From Raw Materials to Finished Products: Ensuring Quality with Industrial Process Refractometers in the Chemical Industry

Ensuring product quality while maintaining process safety and efficiency is paramount in the chemical processing industry. Industrial process refractometers are pivotal in meeting these challenges by providing accurate, real-time measurements of liquid concentration or density. These sophisticated instruments enable manufacturers to monitor and control the quality of raw materials and finished products, ensuring that they meet customer specifications and adhere to stringent safety standards.

Refractometers measure the refractive index of a substance, which changes with the concentration of solutes in a solution. This principle allows them to detect variations in the density or concentration of a liquid, which directly impacts the quality and consistency of chemical products. By integrating refractometers into the production line, manufacturers can conduct in-line monitoring without needing sample removal or lab analysis. This continuous, real-time feedback significantly enhances process control, allowing immediate adjustments to maintain product quality and consistency.

Moreover, the use of industrial process refractometers goes beyond quality control. They contribute significantly to process safety by detecting any deviations in the concentration of hazardous chemicals, thus preventing potentially dangerous situations and monitoring chemical compositions in real time, safeguarding against the risks posed by handling and processing dangerous substances, thereby protecting workers and the environment.

In addition to ensuring product quality and safety, refractometers optimize process efficiency and reduce energy consumption. By facilitating precise control over the production process, they help maintain operations within the optimal range, minimizing waste and reducing the need for costly rework or disposal of off-specification products. This conserves resources and lowers energy costs, as processes can be run at their most efficient points.

State-of-the-art process control management is another area where industrial process refractometers significantly impact. They are integral to advanced control systems, providing crucial data feeding automated decision-making processes. This integration enables chemical manufacturers to achieve high levels of process automation, ensuring consistent product quality through precise control of production variables. Such advanced management systems are essential for maintaining competitiveness in the fast-paced chemical industry, where customer demands for quality and environmental regulations continuously evolve.

Furthermore, the versatility of refractometers allows deployment across a wide range of chemical processes, including those involving aggressive or corrosive substances. Modern refractometers withstand harsh industrial environments, ensuring reliable performance and long service life. This durability is crucial for maintaining continuous operation in processes where uptime is critical to productivity and profitability.

In conclusion, industrial process refractometers are:

• Indispensable tools in the chemical processing industry.
• Offering a multifaceted approach to ensuring product quality.
• Enhancing process safety.
• Improving efficiency.

Their ability to provide accurate, in-line measurements of liquid concentration or density enables manufacturers to control production processes precisely, ensuring that finished products meet the exacting standards demanded by customers. By integrating refractometers into their operations, chemical manufacturers safeguard their workforce and the environment and position themselves to thrive in a competitive and ever-evolving industry landscape.

Miller Energy, Inc.
https://millerenergy.com
800-631-5454

Vaisala Polaris™ Refractometers: Enhancing Process Efficiency and Product Quality

Industrial refractometers are pivotal in process automation, bolstering product uniformity, amplifying productivity, and curbing wastage. These tools determine a substance's refractive index, calculating the extent of light bending as it traverses a sample. This information furnishes critical data regarding a solution's composition and concentration, serving as a linchpin in several industrial operations.

These refractometers prove particularly beneficial in the food and beverage sector, enabling precise quantification of sugar content in various products such as juices and jams. They foster product consistency by ensuring uniformity in flavor and texture while fulfilling regulatory standards. Similarly, in pharmaceutical manufacturing, refractometers determine the concentration of active ingredients in medicines, which is crucial for their efficacy and safety. The pulp and paper industry and semiconductor manufacturing also leverage these devices to assess the concentration of dissolved solids at multiple production stages. Moreover, these instruments gauge the concentration of dissolved solids like salts and acids in chemical production, bolstering the production process's effectiveness.

Automating the refractive index measurement through industrial refractometers eliminates manual testing's need, cutting down on errors and augmenting process efficiency. It also helps reduce labor costs linked to manual testing. These automated refractometers can be integrated into broader process control systems, facilitating continuous monitoring and control of essential process parameters.

Vaisala, a frontrunner in creating and manufacturing environmental and industrial measurement systems, has introduced its new product, Vaisala Polaris™. This innovative product line enhances manufacturing processes, improving productivity, conserving resources and energy, and saving time across diverse industries and countless applications.

