Archive:Disposal of Non-Recyclables in an Environmentally Conscious Way

Waste management systems have evolved from the simple transportation of waste out of residential settlements to recently introduced more complex processes like plasma arc incineration. Only after the 1960s municipal waste management started to improve. Shifting from a purely economic stand-point while planning waste treatment technologies, municipalities started to evaluate the environmental impacts of their choices. This change was brought about by the large environmental damage caused by landfills which could not be overlooked. Some improvements involved the installation of base liner systems in landfills to collect sewage, the development of flue gas scrubbing technology for MSWI (municipal solid waste incinerators), etc. For the first time the aspect of using waste as a resource to make energy was taken into consideration.

Over the past few years, waste management strategies have been greatly supplemented by product related regulation. For example, regulations on packaging, end-of-life treatments and electrical equipment have made the producer responsible for the entire life cycle of the products. Therefore, forecasting the consequences of waste management strategies (environmental, economic and social) has become a highly sophisticated task. The proper disposal of non-recyclable substances is vital to the environment as well as the society. Environmental protection has aroused world wide concern since the end of the 1990s. Political authorities have amended their environmental protection norms and industrial producers are re-designing their manufacturing plants to avoid, collect, sort and recycle waste. Consumers have become selective in choosing environmentally friendly products.

This report will study the waste management strategies based on the statistics for the City of Toronto. Recently, the City has been firmly focussed on diverting waste sent to Michigan landfills to a method that takes environmental, societal and economic aspects into consideration. This is in lieu of the Toronto-Michigan Contractexpiring at the end of 2010. The alternatives evaluated were landfilling of waste in Michigan, incineration, and plasma arc gasification and vitrification.

Project Information

Section 1 Group 15

S. Dhamija (Saguna)
D. Campbell(Dan_Campbell)
H. Panesar (harpreet)
S. Shalchian (shervin.shalchian)

T

Highlights and Recommendations

Functional Analysis
Functionally, landfills and incinerators can both be scaled to handle the city of Toronto's waste requirement which is 3,825 tons per day [1]. Plasma arc gasification is currently in its preliminary testing stages and most data is based on research scaling estimates. The only plasma arc gasification facility in Canada is run by the Plasco Energy Group based in Ottawa. It is operating at one tenth its maximum capacity of 100 tons per day. Thus it would not be unreasonable to doubt the functionality of scaling the plasma arc gasification model run in Ottawa to meet the city of Toronto's requirements. To asses plasma arc gasification as a viable alternative, it is assumed that such scaling is infact possible.

Streamlined Lifecycle Assessment (SLCA)
The process implementation stage and the primary process operation stage contribute most to the environmental impacts of all the alternatives. The streamlined life cycle assessment (SLCA) demnostrates that incineration has the least impact in the area of material use, energy use, solid waste and gaseous waste. This is because of its relative ease of implementation as compared to landfill where the ecology of the exisiting land has to be destroyed before construction [2]. Plasma arc gasification's advanced technology is also difficult to implement as compared to incineration. However, in the primary process operation stage, plasma arc gasification proves to be most environmentally friendly due to its maximum energy production and marketable solid outputs. Although plasma arc gasification has a definate advantage during the primary process operation stage, its drawbacks during its impelementation cannot be ignored.

Cost Analysis
The most feasible solution to disposal of Toronto’s non-recyclable waste is landfill. Currently, Toronto pays Michigan $33 per tonne of waste tipped in the Carleton landfill. This cost will decrease further if Toronto's wase is locally landfilled. If an incineration plant is constructed to handle Toronto’s waste, it will cost $80 per tonne of waste whereas, if a plasma arc gasification plant is built it will cost $55 per tonne of waste. The highest contributor to the cost of incineration is the purchase of air purification equipment as well as the maintenance costs.

