Barangays encouraged to manage their waste

CEBU, Philippines -  Barangays should implement proper waste management and make sure waste can be transformed into reusable energy, this according to the Department of Science and Technology.

Dr. Danilo Jaque, who presented the topic on “Waste Management and Waste To Energy”, raised issues on pollution or climate change, public health and regulatory aspects, which includes law enforcement, policy issuance on emerging technology and clean air act issue on incineration.

He stated that with proper solid waste management there is a potential to create energy potential, carry out soil amendment and produce liquid fertilizer.

There are two general classification of treatment process of wastes: the thermal treatment which includes the composting and anaerobic digestion and the biological treatment, which includes the incineration, gasification, pyrolysis and plasma arc gasification.

Anaerobic digestion is where organic materials (food and garden waste) are converted into methane or biogas in the absence of oxygen. The residual organic digestate is then aerobically composted. These processes take place in an enclosed building and involve the breakdown of organic material in a sealed vessel called a digester. This allows the biogas to be generated.

Incineration is a treatment technology involving destruction of waste by controlled burning at high temperatures; by-product include ash and heated gas (steam) used for boiler; gas emission includes carbon dioxide, carbon oxide, and other harmful gases such Furans and Dioxin. These are clean using emission control devises.

Gasification turns waste into an energy-rich fuel gas known as Syngas. It involves the conversion of waste in a high temperature low oxygen environment, between 800 degrees and 1400 degrees Centigrade. 

The synthesis gas can be fed directly into engines after a clean-up process to produce electricity. Harmful gas emissions are controlled and cleaned.

Pyrolysis is similar to gasification and it involves heating waste to high temperatures (between 400C and 800C) in the absence of oxygen. Synthesis gas, pyrolysis liquid and solid char are produced. 

Plasma Arc technology is a type of gasification technology which uses an electrically powered plasma arc to produce temperatures of around 5,000C to transform organic materials such as food, greenwaste, wood and paper into synthesis gas. The byproducts include Slag, wastewater, distilled water and syngas. Harmful gases are cleaned.

Adoption of appropriate technology to address Municipal Solid Waste is necessary for sustainable development. Anaerobic Digestion is a proven process and technology which can be adopted to address the organic fraction of MSW. Emerging thermal process to degrade MSW has a great potential but must be properly evaluated to ensure compliance to emission standards.

Solar energy

Also discussed during the Science & Technology Conference yesterday at the DOST S&T Complex, in Sudlon, Lahug this city was Solar Energy.

The National Renewable Energy Laboratory (NREL) has developed a solar cell that can convert a record 40.8 percent of the sunlight that hits it into electricity.The new NREL solar cell is a triple-junction device —it uses three layers of photovoltaic material stacked atop one another to catch different parts of the solar spectrum. 

There are two kinds of solar energy systems; the solar photovoltaic system and the solar thermal.

The solar photovoltaic system uses direct and diffuse solar radiation (light) to produce electricity while the Solar Thermal utilizes the direct solar radiation (heat) to produce electrical energy. (FREEMAN)