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Extractants for Biobased Chemicals

CYTOP® phosphine oxide extractants have been shown to lower carbon footprint

Biobased Chemicals

Biorefinery, biobased, bioderived, renewable feedstocks and bioeconomy have all become familiar buzzwords in the chemical industry over the last few years. The reason being the explosion of research, development, and commercialization of alternative sources of key feedstocks to the traditional fossil fuels that society has been dependent on since the industrial revolution. Much of this research, as the keywords suggest, is focused on deriving chemical feedstocks from renewable resources, rather than the traditional petrochemical feedstocks. These sustainable processes are also key enablers of the circular economy.

Liquid-Liquid Extraction in the Biorefinery

In the biorefinery, biomass is separated into its components, which are then further processed into marketable biobased products and bioenergy.1 Where dilute aqueous streams containing organic chemicals are one of the product streams, liquid-liquid extraction technology is a key part of the valorization process. The extraction of carboxylic acids from industrial water streams was studied as early as the 1970’s2 and is practiced industrially in certain pulp and paper mills.3 In more recent times the CYTOP® phosphine oxide range of extractants have been investigated for the isolation of small molecule organics from fermentation streams.4,5


Figure 1: The use of CYTOP® extractants to isolate small molecule organics from a fermentation

CYTOP® phosphine oxide extractants are used to separate small organic molecules (short-chain volatile fatty acids, alcohols and phenol) from dilute aqueous streams and have been shown to have a lower carbon footprint (CO2 per Kg of purified organic) than alternative, low boiling point, extractants.5



CYTOP® 502 and CYTOP® 503 are commercial scale tertiary phosphine oxides that find application as solvents and ligands, and in catalysis and surface treatment in addition to extraction. CYTOP® 503, a liquid at room temperature, was specifically developed as an alternative to CYTOP® 502. To learn more about other specialty phosphorus products, please refer to the Solvay offering at Strem or the Solvay website.


  1.       “The Role of Bioenergy in the Emerging Bioeconomy”, Elsevier, 2019.
  2.       J. Chem. Eng. Data, 1978, 23, 144-148.
  3.       US Patent 8,785,688, July 2014.
  4.       Biochemical Engineering Journal 2020, 160, 107641.
  5.       Bioorg. & Med. Green Chem. 2018, 20, 1791.


Featured Products:

97-6660 Trioctylphosphine oxide, min. 90% TOPO [CYTOP® 502] (78-50-2)

97-1337 Tri-n-hexylphosphine oxide/tri-n-octylphosphine oxide, min. 92% [mixture R3P(O), R2R'P(O), RR'2P(O), R'3P(O)] [CYTOP® 503] (100786-00-3)


Related Products:

CYTOP Products

Phosphorus Ligands and Compounds Booklet

All products sold in collaboration with Solvay




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