Decarbonisation Technology August 2022 issue

Parameter

Value

Power available for hydrogen production, MW

Hydrogen production, Nm 3 /h Carbon capture reboiler duty, MW MeOH distillation reboiler duty, MW

15,400

7.5 6.5 147

MeOH production, tpd

Table 1 Summary of key values in the e-methanol facility

400

600

MeOH selling price

the life of the methanol catalyst. Then the gas mixture is compressed up to the operating pressure of 80 barg in the make-up compressor. The methanol synthesis technology selected takes care of the heat of reaction by raising steam in a steam raising reactor; the generated steam is further used in the distillation reboiler. The conversion per pass is rather low as the reaction runs towards equilibrium, yielding a methanol content at reactor exit close to 5.5 vol%. Crude methanol is recovered at 40ºC, and unreacted gases are recirculated in a large recirculating loop to the high-pressure stage in the make-up compressor. The crude methanol is distilled to AA grade in a distillation column. Steam generated in the methanol reactor is not sufficient to run the reboiler in the distillation column, therefore medium-pressure steam is bled from the pulp mill to balance the energy demand. In compensation, the higher alcohols and other by-products formed in the reactor and the off-gas are used as fuel in the mill’s recovery or auxiliary boilers. Table 1 summarises the key indicators in the e-methanol plant. Economic analysis To evaluate the profitability of the project, the cost of methanol was calculated considering the production rate, and the Capex and Opex of the PtX facility. Fossil-based methanol market price was used as a reference. The results are summarised in Figure 4 . To help understand whether the owner of the facility should look further to invest in a brownfield e-methanol plant, the price of selling electricity to the grid was also plotted (see Figure 4 ). Note that if electricity is not used to produce e-methanol, it is otherwise sold to the grid, marking the break-even point. For a region with low electricity prices of around 20 Euro/MWh, such as the northern part of Scandinavia (Energiförsk, 2021), with plenty of

MeOH prot, Euro/day Oxygen credit, Euro/day Carbon credit, Euro/day

El prot @ 80 euro/MWh El prot @ 20 Euro/MWh

biogenic CO₂ available, it may be worth considering such a facility, as Figure 4 suggests. Recent moves towards sustainable maritime fuels have highlighted the potential of e-methanol (Maersk, 2021) and may foster the deployment of these types of facilities in areas with these conditions (low electricity price and plenty of biogenic CO₂ available). Other regions with plenty of biogenic CO₂, such as South America, may consider this approach if electricity prices are around the same mark and there is an oxygen off- taker nearby, like the pulp mill itself. Figure 4 Economic results from producing e-methanol at different methanol market price. Green and yellow lines indicate profit if electricity is sold, instead of used for e-methanol Conclusions Power to methanol projects can provide an economically attractive route to renewable methanol production when the plant is co-located in a pulp mill or bio-waste site with sources of biogenic CO₂ and a source of renewable electricity. Success factors include short- and long-term market scenarios, site selection and permitting, plant integration with shared utilities, an off- take for oxygen by-product, and sound technical solution selection. The early appointment of a reliable engineering partner with the relevant know-how in all areas around PtX, who supports the project owner’s interests, is fundamental for successful project delivery.

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Raimon Marin raimon.marin@afry.com