GC8000 Process Gas Chromatograph

Measurable object	Gas or volatile liquid (400°C or lower boiling point)
Analysis method	Gas chromatography
Measurable range	Depends on analysis conditions TCD: 1ppm to 100% FID: 0.1ppm to 100% FID (with methanizer): 0.1ppm to 0.1% FPD: 0.1ppm to 0.1%
Number of components to be measured	Maximum of 999 (total number of components in all streams including calibration standard sample streams)
Analysis period	Maximum of 21600.0 seconds (six hours)
Number of streams to be measured	Maximum of 31 (including standard sample streams)
Material of sample-contact parts	RV: 316SS, Hastelloy-C, Rulon, PTFE (Teflon, Bearee) LSV: 316SS, Hastelloy-C, Rulon, Glass, PTFE (Teflon, Bearee), Fluororubber (Viton), perfloroelastomer (Kalrez)
Repeatability	Depends on analysis conditions Gas sample: ±1% of full scale for measuring ranges (2σ) Liquid sample: ±2% of full scale for measuring ranges (2σ)

* The value may vary depending on the specifications and conditions. For details, contact Yokogawa.

Analyzer specifications

Type of protection	Pressurized enclosure and flameproof enclosure
Area classification	FM: Type X Pressurization and Explosion proof for Class I, Division 1, Groups B, C and D. T1 to T4 Type X and Y Pressurization for Class I, Division 1, Groups B, C and D. T1 to T4 ATEX: II2G Ex d px IIB+H2 T1...T4 Gb IECEx: Ex d px IIB+H2 T1...T4 Gb TIIS: Ex pd IIB+H2 T1 to T4
Protection degree of enclosure	NEMA3R, Equivalent to IP54 (dust and water resistant structure)
Operating ambient conditions	-10 to 50°C, 95% RH or less (no condensation)
Weight		Wall-mounting version	Self-standing version
	Type 1	approx. 100 kg	approx. 140 kg
	Type 2	approx. 155 kg	approx. 190 kg
	Type 3	approx. 200 kg	approx. 220 kg
Isothermal Oven
Volume	Large isothermal oven: Approximately 45 L Standard isothermal oven: Approximately 31 L
Setting temperature range	55 to 225°C  (Temperature can be set in one-degree step.)
Temperature control accuracy	± 0.03°C
Temperature control	PID control
Input/Output
Analog Input/Output	Maximum of 16/Maximum of 32
Contact Input/Output	Maximum of 32/Maximum of 20
PC communication	Ethernet communication Protocol: TCP/IP, FTP, Modbus TCP/IP
DCS communication	RS-422 Protocol: MODBUS, Y-Protocol

Utility

Power supply	100/110/115/120/200/220/230/240 VAC ±10%, 50/60 Hz ±5%
Maximum rated power	Type 1: 0.8 to 1.6 kVA Type 2: 1.4 to 2.9 kVA Type 3: 2.0 to 4.3 kVA
Instrument air	Pressure: 350 to 900kPa (50.8 to 130.5 psi) Flowrate: Type 1: 100 to 140 L/min Type 1 with FPD: 130 to 200 L/min Type 2: 150 to 210 L/min Type 2 with FPD: 180 to 270 L/min Type 3: 200 to 280 L/min
Carrier gas	Types: H2, N2, He, or Ar Purity:   Measuring range from 0 to 50 ppm or more: 99.99% minimum (water: 10 ppm or less, organic components: 5 ppm or less)   Measuring range from 0 to less than 50 ppm: 99.999% minimum (water: 5 ppm or less, organic components: 0.1 ppm or less) Pressure:   H2: 500 kPa (72.5 psi) (Supplied with extra-regulator for explosion-proof certification)   Other than H2: 400 to 700 kPa (58.0 to 101.5 psi) Consumption: 60 to 300 mL/min per isothermal oven

The GC Module (GCM) is a concept where all the parameters and functions of a specific GC application are gathered under one section. For analyzers tackling more than one GC application, this allows everything to be segregated into individual virtual GCs for much easier understanding and maintenance. No longer will the technician need to wonder which valve or peak setting applies to which portion of the GC's application. And navigating between the GCMs is as simple as touching the GCM tabs on the screen.

