An Introduction to the Oil and Gas Industry 

The oil and gas industry is one of the biggest industries in the world, making a significant contribution to the global economy. This vast sector is often separated into three main sectors: upstream, midstream and downstream. Each sector comes with their own unique gas hazards. 

Upstream

The upstream sector of the oil and gas industry, sometimes referred to as exploration and production (or E&P), is concerned with locating sites for oil and gas extraction the subsequent drilling, recovery and production of crude oil and natural gas. Oil and gas production is an incredibly capital-intensive industry, requiring the use of expensive machinery equipment as well as highly skilled workers. The upstream sector is wide-ranging, encompassing both onshore and offshore drilling operations. 

The major gas hazard encountered in upstream oil and gas is hydrogen sulphide (H2S), a colourless gas known by its distinct rotten egg like smell. H2S is a highly toxic, flammable gas which can have harmful effects on our health, leading to loss of consciousness and even death at high levels. 

Crowcon’s solution for hydrogen sulphide detection comes in the form of the XgardIQ, an intelligent gas detector which increases safety by minimising the time operators must spend in hazardous areas. XgardIQ is available with high-temperature H2S sensor, specifically designed for the harsh environments of the Middle East. 

Midstream

The midstream sector of the oil and gas industry encompasses the storage, transportation and processing of crude oil and natural gas. The transportation of crude oil and natural gas is done by both land and sea with large volumes transported in tankers and marine vessels. On land, transportation methods used are tankers and pipelines. Challenges within the midstream sector include but are not limited to maintaining the integrity of storage and transportation vessels and protecting workers involved in cleaning, purging and filling activities. 

Monitoring of storage tanks is essential to ensure the safety of workers and machinery. 

Downstream

The downstream sector refers to the refining and processing of natural gas and crude oil and the distribution of finished products. This is the stage of the process where these raw materials are transformed into products which are used for a variety of purposes such as fuelling vehicles and heating homes.  

The refining process for crude oil is generally split into three basic steps: separation, conversion and treatment. Natural gas processing involves separating the various hydrocarbons and fluids to produce ‘pipeline quality’ gas. 

The gas hazards which are typical within the downstream sector are hydrogen sulphide, sulphur dioxide, hydrogen and a wide range of toxic gases. Crowcon’s Xgard and Xgard Bright fixed detectors both offer a wide range of sensor options to cover all the gas hazards present in this industry. Xgard Bright is also available with the next generation MPS™ sensor, for the detection of over 15 flammable gases in one detector. Also available are both single and multi-gas personal monitors to ensure workers safety in these potentially hazardous environments. These include the Gas-Pro and T4x, with Gas-Pro providing 5 gas support in a compact and rugged solution.

Why is gas emitted in cement production?

How is cement produced?

Concrete is one of the most important and commonly used materials in global construction. Concrete is widely used in the construction of both residential and commercial buildings, bridges, roads and more. 

The key component of concrete is cement, a binding substance which binds all the other components of concrete (generally gravel and sand) together. More than 4 billion tonnes of cement is used worldwide every year, illustrating the massive scale of the global construction industry. 

Making cement is a complex process, starting with raw materials including limestone and clay which are placed in large kilns of up to 120m in length, which are heated to up to 1,500°C. When heated at such high temperatures, chemical reactions cause these raw materials to come together, forming cement. 

As with many industrial processes, cement production is not without its dangers. The production of cement has the potential to release gases which are harmful to workers, local communities and the environment. 

What gas hazards are present in cement production?

The gases generally emitted in cement plants are carbon dioxide (CO2), nitrous oxides (NOx) and sulphur dioxide (SO2), with CO2 accounting for the majority of emissions. 

The sulphur dioxide present in cement plants generally comes from the raw materials which are used in the cement production process. The main gas hazard to be aware of is carbon dioxide, with the cement making industry responsible for a massive 8% of global CO2 emissions. 

The majority of carbon dioxide emissions are created from a chemical process called calcination. This occurs when limestone is heated in the kilns, causing it to break down into CO2 and calcium oxide.  The other main source of CO2 is the combustion of fossil fuels. The kilns used in cement production are generally heated using natural gas or coal, adding another source of carbon dioxide into addition to that which is generated through calcination. 

Detecting gas in cement production

In an industry which is a large producer of hazardous gases, detection is key. Crowcon offer a wide range of both fixed and portable detection solutions. 

Xgard Bright is our addressable fixed-point gas detector with display, providing ease of operation and reduced installation costs. Xgard Bright has options for the detection of carbon dioxide and sulphur dioxide, the gases of most concern in cement mixing. 

For portable gas detection, the Gasman’s  rugged yet portable and lightweight design make it the perfect single-gas solution for cement production, available in a safe area CO2 version offering 0-5% carbon dioxide measurement. 

For enhanced protection, the Gas-Pro multi-gas detector can be equipped with up to 5 sensors, including all of those most common in cement production, CO2, SO2 and NO2.

