After waste is converted into energy, what’s next?
Emirates Waste to Energy Company will generate up to 30MW of electricity by displacing almost 450,000 tons of CO2 emissions per year at its plant in Sharjah. But besides producing electricity, it has found ways to extract value from the plant’s residual waste
The emirate of Sharjah will soon be home to the UAE’s first Waste to Energy plant. But as work on the 30MW facility nears completion scheduled for 2021, the company is looking ahead to ensure that residual waste is managed sustainably to support a circular economy.
Developed through the Emirates Waste to Energy Company, a joint venture between Bee’ah and Masdar, the waste-to-energy plant will process 300,000 tons of nonrecyclable solid waste per year
The Sharjah Waste to Energy facility will displace almost 450,000 tons of CO2 emissions per year, and generate up to 30 megawatts of electricity which will be directly supplied to the Sharjah electricity grid to power up to 28,000 homes.
The design of the Sharjah Waste to Energy facility is unique, because there is extensive use of direct air exchange for mechanical system cooling and boiler cleaning with no water consumption, which is ideal given the scarcity of water in the region.
As the first waste-to-energy plant in the UAE, the facility will face specific weather conditions, such as hot and dry atmospheric conditions and strong sandy winds. These environmental conditions have already been factored into the design of the equipment and operations.
The process includes an injection of dry lime powder to treat acid gases at the outlet of the boiler, which optimizes emissions performance, reducing the amount of carbon dioxide released to the atmosphere.
The process starts with a weighbridge for waste collection vehicles, followed by the unloading of waste into a waste bunker, and there will be a control room with an operator who will operate a crane to transfer waste from the bunker and into the boiler.
The combustion grates technology provide waste flow to ensure drying, ignition, combustion, energy release and complete burn-out before reaching the bottom ash outlet. The boiler will recover heat from incinerated waste to produce steam.
The high-pressure, high-temperature steam is converted into electrical energy through a steam turbine that is connected to a step-up transformer that then transfers the electricity to SEWA's grid. The low pressure and low temperature steam runs through an air-cooled condenser to transform into condensate that is reused in the plant again, as part of a closed loop water cycle.
In addition, the Sharjah Waste to Energy facility has adopted a high performance and an innovative flue gas treatment system to ensure that the flue gases can be safely released into the atmosphere. Flue gas is a mixture of gases produced by burning materials in power stations or industrial plants.
Repurposing waste from WTE
There are two primary forms of ash left over from waste to energy incineration is Incinerator Bottom Ash (IBA), otherwise known as bottom ash, and Air Pollution Control Residues (APC), also known as Fly Ash.
To extract value from the residual waste, Bee’ah partnered with UAE-based startup Seramic Materials to explore recycling ashes from the Sharjah Waste to Energy facility by turning it into sustainable, affordable and durable ceramic materials. Bee’ah is also considering processing the ash to be used in the construction industry.
“Bee’ah believes that partnership and co-creation with partners can help to solve some of the region’s greatest environmental challenges – in this case, it is closing the loop for waste-to-energy solutions and furthering zero-waste ambitions here in the UAE,” said HE Khaled Al Huraimel, Group CEO of Bee’ah and Chairman of the Emirates Waste to Energy Company.
Roadmap to Zero-Waste to Landfill
Bee’ah is currently on track to help Sharjah achieve zero-waste-to-landfill by 2021 on the completion of the Sharjah Waste to Energy facility. Bee’ah’s zero-waste strategy includes advanced recycling facilities and generating public awareness on the importance on waste segregation and recycling.
Through its Waste Processing, Treatment & Recovery division, Bee’ah is supportingcircular economy by processing waste to ensure that it is recycled, recovered, regenerated, and put back into the economy.
It is facilitating this process through its state-of-the-art Waste Management Complex, home to some of the world’s most advanced recycling facilities.
Among Bee’ah’s recycling facilities is the Construction and Demolition Waste Recycling Facility which has played an important role in diverting the waste produced from the UAE’s booming construction sector, away from landfill. With a recovery rate of 95%, the facility processes 500,000 tons of construction waste every year to produce five grades of ADQCC-certified aggregates and they are also used in the construction industry in which many products can be produced such as interlock and curb stones.
Through its operations, the facility produces a diverse portfolio of dry recyclables in the UAE, for use in construction, landscaping and cement production, reducing dependency on natural resources and protecting the health of the environment.
HE Al Huraimel added: “Through our operations, we are strategically designing waste out of systems and leading the UAE’s sustainable agenda through investments in green infrastructure and other ventures. Innovations such as waste to energy can help to propel our country’s growth, and ensure that development is underpinned by sustainability.”