Catalytic conversion of CO2 and biomass-derived phenols to high-value chemicals

英国已成为世界上第一个提出到2050年将所有温室气体排放降至净零的主要经济体。该研究项目将致力于利用二氧化碳，这是一种最普遍、最有效的温室气体，用于生产药品和精细化学品的化学中间体，以及不断增长的生物塑料行业。通过生物质衍生苯酚的催化偶联，将探索一条生产芳香族羧酸(ACAs)等高价值化学品的新途径。如果成功，这个项目将是可持续发展和全球减缓气候变化和全球变暖努力的双赢。简而言之，有成熟的制备羧酸的协议，然而，获取羧酸最直接的方法是通过直接羧化[1]。唯一众所周知的羧化反应是Kolbe-Schmitt反应，由于高温和压力的要求，它有自己的挫折[2]。Sadamitsu等人。(2019)设法在常温下使用间苯二酚(一种酚类化合物)并添加有机碱合成相应的水杨酸，实现了Kolbe-Schmitt反应。然而，这类反应需要很长的停留时间，并且仅限于一种特定的酚类化合物，这限制了生物质衍生酚类化合物的使用。此外，添加有机碱需要额外的分离阶段，这在较大规模下可能是昂贵和低效的。尽管最初的报告已经过去了一个半世纪，但还没有有效的酚羧化方法被报道。自1957年以来，一直在努力改进和修改原始报告[2]。这一研究项目的独特之处在于，它不仅专注于二氧化碳的催化转化，还通过探索从生物质中获得酚类化合物的选择来进一步减少碳足迹。将探索的途径是：(1)从生物质热解油中分离酚；(2)木质素的水热液化(HTL)生产酚。生物油使用的唯一障碍是由于产品分布非常广泛而导致的分离[4]。因此，开发选择性催化剂对缩小产品分布具有重要作用，从而使苯酚和生物质的高产率分离成为可能。通过减少二氧化碳和在生物油生产中使用绿色原料来高效的内部生产增值化学品的过程将最终实现商业化。该研究项目旨在通过在传统批处理过程中引入优化的替代生产系统来彻底改变19世纪发现的增长。虽然连续加工有能力生产出更安全和更可持续的工艺，但大多数制造商仍然依赖批量生产。该项目的实验结果将用于模拟和设计连续钻机。Dessimoz等人。(2012)利用微型装置在高压和高温下进行了Kolbe-Schmitt反应的连续反应-强调由于高传质和热性能，适合有效控制工艺参数。微毛细管具有大规模生产的局限性，因此需要将混合与流体速度和压力分离的连续技术。参考文献[1]X.Wu等人，Top Curr.《化学》，第1-60页，2018年。[2]J.Luo等，《化学》。-1欧元。J.，第22卷，第20期，第6798-6802页，2016年。艾尔，化学。《通讯》，第55卷，第66期，第9837-9840页，2019年。《科学论文集》，第2卷，第3期，第1-9页，2020年。

The UK has become the first major economy in the world proposing to bring all greenhouse gas emissions to net-zero by 2050. This research project will be dedicated to utilise CO2, the most ubiquitous and potent greenhouse gas in the production of chemical intermediaries for pharmaceuticals and fine chemicals as well as the growing bioplastic industry. A new promising route to produce high value chemicals such as aromatic carboxylic acids (ACAs) via catalytic coupling of biomass derived phenols will be explored. If successful, this project will be a win-win for sustainable development and for the global efforts to mitigate climate change and global warming.In brief, there are well-established protocols for the preparation of carboxylic acids, however, the most straight forward method for accessing carboxylic acids is through direct carboxylation [1]. The only well-known carboxylation reaction is the Kolbe-Schmitt reaction and it has its own set-backs due to high temperature and pressure requirements [2]. Sadamitsu et al. (2019) managed to achieve the Kolbe-Schmitt reaction at ambient conditions using resorcinol (a phenolic compound) with the addition of an organic base to synthesis the corresponding salicylic acid. However, this type of reaction requires very long residence time and is limited to one specific phenolic compound which restricts the use of biomass derived phenolic compounds. Moreover, the addition of an organic base requires an additional separation stage which can be costly and inefficient at a larger scale. Even though one and a half centuries have passed since the original report, no method has been reported for an efficient carboxylation of phenols. Efforts have only been made for improvement and modification of the original report since 1957 [2]. What makes this research project unique is that it does not focus only on catalytic conversion of CO2, but to further reduce carbon footprint through exploring the options of obtaining phenolic compounds from biomass. The routes that will be explored are, (1) isolation of phenols from biomass pyrolysis oils and (2) production of phenols from hydrothermal liquefaction (HTL) of lignin. The only stumbling block in the use of bio-oils is their separation due to very wide product distributions [4]. Therefore, developing selective catalyst plays an important role in narrowing production distribution, consequently, enables higher yield separation of phenols from biomass. An efficient in-house production process of value-added chemicals through reducing CO2 and the use of green feedstock in production of bio-oil will ultimately allow commercialisation.This research project aims to revolutionise the growth of the 19th century finding by introducing an optimised alternative production system to the conventional batch process. While continuous processing has the ability to produce safer and more sustainable processes, most manufacturers still rely on batch production. Experimental results from this project will be used to simulate and design a continuous rig. Dessimoz et al. (2012) carried out continuous reaction of the Kolbe-Schmitt reaction under high pressure and temperature using a micro-plant - emphasising on the suitability for efficient control of process parameters due to high mass and heat transfer performance. Micro-capillaries have the limitations of large-scale productions, hence continuous technologies that decouple mixing from the fluid velocities and pressures are required. These will be explored in detail in this project.References[1] X. Wu et al.,Top Curr. Chemis, pp. 1-60, 2018.[2] J. Luo, et al., Chem. - A Eur. J., vol. 22, no. 20, pp. 6798-6802, 2016.[3] Y. Sadamitsu et. al, Chem. Commun., vol. 55, no. 66, pp. 9837-9840, 2019.[4] Y. Elkasabi, SN Appl. et.al Sci., vol. 2, no. 3, pp. 1-9, 2020.