Blogs listed by tag: Sulphur dioxide

Industry Overview: Waste to Energy

The waste to energy industry utilises several waste treatment methods. Municipal and industrial solid waste is converted into electricity, and sometimes into heat for industrial processing and district heating systems. The main process is of course incineration, but intermediate steps of pyrolysis, gasification, and anaerobic digestion are sometimes used to convert the waste into useful by-products that are then used to generate power through turbines or other equipment. This technology is gaining wide recognition globally as a greener and cleaner form of energy than traditional burning of fossil fuels, and as a means of reducing waste production.

Types of waste to energy

Incineration

Incineration is a waste treatment process that involves the combustion of energy rich substances contained within waste materials, typically at high temperatures around 1000 degrees C. Industrial plants for waste incineration are commonly referred to as waste-to-energy facilities and are often sizeable power stations in their own right. Incineration and other high-temperature waste treatment systems are often described as “thermal treatment”. During the process waste is converted into heat and steam that can be used to drive a turbine in order to generate electricity. This method currently has an efficiency of around 15-29%, although it does have potential for improvements.

Pyrolysis

Pyrolysis is a different waste treatment process where decomposition of solid hydrocarbon wastes, typically plastics, takes place at high temperatures without oxygen present, in an atmosphere of inert gases. This treatment is usually conducted at or above 500 °C, providing enough heat to deconstruct the long chain molecules including bio-polymers into simpler lower mass hydrocarbons.

Gasification

This process is used to make gaseous fuels from heavier fuels and from waste containing combustible material. In this process, carbonaceous substances are converted into carbon dioxide (CO2), carbon monoxide (CO) and a small amount of hydrogen at high temperature. In this process, gas is generated which is a good source of usable energy. This gas can then be used to produce electricity and heat.

Plasma Arc Gasification

In this process, a plasma torch is used to ionise energy rich material. Syngas is produced which may then be used to make fertiliser or generate electricity. This method is more of a waste disposal technique than a serious means of generating gas, often consuming as much energy as the gas it produces can provide.

Reasons for Waste to Energy

As this technology is gaining wide recognition globally in regards to waste production and the demand for clean energy.

  • Avoids methane emissions from landfills
  • Offsets greenhouse gas (GHG) emissions from fossil fuel electrical production
  • Recovers and recycles valuable resources, such as metals
  • Produces clean, reliable base-loaded energy and steam
  • Uses less land per megawatt than other renewable energy sources
  • Sustainable and steady renewable fuel source (compared to wind and solar)
  • Destroys chemical waste
  • Results in low emission levels, typically well below permitted levels
  • Catalytically destroys nitrogen oxides (NOx), dioxins and furans using an selective catalytic reduction (SCR)

What are the Gas Hazards?

There are many processes to turn waste into energy, these include, biogas plants, refuse use, leachate pool, combustion and heat recovery. All these processes pose gas hazards to those working in these environments.

Within a Biogas Plant, biogas is produced. This is formed when organic materials such as agricultural and food waste are broken down by bacteria in an oxygen-deficient environment. This is a process called anaerobic digestion. When the biogas has been captured, it can be used to produce heat and electricity for engines, microturbines and fuel cells. Clearly, biogas has high methane content as well as substantial hydrogen sulphide (H2S), and this generates multiple serious gas hazards. (Read our blog for more information on biogas). However, there is an elevated risk of, fire and explosion, confined space hazards, asphyxiation, oxygen depletion and gas poisoning, usually from H2S or ammonia (NH3). Workers in a biogas plant must have personal gas detectors that detect and monitor flammable gas, oxygen and toxic gases like H2S and CO.

Within a refuse collection it is common to find flammable gas methane (CH4) and toxic gases H2S, CO and NH3. This is because refuse bunkers are built several metres underground and gas detectors are usually mounted high up in areas making those detectors hard to service and calibrate. In many cases, a sampling system is a practical solution as air samples can be brought to a convenient location and measured.

Leachate is a liquid that drains (leaches) from an area in which waste is collected, with leachate pools presenting a range of gas hazards. These include the risk of flammable gas (explosion risk), H2S (poison, corrosion), ammonia (poison, corrosion), CO (poison) and adverse oxygen levels (suffocation). Leachate pool and passageways leading to the leachate pool requiring monitoring of CH4, H2S, CO, NH3, oxygen (O2) and CO2. Various gas detectors should be placed along routes to the leachate pool, with output connected to external control panels.

Combustion and heat recovery requires the detection of O2 and toxic gases sulphur dioxide (SO2) and CO. These gases all pose a threat to those who work in boiler house areas.

Another process that is classed as a gas hazard is an exhaust air scrubber. The process is hazardous as the flue gas from incineration is highly toxic. This is because it contains pollutants such as nitrogen dioxide (NO2), SO2, hydrogen chloride (HCL) and dioxin. NO2 and SO2 are major greenhouse gases, while HCL all of these gas types mentioned here are harmful to human health.

To read more on the waste to energy industry, visit our industry page.

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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.

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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.

