Research on the Hydrate Formation in the process of Gas Phase CO2 Pipeline Transportation

Abstract

With the development of the third oil recovery in oil fields and CO2 capture, utilization and storage (CCUS) technology, CO2 injection has become an effective means to enhance oil recovery (EOR) and relieve the greenhouse gas effect. The CO2 pipeline transportation technology started relatively late in China, where the gas phase and liquid phase transportation are widely used methods. The CO2 hydrate formation in the process of transportation may reduce the valve, destroy the equipment and even cause pipeline ice blockage, but research in China on CO2 hydrate is not very extensive. In this paper, the CO2 hydrate formation conditions were simulated using HYSYS, and the simulation results were compared with the experimental results to verify the feasibility of the simulation method. Based on this, factors in the influence of gas impurities on CO2 hydrate formation are simulated, and the pipeline transportation process of CO2 hydrate formation are predicted. The results show that when there is a low amount of impurity content, the gaseous impurities such as CH4, N2, H2, O2, have little effect on CO2 hydrate formation in gaseous CO2 pipeline transport. Furthermore, environmental temperature has little effect on the changes in pipeline pressure along the transport route. However, with a change in environment temperature, temperature along the pipeline changes greatly. CO2 will change from a gas state to a liquid state in the pipeline when the ambient temperature is low. In the case of low ambient temperature, a thick insulation layer should be used, and heating of the pipeline may also be required. When the ambient temperature is higher than about 10℃ , there will be no hydrates formed in the pipeline.

Clathrate hydrates: recent advances on CH4 and CO2 hydrates, and possible new frontiers

“…67 Most attention concerns CH4 hydrates because in oil and gas pipelines, water and methane are at contact, sometimes at high pressure and low temperature conditions. CO2 hydrates in pipelines have received attention as a pure species due to their sequestration potential, 68 but it could also be important to quantify how polar species (CO2 and H2S) affect mixed hydrate phase boundary and growth kinetics. In fact, both quantifying accurately the thermodynamic conditions at which hydrates could form, and the kinetics of their growth are important for ensuring pipelines integrity, which is the goal of the industrial sector known as 'flow assurance'.…”

Correlative comparison of gas CO2 pipeline transportation and natural gas pipeline transportation

“…When the conveying pressure is high, the gas-liquid two-phase flow is easy to be produced, so the pressure should not be too high to avoid exceeding the critical pressure. For example, some carbon dioxide pipeline, in the design of alternative provisions, the maximum operating pressure of low pressure gas pipeline does not exceed 4.8Mpa [24].…”

Identification of the Effect of Mass Flow Rate and Hydrogen to Hydrocarbon Ratio on the Thermal Performance of a Shell and Tube Heat Exchanger – An Industrial Case Study

“…Hou et al [10] used the Aspen Plus platform to optimize a catalytic reforming process unit. Zhang et al [11] and Wang et al [12] simulated the CO2 hydrate formation conditions in the process of gas phase CO2 pipeline transportation using HYSYS software. Al-Lagtah et al [13] proposed certain modifications to an existing factory for the gas softening process in order to increase its profitability and durability by means of an optimization tool in Aspen HYSYS.…”