Application of microwaves on the production of liquid biofuels

《2008年气候变化法案》设定了一个具有挑战性的目标，即到2050年将英国的温室气体排放量减少80%。公路运输、航空和航运业的温室气体排放量约占英国的33%，而该行业的最终能源消耗量约占总能源消耗量的38%。英国政府已经认识到使用生物燃料的关键作用，生物燃料是由生物质和废物等可再生资源制成的燃料，以减少运输的碳化并确保能源安全。快速热解正在巩固为将非食用生物质转化为液体（生物油）的途径，可用作生物燃料前体。生物油的氧含量比原油高得多（10-40重量%与< 1重量%相比，（O在后者）。由于这种氧含量，它与石油衍生燃料和基础设施（管道，加工装置，发动机......）不兼容。目前使用。因此，生物油在应用于现有系统之前需要升级阶段以除去氧气。增加提质阶段使得生物质至液体的过程更加复杂，并导致更高的资本和运营成本。现在需要技术突破，才能提供清洁和负担得起的生物燃料。该项目提出了一种新的方法：使用微波加热更简单，更有效的生物质生产生物燃料的过程。微波应用于化学反应显示出类似的优点，任何人都可以观察到在家用微波炉或炉子上加热一杯牛奶时。微波炉更快更干净。此外，针对生物质微波热解的特殊应用，已经生产出具有较低氧含量的生物油。但目前还没有系统的研究表明微波热解的优越性。因此，在这个项目中，我们的目标是了解温度或反应时间的变化如何影响所产生的生物油的量及其组成（氧含量）。我们还在测试一个假设，即与传统的升级相比，微波可以帮助催化升级过程提高所生产的生物燃料的数量和质量。实际上，在生物油的微波改质方面还没有开展任何工作。但根据微波热解的结果和对石油馏分微波改质的一些研究，预计会取得良好的结果;这些研究表明，与传统工艺相比，可以生产出更好的石油。这一假设将通过一项实验室实验方案加以检验。如果微波可以被证明在类似的温度下产生具有较低氧含量的升级生物油，（或更好的）操作条件，则它是更有效的方法，并且当按比例放大时，将可能更经济和可持续。开发微波辅助生物质-液体工艺作为一种经济和可持续的生物燃料生产路线，将有利于生物燃料在英国运输部门的渗透和成本。微波可以对清洁技术的发展产生影响，因为它可以与其他可再生能源技术相结合。微波是由电产生的。使用微波时，如果产生微波所需的电力来自风能和太阳能等可再生能源，则可以避免温室气体排放。此外，微波加热的适用性是巨大的，可扩展到生物质转化之外;它可以用于多个部门，从制药工艺到塑料生产。总的来说，在这个项目中收集的知识将影响微波应用于工业过程的发展，并将帮助英国工业部门在中长期内将自己定位为使用这项技术的世界领导者。

The Climate Change Act 2008 set the challenging goal of reducing the UK greenhouse gas emissions (GHG) by 80% by 2050. The road transport, aviation, and shipping emit approximately 33% of UK greenhouse emissions, and the sector consumes around 38% of the total final energy consumption. The UK Government has acknowledged the key role of the use of biofuels, fuels made from renewable sources such as biomass and waste, in order to decarbonise transportation and ensure energy security.Fast pyrolysis is consolidating as route for conversion of non-edible biomass into liquids (bio-oil) that can be used as biofuel precursors. The bio-oil presents a much higher content in oxygen than the crude oil (10-40 wt.% of oxygen in the former compared to < 1 wt.% of O in the latter). And because of this oxygen content, it is not compatible with the petroleum-derived fuels and infrastructure (pipelines, processing units, engines...) currently used. Therefore, the bio-oil requires upgrading stages to remove the oxygen before being applicable in the existing systems. The addition of the upgrading stages makes the biomass-to-liquid process more complex and incurs in higher capital and operating costs. Technological breakthroughs are now required for clean and affordable biofuels to become available. This project sets out a new approach: using microwaves to heat simpler and more efficient processes for the production of biofuels from biomass. Microwaves applied to chemical reactions have shown similar advantages to those that anybody can observe when heating a glass of milk in the household microwave or on the stove. The microwave oven is faster and cleaner. In addition, for the particular application of microwave pyrolysis of biomass, bio-oil with lower oxygen content has been produced. But there is not systematic study which shows the advantages of using microwave pyrolysis. So in this project we aim to understand how changes in temperature or reaction time have an influence on the amount of the produced bio-oil and its composition (oxygen content). We are also testing the hypothesis that microwaves can aid the catalytic upgrading process to enhance the quantity and quality of the produced biofuel compared to conventional upgrading. There is virtually no work done on the microwave upgrading of bio-oil. But good results are expected based on the results from microwave pyrolysis and some studies on microwave upgrading of petroleum fractions; those have shown that better oil is produced compared to conventional processes. The hypothesis will be tested through a programme of laboratory experiments. If microwaves can be demonstrated to produce an upgraded bio-oil with lower oxygen content at similar (or better) operating conditions than conventional processes then it is a more efficient process and, when scaling it up, will potentially be more economic and sustainable.Developing the microwave-assisted biomass-to-liquid process as an economic and sustainable route for biofuel production will benefit the penetration and cost of biofuels into the UK transport sector. Microwaves can have an impact in the development of clean technologies as it can be coupled with other renewable energy technologies. Microwaves are generated from electricity. GHG emissions can be avoided when using microwaves if the electricity required for their generation is produced from renewable energy sources such as wind and solar power. Moreover, the applicability of microwave heating is huge and extendable beyond the biomass conversion; it can be used in multiple sectors, from pharmaceutical processes to production of plastics. Overall, the knowledge gathered during this project will impact the development of microwaves applied to industrial processes and will help the UK industrial sector to position itself as world leaders in the use of this technology in the mid- and long-term.