Through the years, especially in the most recent few decades, the use and creation of biomass has been under study and practice as to maximize how much it can benefit society as well as the planet as a whole. Biomasses are being used around the world for a magnitude of purposes. So what exactly is a biomass and what can they be used for? Biomasses are any materials and matters derived from living organisms, such as plants, animals or in the case of the focal biomass for this research study, human beings (What is Biomass?, 2011). When the discussion of biomass arises, the typical materials that come to mind are things such as corn, sugar cane or algae, but humans are also responsible for producing biomasses that nothing else in nature can: municipal solid waste. Biomass of Choice: Municipal Solid Waste
Municipal solid waste (MSW), otherwise known as garbage can come from nearly any everyday item, such as packaging from various products, paper products, plastics, metals, etc. Americans produced over 250 million tons of waste in the year 2012 alone. Thankfully, through the help of recycling and repurposing of materials, 34.5% of those wasted materials were spared from being placed in a landfill and polluting the earth (Municipal Solid Waste, 2012). There are three possible ultimate outcomes for where municipal solid waste ends up. These facilities that treat and manage the waste are places such as landfills, energy recovery facilities, and transfer stations. Landfills are the most well-known outcomes and typically are the final resting grounds for municipal solid wastes. Landfills are designated areas of land filled with garbage for retaining, lined with an eco-friendly material to preserve the ground and surroundings of the garbage. Energy recovery facilities take what materials they can collect that are unrecyclable and convert the waste into various forms of energies such as fuel, electricity, etc. which proves very helpful for the environment and helps in reducing the amount of waste going into landfills. Transfer stations are used for unloading garbage collection vehicles and hold these collections to be later loaded onto larger vehicles for further transportation (Municipal Solid Waste, 2012). A total of over 86 million tons of materials were kept from being put into landfills within just one year through the methods of recycling and composting. By doing so, a total of nearly 168 million tons of CO₂ were saved from being emitted into the atmosphere (Municipal Solid Waste, 2012). In the graph below, the breakdown of the percentage of materials used for recycling and composting can be seen. Figure 1. Percentage of waste products recycled and spared from landfills in 2012 (Municipal Solid Waste, 2012)
The resources consulted for this research study were quite informative and elaborate in discussing all aspects associated with municipal solid wastes and landfills. Based on the sources, an increasing total of over 250 million tons of municipal solid waste is generated each year. This waste has a variety of different final destination it may reach. Whether it is combusted or compressed, this everyday garbage can be converted into fuels through several different processes. But these processes cannot happen just anywhere, there are many regulations required to be met based on land, location, climate, etc. These areas as well as the operators of these landfills are closely monitored and inspected regularly, as safety for human and environmental exposure is the biggest concern. Each of the sources ranged in age from the mid-1990s to the modern day. It was important to research the changes seen over the years and how the amount of consumption has grown as well as the number of landfills increased as to accommodate the ever-increasing amount of trash being generated. It’s a natural thought that municipal solid waste, garbage, would only have negative effects on the environment but the sources disproved that erroneous thought thoroughly. This information can be reviewed more entirely in the following paragraphs. Requirements for Location It is important to know that society needs landfills, but it’s crucial that these facilities are operated correctly and in the safest and cleanest way possible. When it comes to maintaining and locating a new landfill site, very specific and strict criteria apply. The most important factor to consider when constructing and allocating a new municipal solid waste landfill is what hazards and dangers do the waste materials being put into the ground pose to the environment. Regulations and restrictions go far deeper than just finding an area of land to use as a landfill site. It is so crucial to the environment and all human being’s health that landfill operators follow the safety criteria put in place by the federal government.
To maximize safety and to follow all the regulations as part of the Clean Air Act, landfill owners and operators may not construct their sites near environmentally and socially sensitive areas and should consider constructing their facilities and temperate areas. These types of areas are airports, wetlands and marshes, seismic impact zones, floodplains, fault areas and other areas deemed unstable. The ideal place for a landfill would likely be a dry, open area like a plain, since it’s such a large area far from the restrictions listed above. It would be nearly impossible to cover the entirety of the rules and regulations for all landfills in such a short period, but for this research we will merely scratch the surface of what it means to have a safe landfill.
Landfills built near airports must be at least 10,000 feet, just under two miles, away from the end of a landing strip. In the case of wetlands, for obvious reasons, the grounds would be too moist and unsettled to create a safe and stable dump site. Sites with high moisture are prone to sinking or sliding which would ultimately dislodge the materials of the landfill and cause pollution to the ground. Much like wetlands, floodplains are also off-limits for many of the same reasons. If an area has experienced a flood within the last century, it is not allowed to be used for municipal solid waste purposes (Criteria for Solid Waste Disposal Facilities, 1993).
