How to optimize the performance of bioreactors using mass controllers.

We are currently in a race against the clock in the development of new vaccines against infectious diseases. In the Biopharmaceutical world, the efficiency and technological productivity of bioreactors is a key point in this development.

Bioreactors create the optimal environmental conditions of temperature, nutrient concentration, pH, dissolved oxygen,… for fermentation and / or production of cell cultures. The higher the yield of the bioreactor cell culture, the greater the probability of obtaining a quality product: Vaccine, drug….

Performance of a bioreactor

There are two fundamental variables that directly influence the operation of a bioreactor, dissolved O2 and pH. Both are directly dependent on accurate and reliable gas flow control.

The amount of O2 dissolved in the medium must be reduced or increased by precise injection of O2 or N2. Given that O2 is relatively poorly soluble in water, the amount of air that allows maintaining an O2 concentration that favors the performance of the bioreactor is usually added constantly.

The pH of the medium is usually regulated by the addition of acids and / or bases. In the case of cell cultures, liquid acids could damage cells, instead acidification is usually done by adding CO2.

For CO2 flow adjustment, bioreactor manufacturers have traditionally used manual valve rotameters. These systems have obvious limitations, so the current trend is to replace them with digital mass flow controllers.

Advantages of mass controllers.

First of all, both rotameters and differential pressure controllers are volumetric systems. Therefore, small variations in Pressure (P) and Tempreature (T) translate into a significant error in the flow measurement. Mass instruments, unlike the previous ones, are totally independent of P and T, and do not require any compensation.

On the other hand, it is evident that an automatic flow control is critical for a good operation of the bioreactor. Despite the economic advantages of rotameters, they do not have any output signal that allows them to automatically handle the variations in the conditions required for optimal operation of a bioreactor.

Other important aspects are the size of the mass controller, and its versatility. For example, the ability to handle different gases (O2 and N2) with the same equipment is always an interesting feature.

Finally, in clean room environments, contamination phenomena can spoil crop batches, with the consequent loss of productivity. Using equipment that is less sensitive to contamination will reduce this risk.

We can conclude that the Smart-Trak mass flow controllers (MFC) from the American company Sierra Instruments can perfectly perform this function.


Most important characteristics of the SMART-Track:

  1. Thermal dispersion measurement technology gives a direct measurement of the mass flow, unaffected by variations in P and T
  2. Its capillary type measurement system provides great measurement linearity regardless of the gas measured. Thanks to its digital electronics, the equipment is delivered calibrated for 10 different gases
  3. “Superior” measurement features; accuracy +/- 1% full scale (for all gases), repeatability +/- 0.2% f.e., and turndown of 50: 1
  4. It incorporates a direct-acting, frictionless, automatic control valve for fast and stable gas flow adjustment between 2 and 100% of the equipment range.
  5. Compact in size, with high quality 316 stainless steel measuring body, and multiple types of process connection available


For more information, you can contact MATELCO, SA.

Combustion control and laser analyzers: non-contact measurements

In most industries, combustion processes are used as a source of heat and energy. For this purpose, boilers, heaters and furnaces, burn fuels such as natural gas, biogas or even waste. When deciding on a new system for combustion control we must take into account the following points:

  1. Investment expenditure (CAPEX)
  2. Maintenance and operation expenses (OPEX)
  3. Potential fuel savings
  4. Maximizing heater performance
  5. Minimization of pollutants such as nitrogen oxides (NOx)


Combustion efficiency

A look at the theory of combustion shows that the ideal operating point is in a slightly lean regime, that is, with an excess of air. Poor combustion ensures that the fuel burns completely in all conditions. As such, the potential for high concentrations of carbon monoxide (CO) and unburned fuel in the combustion gases is minimized. Otherwise, fuel will be wasted and unsafe combustion conditions could result.

Originally only oxygen (O2) was used as a control measure and the operating point was typically between 5% and 10% excess air, which meant low efficiency and high NOx generation. Currently, additional CO measurements are used to avoid fuel-rich operations, and to provide information on the O2 set point. With this additional measurement, the operating point can be reduced to a range of 3% to 6% excess air.



