A Novel Application of Waste Tyres & plastics as Reburn Fuels for NOx Reduction in Large Scale Combustion Systems

废旧轮胎和废塑料代表着英国和欧洲每年产生的大量需要处理的垃圾。英国每年产生的废旧轮胎数量为40万吨，总计3000万个轮胎。在欧盟，每年生产超过250万吨轮胎和1920万吨塑料。目前，产生的绝大多数轮胎和塑料废物被填埋，这是对资源的一种重大浪费。最近的欧共体废物填埋指令(1999)规定，到2006年，禁止在填埋场使用完整轮胎和碎裂轮胎的最后期限。此外，欧盟已将废旧轮胎列为“优先废品流”。塑料也被视为优先的废物流，欧共体包装和包装废物指令(1994)和欧共体废旧电子电气设备(WEEE)指令(2000)为废塑料设定了雄心勃勃的回收和回收目标。此外，欧共体大型燃烧厂指令(2001/80/EC)适用于包括发电站、水泥窑和钢基熔炉在内的各种工厂，并为减少NOx设定了严格的排放目标，例如，1987年后建成的现有工厂被要求在2008年前将NOx水平降低到500毫克/立方米以下，2016年后降低到200毫克/立方米以下(对于工厂和GT；500兆瓦)。虽然使用现有的低NOx燃烧器可以降低NOx水平，但人们担心，将NOx降低到新的EC大型燃烧工厂指令所要求的低水平的改造系统可能无法以合理的成本实现。这项建议旨在通过实际的大规模实验方法，研究使用轮胎和塑料这两种废气作为潜在的再生燃料来减少大型燃烧工厂的NOx。轮胎和塑料的高挥发性和反应性提供了工艺优势，因为与煤炭相比，所需的燃尽时间更短，这将缓解现有大型工厂翻新再燃技术的压力。实验将使用200千瓦的中试反应堆进行。此外，由于废物焚烧与公众对环境问题的负面看法有关，其中一部分工作将涉及全面的排放调查，包括酸性气体、微粒、重金属和二恶英。总之，拟议的工作将提供新的信息，并有助于制定将该技术改造到现有工厂的战略。

Used tyres and waste plastics represent enormous tonnages of waste generated in the UK and Europe each year requiring disposal. Scrap tyre arisings in the UK are 400,000 tonnes per year amounting to 30 million tyres. In the EU, more than 2.5 million tonnes of tyres and 19.2 million tonnes of plastics are generated each year. Currently the vast majority of the tyre and plastics waste generated is landfilled representing a major waste of a resource. The recent EC Waste Landfill Directive (1999) sets a deadline for the banning of whole and shredded tyres from landfill sites by 2006. In addition, the European Union has recognised scrap tyres as a 'priority waste stream'. Plastics are also regarded as a priority waste stream and the EC Packaging and Packaging Waste Directive (1994) and the EC Waste Electrical and Electronic Equipment (WEEE) Directive (2000) set ambitious recycling and recovery targets for waste plastics.Further, the EC Large Combustion Plant Directive (2001/80/EC) applies to a wide range of plant including power stations, cement kilns and steel based furnaces and sets stringent emissions targets for NOx reduction, for example for existing plant built after 1987 plants are required to reduce NOx levels to below 500 mg/m3 by 2008 and below 200 mg/m3 after 2016 (for plants >500MWt). Whilst reduced NOx levels can be obtained by using existing low NOx burners, there is concern that retrofit systems to reduce NOx to the low levels required of the new EC Large Combustion Plant Directive may not be achievable at reasonable cost.This proposal seeks to investigate the use of two waste streams, tyres and plastics, as potential rebum fuels for the reduction of NOx from large combustion plant by way of a practical large scale experimental approach. The high volatility and reactivity of the tyres and plastics give a process advantage due to the shorter bum-out time required compared to coal which would ease the pressure of retrofitting rebum technology on existing full scale plant. Experiments will be undertaken using a 200kWth pilot-scale reactor. In addition, since wastes combustion Is associated with an adverse public perception of environmental concerns, a section of the work will involve a full emissions survey, including acid gases, particulate, heavy metals and dioxins. All together, the work proposed will provide new information and help to develop a strategy for the retro-fit of this technology to existing plant.