Sustainable Manufacturing in Multiphase Continuous Reactors: Aerobic Oxidations

虽然散装化学品通常在有效的连续过程中生产，产生相对较少的废物（E因子<1-5），但高价值化学产品（精细化学品，农用化学品，药品）通常以批量生产，产生大量废物（E因子约为1 - 5）。25-100）。因此，如果连续制造技术能够适用于这些行业，将具有明显的商业优势。连续处理可以促进潜在危险试剂的安全操作，但仍然可以实现低废物转化，例如，通过在非常放热的过程中进行有效的热传递，最大限度地减少危险材料的本地库存。虽然大多数散装化学品的氧化可以在气相中使用分子氧连续进行，但出于安全考虑（例如，形成爆炸性混合物），不能将其用于批量工艺，特别是用于精细化学品制造中的热敏性、不挥发性基质。这导致两种不期望的行为：a）采用昂贵的、原子效率低的、产生废物的化学计量的氧化剂，随之产生负面的环境影响，和B）通过使用不可避免的效率较低的“工作区”来避免氧化转化的趋势。因此，很明显，氧化是一种潜在的关键使能技术。证明在有机溶剂中的有氧氧化具有成本效益、安全性和有效性将具有变革性，因为工业界将认真考虑广泛且不断增加的催化有机转化，并且由于安全问题而不被避免。通过“套叠”后续转化进一步提高效率的潜力也将通过连续的后处理自由氧化来促进。因此，该项目旨在通过开发安全的连续氧化转化，在许多产品的生产效率方面引发一个阶段性变化。

While bulk chemicals are generally manufactured in efficient continuous processes, generating relatively little waste (E-factor <1-5), high value chemical products (fine chemicals, agrochemicals, pharmaceuticals) are usually manufactured in batch units, generating enormous waste (E-factor ca. 25-100). There is therefore a clear business advantage, if continuous manufacturing techniques could be adapted for use in these industries. Continuous processing can facilitate safe manipulation of potentially hazardous reagents that can nevertheless effect low-waste transformations, e.g. by efficient heat-transfer in very exothermic processes & minimising local inventory of hazardous material. Whilst most oxidations of bulk chemicals can be performed continuously using molecular oxygen in the gas phase, safety considerations (exotherm, formation of explosive mixtures) preclude its use in batch processes, particularly for thermally sensitive, involatile substrates found in fine chemical manufacture. This leads to two undesirable behaviours: a) adoption of costly, atom inefficient, waste-generating stoichiometric oxidants, with consequent negative environmental impact, and b) a tendency to avoid oxidative transformations by using inevitably less efficient 'workarounds'. It is therefore clear that oxidation is a potentially key enabling technology. The demonstration of cost-effective, safe, and efficient use of aerobic oxidation in an organic solvent would be transformative since a wide and increasing range of catalytic organic transformations would be considered seriously by industry, and not avoided due to safety concerns. The potential to drive further efficiency by 'telescoping' subsequent transformations would also be facilitated by continuous, work-up free oxidation. Thus, this project aims to instigate a step change in efficiency in the manufacture of many products by developing safe continuous oxidative transformations.