The importance of gas detection in the Petrochemical Industry

Closely linked to oil and gas, the petrochemicals industry takes raw materials from refining and gas processing and, through chemical process technologies, converts them into valuable products. In this sector, the organic chemicals produced in the largest volumes are methanol, ethylene, propylene, butadiene, benzene, toluene and xylenes (BTX). These chemicals are the building blocks of many consumer goods including plastics, clothing fabric, construction materials, synthetic detergents and agrichemical products.

Potential Hazards

Exposure to potential hazardous substances is more likely to occur during shutdown or maintenance work as these are a deviation from the refinery’s routine operations. As these deviations are out of normal routine, care should be exercised at all times to avoid the inhalation of solvent vapours, toxic gases, and other respiratory contaminants. The assistance of constant automated monitoring is helpful in determining the presence of solvents or gases, allowing their associated risks to be mitigated. This includes warning systems such as gas and flame detectors, supported by emergency procedures, and permit systems for any kind of potentially dangerous work.

The petroleum industry is split into upstream, midstream and downstream and these are defined by the nature of the work that takes place in each area. Upstream work is typically known as the exploration and production (E&P) sector. Midstream refers to the transportation of products through pipelines, transit and oil tankers as well as the wholesale marketing of petroleum-based products. The downstream sector refers to the refining of petroleum crude oil, the processing of raw natural gas and the marketing and distribution of finished products.

Upstream

Fixed and portable gas detectors are needed to protect plant and personnel from the risks of flammable gas releases (commonly methane) as well as from high levels of H2S, particularly from sour wells. Gas detectors for O2 depletion, SO2 and volatile organic compounds (VOCs) are required items of personal protection equipment (PPE), which is usually highly visible colour and worn near breathing space. Sometimes HF solution is used as a scouring agent. Key requirements for gas detectors are rugged and reliable design and long battery life. Models with design elements that support easy fleet management and compliance obviously have an advantage. You can read about VOC risk and Crowcon’s solution in our case study.

Midstream

Fixed monitoring of flammable gases situated close to pressure relief devices, filling and emptying areas is necessary to deliver early warning of localised leaks. Multi-gas portable monitors must be used to maintain personal safety, especially during work in confined spaces and supporting hot work permit area testing. Infrared technology in flammable gas detection supports purging with the ability to operate in inert atmospheres and delivers reliable detection in areas where pellistor type detectors would fail, due to poisoning or volume level exposure. You can read more on how infrared detection works in our blog and read our case study of infrared monitoring in refinery settings in Southeast Asia.

Portable laser methane detection (LMm) allows users to pin-point leaks at distance and in hard-to-reach areas, reducing the need for personnel to enter potentially dangerous environments or situations while performing routine or investigative leak monitoring. Using LMm is a quick and effective way to check areas for methane with a reflector, from up to 100m away. These areas include closed buildings, confined spaces and other difficult-to-reach areas such as above-ground pipelines that are near water or behind fences.

Downstream

In downstream refining, the gas risks may be almost any hydrocarbon, and may also include hydrogen sulphide, sulphur dioxide and other by-products. Catalytic flammable gas detectors are one of the oldest flammable gas detector types. They work well, but must have a bump testing station, to ensure each detector responds to the target gas and is still functional. The ongoing demand to reduce facility down-time whilst ensuring safety, especially during shutdown and turnaround operations, means that gas detection manufacturers must deliver solutions offering ease of use, straightforward training and reduced maintenance times, along with local service and support.

During plant shutdowns, processes are stopped, items of equipment are opened and checked and the number of people and moving vehicles at the site is many times higher than normal. Many of the processes undertaken will be hazardous and require specific gas monitoring. For example, welding and tank cleaning activities require area monitors as well as personal monitors to protect those on site.

Confined space

Hydrogen sulphide (H2S) is a potential problem in the transport and storage of crude oil. The cleaning of storage tanks presents a high hazard potential. Many confined-space entry problems can occur here, including oxygen deficiency resulting from previous inerting procedures, rusting, and oxidation of organic coatings. Inerting is the process of reducing the oxygen levels in a cargo tank to remove the oxygen element required for ignition. Carbon monoxide can be present in the inerting gas. In addition to H2S, depending on the characteristics of the product previously stored in the tanks, other chemicals that may be encountered include metal carbonyls, arsenic, and tetraethyl lead.

Our Solutions

Elimination of these gas hazards is virtually impossible, so permanent workers and contractors must depend on reliable gas detection equipment to protect them. Gas detection can be provided in both fixed and portable forms. Our portable gas detectors protect against a wide range of gas hazards, these include Clip SGD, Gasman, Tetra 3,Gas-Pro, T4, Gas-Pro TK and Detective+. Our fixed gas detectors are used in many applications where reliability, dependability and lack of false alarms are instrumental to efficient and effective gas detection, these include Xgard, Xgard Bright, Fgard IR3 Flame Detector and IRmax. Combined with a variety of our fixed detectors, our gas detection control panels offer a flexible range of solutions that measure flammable, toxic and oxygen gases, report their presence and activate alarms or associated equipment, for the petrochemical industry our panels include Addressable Controllers, Vortex and Gasmonitor.

