On-board conversion of methanol to DME, a techno-economic evaluation
report
This study examines the transition from marine diesel to alternative fuels in compression ignition (CI) engines using dimethyl ether (DME) and methanol (MeOH). Currently, dual fuel compression ignition (CI) engines require at least 30% diesel. However, using dimethyl ether (DME) enables the complete replacement of diesel. Due to DME's limited availability and gaseous state, on-board conversion of MeOH to DME is proposed. The Arklow Venture, with a 1740 kW CI diesel engine, serves as the reference vessel. Four DME-MeOH fuel scenarios were analyzed:
1. Direct Injection (DI) of pure DME.
2. DI of DME-crude (DME/MeOH/H₂O mixture).
3. DI of DME-crude (30%) with Port Fuel Injection (PFI) of MeOH.
4. DI of MeOH and PFI of DME-crude (10%).
Cases 2-4, using DME-crude, simplify the conversion process as distillation of the DME product is not required. These cases achieve a higher net conversion efficiency (94.3%) compared to case 1 (90.9%). Total capital investments for cases 1-4 are 2.0, 1.2, 0.52, and 0.24 million EUR, respectively. Fuel-to-engine costs are 28.5, 25.5, 24.1, and 23.6 EUR/GJ. Case 3 is identified as the most viable option considering efficiency, cost, and retrofit maturity. While case 3 offers a feasible solution for completely replacing fossil diesel in CI engines, higher fuel costs compared to MeOH (22.4 EUR/GJ) and diesel (13.3 EUR/GJ) present a challenge without strict regulatory mandates.
1. Direct Injection (DI) of pure DME.
2. DI of DME-crude (DME/MeOH/H₂O mixture).
3. DI of DME-crude (30%) with Port Fuel Injection (PFI) of MeOH.
4. DI of MeOH and PFI of DME-crude (10%).
Cases 2-4, using DME-crude, simplify the conversion process as distillation of the DME product is not required. These cases achieve a higher net conversion efficiency (94.3%) compared to case 1 (90.9%). Total capital investments for cases 1-4 are 2.0, 1.2, 0.52, and 0.24 million EUR, respectively. Fuel-to-engine costs are 28.5, 25.5, 24.1, and 23.6 EUR/GJ. Case 3 is identified as the most viable option considering efficiency, cost, and retrofit maturity. While case 3 offers a feasible solution for completely replacing fossil diesel in CI engines, higher fuel costs compared to MeOH (22.4 EUR/GJ) and diesel (13.3 EUR/GJ) present a challenge without strict regulatory mandates.
Topics
TNO Identifier
1001773
Publisher
TNO
Collation
42 p.
Place of publication
Petten