Energy From Waste Facilities Research Articles

Element composition and mineralogical characterisation of air pollution control residue from UK energy-from-waste facilities

Air pollution control (APC) residues from energy-from-waste (EfW) are alkaline (corrosive) and contain high concentrations of metals, such as zinc and lead, and soluble salts, such as chlorides and sulphates. The EPA 3050B-extractable concentrations of 66 elements, including critical elements of strategic importance for advanced electronics and energy technologies, were determined in eight APC residues from six UK EfW facilities. The concentrations of Ag (6–15mg/kg) and In (1–13mg/kg), as well as potential pollutants, especially Zn (0.26–0.73wt.%), Pb (0.05–0.2wt.%), As, Cd, Cu, Mo, Sb, Sn and Se were found to be enriched in all APC residues compared to average crustal abundances. Results from a combination of scanning electron microscopy with energy dispersive X-ray spectroscopy and also powder X-ray diffraction, thermal analysis and Fourier transform infrared spectroscopy give an exceptionally full understanding of the mineralogy of these residues, which is discussed in the context of other results in the literature. The present work has shown that the bulk of the crystalline phases present in the investigated APC residues include Ca-based phases, such as CaClxOH2−x, CaCO3, Ca(OH)2, CaSO4, and CaO, as well as soluble salts, such as NaCl and KCl. Poorly-crystalline aragonite was identified by FTIR. Sulphur appears to have complex redox speciation, presenting as both anhydrite and hannebachite in some UK EfW APC residues. Hazardous elements (Zn and Pb) were widely associated with soluble Ca- and Cl-bearing phases (e.g. CaClxOH2−x and sylvite), as well as unburnt organic matter and aluminosilicates. Specific metal-bearing minerals were also detected in some samples: e.g., Pb present as cerussite; Zn in gahnite, zincowoodwardite and copper nickel zinc oxide; Cu in tenorite, copper nickel zinc oxide and fedotovite. Aluminium foil pieces were present and abundantly covered by fine phases, particularly in any cracks, probably in the form of Friedel’s salt.

Energy from Waste Facility at Lakeside, London, UK—An Economic and Sustainable Solution to Waste Management

The Lakeside Energy from Waste (EfW) plant is a state-of-the-art facility to convert household, commercial and industrial waste into electrical energy by utilising the heat energy generated from an incineration process to power a super-heated steam turbine. The plant is situated to the west of London, UK, and is incorporated into the existing waste handling strategies in the area. EfW facilities are subjected to very stringent planning processes and have always demanded a high level of architectural presence to satisfy these requirements. Therefore the process equipment is placed inside a large open-spaced steelwork framed shell. This requirement generated a number of structural design and construction challenges for the steelwork frame, including the provision of hybrid columns and large-span curved cellular roof beams. The EfW process requires a continual supply of waste material. In order to facilitate the required volume of material, it is necessary to form a bunker structure within the ground and to extend the walls to the elevated tipping hall floor. Construction of this deep bunker in poor ground conditions necessitated the use of secant piles and innovative slip-form techniques.

Distributed or centralised energy-from-waste policy? Implications of technology and scale at municipal level

Energy-from-waste (EfW) policies can provide an essential part of landfill diversion and climate change strategies. Many UK waste disposal authorities (WDAs) are currently deciding which energy-from-waste policies are most suitable for their respective municipal areas. Such decisions are challenging since the environmental, economic and social implications of any EfW policy must be fully considered, now that planning guidelines require a full Sustainability Assessment. More specifically, WDAs must identify suitable site locations for facilities, and the optimal scale and number of facilities. This paper reports the results from a study that has developed and appraised EfW policy options using Geographical Information Systems and Multi Criteria Analysis modelling. These methods were used to evaluate and compare the impacts of several EfW strategies in the UK administrative areas of Cornwall and Warwickshire. Different strategies have been defined by the size and number of the EfW facilities, as well as the technology chosen, which includes conventional incineration and advanced thermal treatment. The overall conclusion of this work is that distributed small-scale EfW facilities score most highly overall on the chosen decision criteria and that scale is more important than technology design in determining overall EfW policy impact.