The development of a fully continuous process for the synthesis of solketal (4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane) is described. The use of a heterogeneous catalyst, recycle of unreacted starting material, elimination of the need for an entraining solvent, and purification of the product in situ all afford improvements over existing processes. Data generated in model reactions is used to prove the applicability of the process to a counter-current distillation reactor design, and to compute the operating parameters of the reactor.

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In this contribution we provide details of the BP-Johnson Matthey proprietary Fischer–Tropsch technology and the advanced CANS reactor and catalyst system. The advanced CANS catalyst carrier reactor provides superior heat transfer, reduced pressure drop and higher productivity that lead to major economic savings. Fundamental understanding of catalyst behaviour is also key to obtaining a catalyst that is stable over the lifetime of its use. Synthesis, calcination and reduction steps introduce changes in the catalyst properties prior to syngas introduction. In particular, the presence of water can affect the final catalyst performance. The activity of a good catalyst can be significantly reduced by a sub-optimal activation or start-up. Similarly, stable operation and minimising deactivation are vital for long and stable catalyst life, with years of operation without requiring regeneration. In this report we also share a fundamental study on the catalyst activation across different catalyst supports. This combines advanced in situ techniques with reactor testing to explore the role of the support on catalyst performance. The results illustrate the critical need for a logical and systematic catalyst development programme to explore these effects to optimise the whole FT process. The combination of a joint approach in development plays a key role in a long term success in a process. The fundamental catalyst understanding, optimisation and improvements in combination with the novel CANS reactor design maximise their potential and offer the potential for a world leading technology.

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Comprehensive two-dimensional gas chromatography (GCxGC) analysis for 1-alcohols and gas chromatography–mass spectrometry (GC-MS) analysis for carboxylic acids, derivatised as their methyl esters, have been applied to liquid and wax Fischer-Tropsch (FT) hydrocarbon products. These methods in combination with conventional one-dimensional gas chromatography (GC) analysis of the aqueous, gaseous, liquid hydrocarbon and wax products plus conventional high-performance liquid chromatography (HPLC) analysis of the aqueous phase has allowed a quantitative distribution analysis of FT hydrocarbon and oxygenated products to be demonstrated for a Co/TiO2 catalyst operating in a fixed bed gas phase pilot plant utilising CANSTM catalyst carrier devices. The GC-MS method used is, to the best of our knowledge, the first application of this derivatisation route for the quantification of individual carboxylic acids in FT hydrocarbon product streams. Whilst the hydrocarbons and oxygenates that were identified are known compounds formed during the low temperature, Co catalysed, FT process the combination of the multiple analysis techniques used has allowed a level of detail to be gained on the product composition that is seldom reported. Additionally, 1H nuclear magnetic resonance spectroscopy (NMR) and 13C NMR analyses were used to quantify the average concentration of 1-olefin, cis- and trans-2-olefins, 1-alcohol and aldehyde as appropriate for the technique used. Comparison of GCxGC versus 1H NMR and GC-MS versus a KOH titration confirmed the applicability of the chromatographic methods for the quantitative analysis of FT oxygenated compounds. Long-chain 1-alcohols and carboxylic acids, ≥ C3, were found to be present at levels of 1/10th and 1/1000th that of hydrocarbons of equivalent carbon chain length respectively. The 1-olefin:n-paraffin ratio in the hydrocarbon liquid and wax products was found to decrease significantly with increasing carbon chain length and much more so than those of the 2-olefin or 1-alcohol.