Plasma based waste treatment and energy production

Abstract

During the past centuries, industrial processes and energy conversion plants have shown no or little care for environmental quality. The result is a huge accumulation of pollution and hazardous by-products, left as a heritage for the present and future generations. Recuperation of by-products or thermal energy is not only motivated by cost saving, but also by resource saving considerations. Environmental awareness is more than staying within the lines of the existing regulations.By the application of a plasma based system to a wide range of possible feedstocks which are CO 2 neutral, a clean syngas of high caloric value is produced from the organic substances simultaneously with a non-leachable vitrified lava from the inorganic substances. The results will provide the advanced technology for the environmentally friendly treatment of hazardous wastes, biomass and low grade fuel. The driving force behind the task is to give priority to environmental quality at affordable costs. Thus, the investigation of ways to increase the efficiency of the process is very important. A plasma based remediation system is the only technology that prevents undesired pollution in the by-products and end product (such as syngas or other gases). The problem to be solved is twofold: recuperate clean energy from waste and renewables without pollution at affordable costs. Such a technique fulfils the objectives of sustainable development.Today, one of the main reasons that restricts the use of plasma based methods is the cost of electrical energy. The crucial element is the plasma torch performance. Hence, the physics of modern plasma torches is addressed in detail. The optimistic scenario holds the promise to provide 10-15% of the energy needs for the European Union (EU). Thus, the investigation of ways to increase the efficiency of the process is very important.

Waste Gasification by Thermal Plasma: A Review

“…RF or MW plasmas don't have electrode erosion but have low energy efficiency, about 40 % to 70 % (60 % to 90 % for arc torches) [73]. From this review, it clearly appears that the main plasma torch technology applied to waste gasification is the DC technology which is used in all the studies excepted in [32,85,90] In [66], one can notice that the H 2 and CO yields are strongly linked to the original composition of the waste treated and can vary, with the same experimental conditions, from 49.4 vol% to 64.4 vol% for H 2 and from 24.8 vol% to 36 vol% for CO in function of the nature of the waste. It is important to keep in mind that the H 2 and CO rates in the crude syngas is strongly linked to the oxidizing agent injected and/or the moisture content in the waste treated.…”

“…France [78], Czech Republic [71,[79][80][81][82][83][84] and Russia [85][86][87]. The product can be injected in solid form [71] or liquid [78], from a pyrolysis cycle or crushed.…”

“…Due to the absence of complete results in the scientific literature, only few representative plasma gasification processes have been compared [25,32,74,81,85,92,94].…”

“…Some non-transferred 3-phase AC plasma torches used for waste, biomass or coal processing have been described by the IEEP team (Institute for Electrophysics and Electric PowerRussian academy of sciences) in several papers [32,85,86,[105][106][107][108][109][110][111][112]. The electrodes consist of water-cooled copper tubes, and the movement of the arc attachment using the self-magnetic field of the current in the electrodes (rail gun effect) minimizes erosion.…”

Development of a laboratory scale air plasma torch and its application to electronic waste treatment

“…Moustakas et al (2005; reported successful installation and testing of a demonstration 50 kg/h pilot plant with plasma vitrification system to treat industrial hazardous waste, as well as further performance optimization. Tendler et al (2005) presented a review and assessment of the hot temperature discharge physics and processing of the waste, including vitrification, gasification, power generation and environmental advantages. More recently, Hong et al (2006) and Bang et al (2006) developed microwave plasma torches to produce high temperature plasma flame.…”