面向可再生能源消纳的电化工(P2X)技术分析及其能耗水平对比

Technical and Energy Consumption Comparison of Power-to-Chemicals(P2X) Technologies for Renewable Energy Integration

电转氢技术可将富余的可再生能源电能转化为化学能,运用于电力系统中有望实现富余可再生能源的大规模消纳。氢在交通、发电等领域具有重要作用,但受限于燃料电池技术的成熟度,现阶段应用的规模较小,难以匹配富余电量的体量。同时,氢在化工领域具有较大的应用潜力,发展面向可再生能源消纳的电化工(P2X)技术,是解决可再生能源弃电问题的一条有效途径。针对电转氨、电转甲烷、电转甲醇及电转汽油4种主要电化工技术,从市场规模、技术路线、能源转化效率以及示范工程进展4个方面进行了综述,对比分析了4种电化工技术的能效、电耗、边际电价、等效产量及市场占比五大主要技术经济指标。基于低温电解技术路线的研究结果表明:电转甲烷与电转汽油技术综合能效较高(50%);电转汽油技术最具经济性(边际电价为0.37元/k Wh),但合成过程需要一氧化碳,碳排放与技术风险大;电转氨推广将对市场影响最大(17.18%)。此外,电转油的节煤意义显著(降低煤耗约2285万t),电转氨的环保意义显著(减少碳排放约3910万t),是未来电化工技术的两大重要发展方向。面向未来P2X技术的发展,同时对基于高温固体氧化物的高温电化工技术路线的方案与经济性进行了初步探讨与展望。

Power-to-hydrogen(P2 H) technology is expected to consume surplus renewable energy by converting electricity into hydrogen, which is suitable for the application in power systems. Hydrogen has an important role in the fields of transportation and power generation. However, due to the restrictions of fuel cell technologies, the current application of hydrogen in the fields of transportation and power generation is limited and cannot match the volume of surplus electricity. Therefore, relying on the application potential of hydrogen in the chemical market, the development of power-to-chemicals(P2 X) technologies is an effective way to solve the problem of renewable energy consumption. This paper reviews four main P2 X technologies(power-to-ammonia, powerto-methane, power-to-methanol, and power-to-gasoline), and introduces the market scale, technical routes, energy conversion efficiency, and demonstration projects of each technology. On this basis, five major techno-economic indicators(energy efficiency, power consumption, marginal electricity price, equivalent output, and market share) of the four P2 X technologies are compared and analyzed. The results show that the integrated energy efficiency of power-to-methane and power-to-gasoline are relatively high(50%), and the power-to-gasoline technology is the most economical, with its marginal electricity price being 0.37 RMB/kWh. However, the synthesis process requires carbon monoxide, which causes carbon emissions and technical risks. In addition, power-to-ammonia technology will have the greatest impact on the original chemical market(17.18%). Furthermore, power-to-gasoline can reduce coal consumption by 22.85 Mtce and power-to-ammonia can reduce CO2 emission by 39.10 Mt, which are the two promising technologies with the maximal economic and environmental benefits. Finally, this paper discusses the economic indexes of P2 X technologies based on the high-temperature solid oxide cell route.