To find out more on the gas hazards in the petrochemical industry visit our industry page for more information.

The Dangers of Gas Exposure in Wineries

Wineries face a unique set of challenges when it comes to safeguarding workers from the potential harm caused by hazardous gases. Gas exposure has the potential to occur at every stage of the wine production process, from the moment that the grapes arrive at the winery facility, through to the fermentation and bottling activities. Care must be taken at each stage to ensure that workers are not exposed to unnecessary risk. There are several specific environments within the winery facility that pose a risk of gas leakage and exposure, including fermentation rooms, pits, barrel cellars, sumps, storage tanks and bottling rooms. The main gas hazards that are found during the winemaking process are carbon dioxide, and oxygen displacement, but also hydrogen sulphide, sulphur dioxide, ethyl alcohol and carbon monoxide.

What are the Gas Hazards?

Hydrogen sulphide (H2S)

Hydrogen sulphide is a gas that can be present during the fermentation process. It is more commonly present in damp conditions where bacterial action has acted on natural oils. It hides dissolved in standing water until disturbed. The most dangerous occurrence is when cleaning a confined space e.g., a tank where released gases cannot easily escape. A pre-entry check comes up clean, and the standing water is then disturbed upon entry. The risks associated with H2S are that it is potentially hazardous to health, upsetting breathing patterns. Hydrogen sulphide poses severe respiratory risks, even at a relatively low concentration in the air. The gas is very easily and rapidly absorbed into the bloodstream through the lung tissue, which means it is distributed throughout the whole body very quickly.

Sulphur Dioxide (SO2)

Sulphur Dioxide is a natural by-product of fermentation, but it is also commonly used as an additive in the process of organic wine making. Extra SO2 is added during the wine making process in order to prevent the growth of any undesirable yeast and microbes within the wine. Sulphur dioxide can be highly hazardous to health and is a highly toxic gas, causing numerous irritations in the body upon contact. Sulphur dioxide is a gas that can cause irritation to the airways, nose, and throat. Workers who are exposed to high levels of sulphur dioxide may experience vomiting, nausea, stomach cramps, and irritation or corrosive damage to the lungs and airways.

Ethanol (ethyl alcohol)

Ethanol is the main alcoholic product of organic wine fermentation. It helps to maintain the flavour of the wine and stabilizes the aging process. Ethanol is created during fermentation as the yeast converts sugar from the grapes. Wine typically contains somewhere between 7% and 15% ethanol, which gives the drink its alcohol by volume (ABV) percentage. The amount of ethanol actually produced depends on the sugar content of the grapes, the fermentation temperature, and the type of yeast that is used. Ethanol is a colourless and odourless liquid that gives off flammable and potentially hazardous fumes. The fumes given off by ethanol or ethyl alcohol can irritate the airways and lungs if inhaled, with the possibility of intense coughing and choking.

Where are the dangers?

Open Fermentation Tanks

Any worker whose job involves carrying out operations over an open fermentation vessel or tank may be at a high risk of gas exposure, especially to CO2, or oxygen depletion. It has been shown that a worker who leans over the top of an open fermenter during full production, even though they may be as much as 10 feet off the ground, can potentially be exposed to 100% CO2. Therefore, particular care and attention to gas detection should be taken in these areas.

Exposure Due To Inadequate Ventilation

The fermentation process needs to take place in environments that are well ventilated to avoid the build-up of toxic and asphyxiant gases. Fermentation rooms, tank rooms, and cellars are all places that may pose a risk. During cold weather or night-time, increased levels of gas may build up as door and window vents may be shut.

Confined Spaces

Confined spaces such as pits and sumps are often problematic and well known for the potential build-up of hazardous gases. The definition of a confined space in a winery is one that contains, or may contain, a hazardous atmosphere, has the potential for engulfment by material, or an entrant to the environment may become trapped or asphyxiated.

Multiple Units

As a winery grows and expands their operations, they may want to add new production units to meet the demand. However, it is important to remember that potential gas exposure risks differ between environments, e.g., the gas risk in a fermentation cellar is not the same as a barrel room. Therefore, different types of gas detectors may be needed in different areas.

For more information about gas detection solutions for wineries, or to ask further questions get in touch today.

Cross sensitivity of toxic sensors: Chris investigates the gases that the sensor is exposed to

Working in Technical Support, one of the most common questions from customers is for bespoke configurations of toxic gas sensors. This frequently leads to an investigation into the cross sensitivity of the different gases that the sensor will be exposed to.

Cross sensitivity responses will vary from sensor type to sensor type, and suppliers often express the cross sensitivity in percentages while others will specify in actual parts-per-million (ppm) levels.

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