(25e) Minimizing Municipal Solid Waste Accumulation through the Application of Appropriate Technology

Along with population and urbanization in developing countries, the amount of municipal solid waste generated is also increasing. Although programs and initiatives to recycle and manage waste can often be found in the major population centers, these technologies are slow to spread to or are not yet present in the rural areas. Heavily populated urban slums are also lacking in the infrastructure needed to collect and manage trash, particularly plastic packaging. Solving the problems caused by this accumulation of municipal solid waste (MSW) derived plastic is a global challenge. Plastic waste accumulation in landfills and oceans is detrimental to ecosystems as well as public health. In developing regions particularly, where MSW handling infrastructure is limited or unavailable, plastic is often simply left on the ground where it eventually makes it way to the ocean. Because these sources are widespread, the solutions to dealing with this plastic must also be widely dispersed.

Fortunately, many plastics can easily be converted into a fuel oil that can be directly used as a substitute for petroleum derived kerosene or diesel. Plastics commonly found in MSW such as High Density Polyethylene (HDPE), Low Density Polyethylene (LDPE), Polypropylene (PP), and Polystyrene (PS) are all viable raw materials for this process. Plastics such as polyethylene terephthalate (PET) and poly vinyl chloride (PVC) are unfortunately not suitable for this process, due to the presence of oxygen and chlorine respectively in the polymers. The chemistry of converting plastic waste to a hydrocarbon fuel oil is simple and well established. Since, the molecules of these plastics are only made up of carbon-hydrogen chains, when thermally heated to temperatures of approximately 430°C (Wong, et al., 2015), the hydrocarbon chains break, decomposing the polymer, and yielding a hydrocarbon gas, which is then condensed to obtain the fuel oil product. However, industrial processes for carrying out this chemistry are typically not available in the developing regions that are the source of much of the plastic that ends up in the ecosystem. To address this problem, solutions based on combining the principles of appropriate technology with green process engineering are needed.

Appropriate technology (AT) is a design philosophy first described in 1973 by E.F. Schumacher in his book Small is Beautiful. According to Hazeltine and Bull in their 1999 book â??Appropriate Technology: Tools, Choices, and Implicationsâ?, it refers to â??technological choices and applications that are small scale, decentralized, labor-intensive, energy efficient, environmentally sound, and locally controlledâ? (Hazeltine, 1999). AT is simply technology suitable for a specific region, designed to meet specific needs of certain individuals or communities. It differs from industrial scale processes in the sense that AT is specifically intended to be used in rural or underdeveloped regions. AT is low-cost, small-scale, easy to construct, and can be operated by individuals with limited formal technical education. The purpose of AT is not to reproduce industrial technology on a small scale; instead, it is to design specific solutions based upon the resources available in a given region or for a given community.

It is our assertion that appropriate technology is the most viable option for solving the global problem of waste plastic accumulation in developing regions. Therefore, we will make the case that through the utilization of a low-cost easy to use processor for converting waste plastic to fuel oil, a sustainable solution for reducing the volume of waste plastic entering the ecosystem can be achieved. We will address the challenges for implementing such a strategy and discuss how these challenges can be met.