One example of how the GCM design can help is with Parallel Chromatography. Parallel Chromatography is a powerful tool for process GCs that can often reduce analysis cycle times and hardware complexity. But until the GC8000, the implementation of parallel chromatography was cumbersome and difficult as the software for the different parallel chromatography segments were not segregated from one another. This complexity limited the ability of parallel chromatography to be utilized to its full potential. The GC8000 avoids this confusion and complexity by using individual SYS configurations (system clocks) for each individual mini-applications (often called applets).

Flexible and Secure Network Design

The communications network of the GC8000 is based on the industry-standard Ethernet structure to provide flexible yet secure transmission of data to GC maintenance workstations and the plant DCS system. The GC8000 can be set up for either a single Ethernet network or a redundant network with two completely isolated Ethernet networks if desired. 

Built-in native Modbus TCP/IP protocol support for network communications eliminates the need for communication gateways to DCS in many situations. Not only does this simplify the network architecture, but it also removes a potential point of failure in delivering analytical data to the DCS. For communication systems that still require serial Modbus gateways, the GC8000's ASGW is available.

The GC network can even be expanded to include the Advanced Analytical Instrument Maintenance Software (AAIMS) that provides real-time asset maintenance management functions for a wide range of on-line process analyzers such as pH and O2 as well as GCs and FT-NIRs. AAIMS improves the process analysis efficiency by accurately assessing and displaying the KPIs of each analyzer through real-time data acquisition combined with statistical quality control (SQC) analysis. It also provides a common graphical interface for all the plant's analyzers for validation checks and alarm reporting.

Applications in Industries

Petrochemicals	ethylene, polypropylene, polyethylene, BTX, butadiene, vinyl chloride, styrene, alcohol, aldehyde, ester, and vinyl acetate
Petroleum refining	distillation point analysis, PINA/PIONA analysis, FCC, sulfur recovery
Chemistry	chlorides, fluorine compounds, formalin, methanol, urea, ammonia, phenol
Electric power/gas	fuel gas, exhaust gases, coal gasification/ liquefaction, fuel cell
Natural gas	transmission, distribution, gathering, processing
Iron and steel	blast furnace, coke oven
Air plant	organic/inorganic gas analyses
Chemicals	chemicals, agricultural chemicals
Environmental area monitoring	air/soil pollution monitoring, plant/work environmental analyses, analyses (VOC)

 

Refining

Modern society has evolved around the automobile as a source of cheap effective transportation. As the popularity of the automobile grew, so did the demand for the gasoline that powered the car. Supplying this gasoline has grown into one of the largest industries in the world from the efforts to find crude oil to the refining, marketing, and distribution of the finished gasoline.

The modern refinery, at first glance, appears to be a very complex mixture of pipes, vessels, and reactors, but when you break it down into its various units, the refinery is really quite straight forward. The basic intent of a refinery is to take crude oil and separate out the small amount of gasoline that is naturally found in the crude oil. Then the refinery takes the chemicals in the leftover crude oil and reacts them to convert them into gasoline. For example, one of the chemicals found in gasoline is octane. Octane can be made by taking two C4 molecules and reacting them together; which is the purpose of the alkylation unit in a refinery. Other units take the molecules that are too big to be used for gasoline and break them apart by either catalytic cracking or thermal decomposition in a coker.

With all these chemical reactions occurring simultaneously, it is easy to appreciate the importance of on-line chemical monitoring and control. This explains why the refineries were one of the first industries to utilize the process gas chromatograph on a large scale.
 

Natural Gas

The Natural Gas Processing Industry is responsible for delivering the billions of cubic feet of natural gas that is used every day. This is done in four stages:

1. Gas Gathering
2. Gas Processing
3. Gas Transmission
4. Gas Distribution

Below is a simplified drawing illustrating the four steps:

The first stage is Gas Gathering where the natural gas wells are drilled, the gas is extracted and collected to be processed. The next stage is the Gas Processing where the raw field gas is processed at Gas Plants to remove the heavy hydrocarbons and return a high methane “pipeline” quality natural gas. The heavy hydrocarbons that were stripped out of the raw field gas are further processed at a Natural Gas Liquids (NGL) Plant to separate this mixture into pure hydrocarbon products for sale to chemical plants.