Economic Input-Output Life Cycle Analyses (EIOLCA)
Incineration contributes heavily to the emissions of SO₂,CO and gases that cause an increased global warming potential (GWP). Plasma arc gasification also impact the environment with the large about of lead(Pb) emissions. To further explore the impacts of incineration and plasma arc incineration, an in-depth process analysis was carried out. Landfill was not included as a part of this analysis due to the lack of published information on its life long emissions. The results from this analysis proves plasma arc gasification to be a much cleaner process as compared to incineration. However, comparing landfill and plasma arc gasfication EIO-LCA tables, it can be seen that landfill is a cleaner process. Societal Analysis
Societal analysis plays a major role in the successful completion of any project. It is clear that all three waste disposal processes cause people living in the vicinity discomfort at different levels but plasma arc incineration seems to have the least resistance from the public. Public is less aware of plasma arc incineration’s new technology and this avoids pre-conceived notions about its negative impacts as in the case of landfills and incineration plants. This leads to the belief that plasma arc incineration technology might face lesser public opposition and hence be easier to implement. It is common belief that landfills are considered to be a waste of arable land.[3] The use of incinerators is a controvertial because of issues such as emissions of gaseous pollutants and escaping gas particles that may contain small quantities of heavy metals. [4] Incineration and landfills can gain public acceptance only if the concentration of low volatile organic compounds can be guaranteed.

Details

Streamlined Lifecycle Analysis (LCA)

Background Information

The environment impacts of a product through out of its life cycle are estimated by using the Environmental Life Cycle Assessment (LCA) method. Although the Life cycle Assessment method gives a precise description of the environment impacts of the product, it is not feasible because of the time it requires and the amount of data that needs to be gathered. A method that can be used to solve the problems mentioned above is Streamlined Life Cycle Assessment (SLCA). This method allows companies to identify and evaluate the environmental impacts of their products and compare different alternatives.

Steamlined Life Cycle Assesment
	Material Use			Energy use			Solid Waste			Liquid Waste			Gaseous Waste			Total
Alternatives	L	I	P.A I	L	I	P.A I	L	I	P.A I	L	I	P.A I	L	I	P.A I	L	I	P.A I
Resource Acquisition	3	3	2	2	3	3	4	3	2	4	3	3	3	2	2	16	14	12
Process Implementation	2	3	2	1	3	2	2	3	3	4	4	3	1	3	2	10	16	12
Primary Process Operation	3	2	3	2	1	4	3	3	4	3	3	3	1	2	2	12	11	16
Secondary Process Operation	4	3	2	3	3	4	4	3	2	3	4	4	0	3	3	14	16	15
Refurbishment, Recycle, Disposal	3	1	3	3	2	1	4	2	3	2	4	3	1	3	3	13	12	13
Total																65	69	68

The results from Streamlined Life Cycle Assessment differ by a small score count. This is because this analysis deals with scores that are highly subjective and arbitrary. Thus, these scores are relatively the same for all three alternatives. Therefore, the Streamlined Life Cycle Assessment is not a great tool to compare these three alternatives. The Economic Input Output Life Cycle Assessment and Cost analysis was performed to find out which alternative is ranked the best.

Cost Analysis

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The cost analysis is a crucial portion since it is the basis to conducting an Economic Input-Output Life Cycle Assessment (EIO-LCA). This is because the values inputted into the EIO-LCA are those obtained from the cost analysis. These values can be divvied into two separate costs. Direct costs are those expenses that are directly related to the plant or landfill site. Indirect costs are expenses that are related to any other network other than the plant or landfill site (ie. social costs, health care costs etc.). Negative costs are those that generate profit for the company (ie. selling energy). Costs within direct costs are divided into three sections: Capital Costs which are fixed costs, Operational Costs which are costs depended on the life of the plant or site and Refurbishment, Recycling and Disposal Costs which are costs needed once the plant or plant’s major components have completed their service.

