In a Basic Oxygen Furnace
carbon rich molten iron is converted to steel by blowing oxygen through a
top-mounted lance at supersonic speeds into the molten iron. Blowing oxygen
through molten pig iron lowers the carbon content of the alloy converting it
into low-carbon steel.
to a highly competitive industry it is paramount to achieve process control to
ensure max efficiency, maximizing product quality and process safety while
minimizing energy consumption.
Boiler is used in various industries to generate
steam for power production. This is typically done by burning natural gas, coal
or oil. CO and O2 is measured in the boiler to optimize the air to fuel ratio
(combustion control) in order to increase efficiency, reduce emissions and maintain
In addition, CH4 may be also be measured to detect
unburnt hydrocarbons due to burner nozzle malfunction and H2O to detect boiler
pipe breakage and for wet/dry calculation.
Due to the increased environmental focus, more and more governments are putting demands on industry to monitor and report what they emit into the atmosphere. It is also utilized as part of process control to ensure measures can be taken to increase efficiency and further reduce future emissions.
Typical gases for a selection of industries are:
Cement industry: NH3 and HCl
Steel industry: NH3
Power industry: NH3
Waste combustion: HF, HCl & NH3
Petrochemical: Typically, NH3.
H2O is often measured for conversion to dry values.
Clean gas applications are typically quality control measurements typically found in chemical and petrochemical applications to detect impurities in clean gases and end products.
Typical gas measured: CO and CH4 in H2, CO2 in H2, CH4 in CO, H2O in various hydrocarbon gases.
Coke oven gas is a fuel gas consisting of
hydrogen, methane and carbon monoxide. The gas is a side-product when producing
The gas is produced
by heating coal with a high bitumen content in a reducing atmosphere. The
resulting off gas is filtered to remove dust, tar and oil and other impurities
and then used as fuel gas. H2S is measured after the scrubber (process control)
and O2 for process control to measure the amount of excess air added.
Emissions from combustion processes contain gases which are harmful to the environment. Some of these gases include Nitric Oxides (NOx). For environmental reasons the reduction of NOx emissions is very important and is regulated by government in many countries. A common method used to reduce emissions of NOx is the injection of NH3 or Urea. Controlling and monitoring the NH3 concentration is important to optimize the NOx reduction efficiency, and to minimize NH3 emissions.
Sulphur oxides is a significant cause for acid rain. Desulfurization of flue gas from various industries have gained increased focus over the last decades. Sulphur emissions are very harmful for the environment and to human health and are also a significant contributor to acid rain.
Wet scrubbers, are as of today, the most common way to reduce the concentrations of SOx in off- gases.
Vinyl Chloride Monomer (VCM) is used almost exclusively in polyvinyl chloride (PVC) manufacture.
PVC is produced by polymerization of vinyl chloride monomer (VCM).
First, the raw material VCM is pressurized and liquefied, and then fed into the polymerization reactor, which contains water and suspending agents. Next, an initiator is fed into the reactor, and PVC is produced under a few bars pressure at 40 – 60°C. The role of water is to remove and control the heat given off in the polymerization process.
PVC forms as tiny particles which grow until they
reach a desired size. The reaction is then stopped, and any unreacted vinyl
chloride is distilled off and re-used. The PVC is separated off and dried to form a white
powder also known as PVC resin (see flow diagram).
is an important reactant in the production of VCM. O2, when
present in a certain concentration imposes the risk of explosion. It is
therefore crucial to monitor the O2 concentration in the waste gas
continuesly before the incinerator.
H2O, acetylene and ethylene are also measured as part of the process control in
the production of the various plastic products.
Electric arc furnaces are used in steel production to heat the metal, mainly recycled scrap metal, by using an electric arc. Electrodes are lowered into the furnace and high current is then passed through the material, melting the scrap metal where temperatures can reach up to 1800°C. O2, CO2 and H2O are measured at the top of the furnace for process control and to secure ensure optimal melting.
A Fluid Catalytic cracking unit is used in refineries to convert the
heavy portion of crude oil into lighter petroleum products. This is achieved by
breaking down the larger hydrocarbon molecules into smaller molecules by
exposing them to a catalyst and extreme heat. Oxygen content in the incinerator
stack plays a crucial role in the cracking efficiency, the concentration of SO2
in the cracking furnace gas and therefore generation of waste sulfuric acid and
fuel efficiency. The relationship between CO and CO2 indicates the efficiency
of the catalyst.
Fence line monitoring by Open Path detectors is well suited as a safety measure and detection barrier around a production facility. Detectors are normally installed around and above the areas with potential leakage. Neo Monitors can provide measurement solutions for HF, CH4, NH3 and H2S.
Production of nitrogen fertilizer consists of multiple stages.
NH3 is produced from air and natural gas. Urea is then produced from the resulting NH3 and CO2 before it is granulated. These production stages make up the basic steps for further production of different variants of fertilizers.
NH3 is measured in process control and CEMS.
O2 is used for combustion control.
NO2 is used for measuring fertilizer off gas.
