Preparing to ramp up large-scale CCS demonstrations: An engineering-economic assessment of CO_2 pipeline transportation in China

摘要

An integrated carbon dioxide (CO_2) capture and storage (CCS) system requires safe and cost-efficient solutions for transportation of the CO_2 from the capturing facility to the location of storage. While growing efforts in China are underway to understand CO_2 capture and storage, comparatively less attention has been paid to CO_2 transportation issues. Also, to the best of our knowledge, there are no publicly available China-specific cost models for CO_2 pipeline transportation that have been published in peer-reviewed journals. This paper has been developed to determine a first-order estimate of China's cost of onshore CO_2 pipeline transportation. An engineering-economic model based on China-specific data, codes, and standards to the greatest extent possible has been developed for this purpose. Based on the model, five illustrative case studies on pipelines for transporting captured CO_2 from typical Integrated Gasification Combined Cycle (IGCC) and Ultra-supercritical (USC) generating units of250 megawatt (MW), 400 MW, 660 MW, 1000 MW, and 2x1000 MW are carried out. The results show the capital costs of constructing a 100-kilometers (km) pipeline are between $18 million and $102 million, depending on the amount of CO_2 transported. Corresponding figures for the levelized costs are $1.84-$3.06 per tonne of CO_2. Sensitivity analyses are also performed examining the effect of pipeline length and soil temperature on pipeline diameter, as well as flow rate and capital cost on levelized cost. The pipeline length is found to impact the diameter significantly, whereas soil temperature demonstrates insensitivity to pipeline diameter. Both flow rate and capital cost have significant effects on levelized cost. Comparison to other existing models based on either North American or European data implies a major cost difference between developed countries and China: China's cost of onshore CO_2 pipeline transportation is very likely much lower than those estimated in the developed countries. For a 0.02MtCO_2/d case, for example, the levelized cost of CO_2 transportation in China is about two-thirds that of the developed countries.