As an example, we choose a typical ETHYLENE CRACKER , 200 MBTU per heater per hour. By reducing the operating point from 7% excess air to 4%, at a burn rate of 85% to 100%; annual fuel savings are approximately $ 80,000 per heater (assuming $ 2.33 / MBTU). That means that for an Ethylene Cracker with six heating cells, the annual combined fuel savings is almost $ 500,000. At the same time, NOx emission would be reduced by around 33% due to less excess air (figure 1)

Figure 1: Annual fuel savings per heater in k $ (right, blue axis) and reduction in NOx emissions in% (left, yellow blocks) for various operating points relative to a 7% operating point


Combustion optimization technologies

Over time, several different technologies have been developed to optimize combustion. Most of them have been based on one-point measurement sensors (probes), which must be in physical contact with the process gas. Zirconium Oxide (ZrO2) probes and electrochemical sensors are currently the most widely used. However, these sensors suffer rapid degradation due to harsh process conditions; catalyst poisoning or inhibition if exposed to reducing gases (eg sulfur). Furthermore, fuel sensors (COe) are not specific for CO, but rather measure the sum of all fuel gases, that is, they also measure hydrogen (H2) and hydrocarbons.

In contrast to these, Modulable Diode Laser Absorption Spectroscopy (TDLAS) performs measurement without contact with the sample, by interaction of laser light and gas molecules. Measurements can be carried out directly in-process (in situ) through the combustion chamber, thus obtaining representative results from the entire chamber, and not just from a point close to the wall.


Non-contact measurement

Furthermore, by performing non-contact measurement, the analyzers are not exposed to corrosive gases and high temperatures, and a complex sampling system with high maintenance is generally not required. Also, ZrO2 probes require monthly recalibration due to degradation, unlike TDLAS analyzers which are only validated once a year.

The TDLAS analyzer does not require a sample extraction system and maintenance is much lower, which implies a significant reduction in operating expenses (OPEX) compared to other technologies. Additionally, TDLAS analyzers are highly sensitive and selective, thus achieving very low detection limits without interference from other process gases. This means that unlike COe measurements, TDLAS analyzers measure the true value of CO, which leads to further optimization of the operating point.


Combustion analysis solutions

One of NEO Monitors’ solutions for a complete combustion analysis would be two LaserGas ™ III analyzers on site:

  1. Measurement of O2 and process temperature
  2. Measurement of CO, methane (CH4) and water vapor (H2O).



Each LaserGas ™ III analyzer consists of an emitter and a receiver that are mounted on diametrically opposite sides of the combustion chamber. The installation costs of the transmitter-receiver are somewhat higher than those of the measurement sensors at one point; significantly lower maintenance costs and better combustion optimization compensate for this after a short period of operation.


Fuel economy calculations

If we look again at the fuel economy calculation from the previous example and also take into account the difference in CAPEX and OPEX between spot metering type sensors (ZrO2 and CO) and TDLAS analyzers, we get the total TDLAS benefits per heater for the first five years of operation (Figure 2)

 Figure 2: Total TDLAS benefits in k $ per heater during the first five years of operation [/ caption]


For an Ethylene Cracker with six heaters, the benefits after five years of operation are more than $ 2.7 million.

Another solution proposed by NEO Monitors that further reduces investment costs (CAPEX) is with its LaserGas ™ iQ2 analyzer.

This analyzer combines the transmitter and receiver units in a single transducer configuration. In this case, a reflector is used to send the beam back to the receiver so that the beam passes through the monitored gas sample twice. There is also a special probe type version, the LaserGas ™ iQ2 Vulcan , specially designed to replace already installed probes from other manufacturers. In this case, only a single flange is required for installation, which reduces investment costs to a minimum, while preserving the other advantages of laser analyzer measurements.



Other advantages

Other advantages of using LaserGas ™ analyzers for combustion control is that these analyzers can also measure CH4, H2O and process temperature.

