Modern refineries, power plants and fuel or coke consuming industries are committed to stringent environmental regulations and legislations that require a stringent monitoring of combustion gasses. Based on narrow spectral laser bands, the MOD 500 TDL laser technology based gas analyzer has the capability to determine accurately concentrations of Oxygen (O2), Carbon Dioxide (CO2), Carbon Monoxide (CO) and water. All these gasses have in common that they are related to fuel combustion processes. In these processes, hydrocarbons react with oxygen in air to give carbon dioxide and water vapor. Deficient oxygen will lead to the formation of toxic carbon monoxide (CO) and soot. Too excessive amounts of oxygen will affect the flame too. Monitoring of the constituents in combustion gasses allows real time to adjust the ratio between fuel and air in burner systems to complete fuel combustion into carbon dioxide and water. This definitely reduces the fuel consumption without affecting the amount of energy produced (BTU).

5Diode Lasers (TDL) technology with its unique probe enables measuring locations, which were previously difficult to approach. Especially those places where other gas analyzer technologies are hindered by the presence, of even small quantities, of dust. Common TDL applications are sensitive to dirt and require nitrogen purging to lower dust.  In the maintenance free MOD 500, small amounts of dust do not influence the accuracy of the measurement. These analyzers are successfully implementable in a various different industrial flue applications. Static process gas conditions are no longer an obstacle for a MOD 500 installation with the process purge-free probe for inertization and blanketing applications. The purge-free filter probe measures easily in high-dust applications where cross-stack type TDLs typically require high optical purge flows accompanied by the loss of signal intensity.

The MOD 500 has the benefit of being an “all included” laser gas analyzers, where transmitter and sensor are housed in on single devise that is easily installed in pipelines and smokestacks.

The MOD 500 The MOD 500 has the benefit of being a “Single Part TDL Analyzer”. Incorporation of both, the laser and the detector, in one single device makes the MOD 500 easy to install only on one side of a pipe , furnace, on one flange, without the need for alignments and re-alignments, and easy to maintain.

The MOD 500 is applicable in different kinds off applications.

1. Energy Production – Fuel Combustion – Burner Optimization

2Reduction of the cost of energy is a main target in many industries and by energy producers. Reducing the cost of energy saves thousands of dollars in purchasing fuels.

Fuels react with stoichiometric amounts of oxygen to form carbon dioxide, water vapor and heat. However, in case of deficient oxygen, the formation of CO2 is only partially. Under these conditions, environmentally hazardous highly toxic carbon monoxide and soot are by-products of the combustion process, and unnecessarily large amounts of energy are wasted.

On the other side, excessive oxygen supplement leads to cooling and energy, and the energy loss must be compensated by increased fuel consumption.

Depending on the nature of the fuel, for natural gas, the optimized oxygen excess is within the rage of 10-20% while for cokes and excessive oxygen content of 40% is required.

Optimized performance of the burners and the combustion process requires on-line monitoring of predominately the carbon monoxide and the oxygen content in the furnace or in the flue gas. To achieve optimized combustion conditions, by changing the ratio fuel to air must until the lowest concentration of oxygen and of carbon monoxide is measured.

Continuous measuring of the CO and oxygen content with the MOD 500 TDLA gas analyzers are the fundamentals to burner optimizations reduce the cost of energy in furnaces,boilers etc. in refineries, power stations,blast furnaces, and any other type of industrial used furnaces.


Furnaces, Boilers, Heating – The MOD 500 measures specifically and accurately oxygen as well as carbon monoxide and carbon dioxide to generate the energy at highest efficiency. Optimization of the ratio between the air and the fuel flow, to minimize the formation of toxic carbon monoxide and soot and to minimize fuel consumption, but also to reduce excessive air to increase the burner efficiency. This technology is also highly effective and efficient to control the fuel efficiency in package boilers and fire heaters.

