CO2 recovery

The choice of a specific CO2 removal system depends on the overall ammonia plant design and process integration. Important considerations include CO2 sHp required, CO2 partial pressure in the synthesis gas, presence or lack of sulfur, process energy demands, investment cost, availabiUty of solvent, and CO2 recovery requirements. Carbon dioxide is normally recovered for use in the manufacture of urea, in the carbonated beverage industry, or for enhanced oil recovery by miscible flooding. 

The experimental results are summarized in Table 2. CO2 permeance (Rco2), selectivity (oicx)2/N2) and CO2 recovery (Y) increased with decreasing CO2 mole fraction in feed gas. CO2 in the feed gas was successfully concentrated to 97-99 % by the single-stage operation. CO2... 

Khoo, H.H. Tan, R.B.H. (2006) Life Cycle Evaluation of CO2 Recovery and Mineral Sequestration Alternatives. Environment Progress, 25(3), 208-217. 

A 250 kilowatt system is planned for a site in Norway. The system will be operated by Norske Shell to demonstrate that CO2 can be economically recovered. The CO2 recovery technology is being developed by Shell Hydrogen. The CO2 could be sequestered in underground reservoirs or could be used for special applications such as fish farms or agricultural greenhouses. The test system will be sited at a fish hatchery. The system is expected to begin operation in early 2003. 

From investigations reported in Chapter 6.6, it is obvious that the production-costs will mainly be dominated by the overall energy consumption, which will depend on the solvent flow-rate, extraction-, and separation conditions, and the process design features such as the isobaric- or non-isobaric, single- or cascade-mode working, CO2 recovery, the individual execution of particular plant components, and the degree of automation. 

Replace PSA with CO2 Recovery 15-20% 4-10% Decrease Same Increase Low/ High Purity Benefits in Refinery Units... 

Tertiary oil was increased up to 41% over conventional CO2 recovery by means of mobility control where a carefully selected surfactant structure was used to form an in situ foam. Linear flow oil displacement tests were performed for both miscible and immiscible floods. Mobility control was achieved without detracting from the C02-oil interaction that enhances recovery. Surfactant selection is critical in maximizing performance. Several tests were combined for surfactant screening, included were foam tests, dynamic flow tests through a porous bed pack and oil displacement tests. Ethoxylated aliphatic alcohols, their sulfate derivatives and ethylene oxide - propylene oxide copolymers were the best performers in oil reservoir brines. One sulfonate surfactant also proved to be effective especially in low salinity injection fluid. 

Patton, J.T., and Saner, W.B. CO2 Recovery of Heavy Oil The Wilmington Field Test, Society of Petroleum Engineers of AIME. 58th Annual Technical Conference and Exhibition, San Francisco, California, 10-5-83. 

Psia, (b) co-current CO2 rinse at that pressure with recycle of effluent gas as feed, (c) counter-current evacuation to - 2.5 Psia with simultaneous steam pui e, and (d) counter-current pressurization with a part of CO2 depleted product gas from step (a). The effluent gas from step (c) is partly used as the purge gas in step (b) after recompression, and the balance is withdrawn as the recovered CO2 product gas. The inert gas and CO2 recoveries from the feed gas are, respectively, - 100 and 78% [21]. This application may be attractive for green house gas emission control (CO2 sequestration from a hot flue gas or CO2 removal from combustion gases for power generation). 

Stucki S, Schuler A, and Constantinescu M, Coupled CO2 recovery from the atmosphere and water electrolysis Feasibility of a new process for hydrogen storage. International Journal of Hydrogen Energy 1995, 20(8), 653-663. 

The project addresses the implementation of a CO2 recovery plant based on the chemical... 

The research locally developed on a CO2 removal pilot plant currently in use for research aims, revealed the high efficiency of CO2 recovery from flue gas, high carrying capacity of the monoethanolamine solution and satisfactory regeneration with low energy consumption. 

However the coal system inevitably has a high CO2 emission which would contribute global warming. The problem "CO2 emission" in Fig. 1 will be technologically able to be removed by CO2 recovery disposal. But the total consumption of fuel resource would be rather accelerated (Fig. 2, -AEi) that we cannot find any sustainable prospect over there. 

Figure 2 Fossil fuel system in addition of CO2 recovery disposal -AF. 1 process energy for CO2 recovery.

Coal system (Fig. 2) can join with a solar hydrogen system which is very difficult in the global transportation, at the processes of CO2 recovery and fuel synthesis (Fig. 3). 

CO2 recovery process (about 20-25% of coal energy, in recent technology). 

There are some problems to recover the CO2 from synthetic fuel use, although it is technically possible. The synthetic fuel such as methanol or synthetic gasoline are not only clean fuel but high cost fuel. Mainly economical reason, these synthetic fuel will not apply to coal-type electric generation, but mostly to automobile engine fuel. The application of CO2 recovery for such small apparatus is quite unfavorable in nowadays technology. 

In this point of view, a CO2 recovery from synthetic fuel use is quite desirable. 

It is very difficult to stop the increasing of number of cars. The small size CO2 recovery apparatus for flue gas will be needed but very much difficult. Perhaps only hope will be found in fuel cell generation. In principle, fuel cell is able to avoid air-N2 dilution at the oxidation of fuel on the surface of electrode. 

If we succeed to increase a percentage of CO2 recovery from synthetic fuel use, finally, we may approach to perfect Carbon-recycle system, without an abrupt change. The ultimate scheme is shown in Fig. 5. 

The problem (3). A chemical process in general, 100% yield of recovery will never achieved. In the case of CO2 recovery from flue gas, it becomes very difficult when higher than 95%, considering the process energy consumption. Even in future, about 5% of carbon should be helped from outside of the system. However, this percentage of carbon sources will be able to supply from the municipal wastes and industrial refuse in future society. 

For the CO2 recovery from fossil based power stations an additional primary energy input is required, producing supplementary CO2 emissions. The overall energy efficiency of the methanol vectors and the CO2 balance of the fossil based recovery process will be compared to the CO2 recovery from the atmosphere and to the conventional crude oil-gasoline system. 

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