  • CH4. During the start-up phase of a combustion process, information on the concentration of CH4 is essential for safety reasons, to prevent explosions.
  • H2O. H2O measurement can be used to detect tube ruptures in boilers, and / or convert wet-base to dry-base measurements, thus ensuring concordance with measurements provided by typical extractive analysis systems (on a dry basis).
  • Temperature. A TDLAS-based process temperature measurement is the best solution for proper compensation of concentration measurements.


Expenditure reduction in the measurement of cationic or acidic conductivity


The online analysis of CACE (conductivity after cation exchange or also acidic or cationic conductivity) is the most necessary parameter to monitor and control the quality of the water-steam cycle of any thermal power plant and process steam in industrial plants.

Typical points of conductivity measurement in water-steam cycles by IAPWS (International Association for the Properties of Water and Steam) include; condensate, feed water, boiler water, steam and replacement water.

The usual practice has been the use of cation exchangers based on resin for the analysis of CACE, which, however, are consumed depending on the water sample, the pH of the sample and the design of the resin column. Therefore, frequent and regular human manipulation is required. This goes against the philosophy of online analytics, which aims to operate in the most autonomous way possible.

Depending on the configuration and layout of the plant, for example in a combined cycle power plant (CTCC) with 2 blocks configured in 2-2-1 (2 gas turbines feeding 2 boilers type HRSG, which supply a turbine of common steam) about a total of 24 CACE analyzers are needed, without considering auxiliary equipment.

Theory and practice

In combined cycles, with AVT (All Volatile Treatment) treatment with a pH of about 9.7 and sample flow rate of 8 liters per hour, the typical 1 liter resin per analyzer is consumed in about 8 weeks. However, this is a theoretical value. The practice shows that for the start-up or change of load of the plants, the impurities in the cycle cause a faster resin consumption, so that 4-6 weeks seems to be a more realistic consumption rate. Nuclear power plants operating at a higher pH have a higher resin consumption and the need for replacement or regeneration is even more frequent.



In the previous example, annual savings of more than $ 37,000 were achieved. The renewal of existing analyzers by a CACE analyzer is quickly amortized.







Conductivity before and after cation exchange with an EDI module for automatic and continuous resin regeneration.
Save operating costs and measure more safely to obtain reliable data constantly.
Automatic calculation and visualization of the concentration of the alkalizing agent and the pH (VGB 450L directive).

Continuous monitoring of:

• Specific conductivity
• Acid Conductivity
• pH value or alkalizing agent

No expensive resin columns are required:
No resin exchange.
It does not need maintenance.
Without chemical products.

Use of a calorimeter to measure the calorific value in torches

In the industrial field, a good design of torches is vital to allow the maximum destruction of “residual gases”. Good design guarantees minimal harmful emissions to the atmosphere. In turn, efficient design and operation will reduce the operating costs.

Residual gases, sent to the torch for destruction, may come from different points of the process. Therefore, monitoring of its calorific power is vital. To ensure maximum efficiency in combustion. In addition it will allow to determine if this gas can be used like fuel by itself, or if it will require enrichment with an auxiliary fuel.

The micro-combustion calorimeters provide a direct measurement of the calorific Power. The sample gas, pre-mixed with a combustible gas, is burned in the equipment. This causes a variation of temperature, which is proportional to the calorific Power. In this way the analyzer provides a direct measure of the calorific Power.

Our analyzer CalorVal, of the American company Control Instruments, belongs to this category of analyzers. Robust and reliable, its design and manufacture have been tested in numerous facilities. This analyzer is capable of supporting the rigorous environmental conditions required in this type of application. It is therefore the optimum solution for the control of the calorific Power in torches.

Simple installation, quick response

The CalorVal is a lightweight and compact analyzer. Suitable for direct field mounting, next to the measuring point. It does not need mounting in a case of analyzers. So it is possible to dispense with long heated lines for sample transport, sample pumps and conditioning systems. The response time is reduced (less than 4 seconds), allowing a fast adjustment of the auxiliary fuel flow of the torch when necessary.