Incineration vs. Landfill

The constructing, operation, maintenance and other direct costs are about four times greater for an incineration plant than a landfill site. Such a difference is created due to the technology required to run an incineration plant. Because of the pressure build-up from anti-incineration groups, incinerator plants are forced to purchase and maintain a state-of-the-art air filtering system [www.oneia.ca/files/EFW%20-%20Knox.pdf] . This is seen from the air purification equipment and the commercial machinery repair and maintenance costs. Thus it is because of the opposition created from such groups that has increased the large difference in direct costs, this is seen from the table above as excluding the two sectors mentioned would result in a similar amount of direct costs.

Even though landfills do release more furans and dioxins [www.oneia.ca/files/EFW%20-%20Knox.pdf], the health risks caused by incinerator plants emit a greater amount of sulphuric dioxides which causes asthma and other respiratory illnesses [1]. Thus, using an incinerator uses a bigger portion of the overall healthcare budget than using a landfill site to dispose the non-recyclable waste.

However, an incinerator plant generates a larger profit than a landfill site. This is mainly because a greater amount of energy is released by burning the waste rather than letting it settle in one spot collecting the methane is emits. Furthermore, a landfill will collect only about 30% of the total methane produced [2]. However, when comparing to a conventional power plant, incineration is seen as an inefficient way of producing electricity [3]. Despite the greater profit made by an incinerator plant, a landfill site will cost about four times less over a ten year due to its relative inexpensive direct and indirect costs.

Plasma Arc Incineration (PAI) vs. Landfill

A plasma arc incineration plant generates about three times the amount of direct costs than a landfill site. This is due to the advanced technology being used for a plasma arc incinerator plant. The manufacturing of such equipment can be expensive and with beta testing and research in progress, direct costs are increased by a substantial amount.

A plasma arc incinerator plant also uses a major portion of the overall health care budget. This is due to the greater amount of SO2 released. Note that even though an EIO-LCA refers back to the cost analysis, this specific indirect cost is dependant on the EIO-LCA as it presents the gaseous fumes released and thus gives an estimate on how big of a roll each alternative respectively plays on respiratory illnesses. Because this is a comparative analysis, this figure is used to show which alternative has a bigger impact on healthcare costs in money value.

A great advantage to using a plasma arc incinerator is the profit it makes from selling generated power. Even though a large portion of the budget is contributed towards the high end technology used for PAI, the income compensates a major portion of its expenses. It is because of this large income that presents PAI as a better solution than incineration according to this analysis. Nonetheless, the total cost for a plasma arc incinerator plant is about three to four times that of a landfill site.

EIOLCA

The majority of environmental impacts for the disposal methods explored occur during their use phases. These impacts cannot be tracked well using EIOLCA methods. As such, a hybrid EIOLCA method was employed to compare disposal methods, supplementing available EIOLCA data with data for direct emissions occurring during the use phase. EIOLCA data was found for implementation and disposal costs for each type of facility, and for economic activity during usage phases.

Landfill

Before a landfill is constructed, the suitability of a location is evaluated through studies of local geology, transportation costs, and societal factors. Environmental impacts are incurred for these studies primarily through power generation for offices. Land must then be cleared and landscaped before a liner is installed to contain leachate. Machinery for moving and compacting waste in the landfill is then purchased. As waste is added in layers it is covered with soil, and once capacity for a section is reached, wells for landfill gas and leachate are installed. Landfill gas recovery and power generation equipment is then installed. Trucking waste to the Carleton Farms landfill in Michigan creates significant air emissions. Direct air emissions from a landfill are primarily methane and carbon dioxide, the proportion of which varies depending on the efficiency of landfill gas recovery.

Incineration

An incineration plant requires a large capital investment in process equipment, including material handling equipment, incineration vessels, flue gas scrubbers, and power generation equipment. Throughout the life of a plant, periodic maintenance is performed. Decomissioning costs include demolition, recovery of scrap metals and disposal of residual solid wastes.

Plasma Arc Gasification and Vitrification

A plasma arc plant involves an even greater capital investment than incineration for assets of a similar nature. Decommissioning costs similar to incineration are also incurred at the end of plant life. Throughout the life of the plant numerous valuable by-products are sold, including aggregate from slag, and sulphur for fertilizer production.