No abstract

In this work, hydrate−liquid water−vapor (H−L W −V) equilibrium data for methane (CH 4 ), carbon dioxide (CO 2 ), and four synthetic carbon dioxide (CO 2 ) rich natural gas mixtures are measured. The measured pressure and temperature are in the range of (1.10 to 15.29) MPa and (272.15 to 290.15) K, respectively. In addition, a thermodynamic model based on Peng−Robinson (PR) EoS coupled with van der Waals−Platteeuw and modified Krichevsky and Kasarnovsky (KK) equation has been used for prediction of the equilibrium condition. The comparison between experimental measurements and model prediction shows excellent agreement obtained with an absolute average error of temperature (AAE) as low as 0.09. Additionally, the enthalpy of dissociation for simple and mixed gas hydrates is estimated using the measured equilibrium data by applying the Clausius−Clapeyron equation.

Presently, the major factor hindering the monetization of high carbon dioxide gas field is the high capital cost for the Acid Gas Removal System (AGRS). Several technologies have been evaluated by the industry so far including the membrane system and phase separation system such as cryogenic distillation. Based on the previous studies on Integrated Coal Gassification Combined Cycle (IGCC), a new model of carbon dioxide removal through the formation of carbon dioxide hydrate is proposed. The concept capitalized on the difference in the phase equilibria of carbon dioxide and the rest of the gas making up natural gas component such as methane, nitrogen and butane. Using this concept, the operating parameters are chosen to be in region of thermodynamic equilibrium of carbon dioxide, while at the same being in the hydrate dissociation region of other gas components by varying the pressure and temperature. The selectivity of carbon dioxide as the main guest molecule for the hydrate encapsulation is further promoted via the optimization of thermodynamic and kinetic properties, including the solubility of carbon dioxide in water and increasing carbon dioxide hydrate formation rate via the optimization of hydrodynamic properties. These variables are assessed in the continuous bench scale where hydrate slurries are formed in the tank reactor, and upon separation from the unreacted gas, is dissociated as the carbon dioxide rich stream. The performance indicator of the system is the amount of the carbon dioxide captured in the outlet stream compared to the feed gas. The paper discussed the separation system and its trending with operating parameters.

Exploration and production of sour gas field raise the need for CO2 management to minimize the adverse effect of green house gas venting to the environment. It is a fine balance between the sunken value of CO2 reinjection and value creation in CO2 conversion to value product, essential in ensuring project’s economic viability. Conversion to methane is selected due to the ease of integration with current process facility. Catalytic conversion of CO2 to methane are reported here over metal oxides (Al2O3, ZrO2 and La2O3) supported Nickel base catalysts over a range of temperature and GHSV with fixed H2/CO2 molar ratio. The catalysts were prepared by wet impregnation technique at room temperature. It was then characterized with X-Ray Diffraction (XRD), Brunauer–Emmett–Teller (BET), Temperature Programmed Reduction (TPR) and Temperature Programmed Desorption (TPD). All catalyst systems showed trend of decreasing CO2 conversion when the GHSV is increased from 10000 to 15000 h-1, which is in line with short reactant contact time. The impact is more pronounced at low temperature of 300 °C, but at high temperature of 400 °C, the conversion is almost comparable irrespective of GHSV. Experimental results indicate that Ni/Al2O3 gives the highest CO2 conversion of 74% while 7% and 67% for Ni/ZrO2 and Ni/La2O3 respectively. There is a prospect for further scaling up to complement the current commercial catalyst proven for handling low concentration of CO2.

Permanent abatement of CO2 has become a major challenge in many gas field developments especially within this South –East Asia region. Among the challenges are on how to dispose or utilize this huge amount anthropogenic CO2 safely and economically. Therefore, the objective of this study is to identify the best technology for non-catalytic CO2 Direct utilization to manage and support economic development of high CO2 gas field in Malaysia. A Market survey was conducted to a few shortlisted technologies to assess on the technology landscape and the market potential. The feedback was analyzed based on the criteria established on the basis of company requirement. From the study, ‘Mineral Carbonation’ has been identified as one of the potential technology solution for permanent sequestration of CO2 in Malaysia. The future of this technology application is very promising due to the availability of the local feedstock, mineral waste and the potential market of this product especially for carbonate product such as precipitated calcium carbonate (PCC). However, this technology still possesses some technical challenges due to slow kinetic reaction. For a large scale application, this will become more demanding especially in terms of footprint as the current technology is mainly on batch process. Therefore, the current R&D should look into area where this process kinetic can be improved and to look into continuous or semi-continuous process for smaller footprint.