100
12
A
B
0.1
75% DW / 25% HC 75% DW / 25% HC 60% DW / 40% HC Bio - oil blend HDO product 50% DW / 50% HC
10
80
0.05
8
60
6
0
440
460
480
500
40
4
20
2
0
0
250
300
350
400
450
500
0
200
400
600
Intensity (a. u.)
Temperature (˚C)
Figure 3 Simulated distillation profiles of bio-oil blend, HDO effluent, and DW/HC products using different ratios of DW and HC catalyst: (A) Accumulated mass vs temperature. (B) Differential profiles with peaks indicating linear paraffins (for example, C1₈) in the HDO product and their absence in the DW/HC products. The inset in Figure B shows the reduction of the high-boiling tail when using more HC catalyst
relevant process conditions were used: 51 bar(g) H₂, LHSV ≈0.58 h ⁻ ¹, and gas-to-oil ratio ≈2,000 Nm³·m ⁻ ³. HDO was performed at three different temperatures, denoted as low (T), medium (T + 10°C), and high (T + 30°C). Batches of liquid HDO effluent were collected and routed to a DW/HC step. Stage 2: DW/HC (four positions). Commercially relevant process conditions were used: 51 bar(g) H₂, LHSV ≈1.4 h ⁻ ¹, and gas-to- oil ratio ≈500 Nm³·m ⁻ ³. Testing results • Study design: A 16-fold trickle-bed unit was used to evaluate the HDO and DW/HC steps in parallel. To this end, 12 reactor positions were filled with commercial HDO catalyst (stage 1), and four positions were filled with different ratios of stacked commercial DW/HC catalyst (stage 2), as seen in Figure 2. • HDO: To investigate the HDO stage in detail in 12 out of the 16 high throughput reactors, the mixture of field cress and rapeseed oil was fed according to conditions described above. The gas phase was sampled multiple times per day via online gas chromatography to follow the formation of H2S, H2O and gas-phase hydrocarbons. Meanwhile, the liquid effluent was sampled once per day and analysed via
S/N/O and density measurements, and via simulated distillation. To map a broad parameter space in a parallelised manner, the individually heated reactors were used to run the HDO step at low (T), medium (T + 10°C), and high (T + 30°C) temperatures at individual reactor positions. Independent of temperature, values of N <1 ppm, S <2 ppm, and O <150 ppm were observed throughout the first week of HDO testing, indicating that removal of heteroatoms from the bio-oil feed was fast and complete. Decomposition of the fatty acid triglycerides could also be observed via simulated distillation of the liquid effluent, where the boiling range shifted from approximately 600°C (bio-oil feed) to approximately 300-350°C (C18-C22 paraffins), and via the presence of CO x , H2O, and propane in the effluent gas phase. At the start of the test program, 10 of the HDO reactors were operated at the highest temperature (T + 30°C), and liquid product from these positions was collected for subsequent feeding to the DW/HC reactor. The cloud point of the HDO effluent was measured at +27°C, while the goal was to decrease the value during the subsequent DW/HC step. To assess the effect of HDO temperature on DW/HC catalyst performance, all HDO reactors were
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