Underground coal gasification (UCG) has the potential to provide a source of energy or chemical feedstock derived from coal seams, where traditional mining methods are not suitable or are uneconomical. This paper presents the life cycle inventory models developed for the UCG processes and three alternative syngas utilisation options with and without CO₂ capture and storage. The paper compares the life cycle carbon footprint of two different conventional above ground coal fired power generation options with UCG Integrated Gasification Combined Cycle power generation with/without CCS for two different lignites and one bituminous coal. One of the lignites is then used to compare the life cycle performance of different syngas utilisation options: power generation, ammonia production with power generation, and methanol production with power generation. It was found that the life cycle carbon footprint of conventional above ground coal fired power generation is very much dependent on the in-situ methane content of the coal used, and methane emissions experienced during mining and accompanying upstream processes, whereas the same for UCG-IGCC power depends more on the process dependent syngas composition. UCG methanol production with associated power and CCS is shown to release more life cycle CO₂-eq emissions per tonne of lignite consumed than that of UCG ammonia production with associated power and CCS and UCG CCGT power generation with CCS. Furthermore, when chemicals production from UCG is considered as the main objective, the most substantial improvements in comparison to conventional methods are associated with UCG ammonia process per tonne of chemical produced.

在传统的采矿方法不适合或不经济的情况下，地下煤气化（UCG）有潜力提供来自煤层的能源或化学原料。本文介绍了为UCG工艺开发的生命周期清单模型以及带有和不带有CO _2的三种替代合成气利用选项捕获和存储。本文比较了两种不同的传统地上燃煤发电选项与两种或两种不褐煤和一种烟煤的UCG集成气化联合循环发电（带/不带CCS）的生命周期碳足迹。然后使用一种褐煤来比较不同合成气利用选项的生命周期性能：发电，发电产生氨，发电产生甲醇。研究发现，传统的地上燃煤发电的生命周期碳足迹在很大程度上取决于所用煤的原位甲烷含量，以及在开采和伴随的上游过程中所经历的甲烷排放，而对于UCG-IGCC，相同的功率更多地取决于过程相关的合成气组成。UCG甲醇生产以及相关的动力和CCS可以释放更多的生命周期CO每吨消耗的褐煤₂当量排放量比使用联合动力和CCS的UCG氨生产和使用CCS的UCG CCGT发电要少₂ eq排放。此外，当将以UCG生产化学品作为主要目标时，与传统方法相比，最重大的改进与每吨所生产化学品的UCG氨法工艺相关。