The “pipeline” quality natural gas now enters the third stage where the Gas Transmission companies transport it the hundreds or even thousands of miles to where it’s needed by the consumer. The final stage is where the Gas Distribution companies buy the gas from the transmission companies and then they distribute the gas to each consumer whether it’s a residential home or a large power plant.

At each stage, the ownership of the gas may change and so one of the most common applications for a process gas chromatograph is to monitor the quality of the gas for BTU content and composition. For example, the gas processing plants take the raw field gas from the pipeline which has high BTU content due to the high concentration of heavy hydrocarbons. The heavy hydrocarbons are removed and then the processed gas is returned to the pipeline at a lower BTU value. They pay the pipeline company based on the volume of gas and the BTU “shrinkage” between the inlet to the plant and the outlet.

The gas processing industry has very different requirements than most process gas chromatograph users. While the analytical aspect of the applications is quite easy, the environmental requirements are very demanding. Quite often, the analyzer may be miles from the nearest technician monitoring the natural gas in the pipeline. Therefore, low utility consumption, reliability, and simplicity of design become the most important considerations. It is also necessary for the analyzer to be able to communicate over a remote communication system since the analyzers are literally scattered across the countryside.
 

Petrochemical

The Petrochemical Industry manufactures the chemicals found in many consumer products used every day; plastics, cleaners, fertilizers, insecticides, etc. It’s a very diverse industry that takes many of the petroleum-based chemicals and converts them into more useable forms. One of the largest segments in this industry is responsible for the production of the various plastics and resins used by today’s society.

Plastics and resins are made by polymerizing a compound to form long chains of molecules. For example, polyethylene plastic is made by catalytically reacting many ethylene molecules together to form long polymers made up of thousands of ethylene molecules.

These polymers often resemble white flakes or powder and are then extruded at high heat to form small pellets of plastic. Quite often, a pigment is added during extrusion in order to give the plastic a different color. These pellets are then sold to various companies that mold the plastic into different industrial and consumer items.

The process gas chromatographs used in the Petrochemical industry are often required to analyze many compounds that are difficult to detect, corrosive, or toxic. The design of the analyzer routinely uses sensitive detectors, sophisticated column techniques, special hardware, and exotic materials of construction. The benefits of the analyzer need to be carefully weighed against the equipment costs and long-term maintenance costs.
 

Environmental area monitoring

The Environmental Monitoring market for process gas chromatographs has grown out of the desire by various industries to provide a safer workplace for the employees and to minimize their impact on the local environment. Many chemical processes require the use of chemicals that need to be monitored in case of an accident or leakage. It is also frequently necessary to monitor the incineration of hazardous materials to ensure complete and safe destruction.

The guidelines for establishing limits on hazardous compounds can come from a variety of sources such as the EPA, OSHA, Industrial Agencies, or Corporate Safety Departments. Once a hazardous compound is identified, a monitoring program needs to be established to ensure the levels are kept within safe limits. For the majority of applications, only occasional checks need to be made such as monitoring for certain pollutants in wastewater. But some applications require continual automatic monitoring of the air, water, or chemical process.

A process gas chromatograph is well suited for many of these types of applications because it has the ability to monitor 10, 20, or even 30 different plant locations from a single instrument. A process gas chromatograph can also use various detectors that give it the sensitivity to measure at very low concentrations since it sometimes becomes necessary to monitor down to the parts per billion level.

A typical installation would require an analyzer to monitor multiple sampling points and if the concentration of the hazardous compound is found to exceed safe limits, the analyzer would trigger an alarm system. The analyzer is also frequently tied into a data acquisition system (DAS) to store the data for later verification and to generate the reports often mandated by the governing regulations.

It is desirable for the analyzer to be as reliable as possible since an analyzer that is frequently down for maintenance can allow a plant to enter an unsafe situation without being aware of it. The analyzer must also be easy to work with since many users may not have had prior experience with process gas chromatographs. 

The Environmental monitoring market puts unique demands on the process gas chromatograph. Good sensitivity, multiple sampling points, and data logging are necessary for a complete system to function properly.