A flare stack is a combustion device which is used to burn off flammable waste gases.
Flaring is mainly used for safety reasons in order to handle unplanned over-pressure, or during startups and shutdowns on industrial plants.
Oxygen is measured in the Hydrocarbon mix before the gas is flared.
O2 is reduced or removed before the compressor stage in order to minimize the explosion risk.
These applications are close to zero gas applications and both Single Path and Multipass instruments are suitable.
(Fume treatment center/Gas treatment center)
Emissions from the Aluminium smelting process contains harmful gases for the environment, one of these gases is Hydrogen Fluoride (HF). The aluminium smelting process generates large amounts of HF gas, the majority of this gas is captured and treated in wet or dry scrubbers.
NEO Monitors LaserGas™ II SP HF monitor is an excellent instrument for process and emission control, because of its low detection limit for HF gas, short response time and low maintenance requirements. HF emission is subject to increasingly stringent national and regional regulations, due to the demand for toxic gas measurement in the environment along with the emphasis on safety.
Industrial furnaces are used to provide heat for a process or a reaction. Heat is generated by an industrial furnace by mixing fuel with air or oxygen. The residual heat will exit the furnace as flue gas. Furnace designs vary as to their function, heating duty, type of fuel and method of introducing combustion air. The key to good combustion is simultaneous multicomponent stack gas measurement to enable optimum air: fuel ratio control. This ensures that the energy produced by the combustion process is not wasted in heating unnecessary air while all the fuel is completely combusted. Oxygen and carbon monoxide are used as the primary indicators of the combustion efficiency.
Like CEMS, greenhouse gas emissions have also gained increased focus. More and more demands are being placed on the various industries to both measure and reduce greenhouse gas emissions.
Typical greenhouse gases that are measured is: CF4, CO2 and CH4.
Incineration is a waste treatment process that involves the combustion of organic substances contained in waste materials. Incineration of waste materials converts the waste into ash, flue gas and heat.
The ash is mostly formed by the inorganic constituents of the waste and may take the form of solid lumps or particulates carried by the flue gas.
The flue gases must be cleaned of gaseous and particulate pollutants before they are dispersed into the atmosphere.
O2 and CO is measured for combustion control, while HCl and H2O is measured for CEMS.
The rotary kiln is a cylindrical vessel, inclined slightly to the horizontal. The material is fed into the upper end of the cylinder. As the kiln rotates, the materials gradually move towards the lower end, and they may go a certain amount of stirring and mixing. Hot gases pass through the rotary kiln, usually in the opposite direction to the material.
Kilns are commonly used for the pyro-processing stage of manufacture of Portland and other types of hydraulic cement and mineral ore. They are also used in various waste incineration processes.
CO and O2 are commonly measured to ensure correct process conditions.
H2S is measured in order to verify the quality and purity of the natural gas, and for corrosion control.
As part of the low-level radiation waste handling system at the reprocessing plant, H2O is measured in order to prevent corrosion. In the same system O2 is measured as part of explosion prevention measures.
HF is also measured at the scrubber outlets.
Process heater is a direct-fired heat exchanger that uses the hot gases of combustion to raise the temperature of a feed flowing through coils of tubes aligned throughout the heater. Depending on the use, these are also called furnaces or fired heaters. Process heaters are used throughout the hydrocarbon and chemical processing industries, such as refineries, gas plants, petrochemicals, chemicals and synthetics, olefins, ammonia and fertilizer plants. Not only fuel cost, but emissions, safety (from air leaks, tube leaks, and fuel or burner problems) and product quality (temperature control) are all issues which may be optimized by use of a LaserGas™ instrument. Typical gases measured include: O2, CO and CH4.
Explosion prevention measurements is used across all types of industries.
These applications are typically zero gas applications to prevent explosive gases reaching their LEL (Lower explosion limit).
Typical gases measured are: O2, CH4, CO and H2.
Treatment of raw natural gas and refining crude oil generates Hydrogen Sulfide as by-product.
A Sulfur recovery unit recovers sulfur from H2S in the raw gas for use in other processes or industries. This is achieved by using multiple converter stages where the H2S and air is sent through a reaction furnace, and sulfur is extracted from the H2S. Good process control is necessary in order to achieve optimal recovery.
H2S and SO2 is measured, and it is the relation between these two gases that indicates how well the SRU process is performing.
Syngas, or synthesis gas, is a fuel gas mixture consisting primarily of hydrogen, carbon monoxide, and very often some carbon dioxide. The name comes from its use as an intermediate in creating synthetic natural gas (SNG) and for producing ammonia or methanol. Syngas is usually a product of coal gasification and the main
application is electricity generation. CO2 is measured as part of the process
The tail gas treating unit is located after the SRU and is actually an
integral part of the SRU process.
Any remaining unreacted
sulfur compounds that were not converted in the SRU are here converted to H2S
and recycled back to the SRU for additional processing. The SRU tail gas is
heated and sent to the catalytic reactor where essentially all of the sulfur
compounds are converted into H2S.