Plasma reactor, gasification

Gasification of waste plastics in a plasma reactor and the application of the high calorific gas produced for production of electricity, followed by using waste heat from the turbine for steam generation, has been presented by German inventors [50]. There is no information about process efficiency and the main advantage of the solution is the possibility of using various feed compositions. 

Plasma gasification is a generic-type process that can accommodate virtually any input waste material in as-received condition, including liquids, gases, and solids in any form or combination. Also, moisture content is not a problem. Liquids, gases, and small particle-size waste materials are very easily and efficiently processed. Bulky items, such as household appliances, tires, and bedsprings, can also be readily accommodated without loss of destruction efficiency. The reactor vessel and waste feed mechanism are designed for the physical characteristics of the input waste stream. Even waste materials such as low-level radioactive waste can be processed to reduce the bulk and encapsulate the radioactive constituents to reduce leachability. 

As a result of this effort, industrial plasma torches have been developed which can be utilized for high temperature processing of a variety of materials. EnerSoI has successfully applied plasma torches in multiple reactor systems for the gasification of materials. 

The distinguishing characteristic of non-plasma and plasma methods of gasification is that the products are different the non-plasma conventional carbonization process yields gas and tar plasma processes yield gas and soot. Based on the representative data collated for hvab coal in Table 17 it is inferred that the gas from carbonization is richer in methane, the chief component of natural gas and the preferred product the gas from plasma is richer in acetylene. In most of the plasma methods collated in Table 17 the gas temperatures were 1300 K or more and any methane formed would readily decompose to yield acetylene. Clearly, in-so-far as the plasma formation of methane is concerned the temperature region of 700—1000 K needs to be investigated. Her 60 Hz discharges, with or without electrodes, in reactors heated to the desired temperature may be advantageous. 

Lemoine A, Jurewicz J. Gasification of biomass in plasma spouted bed reactor. Inti. Symposium on Plasma Chemistry, Prague, Czech Republic, 1999. 

Based on the type of thermal destruction process selected, there are several different commercial designs and configurations of the reactor that have been utilized for a particular application. Some of the most commonly used technologies include rotary kilns, starved air incinerators, fluidized beds, mass-bum incinerators, electrically heated reactors, microwave reactors, plasma, and other high-temperature thermal destruction systems. Recent advances include gasification and very high temperature steam reforming. 

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