Energy recovery from waste in India:an evidence-based analysis

The uptake of Waste-to-Energy (WtE) in India has not been successful and the majority of plants have failed to sustain operations. There is a lack of detailed on-the-ground research examining the causes of plant failures and the issues regarding the WtE supply chain. Thus, this study set out to identify how WtE practices in India can be improved by gathering and evaluating empirical evidence. Local government officers, industry practitioners and academics involved in waste management in India were consulted. Quantitative data were collected on three case study plants: an incinerator, a gasification plant and a plant co-firing waste with coal. The gathered information was evaluated by making a comparison with two European waste incinerators. The major problem with WtE in India has typically been perceived to be poor source segregation; however, the case study plants highlight that severe contamination has been occurring during transport and storage. In comparison to the European incinerators, the WtE plants in India had a low capital cost (around 1–2 million €/MW), but total particulate matter emissions were a hundred times higher, ranging from 65 to 75 mg/Nm3. We conclude with recommendations for delivery contracts, financial incentives and regulations on dumpsites, ash disposal and stack emission measurements

Temperature Measurement in WTE Boilers Using Suction Pyrometers

The temperature of the flue-gas in the post combustion zone of a waste to energy (WTE) plant has to be maintained within a fairly narrow range of values, the minimum of which is prescribed by the European Waste Directive 2000/76/CE, whereas the maximum value must be such as to ensure the preservation of the materials and the energy efficiency of the plant. A high degree of accuracy in measuring and controlling the aforementioned temperature is therefore required. In almost the totality of WTE plants this measurement process is carried out by using practical industrial thermometers, such as bare thermocouples and infrared radiation (IR) pyrometers, even if affected by different physical contributions which can make the gas temperature measurements incorrect. The objective of this paper is to analyze errors and uncertainties that can arise when using a bare thermocouple or an IR pyrometer in a WTE plant and to provide a method for the in situ calibration of these industrial sensors through the use of suction pyrometers. The paper describes principle of operation, design, and uncertainty contributions of suction pyrometers, it also provides the best estimation of the flue-gas temperature in the post combustion zone of a WTE plant and the estimation of its expanded uncertainty