Minimum maintenance

Its particular design, with a camcorder and a fully heated sampling system, avoids the possible condensation of less volatile water vapor and hydrocarbons. Otherwise these could be lost, caused inaccuracies in the measure. In addition the presence of condensates could lead to maintenance problems. This feature, coupled with its simple but efficient Venturi suction sampling system, without pump or mobile parts, reduces the maintenance of the equipment to the minimum possible.

Direct measurement, with universal response

The own technology of Control Instruments applied to the CalorVal, allows to measure the calorific power of a wide variety of gases. Although the equipment has been calibrated for a particular gas, it provides an excellent cross calibration for many other gases, with minimal measurement errors when varying the composition of the sample.

The CalorVal provides a uniform response for a wide range of combustible gases and vapors. Including heavy hydrocarbons, carbon monoxide and hydrogen, as well as many other compounds commonly present in waste gases.

If you need to resolve any questions or queries you may have about the gas analyzer, simply fill out the form on our website and one of our experts will contact you as soon as possible.

The automatic sludge mantle level detector

The automatic sludge mantle level detector is an optical measuring system, without moving parts, robust and reliable.



Optimize energy consumption.
Automation of sludge pumping. Instead of pumping at fixed times, pump when really necessary.

Optimize water removal to reduce expensive additional processing (belt presses, digesters, centrifuges, etc.)
Automatically maximize the density of the sludge layer, avoiding pumping large volumes of sludge by pumping water unnecessarily.

Maintain the preferred mud depth.
Automating control of the sludge layer. Overflow and process problems are avoided with this interface level analyzer.

Reduce pump wear. Pump only when necessary.

Maximize operator time and energy.
It installs quickly and easily, without the need to calibrate. Simplify the operation with a durable level measuring instrument.

Reduce the cost of chemical dosing in the DAF or CAF flotation system
Optimize the adjustment of the flocculant precipitate (floc) process and the coagulant dose control.


In municipal water treatment plants (ETAP) and municipal and industrial wastewater (WWTP).

  • Primary and secondary clarifiers
  • Inclined plate clarifiers / separators (Lamellars)
  • Dissolved air flotation tanks (DAF) or cavitation air (CAF)
  • Tank Decantation / Control Decantation.
  • Extraction of minerals such as iron, zinc, copper …
  • Industrial process + clarification of wastewater as in the paper, chemical industry …
  • Batch sequential reactor (SBR)
  • Settling tanks


The LED light beam automatically adjusts its intensity to detect sludge coverage and supernatant interface levels in primary or secondary sludge, or in light flocs

  • The detection of the mud level interface is not distorted by the curved walls of the tanks with lamellae
  • Advanced Self Diagnosis
  • Ultra high intensity infrared rays
  • Automatic beam intensity control
  • Linear 4-20 mA output with mud interface level depth
  • Relays of set point for the depth of the high and low sludge layer

Ask us any questions about the operation of this analyzer and our team of experts in water analytics will advise you technically. Send your email from the contact section.

Analizador in situ IQ² Vulcan (TDLS)

The LaserGas IQ² analyzer, from the Norwegian firm NEO Monitors, is the first TDLAS multiparameter laser analyzer on the market . It is able to analyze up to 4 gases (CO, O2, CH4 and H2O) and temperature with the same equipment.

In this way we could control the combustion (O2 and CO) using the same equipment and simultaneously have an alarm for burner failure (increase in CH4) and / or pipe breakage in boilers (increase in H2O)

The instrument is based on the absorption of infrared radiation by gas molecules (TDLAS). An absorption line in the IR band is selected in which only the gas to be measured has absorption, thus eliminating possible interference due to other compounds present in the sample.

Its new configuration with transmitter and receiver integrated in the same housing facilitates the assembly of the equipment. It is available in addition to configuration with insertion probe (Vulcan), in version for measurement through conduit (X-stack) and “open path” (Open Path)

Minimum / maximum measuring ranges:

CO: 0-100 ppm up to 10,000 ppm * m with limit detection / accuracy = 3 ppm
O2: 0-2% up to 25% with limit detection / accuracy = 0.05% vol
CH4: 0-1% up to 5% with limit detection / accuracy = 0.01% vol

  • Optical path length: 1 m
  • Maximum gas temperature: 850ºC
  • High sensitivity and precision
  • Without interference with other gases contained in the sample
  • Quick response time


  • Combustion analysis.
  • Boilers
  • Process ovens
  • Electrostatic precipitators
  • Recovery of residual gas VCM (vinyl chloride monomer)
  • Gas reformer

If you need to answer any questions or queries you may have about the gas analyzer, just send us an e-mail from the contact section and one of our experts will contact you as soon as possible.