Vaisala Polaris™ leverages an optical measurement principle that coupled with the absence of moving parts, negates the need for regular maintenance. This feature positions the product as an efficient, reliable solution for businesses necessitating consistent measurement readings. The product easily synchronizes with Vaisala's Indigo520 transmitters right out of the box, ensuring a smooth setup process. Vaisala has also curated a library of over 500 concentration models to enable exact measurements of diverse dissolved solids, meeting clients' requirements.

With no risk of drift due to particles, bubbles, or color influencing the readings, Vaisala Polaris™ guarantees unmatched precision. Its long-term stability and absence of moving parts promise several years of consistent, accurate measurements. Moreover, Vaisala offers an Engineer to Order service for more extensive needs, enabling product customization to suit the specific requirements of their clients.

In summary, industrial refractometers are:

• Indispensable tools in process automation.
• Boosting product quality and uniformity.
• Enhancing efficiency.
• Minimizing waste and costs.

As automation technology progresses, these monitoring instruments' significance is poised to escalate in industrial environments. With its superior performance, Vaisala Polaris™ is a state-of-the-art technology ideally suited for your application.

Miller Energy, Inc.

800-631-5454

https://millerenergy.com

What is Refractometer Critical Angle Measurement?

Vaisala refractometers use the critical angle measurement principle. A refractometer's three essential components are a light source, a prism, and an image detector. 

DOWNLOAD THE REFRACTIVE INDEX MEASUREMENT PAPER HERE

The light source sends rays to the prism and process interface at different angles. Rays with a steep angle partly reflect at the image detector and partially refract at the process. Low-angle rays reflect entirely on the detector. The angle from which the total reflection starts is called the critical angle. 

The CCD camera detects a bright and dark field corresponding to partly reflected and totally reflected light. The position of the borderline between the bright and the dark area correlates with the critical angle, which is a function of the refractive index and correlates with the solution's concentration.

A built-in temperature sensor measures the temperature T on the interface of the process liquid. The sensor converts the refractive index nD and temperature T into concentration units. 

Vaisala K-PATENTS refractometer can indicate different scales, for example, Brix, liquid density, or concentration by weight. The diagnostics program ensures that the measurement is reliable.

Miller Energy, Inc.

800-631-5454

https://millerenergy.com

Process Refractometers for Water Treatment Chemical Concentration Monitoring

INTRODUCTION

Pure water treatment removes undesirable chemicals, biological contaminants, suspended solids, and gases from raw water. Water purification aims to produce water for a specific purpose, such as human consumption and medical or industrial use.

Polyaluminium coagulants are increasing use in potable water treatment plants, particularly for soft, colored surface waters. Polyaluminium chloride (PACl) is gradually replacing Alum (aluminum sulfate), a commonly used coagulant in water treatment plants. Alum coagulates at a limited pH range (between 5.5 and 6.5) and often requires alkali to the raw water to achieve the optimum coagulation pH. Furthermore, the alum floc produced is particularly fragile, which is vital if a coagulant is required to maximize color removal in a microfiltration-based water treatment process.

APPLICATION

Water treatment by chemical precipitation is a complex process. It starts with adding flocculants, specifically, Polyaluminium Chloride (PACl) and Sodium Hydroxide (NaOH). PACl is a synthetic polymer dissolved in water. It precipitates in big volumetric flocs, which absorb suspended pollutants in the raw water. The turbidity of the raw water defines Polyaluminium Chloride quantity. PACl concentration must be higher than 10 % To keep the flocculation process smooth. Polyaluminium Chloride is stable in the storage tank; however, it tends to crystallize after some time. Vaisala K-PATENTS® refractometer monitors the concentration of PACl to inform about the need for tank or pipe cleaning, thus preventing blockage caused by the PACl crystals.

NaOH regulates pH level, increases alkalinity, and neutralizes acids in the water. In alkaline water, the coagulation and flocculation processes work more effectively. Moreover, sufficient alkalinity prevents dissolving the lead from pipes and pipe fittings and reduces the corrosive effect of the water to iron pipes.

Further, particles suspended in water start to precipitate and agglomerate to form larger particles, known as flocs. The flocs are then settled at the bottom, forming sludge, and then removed from the process. After separating most of the floc, the remaining suspended particles and unsettled floc get filtered to remove water.

