A biomass-to-liquid (BTL) plant utilizes Fischer-Tropsch synthesis to produce synthetic fuels from syngas. The table below shows the relative yield of four hydrocarbon fractions obtained from a test run of the reactor, along with the current market demand for each fraction.
| Hydrocarbon fraction | Relative yield obtained (%) | Market demand (%) |
|---|---|---|
| Light gas fraction (C1−C4C_1 - C_4C1−C4) | 15 | 25 |
| Synthetic gasoline (C5−C11C_5 - C_{11}C5−C11) | 20 | 45 |
| Synthetic diesel (C12−C20C_{12} - C_{20}C12−C20) | 25 | 28 |
| Heavy paraffin wax (C21+C_{21}+C21+) | 40 | 2 |
Identify the hydrocarbon fraction for which the relative yield obtained exceeds the market demand.
105 exam-style questions on Edexcel GCSE Chemistry 9.1 Fuels, covering 9.1.1 Hydrocarbons and crude oil, 9.1.2 Fractional distillation of crude oil and its fractions, 9.1.3 The alkanes as a homologous series, 9.1.4 Complete and incomplete combustion, 9.1.5 Pollutants from burning fuels, 9.1.6 Hydrogen as a fuel and non-renewable fossil fuels, and 9.1.7 Cracking of larger alkanes. Each one has a worked solution and a mark scheme showing where the marks go.