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The importance of Gas Detection in the Water and Wastewater Industry 

Water is vital to our daily lives, both for personal and domestic use and industrial/commercial applications. Whether a facility focuses on the production of clean, potable water or treating effluent, Crowcon is proud to serve a wide variety of water industry clients, providing gas detection equipment that keeps workers safe around the world. 

Gas Hazards 

Apart from common gas hazards known in the industry; methane, hydrogen sulphide, and oxygen, there are bi-product gas hazards and cleaning material gas hazards that occur from purifying chemicals such as ammonia, chlorine, chlorine dioxide or ozone that are used in the decontamination of the waste and effluent water, or to remove microbes from clean water. There is great potential for many toxic or explosive gases to exist as a result of the chemicals used in the water industry. And added to these are chemicals that may be spilled or dumped into the waste system from industry, farming or building work. 

Safety Considerations  

Confined Space Entry 

The pipelines used to transport water require regular cleaning and safety checks; during these operations, portable multi-gas monitors are used to protect the workforce. Pre-entry checks must be completed prior to entering any confined space and commonly O2, CO, H2S and CH4 are monitored. Confined spaces are small, so portable monitors must be compact and unobtrusive for the user, yet able to withstand the wet and dirty environments in which they must perform. Clear and prompt indication of any increase in gas monitored (or any decrease for oxygen) is of paramount importance – loud and bright alarms are effective in raising the alarm to the user. 

Risk assessment 

Risk assessment is critical, as you need to be aware of the environment that you are entering and thus working in. Therefore, understanding the applications and identifying the risks regarding all safety aspects. Focusing on gas monitoring, as part of the risk assessment, you need to be clear on what gases may be present.  

Fit for purpose 

There is a variety of applications within the water treatment process, giving the need to monitor multiple gases, including carbon dioxide, hydrogen sulphide, chlorine, methane, oxygen, ozone and chlorine dioxide. Gas detectors are available for single or multiple gas monitoring, making them practical for different applications as well as making sure that, if conditions change (such as sludge is stirred up, causing a sudden increase in hydrogen sulphide and flammable gas levels), the worker is still protected.  

Legislation   

European Commission Directive 2017/164 issued in January 2017, established a new list of indicative occupational exposure limit values (IOELVs). IOELV are health-based, non-binding values, derived from the most recent scientific data available and considering the availability of reliable measurement techniques. The list includes carbon monoxide, nitrogen monoxide, nitrogen dioxide, sulphur dioxide, hydrogen cyanide, manganese, diacetyl and many other chemicals. The list is based on Council Directive 98/24/EC that considers the protection of the health and safety of workers from the risks related to chemical agents in the workplace. For any chemical agent for which an IOELV has been set at Union level, Member States are required to establish a national occupational exposure limit value. They also are required to take into account the Union limit value, determining the nature of the national limit value in accordance with national legislation and practice. Member States will be able to benefit from a transitional period ending at the latest on 21 August 2023.  

The Health and Safety Executive (HSE) state that each year several workers will suffer from at least one episode of work-related illness. Although, most illnesses are relatively mild cases of gastroenteritis, there is also a risk for potentially fatal diseases, such as leptospirosis (Weil’s disease) and hepatitis. Even though these are reported to the HSE, there could be significant under-reporting as there is often failure to recognise the link between illness and work.  

Under domestic law of the Health and Safety at Work etc Act 1974, employers are responsible for ensuring the safety of their employees and others. This responsibility is reinforced by regulations. 

The Confined Spaces Regulations 1997 applies where the assessment identifies risks of serious injury from work in confined spaces. These regulations contain the following key duties: 

  • Avoid entry to confined spaces, e.g., by doing the work from the outside. 
  • If entry to a confined space is unavoidable, follow a safe system of work.
  • Put in place adequate emergency arrangements before the work start. 

The Management of Health and Safety at Work Regulations 1999 requires employers and self-employed people to carry out a suitable and sufficient assessment of the risks for all work activities for the purpose of deciding what measures are necessary for safety. For work in confined spaces this means identifying the hazards present, assessing the risks and determining what precautions to take. 

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 T4x, Clip SGD, Gasman, Tetra 3, Gas-Pro, T4 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 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 wastewater industry our panels include  Gasmaster.    

To find out more on the gas hazards in wastewater and water treatment visit our industry page for more information.  

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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.

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Gold Mining: What gas detection do I need? 

How is gold mined?

Gold is a rare substance equating to 3 parts per billion of the earth’s outer layer, with most of the world’s available gold coming from Australia. Gold, like iron, copper and lead, is a metal. There are two primary forms of gold mining, including open-cut and underground mining. Open mining involves earth-moving equipment to remove waste rock from the ore body above, and then mining is conducted from the remaining substance. This process requires waste and ore to be struck at high volumes to break the waste and ore into sizes suitable for handling and transportation to both waste dumps and ore crushers. The other form of gold mining is the more traditional underground mining method. This is where vertical shafts and spiral tunnels transport workers and equipment into and out of the mine, providing ventilation and hauling the waste rock and ore to the surface.