In the filtration phase, the water goes through the layers of anthracite, sand, and gravel. As a result, organic compounds contributing to taste and odor get removed. Other remaining particles get trapped by adhering to the sand and gravel particles.

After harmful micro-organisms get removed through filtering, it is necessary to add disinfecting chemicals to the water to inactivate any remaining pathogens and potentially harmful micro-organisms. One of the disinfecting chemicals used is Sodium Hypochlorite (NaOCl). When dissolved in water, this chemical releases chlorine, which is an efficient and safe disinfectant if added in a sufficient amount. Apart from sodium hypochlorite, liquid chlorine and chlorine dioxide are also choices as disinfectants.

Fluoride may also be added to the water to reduce tooth decay and prevent chronic diseases. However, fluoride in the water must not exceed recommended levels. Excessive levels of fluoride can be toxic or cause undesirable cosmetic effects such as staining of teeth.

Sodium Hypochlorite is unstable and quickly decomposes. The stability of NaOCl solution is dependent on the following factors:

• Hypochlorite concentration
• The temperature of the solution
• PH value of the solution
• The concentration of the impurities during catalyzing decomposition
• Exposure to light

With the process refractometer, it is possible to monitor NaOCl concentration and control the disinfection conditions.

The water purification disinfection stage happens in the disinfectant basin. Then, corrosion control assures the high quality of the purified water. Finally, the pure water gets stored for further consumption.

INSTRUMENTATION AND INSTALLATION

Vaisala K-PATENTS® Teflon Body Refractometer PR-23-M provides in-line measurements of Polyaluminium Chloride and Sodium Hydroxide at the initial stage of purification, ensuring the efficient flocculation of undesired particles. In addition, through the measurement of Sodium Hypochlorite and Fluoride at the water disinfection stage, high-quality purified water at the outlet is assured.

Refractometer installations happen in three different points in a by-pass loop between each chemical tank pump outlet and the treatment point. The refractometer allows monitoring the chemicals concentration at the exit from the storage tank to the pipe treatment point.

Typical measurement ranges are:

• PACl is ca. 10-11 %
• NaOH is ca. 40-45 %
• NaOCl is ca. 8-12 %

Miller Energy, Inc.
https://millerenergy.com
800-631-5454

Refractometry in Oil Refining and the Petrochemical Industry: Sulfuric Acid Alkylation

SULFURIC ACID, H₂SO₄

Typical end products

• Alkylate (premium higher-octane gasoline blending stock for motor fuel and aviation gasoline).

Chemical curve: Sulfuric acid 88-100 R.I. per Conc wt.-% at Ref. Temp. of 20 ̊C

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DOWNLOAD THE PDF VERSION OF THIS APPLICATION NOTE
FROM THE MILLER ENERGY WEB SITE HERE

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Introduction

Motor fuel alkylation using sulfuric acid (H2SO4) or liquid hydrofluoric acid (HF) is one of the oldest catalytic processes used in petroleum refining. The purpose of the alkylation is to improve motor and aviation gasoline properties (higher octane) with up to 90 % lower emissions compared to conventional fuel usage.

The problem with HF is that the catalyst forms a hazardous air pollutant when released as a superheated liquid, while H2SO4 does not. Therefore nearly 90 % of all alky units built since 1990 have adopted the H2SO4 technology. 

The leading alkylation unit licensor, with a 90 % share of the market, is DuPont (Stratco®). Another licensor is EMRE (Exxon Mobile Research Engineering, formerly K.W. Kellogg).

Application

In the process, isobutane is alkylated with low molecular weight olefins (propylene, butylene and pentylene) in the presence of a strong acid catalyst to form alkylate (the premium higher-octane gasoline blending stock). The catalyst (sulfuric acid) allows the two-phase reaction to be carried out at moderate temperatures. The phases separate spontaneously, so the acid phase is vigorously mixed with the hydrocarbon phase to form higher molecular weight isoparaffinic compounds.

After the reactor, the mixture enters a separation vessel where the acid and hydrocarbon separate. The acid is then recycled back to the reactor.

Instrumentation and installation

The K-Patents Process Refractometer PR-43-GP is installed after the settlers to continuously monitor in real-time the concentration of acid in the process.

The concentration of sulfuric acid is critical to achieve the complete consumption of isobutane. A highly variable concentration of isobutane in the feedstock upsets the sulfuric acid content in the process.

