Review and Evaluation of Alternative Chemical Disposal Technologies (1996) / Chapter Skim
Currently Skimming:
4 CATALYTIC EXTRACTION PROCESS TECHNOLOGY
4 CATALYTIC EXTRACTION PROCESS TECHNOLOGY
Pages 25-71
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 25... ...
Destruction of HD and VX by CEP is accomplished in a series of unit operations after the ton containers have been opened and the contents transferred to interim storage tanks. CEP has been designated by the U.S.
|
From page 26... ...
According to the TPC, because CEP is carried out at low oxygen potential and decomposes feed molecules to elements regardless of their starting molecular structure, the process provides neither pathways nor precursors for the formation of oxides of nitrogen or sulfur or the formation of dioxins and furans. The TPC has reported that it expects the process residuals from treating VX or HD, the ton containers, and dunnage to be ferrous alloys, aqueous hydrochloric acid, elemental sulfur, and a synthesis gas.
|
From page 27... ...
.. ~ _ Product Full Ton Containers Water , , Area 100 Liquid Agent, Punched TCs Area 200 Cutting Water/Abrasive Flushing Water Rinsing Water 1 _ Synthesis Gas HCI, H2S FeCI2 Area 300 FeCI2 Slurry I .
|
From page 28... ...
Slab formed by the interaction of debris entering with the emptied ton containers, lime-based decontamination solutions, and dunnage can be removed in the same way molten metal is removed. Synthesis _Gas Product (~3,900,000 Ibs)
|
From page 29... ...
Thus, there is no long-established precedent from industrial experience for the complete reaction of injected gases with a molten metal bath to the very low level of residuals required for agent destruction. The pane]
|
From page 30... ...
(If nitrogen were used as the inert make-up gas, N2 would also be a significant component of the initial bubbles.) Catalysis by the Bath and the Formation of Intermediates There is ample evidence in the peer-reviewed literalure to support the TPC's position that the molten metal bath serves as a true catalyst by decreasing the activation energy for dissociation of organic molecules, participating in the formation of intermediates, and increasing the efficiency of product fonnation without itself undergoing change (Satterfield, 1991~.
|
From page 31... ...
by keeping the bath below saturation. The strategy is to remove alloyed bath metal at intervals by tapping, while adding moTten iron by processing ton containers.
|
From page 32... ...
Partitioning of Products among Metal, Slag, and Gas Phases To some extent, the process residuals from CEP can be customized by adding appropriate cofeeds or controlling operating conditions. As noted above, the design specifies that oxygen cofeed is provided in stoichiometric proportion to convert carbon in the feed material and the methane cofeed to CO at the desired carbon concentration and temperature of the bath.
|
From page 33... ...
However, in response to the concerns of communities near the storage sites, the TPC has subsequently changed the design to include three 4-m3 storage tanks, in parallel, in the synthesis gas line prior to the gas turbine. Each tank has the capacity to store 15 minutes of anticipated output of synthesis gas pressurized to 20 atmospheres, gauge (300 psi")
|
From page 34... ...
Demonstrated hot metal operation for >700 hours. Automated heating to maintain bath temperature.
|
From page 35... ...
PROCESS OPERATION Process Description The TPC provided the following process diagrams, which will be referred to in this and ubsequent sections as needed: Block flow diagram for CEP facility (Figure 4-4) CEP process flow diagram for VX feed injection system into CPU-2 with premelting chamber for ton containers (Figure 4-5)
|
From page 36... ...
Oxygen/Steam Natural Gas Inert Gas In a case requiring venting gases from the CPUs, piping' or other vessels by way of the pressure relief system (Figure 4-8) ' the on-line caustic scrubbers would further destroy any agent that might potentially
|
From page 37... ...
· 1 - i · ITniueycetirOen · l , Modules , ~i Area 500-Synthesis Gas Utilization Atmosphere ~_ _ I ~ I I Alternative I Natural Gas , ~Steam ~ -~ ~ ~ ~~ - i Methane ~~ ~ ~Power I ~Reformer ~ ~Generation ! 1 Synthesis Gas ________ , 1 · .
|
From page 38... ...
1 (a-, -Da ' Con N.N.F. r - - -I FIGURE 4-5 CEP process flow diagram for VX feed injection system into CPU-2, with premelting chamber for ton containers.
|
From page 39... ...
