Recycled solid waste: A new source of energy

08:21 | 03/03/2014 Science - Technology

(VEN) - Residents in Hanoi currently discard an estimated 5,000 tonnes of solid waste per day, over 98 percent of which is buried. However, about 85-90 percent of waste burial sites fail to meet hygienic requirements and pollute the environment. If the situation continues, Hanoi will have no place to bury waste by 2015.

Turning waste into bricks

Hanoi Science and Technology Department Director Le Xuan Rao said that Vietnam had encouraged the application of advanced technologies in recycling solid waste in order to minimize burial needs.

One of the solutions that scientists want Vietnam to take is applying the Waste-to-Energy (WtE) technology.

WtE works on a closed production line where waste can be classified, treated and turned into thermoelectricity or materials such as glass and bricks. Scientists highly appreciate this technology because it helps minimize environmental pollution by reducing the amount of waste that is discarded to the environment by 90 percent while creating energy and materials. Moreover, the application of this technology does not require any land for burial. A special advantage of the WtE technology is that is allows waste to be automatically classified at the first step.

The Center for Environmental Research and Technology Transfer has created a technology that allows waste to be treated and turned into bricks and concrete at low costs while ensuring that their quality is equal to that of commercial bricks and concrete sold in the market. However, this is just a small-scale project.

Many scientists share the opinion that the WtE technology does not have advantages in terms of economic benefits but will create a clean environment for future generations. However, the biggest hindrance to the application of this technology in Vietnam is that is requires big investments. Actually, not every business is financially capable to apply this technology.

Promoting RPF production

Creating a new source of energy from waste to replace coal at paper, cement and steel plants is the objective of a cooperation program between the Hanoi Urban Environment Company Limited (URENCO) and Japanese partners. In 2010, URENCO began to send paper and plastic wastes from Hanoi to Japan for trial use as materials to produce Refuse Paper & Plastic Fuel (RPF) pellets at the factory of the Ichikawa Company Limited, and satisfactory results have been achieved. RPF pellets are a kind of high-quality solid fuel manufactured from used papers and waste plastics. In Japan and some other countries, RPF has been widely used to replace fossil fuels such as coal and coke in producing cement, steel, paper, sugar and thermoelectricity. The production cost of RPF equals just nearly 50 percent of the production cost of coal.

“Vietnam still has no RPF production facility. After learning about this technology and how it has been applied to produce RPF pellets in Japan, scientists found that the technology could absolutely be applied in Vietnamese cities, especially Hanoi. However, the classification of waste in Vietnam remains ineffective and those kinds of waste which can be recycled are yet to be sorted out. Therefore, businesses must choose the most suitable production lines. Waste treatment charges in Vietnam are very low, so if they fail to sell RPF pellets, businesses will suffer losses./.

Relevant state authorities predicted that after 2015 Vietnam would face coal shortages. RPF production can help Vietnam considerably reduce the area of land required to bury waste. URENCO and Ichikawa are preparing to build an RPF production facility in Hanoi’s Soc Son District.

Viet Nga