It is important to determine the proper quantity of acid that will be fed into the process. This is achieved by combining routine sample titration analysis with continuous acid monitoring by the K-Patents Process Refractometer. Real-time measurements reduce the need for sampling and laboratory analyses that cause delay in the implementation of any necessary adjustments to the acid flow.

Continuous monitoring removes the uncertainty involved between titration measurements. The K-Patents refractometer will indicate any gradual fluctuations in the acid flow, allowing precise control over efficient acid consumption and resulting in cost savings. It is also useful in preventing acid runaway, an unwanted situation commonly described as wild acid.

Acid runaway may happen when the acid strength drops below 85-87 % H2SO4. As a result, the reactions between olefins and isobutane turn into reactions of olefins only, producing polymers known as acid sludge, ASO or red oil.

The K-Patents refractometer is not affected by acid soluble oil (ASO). The refractometer indicates actual acid strength regardless of the amount of hydrocarbons present, which is essential when transferring acid emulsion. It is also an extremely useful tool in real-time process acid strength measurement during agitated conditions.

The initial acid concentration is typically 85-100 % and the temperature is 15 °C (59 °F). The benefits of the K-Patents refractometer’s continuous monitoring system include substantial cost savings due to reduced acid consumption, and smooth alkylate production without acid runaways.

The K-Patents Process Refractometer System for Alkylation Acid Measurement Consists of:

1. The K-Patents Process Refractometer PR-43 for hazardous locations in Zone 2. or The K-Patents PR-43 Intrinsically Safe model for installations in hazardous locations up to Zone 0.
2. Optional parts:
   1. Different flow cell options for easy sensor installation
   2. EXd enclosure for easy isolator and transmitter mounting
   3. Parts for a start up
   4. Spare parts supplied for two years of operation
   5. Start-up and commissioning service
3. User specified tests and documentation.

Alloy C-276/ASTM C276 should be considered as wetted parts material when the acid piping flow velocity is at a maximum of 6 m/s (20 ft/s). Alloy 20 can be considered when acid piping flow velocity is at a maximum of 1.8 m/s (6 ft/s). However, it is the responsibility of the end-user to specify the appropriate material, ensuring that it is satisfactory for the intended operating requirements.

Non-sparking incentive (Ex nA) and intrinsic safety (Ex ia) approvals are available for hazardous area installations.

Always consult an applications expert with any process-critical instrumentation application. By doing so, you will ensure a successful, safe, and efficient deployment.

Miller Energy, Inc.
https://millerenergy.com
800-631-5454

Reprinted with permission from K-Patents.

Industrial Refractometers Used in Process Control

Refractometer for pharmaceutical use (K-Patents).

Part physics, part material science and part chemistry, refractometry is the process which measures the composition of known substances by means of calculating their respective refractive indexes (RI). RIs are evaluated via a refractometer, a device which measures the curve, or refraction, resulting when the wavelength of light moves from the air into and through a tested substance. The unitless number given by the refractometer, usually between 1.3000 and 1.7000, is the RI. The composition of substances is then determined when the RI is compared to a standard curve specific to the material of the substance.

Process refractometers provide the analysis to quickly, reliably, and very accurately identify a sample and determine it's concentration and purity levels. They measure the refractive index and temperature of flowing liquids, and apply mathematical functions to determine the concentration of dissolved solids.

Common industrial refractometer applications are:

• Calculating beverages’ amount of sugar dissolved is water.
• In commercial food applications such as juice production or tomato processing, refractometers are used to measure degrees Brix (Tthe Brix scale relates refractive index to sugar concentration, and is a key way to maintain consistency).
• In the pharmaceutical industry, process refractometers are used to monitor and control concentration levels during supersaturation, a critical process in crystallization.
• In pulp and paper production, process refractometers for measuring dissolved solids in black and green liquor during the chemical recovery process.

Equipment manufacturers have developed numerous refractometer configurations tailored to specific each use and application. Each has a set of features making it the advantageous choice for its intended application. Product specialists can be invaluable sources of information and assistance to potential refractometer users seeking to match the best equipment to their application or process.

For more information on industrial refractometers, contact Miller Energy by visiting https://millerenergy.com or by calling 908-755-6700 in New Jersey or 610-363-6200 in Pennsylvania.