To decrease the greenhouse gas emissions of the maritime transport sector, synthetic fuels produced by combining biomass gasification and electrolytic hydrogen have been identified as relevant alternatives to fossil fuels. Dimethyl ether (DME) is a synthetic fuel that is suitable for direct use in commercial diesel ship engines. In this work, the production of DME via two different synthesis routes (one- and two-stage DME synthesis) from agricultural residues (wheat straw) or forestry residues (bamboo) and renewable electricity was investigated. In the four investigated plants, solid oxide electrolysis cells were used to produce hydrogen. The DME production systems were designed to operate using only wind and solar electricity. The energy and carbon efficiencies of the plants were evaluated by using detailed thermodynamic models. The performance of the plants was fed into an optimization model, and the levelized cost of fuel (LCOF) was minimized by optimizing the size and hourly operation of the DME production systems, including the DME synthesis plant, solid oxide electrolyzer, hydrogen storage, solar and wind power production, and batteries. The results show that the systems using a two-stage synthesis achieve higher carbon and energy efficiencies than one-stage systems. However, the lowest LCOF of 115 €/MW h was reached by the plant using bamboo and a one-stage synthesis. This system had a hydrogen and electricity consumption of up to 45% lower than the alternative systems, leading to lower cost of the power supply, storage, and electrolysis units. A sensitivity analysis showed that the LCOF of the plants is highly sensitive to variations in the cost of electrolyzers, biomass, and the DME synthesis plant.

中文翻译：

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不同生物质资源与离网可再生电力生产二甲醚的技术经济分析

为了减少海运部门的温室气体排放，通过生物质气化和电解氢相结合生产的合成燃料已被确定为化石燃料的相关替代品。二甲醚 (DME) 是一种合成燃料，适合直接用于商用柴油船舶发动机。在这项工作中，研究了通过两种不同的合成路线（一级和两级二甲醚合成）从农业残留物（麦秆）或林业残留物（竹子）和可再生电力生产二甲醚。在四个被调查的工厂中，固体氧化物电解池用于生产氢气。 DME 生产系统设计为仅使用风能和太阳能运行。通过使用详细的热力学模型评估工厂的能源和碳效率。将工厂的性能纳入优化模型，并通过优化 DME 生产系统（包括 DME 合成工厂、固体氧化物电解槽、储氢、太阳能）的规模和每小时运行来最小化燃料平准成本 (LCOF)。以及风力发电和电池。结果表明，采用两阶段合成的系统比一级系统具有更高的碳效率和能源效率。然而，使用竹子和一步合成的工厂达到了 115 €/MW h 的最低 LCOF。该系统的氢气和电力消耗比替代系统低 45%，从而降低了供电、存储和电解装置的成本。敏感性分析表明，工厂的 LCOF 对电解槽、生物质和 DME 合成工厂的成本变化高度敏感。