Two-stage plasma process for converting waste into fuel gas and apparatus therefor

Abstract

A two-step gasification process and apparatus for the conversion of solid or liquid organic waste into clean fuel, suitable for use in a gas engine or a gas burner, is described. The waste is fed initially into a primary gasifier, which is a graphite arc furnace. Within the primary gasifier, the organic components of the waste are mixed with a predetermined amount of air, oxygen or steam, and converted into volatiles and soot. The volatiles consist mainly of carbon monoxide and hydrogen, and may include a variety of other hydrocarbons and some fly ash. The gas exiting the primary gasifier first passes through a hot cyclone, where some of the soot and most of the fly ash is collected and returned to the primary gasifier. The remaining soot along with the volatile organic compounds is further treated in a secondary gasifier where the soot and the volatile compounds mix with a high temperature plasma jet and a metered amount of air, oxygen or steam, and are converted into a synthesis gas consisting primarily of carbon monoxide and hydrogen. The synthesis gas is then quenched and cleaned to form a clean fuel gas suitable for use in a gas engine or a gas burner. This offers higher thermal efficiency than conventional technology and produces a cleaner fuel than other known alternatives.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a method and apparatus for a two-stage conversion of organic components contained in solid and / or liquid waste, at high plasma temperature, into a fuel gas suitable for use in a gas engine or turbine for the production of electricity or a gas burner for the production of steam, or in chemical synthesis reactions.[0003]2. Description of the Prior Art[0004]Numerous methods have been proposed for the conversion of waste into energy. The most common method is incineration. In incineration systems, waste is typically introduced in a high temperature chamber and reacted with large amounts of air. The process can be one stage or two stages. Whether the incineration process is one stage or two stages, the process always uses large amounts of air, resulting in the production of large amounts of hot off-gas, typically laden with entrained particulates and acid gas components. Thermal energy is typ...

AI Technical Summary

Benefits of technology

The present invention proposes a two-stage plasma process for converting waste into fuel gas in a more efficient and clean way than incineration. The first stage involves vitrifying or melting the inorganic components of the waste and partially gasifying the organic components. The second stage involves completing the gasification reactions and cleaning the fuel gas. The plasma energy serves as both the vitrification and activation energy for the gasification reactions. The process produces a high-quality fuel gas that can be used in a gas engine or turbine for production of electricity or in chemical synthesis reactions. The process is efficient and produces minimal emissions.

Problems solved by technology

This means that significant amounts of electrical energy must be used for dissociation.

Electrical energy is an expensive form of energy and it is important to use it as efficiently as possible.

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