Fundamental study of biofuel combustion: flame stabilisation and emissions using advanced optical diagnostics

在世界范围内，能源转换目前以化石燃料的燃烧为主。发电和运输是主要的能源消耗者，对大气中的二氧化碳、氮氧化物和颗粒物排放有很大贡献。公众越来越多地意识到颗粒物对健康的潜在影响。这包括患癌症、哮喘的风险更高，以及可能导致神经退行性疾病(例如阿尔茨海默病)。在英国，燃烧过程中的颗粒物(PM)是造成城市空气质量差的重要因素；据报道，每年有超过2.5万人死亡可归因于长期暴露在人为颗粒物空气污染中。根据DEFRA的报告，糟糕的空气质量是英国公共健康面临的最大环境风险，估计每年造成27亿GB的生产力损失。空气污染还会破坏自然环境，导致土壤和水道酸化。一个显而易见的解决方案可能是用电动汽车取代汽车，然而，这项技术受到续航里程、充电时间和电池成本的限制--目前全球还没有足够的基础设施来直接取代内燃机驱动的汽车。另一个互补的解决方案是寻找为减少NOx和颗粒物等破坏性排放而量身定做的替代燃料。由于与现有的加油站基础设施重叠，这项研究的主要目的是从根本上了解主要生物燃料的燃烧性能和排放特性。这是帮助开发下一代低碳技术的关键知识。主要目标是：(1)利用激光诱导击穿光谱和激光诱导荧光等先进光学诊断技术提供喷雾火焰行为和排放研究的高质量实验数据；(2)基于COSILAB(燃烧模拟实验室软件)开发新的燃烧化学动力学模型，预测烟尘和氮氧化物排放；以及(3)与工业界和学术界合作，研究下一代生物燃料的发电和运输应用。在拟议的研究中，目标生物燃料是：(1)乙醇、(2)异戊醇、(3)二甲醚(DME)和(4)组合燃料-乙醇、异戊醇、二甲醚和生物甲烷。这些关键燃料可能是下一代生物燃料。这些燃料的生产路径要么是既定的，要么是可以实现的。乙醇和二甲醚已经从发动机测试中显示出排放减少的证据。对燃烧化学的了解对于提供低NOx和碳烟排放的燃烧系统是至关重要的。我们将详细研究各种湍流条件对局部化学反应的影响。

World-wide, energy conversion is currently dominated by the combustion of fossil fuels. Electricity generation and transport are key energy consumers and contribute significantly to atmospheric CO2, NOx, and particulate emission. There is an increasing awareness in the public eye of the potential impact of particulates on health. This includes a higher risk of cancer, asthma and a potential contribution to neurodegenerative disorders (e.g., Alzheimer's disease). In the UK, particulate matter (PM) from combustion processes is a significant contributor to poor air quality in urban areas; it has been reported that more than 25,000 deaths per year could be attributed to long-term exposure to anthropogenic particulate air pollution. As reported by DEFRA, poor air quality is the largest environmental risk to public health in the UK, contributing to an estimated £2.7 billion per year in lost productivity. Air pollution also results in damage to the natural environment, contributing to the acidification of soil and watercourses. An obvious solution might be to move towards the replacement of vehicles with electric, however, this technology is limited by range, recharge times and the cost of the battery - for which there is currently not the sufficient global infrastructure to directly replace vehicles powered by internal combustion engine powered. Another complementary solution is to find alternative fuels that are tailored to reduce destructive emissions such as NOx and particulates. This has the advantage that it could be rapidly deployed due to the overlap with existing fuel station infrastructure.The main aim of the proposed research is to provide a fundamental understanding of the combustion performance and emissions characteristics of key biofuels. This is vital knowledge to aid the development of next-generation low carbon technologies. The key objectives are: (1) to provide high-quality experimental data from a study of spray flame behaviour and emissions using advanced optical diagnostic techniques such as laser-induced breakdown spectroscopy and laser-induced fluorescence, (2) to develop new combustion chemical kinetic models, based on COSILAB (Combustion Simulation Laboratory software), predicting soot and NOx emissions and (3) to establish collaborations with industrial and academic partners to investigate power generation and transport applications for next-generation biofuels. In the proposed research, the targeted biofuels are: (1) ethanol, (2) iso-pentanol, (3) dimethyl ether (DME) and (4) combined fuels - ethanol, iso-pentanol, DME and biomethane. These key fuels are potentially next-generation biofuels. The production paths of these fuels are either well established or achievable. Ethanol and DME have already shown evidence of reduced emissions from engine tests. The understanding of combustion chemistry is essential to enable the delivery of a low NOx and soot emission combustion system. How the local chemistry is influenced by various turbulent flow conditions will be examined in detail.