Analysis of ton containers prior to processing is not necessary, provided they are not stored prior to CEP treatment. (Interim storage of emptied containers would require cleaning to the 3X standard.)
|
From page 40... ...
Operational Modes Substantial time is required to heat the CEP system, including the CPUs and the gas handling trains, to operating temperature or to coot the system from operating to ambient temperature. Therefore, it is preferable to operate a CEP facility continuously, 24 hours per day, for extended periods.
|
From page 41... ...
recovery area) · switching from inert gas feed to feed streams of methane, oxygen, and finally agent Shutdown to a hot standby mode requires gradual substitution of an inert gas for agent, oxygen, and methane to keep the tuyeres open; readjustment of the electrical power to keep the baths molten; and maintaining the gas handling trains for both CPUs at operating 41 CWR Process Gas ,, ~, I I 1 1 To R Y-20 1 Watt r S al i ds /S al uti on 40 Ib./hr.
|
From page 42... ...
to ZD Heat Duty(Btu/hr) FIGURE 4-7 CEP process flow diagram for VX CPU-1 gas handling train.
|
From page 43... ...
Feed Streams This section discusses only the feed streams into the facility and not the internal process streams. 43 VT-356 AIB/C CR-355 Synthesis Gas Sample Tanks Synthesis Gas Reciprocating Compressor 3 Stage - Vendor Package VT- 3 5 6 A/B/C N N F | _ N.N.F.
|
From page 44... ...
Source: M4 Environmental L.P., 1996b. addition of ton containers can be synchronized with the agent feed rate, as explained in the section on Catalysis by the Bath and the Formation of Intermediates.
|
From page 45... ...
The TPC plans to use pipeline natural gas as the methane source, with no on-site storage. - Decontamination Solution The TPC submissions do not specify the required quantity of decontamination solution, but it should be less than the amount required in the baseline system because CEP does not require decontamination of ton
|
From page 46... ...
Prefrealment Requirements Cleaning the ton containers is not necessary in this process. if the Army requires precleaning of the ton -..,;..................................
|
From page 47... ...
Fe Accumulation into CPU-1 Metal Bath CPU-2 sHol~veWt Liquid HD CPU-1 _ ~ Metal Chloride Slurry ED E3E 3 Co-reactants 47 Methanol _ Methanol Product ~ Production Deionized Water Cofeeds Synthesis Gas TrHaaindli 9 ·C?
|
From page 48... ...
, will be burned along with natural gas in a gas turbine generator to supply in-plant electricity needs, subject to permit approval. The TPC projects that the effluent gas released to the atmosphere from the gas turbine will have the composition shown in Table 4-4.
|
From page 49... ...
It includes methods for processing ton containers, decontamination solutions, and dunnage, as well as for destructive processing of chemical agents.
|
From page 50... ...
so o c~ ct c~ ~ ·c~ ~oo oo o ~o ;^ 'e o cr)
|
From page 51... ...
of these feed materials are converted to usefu! products, including iron-based alloy, synthesis gas for power generation, aqueous HC1, and elemental sulfur.
|
From page 52... ...
Video surveillance provides visual monitoring of the entire process, end to end. The process monitoring and controlling requirements for the feeds to the CPU reactors include gas mass-flow controllers for the oxygen, inert gas, and natural gas streams and liquid flow controllers for agent and for solutions used to clean ton containers.
|
From page 53... ...
Gas chromatographs, mass spectrometers, and the continuous emission monitoring system are capable of analyzing the feed, internal process, and residual streams to meet regulatory and operational requirements. Monitoring Synthesis Gas prior to Combustion The TPC plans to choose among one of three analysis systems during the next stage of design.
|
From page 54... ...
The large mass of the metal bath provides commensurately large thermal inertia, which prevents a significant temperature excursion in the event of perturbations in the feed rate of agent or cofeeds. The bath mass provides a margin of safety for bath composition and feed rate and allows the CPU to operate over a relatively wide range of conditions.
|
From page 55... ...
Essential services for a no-feed, hot standby condition can be provided by the gaspowered turbine generator used to recover energy from the synthesis gas. If a turbine generator is not installed, a diesel generator capable of a 10-minute response from cold start can be used to provide power for standby services.
|
From page 56... ...
