• Energy Research

Efforts to provide alternative resources and technologies for producing liquid fuel have recently been intensified. Different levels of dependence on oil imports and carbon prices have a significant impact on the composition of the cost-minimizing portfolio of technologies. Considering such factors, how should China plan its future liquid fuel industry? The model for supporting the technology portfolio and capacity configuration that minimizes the total system cost until 2045 is described in this study. The results obtained for different carbon prices and levels of dependence on oil import indicate that the oil-to-liquid fuel (OTL) will remain dominant in China's liquid fuel industry over the next three decades. If the carbon price is low, the coal-to-liquid fuel (CTL) process is competitive. For a high carbon price, the biomass-to-liquid fuel (BTL) technology expands more rapidly. The results also reveal that developing the BTL and CTL can effectively reduce the oil-import dependency; moreover, a high carbon price can lead to the CTL being replaced with the low-carbon technology (e.g., BTL). Improvement in energy raw material conversion and application of CO2 removal technologies are also effective methods to control carbon emissions for achieving the carbon emission goals and ultimately emission reduction targets.

There is a growing interest in the power-to-liquid (PTL) technology, especially in using electricity from renewable sources to generate H2, and then coupled with CO2 captured from various sources (e.g., coal-fired power plants) to produce liquid fuels (e.g., gasoline). As a negative emission technology, the product of PTL could be used in the internal combustion engine vehicles (ICEV) and thus cause limited shifts in current energy infrastructure and automobile industry compared with the electrification paths. However, it is still unknown whether the PTL technology could be adopted and contributed to reaching carbon neutrality in China's transportation sector. Against this, a novel model of the liquid fuel supply system considering multiple low-emission technologies, including PTL, is constructed to evaluate PTL's potential contribution and cost to the carbon-neutral target of China's transportation sector. Results show the following: First, PTL can achieve a maximum 93% carbon emission reduction compared with oil to liquid (OTL). Second, the most cost-effective deployment strategy for PTL is to increase the total cost by 5–10%. Third, international oil prices and technology-learning effects have significant impacts on the diffusion of PTL. Fourth, PTL can be a supplementary solution to achieve net-zero emissions in the transportation sector.

Existing techno-economic analyses of modern coal chemical technologies (MCCTs) neglect water constraints, which may underestimate the production cost of MCCTs and thus mislead investment activities. Considering this background, this study incorporated water scarcity and indirect water cost into a classic techno-economic evaluation model of MCCT. Using this model, our work evaluated and compared the techno-economic indicators with the latest data for four typical MCCTs, including coal-to-liquids (CTL), synthetic natural gas (SNG), coal-to-olefin (CTO), and coal-to-ethylene glycol (CTEG). The results demonstrate the following: 1) The production costs of CTL, SNG, CTO, and CTEG are 5185 CNY/t, 2653 CNY/kNm3, 5918 CNY/t, 4055 CNY/t, respectively. Under the current prices of oil-related products, investment in SNG and CTEG would be risky, investment in CTL should be considered cautiously, and investment in CTO could lead to a profit. 2) Under the current market price of water resources, which does not consider the water constraint of MCCTs, the production cost would be underestimated by at most 12.4% for CTL, 10.6% for SNG, 27.5% for CTO, and 32.4% for CTEG. The sensitivity of the results to some key parameters and investment recommendations considering profitability, capital investment, material consumption, water constraints, and CO2 emissions are also discussed and provided.

AbstractThe diffusion of new energy vehicles (NEVs), such as battery electric vehicles (BEVs) and fuel cell vehicles (FCVs), is critical to the transportation sector’s deep decarbonization. The cost of energy chains is an important factor in the diffusion of NEVs. Although researchers have addressed the technological learning effect of NEVs and the life cycle emissions associated with the diffusion of NEVs, little work has been conducted to analyze the life cycle costs of different energy chains associated with different NEVs in consideration of technological learning potential. Thus, relevant information on investment remains insufficient to promote the deployment of NEVs. This study proposes a systematic framework that includes various (competing or coordinated) energy chains of NEVs formed with different technologies of power generation and transmission, hydrogen production and transportation, power-to-liquid fuel, and fuel transportation. The levelized costs of three typical carbon-neutral energy chains are investigated using the life cycle cost model and considering the technological learning effect. Results show that the current well-to-pump levelized costs of the energy chains in China for BEVs, FCVs, and internal combustion engine vehicles (ICEVs) are approximately 3.60, 4.31, and 2.21 yuan/GJ, respectively, and the well-to-wheel levelized costs are 4.50, 6.15, and 7.51 yuan/GJ, respectively. These costs primarily include raw material costs, and they vary greatly for BEVs and FCVs from resource and consumer costs. In consideration of the technological learning effect, the energy chains’ well-to-wheel levelized costs are expected to decrease by 24.82% for BEVs, 27.12% for FCVs, and 19.25% for ICEVs by 2060. This work also summarizes policy recommendations on developing energy chains to promote the diffusion of NEVs in China.