Electrosynthesis in chemical manufacture is the synthesis of chemical compounds in an electrochemical cell. The main advantage of electrosynthesis over an ordinary redox reaction is avoidance of the potentially wasteful other side reactions and the ability to precisely tune the required power input to achieve the chemical reaction, thereby avoiding unnecessary energy usage. Good electrosynthetic conditions use a solvent and electrolyte combination that minimizes electrical resistance, with electrodes selected to provide favorable electron transfer properties towards the substrate whilst minimising the activation energy for side reactions.
Historically however, despite the large number of chemicals available in the market, electrochemical synthesis of chemicals has been limited to a narrow spectrum. The reasons for this are attributed to a lag in chemical and engineering technology, a lack of suitable resources for cell construction, and importantly the prohibitive capital costs, particularly of electrochemical reactors.
C-Tech Innovation have developed a range of low capital cost reactors which can have a major impact upon manufacture of high value chemicals such as pharmaceutical or fragrance and flavour intermediates. Thus many functional group transformations commonly employed in research lab synthesis, but considered too challenging to scale-up in the context of manufacture, either because of the hazardous nature of the chemical reagents traditionally employed, high cost, or formation of significant amounts of waste, may now be possible using electrochemical synthesis.
Combining its extensive knowledge of electrochemistry, with significant experience in chemical process scale-up, C-Tech have built up a unique understanding of physical properties such as mass transfer, current distribution, chemical kinetics and heat transfer which are key in delivering efficient electrosyntheses where selectivity, high conversion and high productivity are objectives.
C-Tech employs novel designs (based on flow electrochemistry), multi-scale models (to deliver full fundamental understanding) and chemistry (to supply important electrochemical transformations appropriate to production of many high value chemicals) to provide our clients with:
- High selectivity and product yields, with no environmentally problematic by-products (>90%)
- High current efficiencies > 70%
- Low Energy (electricity) consumption per kg of desired product < 8 kWh/kg of product
- Processes developed for cleaning electrodes to meet GMP and deliver long service life > 1000 h between cleaning steps
- Membrane lifetime (divided cell designs) > 2000 h
- Simple work-up of the electrolysis products, reduction in associated energy use of 20%
- Simple removal and recycling of the electrolyte (or elimination of electrolyte)
- High concentration of the end product in the reaction stream > 10% (w/v)
Some examples of electrosynthesis chemistries previously developed by C-Tech Innovation include:
- Copper and Arsenic organometallic compounds used in the manufacture of pharmaceutical active intermediates
- Sodium iodate and periodate
- L – Cysteine