Gas detection in mining

When relating to gas detection, the process of health and safety within mines has developed considerably over the past century, from morphing from the crude usage of methane wick wall testing, singing canaries and flame safety to modern-day gas detection technologies and processes as we know them. Ensuring the correct type of detection equipment is utilised, whether fixed or portable, before entering these spaces. Proper equipment utilisation will ensure gas levels are accurately monitored, and workers are alerted to dangerous concentrations within the atmosphere at the earliest opportunity.

What are the gas hazards and what are the dangers?

The dangers those working within the mining industry face several potential occupational hazards and diseases, and the possibility of fatal injury. Therefore, understanding the environments and hazards, they may be exposed to is important.

Oxygen (O2)

Oxygen (O2), usually present in the air at 20.9%, is essential to human life. There are three main reasons why oxygen poses a threat to workers within the mining industry. These include oxygen deficiencies or enrichment, as too little oxygen can prevent the human body from functioning leading to the worker losing consciousness. Unless the oxygen level can be restored to an average level, the worker is at risk of potential death. An atmosphere is deficient when the concentration of O2 is less than 19.5%. Consequently, an environment with too much oxygen is equally dangerous as this constitutes a greatly increased risk of fire and explosion. This is considered when the concentration level of O2 is over 23.5%

Carbon Monoxide (CO)

In some cases, high concentrations of Carbon Monoxide (CO) may be present. Environments that this may occur include a house fire, therefore the fire service are at risk of CO poisoning. In this environment there can be as much as 12.5% CO in the air which when the carbon monoxide rises to the ceiling with other combustion products and when the concentration hits 12.5% by volume this will only lead to one thing, called a flashover. This is when the whole lot ignites as a fuel. Apart from items falling on the fire service, this is one of the most extreme dangers they face when working inside a burning building. Due to the characteristics of CO being so hard to identify, I.e., colorless, odourless, tasteless, poisonous gas, it may take time for you to realise that you have CO poisoning. The effects of CO can be dangerous, this is because CO prevents the blood system from effectively carrying oxygen around the body, specifically to vital organs such as the heart and brain. High doses of CO, therefore, can cause death from asphyxiation or lack of oxygen to the brain. According to statistics from the Department of Health, the most common indication of CO poisoning is that of a headache with 90% of patients reporting this as a symptom, with 50% reporting nausea and vomiting, as well as vertigo. With confusion/changes in consciousness, and weakness accounting for 30% and 20% of reports.

Hydrogen sulphide (H2S)

Hydrogen sulphide (H2S) is a colorless, flammable gas with a characteristic odour of rotten eggs. Skin and eye contact may occur. However, the nervous system and cardiovascular system are most affected by hydrogen sulphide, which can lead to a range of symptoms. Single exposures to high concentrations may rapidly cause breathing difficulties and death.

Sulphur dioxide (SO2)

Sulphur dioxide (SO2) can cause several harmful effects on the respiratory systems, in particular the lung. It can also cause skin irritation. Skin contact with (SO2) causes stinging pain, redness of the skin and blisters. Skin contact with compressed gas or liquid can cause frostbite. Eye contact causes watering eyes and, in severe cases, blindness can occur.

Methane (CH4)

Methane (CH4) is a colorless, highly flammable gas with a primary component being that of natural gas. High levels of (CH4) can reduce the amount of oxygen breathed from the air, which can result in mood changes, slurred speech, vision problems, memory loss, nausea, vomiting, facial flushing and headache. In severe cases, there may be changes in breathing and heart rate, balance problems, numbness, and unconsciousness. Although, if exposure is for a longer period, it can result in fatality.

Hydrogen (H2)

Hydrogen Gas is a colorless, odourless, and tasteless gas which is lighter than air. As it is lighter than air this means it float higher than our atmosphere, meaning it is not naturally found, but instead must be created. Hydrogen poses a fire or explosion risk as well as an inhalation risk. High concentrations of this gas can cause an oxygen-deficient environment. Individuals breathing such an atmosphere may experience symptoms which include headaches, ringing in ears, dizziness, drowsiness, unconsciousness, nausea, vomiting and depression of all the senses

Ammonia (NH3)

Ammonia (NH3) is one of the most widely used chemicals globally that is produced both in the human body and in nature. Although it is naturally created (NH3) is corrosive which poses a serve concern for health. High exposure within the air can result in immediate burning to the eyes, nose, throat and respiratory tract. Serve cases can result in blindness.

Other gas risks

Whilst Hydrogen Cyanide (HCN) doesn’t persist within the environment, improper storage, handling and waste management can pose severe risk to human health as well as effects on the environment. Cyanide interferes with human respiration at cellular levels that can cause serve and acute effects, including rapid breathing, tremors, asphyxiation.

Diesel particulate exposure can occur in underground mines as a result of diesel-powered mobile equipment used for drilling and haulage. Although control measures include the use of low sulphur diesel fuel, engine maintenance and ventilation, health implication includes excess risk of lung cancer.

Products that can help to protect yourself

Crowcon provide a range of gas detection including both portable and fixed products all of which are suitable for gas detection within the mining industry.

To find out more visit our industry page here.

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