Land that sits on faulty areas as well as seismic impact zones may not be home to a landfill due to the unstable ground. If dump sites do for some
reason become approved to be put into these sort of land areas, the landfill must be designed to withstand the negative effects of ground shifting that may come with natural disasters such as earthquakes. The final land restriction is the broadest but has been worded in such way as to encapsulate all other criteria that could be assessed when building sites. These areas are generally referred to as unstable areas. These places may have no specific name such as a seismic impact zone or a wetland, but still would be found unreasonable to utilize. These areas may be prone to mud/rockslides, sinkholes, very heavy rainfall, high levels of moisture, and explosion sites (Criteria for Solid Waste Disposal Facilities, 1993).
The reasons each of these areas are considered unfavorable is because any unstable land could cause multiple types of pollutions. Landfill operators are not only told where they can and cannot hold their sites, they are also regulated how they maintain and clean their areas. Municipal solid waste cannot just be put into the ground, covered and forgotten, landfills must be assessed for ground water pollution (testing to see if the waste has seeped into the water used for the public has been in any way harmed), how well it is covered, air quality around the site, how easily accessible the area is, explosive gas emitted from the waste, and vermin.
It’s necessary that landfills be designated to areas out of the way of residencies and in low-access places. Only owners and professionals should access these harmful areas so they need to be out of reach for everyday people. These areas are for federal use only and should under no circumstance be used for personal trash dumping, aside from that, these areas are toxic and dangerous (Criteria for Solid Waste Disposal Facilities, 1993).
It’s strange to think that sites that hold our everyday waste products need to be regulated for cleanliness but this is extremely vital for the environment and our health. One of the biggest safety precautions taken by landfill owners is the composite liner necessary for dumping. These liners are essentially massive sheets covering the entirety of the exposed soil and earth in the landfill hole. These materials are designed to withstand wear
and tear for the trash and are flexible enough to move with the natural shifts of the earth (not including things such as earthquakes or faults) (Landfills, 2014). Like the liner that keeps the earth safe from soil and groundwater pollution, coverings are also needed for all landfills. It is mandatory that landfills be covered at the end of EVERY day of operation with a minimum of six inches of natural earth material such as dirt. Doing so protects the environment from being over exposed to chemical emissions, fire, off-putting smells, loose trash being taken by the wind, pest exposure, etc. This step helps regulate the other criteria necessary for assessment, such as the air quality and what the government call “vectors” or in laymen terms, pests (Landfills, 2014).
Naturally with garbage come things such as flies, maggots, rats and other disease-ridden pests. These organisms are obvious threats if humans are exposed to them and by keeping the areas covered and concealed, the lower the chances of exposure are. The covering of the landfill also reduces pollutants into the air, keeping the quality of the air high. Owners of landfills are regulated depending on which state they reside in when it comes to the burning of waste. Only certain materials may be burned as to keep the air pollution as low as possible (Criteria for Solid Waste Disposal Facilities, 1993).
All landfill owners and operators are required by federal and state laws to keep a log of records of events taken place at their respective sites. Every site is subject to random searches and inspections of the properties and as well as its records. Each worker and owner of these sites are required to complete a certain amount of training before operating and ensure the utmost knowledge of the risks associated with municipal solid waste and to keep operations running as smoothly and efficiently as possible (Criteria for Solid Waste Disposal Facilities, 1993). Method of Production
Typically society considers biomass fuels and energies to be produced from organic, natural resources, but newer technologies are finding ways to convert man-made product waste into energy. According to the California Energy Commission, MSW is one of the three top waste-converted-to-energy
processes. There are several possible ways to go about the conversion process, some of which have been discussed in class. These processes are called mass burn, refuse-derived fuel and energy and pyrolysis, otherwise referred to as thermal gasification.
The most common of the three technologies is mass burn. This process is performed by collecting the untouched waste in landfills, taking the waste to large storage facilities where all the waste is gathered together and large machinery compiles it all together. Large wastes such as refrigerators or ovens are removed from these waste gatherings. This waste is then rerouted to the combustor and fed into a boiler. The heat released from this process is used for the conversion of water to steam which is then used to run steam turbines to generate power. The machinery working through this process can be seen below. Figure 2. Machinery compiling refuse to be converted to fuel (Municipal Solid Waste Power Plants, 2015)
Then there is refuse-derived fuel. This does not look like typical liquid fuel but rather is formed into small pellets. These pellets are the by-product of operations involving the recovery of various resources. This technology sifts out unwanted, incombustible materials like metals and glass. What remaining materials are used as the refuse-derived fuels. There are a few uses for these fuels in various types of boilers such as multi-fuel boilers that burn oil or coal alongside refuse-derived fuels to create energy, fluidized bed boilers and traveling grate spreader-stokers (Municipal Solid Waste Power Plants, 2015).