Power Plants are often versatile to burn different types of fuel, such as gas, heavy oil or cokes. In power plants, the concentration of O2 and CO are of main importance in adjusting the ratio between air and fuel, which provides highest fuel combustion energy yield with lowest excessive air. High levels of CO indicate deficient oxygen, while high levels of oxygen indicate a burner fall out. Its specificity to measure accurately and fast O2, CO and CO2, its none-sensitivity against dust and it feasibility to be placed in hot areas, enables placement of the MOD 500 close to the burners for measuring their performance. Aside from the burner itself, MOD 500 analyzers are also implementable for on-spot detection in peripheral units, such as CO boilers and flue stacks.


2. Petroleum Industries and refineries.

Different applications with different purposes exist for the application of the MOD 500 in refineries.

Energy formation and fuel consumption are major expenses in operating refineries. Refinery fuels include natural gas, or other fossil oil based fuels. Many refineries, as well as other power stations, must have the ability to switch between different types of fuels if necessary. Economized energy consumption requires measuring CO and O2 in furnaces and flue gasses.

The MOD 500 is also an efficient tool in the regeneration of catalyst in the FCC., as well as a detection of catalyst affecting humidity in the CCR. Its utility also increases the efficiency of the flare stack.


FCC Unit Combustion OptimizationThe catalyst in the FCC unit cracks heavy fuel into naphtha and cycle oils. During the cracking process, the catalyst coats itself with a layer of coke, which is removed by combustion in the catalyst regenerator, by overheated air. Flue gas leaving the generator is rich in carbon monoxide and is further combusted to CO2 in a CO boiler. Implementation of the MOD 500, especially in the presence of high dust loads in the CO boiler enables to measure the CO and CO2 contents in a difficult environment.

Catalytic Reformers convert low octane naphtha’s to high octane aromatic reformate and hydrogen. Accurate and specific detection of low levels of moisture controls and to prevents deterioration of the catalyst by moisture.

Flare Stacks are utilized in refineries to incinerate waste gasses and to prevent over pressuring. Measuring the oxygen content in the gas- air mixture with the MOD 500 is highly important to regulate the flame without interference by hydrocarbons, such as observed in paramagnetic systems.

3. Chemical Processes Industries

Oxygen is a chemical reagent in various processes in the chemical industries, which are proceeded in the vapor phase, and require a stringent control of the oxygen content.


Process Control in chemical and in petrochemical industries includes in many cases the detection of oxygen and humidity. The selectivity of the MOD 500 is a major feature to determine accurately the oxygen content in processes such as the production of formaldehyde from methanol, and of vinyl chloride monomer, which serves as a monomer of PVC, and is produced from chlorine and ethylene.

4. Safety and Environment

4Nowadays, industrial safety and environmental care are of great concern, as each event may cause enormous financial losses, and harming the reputation of a company. Measuring the content of CO and/or oxygen are critical parameters in safety to prevent a toxic environment on one hand and on the other hand, to prevent oxygen levels that can lead to explosion of chemicals, organic materials and dust. From an environmental point of view, his is true not only in chemical and petroleum industries, but in each plant where fuel is burned, such as in furnaces, boilers, incinerators, waste treatment, VOC treatmentetc.

The formation of highly toxic carbon monoxide is formed in the absence of sufficient air and oxygen, endangering acutely health. Adequate monitoring of the CO content in furnaces etc. and in chimneys is a key player in the prevention of carbon monoxide poisoning.

Many chemical are sensitive to the presence of oxygen. They may undergo spontaneous oxidation or decomposition. In other cases where the presence of oxygen may lead to fire and explosion conditions.


Thermal Oxidizers eliminate volatile organic compounds (VOC) in gas streams with high efficiency. By fast measuring the O2 and CO content with the MOD 500, continuous control and adjustment of the correct ratio between the VOC rich gas streams and air is quickly established, to optimize the process. Other types of analyzers are too slow efficient performance of this task.

Blanketing of liquids stored in tanks blanketed with an inert gas, like nitrogen, to prevent explosion or fire conditions, and require continuous measuring of the oxygen content. If the oxygen content is too high, oxidation may occur affecting the material, or worse, the development of explosion and/or fire conditions. To prevent this from happening continuous monitoring of the oxygen concentration inevitable. With a proper sampling system, the rapid response conditions of the MOD 500 makes TDLA technology very beneficial for this purpose.

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