创新煤炭开发利用技术以降低煤炭从生产到利用全生命周期内的碳排放，是符合我国能源禀赋特点的煤基清洁能源路线。地下气化是深部煤炭原位开采的潜力方式之一，耦合CCS/CCUS(碳捕集与封存/碳捕集、利用及封存)的深部煤炭地下气化制氢技术路线不仅可以利用丰富的深部煤炭资源，而且有望成为一种理想的煤基低成本制氢路线。基于世界上唯一的千米级深部煤炭地下气化试验数据，结合Aspen Plus过程模拟，开展了深部煤炭地下气化制氢碳排放核算及碳减排潜力分析。与商业化的Lurgi煤炭地面气化制氢路线作对比，利用生命周期评价方法建立了2种工艺的全生命周期碳排放计算模型，比较了2种制氢路线的生命周期碳排放。评估了深部煤炭地下气化制氢的CCS/CCUS路径及碳减排潜力。研究结果表明，在氢气生产能力为12亿Nm3/a情形下，深部煤炭地下气化制氢和Lurgi煤炭地面气化制氢生命周期内的碳排放分别为3.29×106 t CO2-eq (当量二氧化碳)和3.93×106 t CO2-eq，其中以废气形式直接排放进入大气的二氧化碳量分别为2.09×106 t和2.24×106 t。在氢气生产阶段的主要碳排放源为废气，包括酸性气体脱除单元排出的废气和甲烷重整单元排出的烟气。深部煤炭地下气化制氢工艺所带来的高甲烷含量特征导致生产1 kg氢气时，甲烷重整单元烟气贡献的CO2排放量达到8.84 kg。间接排放方面，由于深部煤炭地下气化直接采用液态水作为气化剂而不需要消耗外界蒸汽，因此蒸汽消耗带来的碳排放低于地面气化。Lurgi煤炭地面气化上游包含煤炭采选及煤炭运输阶段，尽管这两阶段的碳排放占比只有6.7%，但仍然会带来2.63×105 t CO2-eq的碳排放。若深部煤炭地下气化空腔在地质安全风险评估的前提下用于CO2地质储存，储存量可以达到CO2排放总量的61.8%，若再配套47万t/a的尿素装置，即可有效利用其余的CO2，形成近零排放的深部煤炭地下气化制氢及尿素联产技术路线。研究结果为深部煤炭地下气化制氢提供了碳排放定量评价的科学依据。

Innovating coal development and utilization technology to reduce carbon emissions during the whole life cycle of coal from production to utilization is a coal-based clean energy route that meets the characteristics of China's energy endowments. Underground gasification is one of the potential methods of deep coal in-situ mining, coupled with CCS/CCUS (Carbon Capture and Storage/Carbon Capture， Utilization and Storage) deep coal underground gasification hydrogen production technology route can not only utilize the rich deep coal resources, but also is expected to become an ideal of coal-based low-cost hydrogen production route. Based on the world's only kilometerlevel deep coal underground gasification test data, combined with Aspen Plus process simulation, the carbon emission accounting and car-bon emission reduction potential analysis of deep coal underground gasification hydrogen production were carried out. Compared with the commercial ground Lurgi fixed bed pressurized gasification hydrogen production route, the life cycle assessment method is used to establish the whole life cycle carbon emission calculation model of the two processes, compared the life cycle carbon emissions of the two hydrogen production routes.The CCS/CCUS path and carbon emission reduction potential of the underground gasification of deep coal are further evaluated.The results show that the carbon emissions during the life cycle of underground gasification of deep coal and ground gasification of Lurgi coal are 3.29×109 t CO2-eq and 3.93×106 t CO2-eq in the case of hydrogen production capacity of 1.2 billion Nm3/a, respectively, and the carbon dioxide directly emitted into the atmosphere in the form of exhaust gas is 2.09×106 t and 2.24×106 t, respectively. The main carbon emitters in the hydrogen production phase are exhaust gases, including exhaust gases from acid gas removal units and flue gases from methane reforming units. The high methane content characteristics brought about by the underground gasification process of deep coal lead to the CO2 emissions contributed by the flue gas of the methane reforming unit to 8.84 kg when producing 1 kg of hydrogen.In terms of indirect emissions, deep coal underground gasification directly uses liquid water as a gasifier without consuming external steam, so the carbon emissions caused by steam consumption are lower than that of ground gasification. The upstream of Lurgi coal surface gasification includes the coal mining and processing and coal transportation stages, and although the carbon emissions in these two phases are only 6.7%, but still bring 2.63×105 t CO2-eq. If the deep coal underground gasification cavity is used for CO2 geological storage under the premise of geological safety risk assessment, the storage capacity can reach 61.8% of the total carbon emissions, and if the urea device is supported by 470,000 tons / year, the remaining CO2 can be effectively used,to form a near-zero emission deep coal underground gasification hydrogen production and urea co-production technical route. The research results provide a scientific basis for quantitative evaluation of carbon emissions for hydrogen production from deep coal underground gasification.

0 引言
1 生命周期碳排放核算方法
1.1 系统边界
1.2 计算模型
2 深部煤炭地下气化制氢碳排放分析
2.1 工艺流程与过程参数
2.2 清单分析
2.2.1 煤炭采选
2.2.2 煤炭运输
2.2.3 UCG模块建设
2.2.4 氢气生产
2.3 碳排放计算结果
2.4 深部煤炭地下气化制氢耦合CCS/CCUS的减
3 结论