Lastly, the technology discussed in class, pyrolysis is also used. This process decomposes the organic materials within the waste collection at high temperatures with no exposure to oxygen. This process yields various by-products that can be used for a multitude of purposes, these products being solid remains, liquids and flammable gases which can be used for either boilers like RDFs or combustion generators. The gas given off by this process are then combusted and the collected heat is used to convert water to steam which is then used to power various steam engines (Municipal Solid Waste Power Plants, 2015). This is the main process I would choose to use if
I were to oversee a MSW repurpose plant. This method appears to be the most efficient and environmentally friendly. It uses few resources to process and it yields several beneficial by products that can be used as power. Figure 3. Fate of municipal solid waste, including pyrolysis (Pollution Free Pyrolysis System in Municipal Solid Waste, 2014)
Product Markets around Location
The product markets surrounding municipal solid waste are for things such as plastics or any other possible items that can be recycled or repurposed. Just to put into perspective, plastics comprise around 13% of landfills, or 32 million tons in one year alone. Of this staggering amount, 9% is recycled. Recycled products are manufactured through a specific process: the plastic materials are taken to a collection facility, sorted based on what type of plastic it was, bundled together, then sent off to be broken down. The plastics are then cleaned, broken down into small pieces then again shipped to another facility where they will be melted down and formed into new plastic products such as bottles or plastic packaging (Plastics, 2014).
The market for recycling is increasing and expanding and creating these various repurposed products is creating a more stable and long-term market. There are several benefits associated to buying into the recycling market. By using repurposed products, more trees and other natural resources can be spared, energy is saved tremendously in making recycled products, in fact when recycling aluminum, it takes about 95% less energy than creating aluminum from new, raw materials. Buying recycled reduces the amount of emissions going into the atmosphere and environment, it cuts down the amount of waste going into landfills, and creates more jobs since this market is continuing to expand (Buying Recycled, 2012).
There are many forms recycled products come from and even more purposes for these items. Recycled items are either pre-consumer, post-consumer and recovered materials. Pre-consumer materials are recycled prior to being used by someone, the best example being scrapping paper that are planned to be recycled at a paper mill. Post-consumer materials, as the name implies, are the most common materials most people know of, the products that are
recycled after being used. Recovered materials are a little different. These are materials or byproducts collected from landfills that are repurposed for different means, unlike with pre- and post-consumer materials that are reused as their original intent (Buying Recycled, 2012).
The products within this market are items such as office supplies, clothing, vehicle parts and components, building materials, etc. As far as federal regulations on recycling, many recycled products do not contain only recycled materials, often it’s a combination with virgin materials, these descriptions may not be directly stated but the product will be labeled with a percentage of post-consumer content. It is also required that federal agencies buy recycled items, under the Executive Order #13101 (Buying Recycled, 2012), a step in the best direction for the higher powers of this country. Economic Evidence
As with all biomasses, the costs of producing fuel aren’t exactly cheap. But in many cases, the costs can be off-set depending upon the means of production. Many MSW plants receive revenue via the fuel suppliers who take the fuels, in contrast with typical facilities that are required to buy the fuel for themselves. This money received by the municipal solid waste plants are called tipping fees. These tipping fees and the process by which MSW are converted o fuels are overall much less costly than other technology types (Municipal Solid Waste Power Plants, 2015).
With landfills and municipal solid waste, the discussion of recycling is always brought into play. The recycling market and the field of recycling as well as landfills has been expanding, creating more jobs, reducing the amount of raw materials needed to create products, all of which lowers costs significantly and opens all sorts of job opportunities for Americans.
Some issues related to economics when it comes to waste are household income as well as geography. Depending upon where people live, there are different regulations as to where trash can be taken or dumped or even burned. Higher income households tend to give off more trash, creating more landfill and potentially toxic waste. These household also tend to buy more pre-packed
meals to save time cooking, resulting in a greater number of waste outputs due to the number of containers and packages being purchased, in turn creating more waste to end up in landfills (Beede & Bloom, 1995). Effects on the Environment
Like all fuels, energies created from municipal solid waste have both positives and negatives. Federal and state laws require power plants be safe enough for human and environmental exposure. When fossil fuels are burned, they release chemicals into the atmosphere that are unlike today’s typical chemicals. These emissions are unfamiliar today since the fossils are from so long ago, that the by-product can be highly hazardous to humans. The products MSW’s come from were almost all originally made by trees or other natural organisms, so when they are burned off they are simply just releasing the chemicals they had once been taking in and filtering when they were plants, and for this reason, the emissions don’t effect the environment much since the process basically cancels out (Municipal Solid Waste, 2013).
Obviously, when MSW is converted to a recycled product or burned, it is being saved from a landfill, ultimately improving the environment that way. It is required that these facilities such as power plants be tested regularly as to ensure the utmost safety for human beings and the environment (Municipal Solid Waste, 2013).
Summary and Conclusion
Biomasses as fuels are helping restore the earth back to the beautiful, clean planet it should always be. It’s typical to think of different types of plants as being the only biomasses that could produce fuel, but this is a misconception. Using municipal solid waste to generate fuels is helping the economy, various product markets, and the environment. The bones of chicken we drop in the trash after dinner, the newspaper we toss out when we finish the crossword puzzle, even the old pair of sneakers that just have too many holes in them, can one day go from your garbage can to being processed and used to power a steam turbine.
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