Environmental Chemistry and Conditions Nomina/ /ntew~/ Environmenta/ Condifions The CEP processing conditions described here are based on the submitted design, which is preliminary and subject to revision during further design and development. For processing HD, the nominal chemical environment in CPU-2, where ton containers and dunnage are processed, is a molten iron phase containing a controlled concentration of carbon and a gas phase consisting of H2, CO, H2S, and HCI.
|
From page 57... ...
Atmospheric contaminants TABLE 4-6 Flow Rates in the Gas Handling Train for HD Processing Gas Handling Service or Equipment Flow Rate Reactor offgas HCl product Quench water to reactor offgas Primary HCl recovery column overhead Recycle liquid to primary column Primary column pump-around Makeup water to secondary column Offgas to sulfur recovery 750 acfm (3541/s)
|
From page 58... ...
Reactor Omegas Piping. Hot offgas in the gas handling train is transferred in a jacketed pipe, which is designed to be cooled with water to maintain the pipe temperature within the maximum temperature limit for carbon steel.
|
From page 59... ...
Still another variation is to evacuate the system and then break the vacuum with the inert gas, with several repetitions. The TPC plans to decide which procedure to use in this facility during the detailed design phase and will incorporate it into the operating instructions.
|
From page 60... ...
. The failure modes in the gas handling train that are of some concern are loss of coolant in the offgas precooler (which could damage downstream equipment)
|
From page 61... ...
In the gas handling train, the quench water source has assured backup water sources, such as the firewater system. The backup water source ensures that hot offgas from the CPUs is cooled to prevent damage to the gas handling train.
|
From page 62... ...
EVALUATION OF ALTERNATIVE TECHNOLOGIES Because operations at the two sites will be of short duration (about one year each) and the number of process cycles to be completed is fairly low (1,700 ton containers at each site, plus miscellaneous discrete items)
|
From page 63... ...
For example, the punch-and-drain equipment for ton containers has operated successfully at the JACADS chemical demilitarization facility. CPU Equipment The state of development of the CPU and related equipment is described above in the Technology Status section.
|
From page 65... ...
The DRE calculation was limited by the amount of agent processed and the lower detection limit of the analytical method. In another test, diazinon, which is structurally similar to VX, was reported to have been converted to synthesis gas, with the phosphorus and sulfur from the diazinon retained in the metal phase as an Fe-S-P alloy.
|
From page 66... ...
As another example, the capability in the CEP design for treating emptied ton containers to the equivalent of 5X condition by melting and processing them immediately reduces the risk from handling the containers. The process-safety risk factors inherent in CEP include issues associated with high-temperature molten TABLE 4-8 Specific Processing Rates of Bench Tests Relative to Full-Scale Design Rates Specific Processing Rate (kg agent/hour/l,OOO kg bath metal)
|
From page 67... ...
storage and feed CPU- 1 Premelting chamber to CPU-2 CPU-2 CPU-2 offgas quench, scrub, particulate removal, and compressor Gas quench and particulate removal HC1 recovery Sulfur recovery Gas compression and retention/analysis Power generation Steam-methane reformer (option for methanol recovery Methanol production (option for methanol recovery Sulfur product storage HC1 product storage Methanol product storage (option for methanol recovery) a Inert gas storage and feed Oxygen storage and feed Natural gas feed Air plant air and instrument air Water plant, potable, cooling, boiler feed, and chilled Steam generation and condensate handling Electricity Diesel power backup Scrubber (decontamination solution)
|
From page 68... ...
SCHEDULE Figure 4-11 is the latest schedule submitted to the AltTech Pane! from the TPC for the major activities and milestones in a chemical demilitarization program to use CEP technology at the Aberdeen and Newport sites.
|
From page 69... ...
The facility for this pilot/demonstration phase at each site will be equipped with enough gashandling capability to ensure protection of human health and the environment, but the full gashandling train will not be installed until full-scale operation. The TPC foresees no scale-up effort required to move from pilot testing to full-scale processing.
|
From page 70... ...
The full-scale operation at each site is designed to be continuous, 24 hours per day, at the agent feed rates specified above in the Feed Streams section. The scrubbed offgas is either combusted with natural gas in a gas turbine generator to produce electricity for the plant or converted to methanol.
|
From page 71... ...
(The schedule refers to the activity as phase 1 of decontamination and decommissioning.) Additional time will probably be required for decontaminating and decommissioning the central building and the associated infrastructure.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.