New representative of Matelco for Spain and Portugal

Detector nivel manto de lodos

Matelco expands its products, with the range of mud level detectors from the Canadian company Markland Specialty Engineering Ltd. ( ).

The importance of good control of the mud mantle level will allow us to pump the sludge when it is really necessary. Avoiding overflows, and excess of water.

We are delighted to be able to incorporate your products into our catalog. Thus be able to provide new solutions to the automatic or manual control of the mud mantle.

For more information contact MATELCO, S.A tel. , or by email form from the contact section.

Turbidity measurement for corrosion products in the water-steam cycle

Turbidity measurement as trend monitor for particulate corrosion products

Corrosion product monitoring is essential to determine the effectiveness of the cycle chemistry treatment program.

Lukas Staub, Michael Rziha y Marco Lendi. VGB PowerTech 3|2019

Read the original full article here: Turbidity measurement as trend monitor for particulate corrosion products”

Conference on gas analysis and risks arising from leaks with the ADOS company, our new partner

ADOS: new analysis solutions, gas control and risks derived from leaks.

This week we had the pleasure of sharing with our new partner, the german company ADOS ( a very interesting day. It was focused on the analysis of gases and the risks derived from the leakage of potentially dangerous gases in the environment. A good gas control will allow us, early enough, to detect these gases and avoid unnecessary risks. We are delighted to be able to incorporate their products into our catalog. They provide new solutions that minimize the risks derived from the emission of gases. That also helps for protecting people and improving the environment.

For more information contact MATELCO, S.A tel. . You also can use our email form from the contact section.

Factors that impact the accuracy of mass flow meters saw by thermal dispersion; the flow profile and its conditioning PART III

We finish this series of articles on mass flow meters talking about the influence of flow conditioners.

Flow conditioners according to straight sections

The multiple disturbances prior to the equipment have a cumulative effect on the flow profile. If it is not possible to have enough straight sections it is advisable to use a flow conditioner.

The flow conditioners can provide a uniform flow profile at the sensor location. This flow profile is different from the flow profile that occurs when we have the optimal straight stretches for the application. It is essential to calibrate the flowmeter with the flow conditioner knowing the details of the location point. With this we refer to: type of gas, characteristics of the pipeline, straight ascending sections available, disturbances and depth.

Flow conditioners of the Sierra brand: If the straight sections are insufficient, the two types of flow conditioners provide a uniform flow profile.

Online flowmeter: For this type the flow conditioner is integrated into the body of the flow meter.

Conditioner for insertion meters: The assembly of two conditioning plates located between two flanges can be effective. The end user is the one who supplies the flanges for this installation

Conditioner for insertion meters

Internal flow conditioner for insertion style meter


Importance of flow conditioning

Table 1. This table demonstrates the importance of flow conditioning with the Recommended pipe diameters prior to the equipment.


Table 1 shows the length section required in the pipes for a mass flow meter with integrated flow conditioning, compared to an orifice plate.
In all cases, the flow conditioning significantly reduces the recommended distance (straight stretches) prior to the equipment, for a correct installation of the mass meter by thermal dispersion.


Considering Sierra mass flowmeters by thermal dispersion in any application, the location must first be determined with care. It should also be reasoned a posteriori that the most convenient location may not offer the most accurate results. It is important to provide the manufacturer of the thermal mass flow meter, the conditions of application of the end user. That means the data on the pipe, the mixture of gas or gases used, the pressure of the process, and the route as the alterations thereof. In that case the manufacturer will offers us the most appropriate flow meter. The result would be the correct and propitious calibration of the meter in the factory.

For more information contact MATELCO, S.A tel. . You also can use our email form from the contact section.

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