste heat is converted into electricity and useable heat by capturing the heat at source and displacing it through a working fluid to power a turbine. The ORC system is driven by a heat source, such as a biomass boiler or escaping heat from an industrial Furness. For optimum financial benefits achievable under the Renewable Heat Incentive, combine an ORC system with a biomass boiler.
Anaerobic digestion (AD) is another method of generating energy from waste. The process of anaerobic digestion involves food and animal waste and other organic matter, which is broken down to produce biogas and also manage waste. Biogas can be used to produce heat, when burned in a gas boiler and, with a CHP unit, both heat and electricity.
These innovative Waste to Energy technologies are an effective and efficient way of converting waste into electricity, heat and fuel. They use little or no oxygen, reduce the amount of waste used as landfill, produce fewer emissions and, with minimum damage to the ecosystems, are much better for the environment.
By using your own on site waste, you’ll no longer need to pay for waste to be disposed of, you’ll save money on your energy bills and earn extra money from government incentives in the process.
Environmental Energies will deliver the most effective solution for your business by utilising the most appropriate type of Waste to Energy technology, based on the type and volume of waste you are looking to transform, and the nature of energy you need to produce.
From initial design and planning, through to supply, installation and maintenance, our bespoke Waste to Energy packages provide an exceptionally profitable solution for transforming unusable waste into usable energy.