Mineral carbonation is a process where carbon dioxide (CO2) is converted into solid carbonates. The product of mineral carbonation is obtained when CO2 is being contacted with alkaline earth metals, such as calcium and magnesium. In this research, the team focusing on producing precipitated calcium carbonate (PCC), as a solution to manage CO2 release which comes from high CO2 content natural gas field production. To make this process economically feasible, the team has researched obtaining valuable PCC quality which is marketable in various industries. The quality mainly measured in terms of particle size, where the particle size will determine the application of the PCC. This study investigates the effect of feed solution retention in reactor towards PCC particle size, using continuous mineral carbonation system. In this system, Milk of Lime, which is Calcium Hydroxide (Ca(OH)2) solution used as feed. To produce this solution, 7 g/L Calcium Oxide (CaO) is suspended in deionized water and stirred. This solution is injected in the range of 0.8 L/min to 1.2 L/min into pressurized CO2 in the range of 10 bar to 80 bar. The retention time is varied by using mechanically modified reactor inlet cap, where the feed inlet time is delayed by elongation of feed injector inside the reactor by 15 cm (NEWCAP). Particle size of the product was analyzed by using Malvern Mastersizer 3000. Experimental data show that by shortening the feed solution retention time inside the reactor, will produce smaller particle size. Using the unmodified reactor inlet, the obtained product particle size ranging (D50) from 15 micron to 25 micron. On the other hand, using NEWCAP reactor inlet the obtained particle size ranging (D50) from 8 micron to 20 micron.

CO2 utilization into minerals is one of the most efficient methodologies although much research concerns the utilization of CO2 to produce chemicals. The production of precipitated calcium carbonate (PCC) from three different starting materials has been reported. The gas-liquid reaction is carried out by bubbling carbon dioxide into a solution of lime products with fixed parameters of 99% CO2 purity, 4.0 L/min of flow rate and 1500 rpm stirring rate at atmospheric pressure. The PCC was then characterized for X-Ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-Ray fluorescence (XRF) and particle size. Experimental results indicate that the PCC produced from quick lime showed the highest yield of 17.27 g, however there is no significant difference for both carbide lime and hydrated lime at 12.04 g and 11.57 g respectively. Morphology, phase structure and particle size of PCC produced reveals insignificant influence with different starting materials. Producing PCC from CO2 and natural minerals can be a potential method of reducing CO2 emissions by locking-up CO2 in a stable mineral form, whilst at the same time turning low quality natural minerals into high valuable products.

This paper describes the experience of PETRONAS in sustainable development of a high CO2 gas field. The development project which have a potential of storing 23MTPA of CO2 in a nearby offshore saline aquifer is energy intensive. The operational cost of operating the high duty CO2 capture, transport and reinjection (or CCS) facilities has a negative impact on the overall project economics. As such, optimizing the energy footprint of the CCS facilities is imminent. As a means to achieve the desired duty reduction, the project have identified potential energy recovery from the high pressure well stream via the adiabatic turboexpander gas expansion, deployment and integration of the liquid CO2 pumps as opposed to the conventional higher duty compressor systems and utilizing low BTU gas turbine drivers to avoid the high duty fuel gas separation penalty. The aggregate duty reductions achieved has met the initial project expectation. However, the deployment of these technology is rather new for offshore service and a proper technology qualification exercise is a necessity.

Precipitated calcium carbonate (PCC) is synthetic calcium carbonate that has high purity of more than 98 wt% of CaCO3 content.  Owing to its unique characteristic whereby its shape and size can be controlled to tailor to various applications, PCC has seen great demands in many industries such as paper, paint, plastic, food, ceramics, cosmetics, pharmaceutical, and many others.  PCC can be synthesized via various methods and the most often used method in industry is via carbonation process.  This process has caught interest of the oil and gas industry for utilizing existing carbon dioxide waste from plant processes.  Precipitation of PCC is carried out using hydrated lime under various conditions at different gas purity (1 mol% CH4 + 99 mol% CO2 , 40 mol% CH4  + 60 mol% CO2 ), different gas flowrate, and different stirring rate.  All experiments are carried out using 1 litre of ionic solution at ambient conditions.  All samples are characterized using Field Emission Scanning Electron Microscopy (FESEM), Particle Size Distribution, X-Ray Diffraction (XRD), and X-Ray Fluorescence (XRF).  FESEM analysis shows different surface morphology for different methane content with calcite formation.  The particle size for all PCC produced at different parameters are comparable at the range 5-9 microns depending on the mixing rate used whereas XRF results indicate very high purity of CaCO3 of more than 99 wt%.

Development of ultra high CO2 field in Malaysia is the next frontier as far as contaminated green field development is concerned. Large hydrocarbon reserve is a major driver to mature technology to support the development of contaminated fields. However, managing the contaminant CO2 is still a major drawback as far as technology is concerned. Base case consideration for CO2 emission mitigation for offshore high CO2 gas fields had always been geological injection even though it deteriorates the overall field economics to a point which may prove to be prohibitive for some field development cases. An alternative method to mitigate CO2 would be the conversion of CO2 to higher value products which provides return in the form of additional revenue or profit. The monetory income from the conversion of CO2 can be utilized to either fully or partly offset the high cost of CO2 injection. This paper attempts to summarise the experience based on feasibility study, technical consideration and lesson learnt by PETRONAS to mitigate the CO2 emissions from the development of such high CO2 gas fields. The summary is done in the context of selecting the suitable CO2 mitigation technology, scale of conversion, maturing the technology and economic consideration as an integral part of the field development.