Process and System For Manufacturing Improved Heat Value Solid Fuel From Solid Waste

Abstract

A method for manufacturing solid fuel, including estimating a heat value for at least a portion of a combustible waste stream. At least one type of combustible polymer is added to the combustible waste stream as needed to raise the estimated heat value of the portion of combustible waste stream to a desired heat value. The combustible waste stream is heated and mixed with the at least one type of combustible polymer to increase the structural integrity of a solid fuel formed from the mixed combustible waste stream and to increase the hydrophobic properties of the solid fuel. The heated and mixed combustible waste stream is pressed into objects of solid fuel, such as briquettes, which are substantially hydrophobic.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a Continuation-In-Part of U.S. patent application Ser. Nos. 13 / 090,349 and 13 / 090,356 filed Apr. 20, 2011 and claims priority to U.S. Provisional Application Nos. 61 / 325,941 and 61 / 325,946 filed Apr. 20, 2010 and U.S. Provisional Application No. 61 / 620,939 filed Apr. 5, 2012.FIELD OF THE INVENTION[0002]This invention relates to the conversion of solid wastes, such as Residential Solid Waste (RSW) and / or Municipal Solid Waste (MSW), to a solid fuel that has an improved heat value and stability, preferably for use as a fuel supplement.BACKGROUND OF THE INVENTION[0003]While recycling of MSW has increased dramatically over the last 15 years through incentives and community education, MSW itself has grown in volume during that same period to over 220 million tons in North America alone. Recycling has increased 42% during this period, but has plateaued at approximately 30% of the total waste. This problem has affected munici...

AI Technical Summary

Benefits of technology

The present invention relates to a method of making a solid fuel that is impervious to water, resistant to leaching, easy to handle, and stable without degrading. The method involves removing non-combustible materials from a waste stream of solid materials and estimating a heat value for the remaining combustible materials. Combining this combustible material with a type of combustible polymer raises its heat value and increases its structure and hydrophobic properties, resulting in solid fuel objects with a desired shape that are stable and hydrophobic.

Problems solved by technology

This problem has affected municipalities, states and the federal government, from a financial, as well as capacity of volume perspective.

This presents significant problems for municipalities including present landfills are at or near capacity, and they are faced with significant post-closure costs and maintenance.

There is a lack of new land for landfilling and, even where land is available, permitting processes are expensive and time-consuming, and the social issue of not in my backyard (NIMBY) exists.

As EPA regulations become more detailed and geared to reducing air pollution, the WTE field is faced with a very costly solution of emission reduction.

Typically specialized bag collectors and scrubbers are installed at a very steep capital expense.

WTE facilities have had limited success in reducing emissions, and enhancing BTU values.

These factors render the RDF a very ineffective low value fuel.

Although this produces a limited amount of methane, the reduction of MSW to a landfill is 0%, and does not provide front end value.

The process is effective is producing economic value, but does not optimize waste reduction.

Plasma arc is still in development stage and has limited commercial success.

While various conventional processes use mainly light and organic fractions of the waste stream, the majority of the waste stream still needs to be landfilled.

The average pelletizing machine is typically limited to 3-5 tons per hour of production.

To achieve an effective commercial production rate of 25 tons per hour, a minimum of 5 systems would be deployed, resulting in an extremely capital intensive operation.

Pelletizing also produces pellets that are subject to degradation and structural changes to the pellet.

To prevent moisture absorption, the majority of pellets need to be siloed, which requires capital expenditure for the plant.

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