基于水足迹理论的煤制油产业布局评价

煤制油是我国应对石油危机的重要途径之一,但其高耗水的特点使其备受争议。利用水足迹理论对全国五大煤炭基地2015年规划的煤制油产业进行了蓝水足迹和灰水足迹的测算,分析了煤制油产业对这些区域水资源的耗用情况及冲击程度。结果显示,神东、晋东和新疆伊犁3个基地的煤制油产业蓝水足迹超过了1亿t、灰水足迹超过了3亿t,其中神东地区作为最大的煤制油产地两项数值分别达到1.9亿t和4.1亿t与当地水资源总量对比,宁东地区煤制油耗水冲击最大,占当地水资源总量的28.2%;新疆伊犁地区比例最小,为0.36%。通过对这5个煤炭基地以区域为尺度的水足迹结构分析和评价比较,得出了两种煤制油工艺的水资源消耗差异,并且为煤制油产业在五大基地的合理布局给出了依据,与此同时为接下来煤制油产业的技术革新和流程优化也提出了相应的建议。

The coal-oil industrial layout evaluation based on water footprint theory

"The Water Footprint Concept" as introduced by Hoekstra(2002), indicates the consumption of water needed for the production of the goods and services in a certain period of time consumed by any of the known population (a country, a region or a person). The products and services referred here contain the necessary human food, all kinds of daily necessities, domestic water and environmental water. Green water, Blue water and Gray water are the three components of the water footprint. This can be used to reveal the water consumption in the process of industrial activity and provide scientific basis to manage and regulate water usage in industrial production activities. Coal Oil/CTL, also known as Coal Liquefaction, is short for the coal chemical technology of producing liquid fuels and chemical raw materials based on coal. There are usually two technical routes: Direct Coal-Oil and Indirect Coal-Oil. The Coal-Oil industry is a strategic choice for China to cope with the oil crisis. Due to the high water consumption, however, the industry brings about many controversies. Based on water footprint theory, we calculated the blue water footprints and gray water footprints of the planned coal-oil industries in the nation''s five largest coal bases: Shendong, Jindong, Ningdong, Shanbei and Xinjiang Yili. The water footprint includes direct water footprint and life cycle water footprint. The former means the water footprint associated directly with the production while the latter means the water footprint in the whole production supply chain. As the coal-oil industry consumes large amounts of coal and power resources, so the water footprints in coal plant and thermal power plant are both considered in the life cycle water footprint. Thus, we not only calculated the power consumption of the thermal power plant and coal plant themselves but also took the coal consumption in thermal power plant into account. The results show that three out of five coal bases, Shendong, Jindong,and Xinjiang Yili have over 100 million tons of blue water footprint and their gray water footprint exceeded 300 million tons. Among them, for Shendong region as the largest coal-oil producer, these two values reached 190 million tons and 410 million tons respectively. From 2015 on,every year 7.26 million tons of oil is expected to be produced. Among the blue water and gray water footprints, the life cycle water footprint that includes coal and power resources water footprints accounted for nearly 50%. Therefore the life cycle water footprint has become a very important part of the water footprint. In addition the coal plant water footprint is much greater than thermal power plant. Compared with the local regional water resources, the utilization of water resources in Ningdong region is the largest (28.2%) and Xinjiang Yili region the smallest (0.36%). The results also show the regional average blue water and gray water footprints data of the coal-oil industry is basically the same: to produce 1 ton of oil the average blue water footprint is 20-26 tons while the gray water is 56-62 tons. All in all, the coal-oil industry layout planning should follow the principles of supply-side management and be based on local water resources and water environmental capability.