A performance assessment for CO2 conditioning with polymeric membranes to start an EOR project in Argentina

LILIANA ALE RUIZ; JUAN PABLO GUTIERREZ; ELEONORA ERDMANN

Toronto

Congreso; XXIX Interamerican Congress of Chemical Engineering incorporating the 68th Canadian Chemical Engineering Conference; 2018

The potential of the Enhanced Oil Recovery (EOR) by using carbon dioxide (CO2) relies on two main impacts. One of them is the sustainability and the other economic benefit, this technology can successfully capture thousands of tons of CO2 according COPE Paris while increasing the production of mature oil and gas wells.In this work, we evaluate the performance of polymeric membrane plants, to separate CO2 from methane, in order to use it as EOR fluid. For the purpose we employ the process simulator Aspen Hysys together with a module that represents the polymeric barrier to catch the molecules of CH4.The goal of the process is to achieve a high-purity CO2 permeate, at high pressures. All the values respect to the inlet conditions and assumptions done are reported in the article. Also we compare the performances of different polymers currently used in industries: polycarbonates (PC), celluloseacetate (CA), polyamide (PA), polyamide-imide (PAI), polyamide thin-film composite, and polyether (PE). The importance of the use of different materials is the possibility to evaluate total membrane area, permeabilities and operating conditions. A comparative and integral discussion of the alternative considers three fundamental aspects: residual gas quality, hydrocarbon recovery, andcompression power to carry out the separation. The three aspects are of significant importance due to the necessity of reducing the amount of waste methane while increasing the CO2 concentration, but with the minimal energy requirement respect to the compression power, normally high in this kind ofplants. Regularly, these three variables can be improved simultaneously with the increase of the compression stages, with intercooling stages. The location and the required power of compressor are very important aspect to consider and thus they increase the robustness of the problem and consequently the precision of the results. For decision-making, we also calculate the operating andutilities costs of each of the alternatives.In our analysis we consider the process flow diagrams shown in Figure 1.Among the results, it is noticeable that all the analyzed membrane modules achieve the specification regarding the concentration of CO2. A good recovery is observed with the PC and PAI materials, arranged according to D, at similar values of compression power. The PI membranes offer a great recovery of CH4, with values lower than 57 kW. The same performance is observed with CA,however the power is increased by 16%. Generally, the less the CH4 wastes, the greater membrane area and higher compression power. In this aspect, the inclusion of the economic factor was crucial and lead the authors to conduct a better conclusion.