【Q&A Question 237】2017.08.25
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【Q&A Question 237】August 25, 2017: What are the hazards of hydrogen sulfide to humans and equipment? The reference answer can be seen after responding; points will be awarded for identifying the key points. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) At low H2S concentrations, inhalation can cause dizziness, headaches, vomiting, general weakness, an H2S-like odor in the exhaled breath, constricted pupils, and slowed reactions. When the concentration exceeds 0.1 milligrams per liter, just a few breaths in can lead to sudden unconsciousness and death from asphyxiation. At temperatures above 260°C, H2S reacts with Fe to form FeS, which blocks the catalyst beds. In an H2 environment, H2S accelerates the corrosion of steel, causing the walls of equipment such as furnace tubes and reactors to thin out, reducing their ability to withstand pressure and leading to equipment failures such as overheating and leaks. Scoring criteria: 2 Wealth points for incorrect attempts; 3–8 points for *incomplete* answers. 10 Wealth points for correct answers, provided along with a detailed explanation; 15–20 Wealth points if the answer is correct but lacks sufficient details. Please score according to these criteria. Note: If there are editing records after answering, only points will be awarded to those who participated. For continuous malicious spamming, 2 points will be deducted each time, with no upper limit. Pure numbers, pure emojis, or random letters that have nothing to do with the answer are all considered malicious spamming; points will start to be deducted after three warnings. 2017 Q&A Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657793-1-1.html 2017 Daily Question Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657794-1-1.html 2016 Q&A Summary Thread (updates completed) http://bbs.hcbbs.com/thread-1597792-1-1.html Petrochemical Sector – “Creative Ideas for Energy Saving” Campaign (Phase 2 is in full swing) http://bbs.hcbbs.com/thread-1666758-1-1.html 2017 Coal Chemicals – “My Technical Upgrades” http://bbs.hcbbs.com/thread-1786290-1-1.html
1. Hydrogen sulfide is a potent inhibitor of cytochrome oxidase; it can bind to the trivalent iron ions in the oxidized form of cytochrome oxidase in the respiratory chain of the mitochondrial inner membrane, thereby inhibiting electron transfer and oxygen utilization, leading to hypoxia within the cells and causing cellular asphyxiation. 2. Wet hydrogen sulfide can cause corrosion to equipment (hydrogen bubbling, hydrogen-induced cracking, hydrogen sulfide stress corrosion cracking...........)
It has a strong irritating effect on mucous membranes. It is soluble in water; at 0°C, 1 mole of water can dissolve about 2.6 moles of hydrogen sulfide. An aqueous solution of hydrogen sulfide is called hydrosulfuric acid; it is a weak acid. When heated, hydrogen sulfide escapes from the water. Hydrogen sulfide is a highly acute poison; inhaling even small amounts of it in high concentrations can be fatal in a short time. Low concentrations of hydrogen sulfide have effects on the eyes, respiratory system, and central nervous system.
Answer: At low H2S concentrations, inhalation can cause dizziness, headaches, vomiting, general weakness, an H2S-like odor in the exhaled breath, constricted pupils, and slowed reactions. When the concentration exceeds 0.1 mg/L, just a few breaths in can lead to sudden unconsciousness and death from asphyxiation. When the temperature is above 260°C, H2S reacts with Fe to form FeS, which blocks the catalyst bed. In an H2 environment, H2S accelerates the corrosion of steel, causing the walls of equipment such as furnace tubes and reactors to thin out, reducing their ability to withstand pressure and leading to equipment failures such as overheating and leaks.
Hydrogen sulfide is highly toxic; it irritates the eyes and respiratory system, hinders the body’s oxidation processes, and causes oxygen deficiency in the body. When the concentration of hydrogen sulfide in the air reaches 0.0001%, it can be detected by human sense of smell； When the hydrogen sulfide concentration reaches 0.0005%, mild poisoning occurs after a few hours, with excessive salivation and clear nasal discharge as well as difficulty breathing ； When the hydrogen sulfide concentration reaches 0.02%, people will suffer severe poisoning, experiencing dizziness, headaches, vomiting, and weakness in the limbs ； When the hydrogen sulfide concentration reaches 0.05%, a person will quickly lose consciousness and experience spasms; without prompt treatment, there is a risk of death ； When the hydrogen sulfide concentration reaches 0.1%, death occurs in an extremely short time.\x0dThe Coal Mine Safety Regulations stipulate that the maximum allowable concentration of hydrogen sulfide in mine air is 0.00066%.
At low H2S concentrations, inhalation can cause dizziness, headache, vomiting, general weakness, an H2S-like odor in the exhaled breath, constricted pupils, and slowed reactions. When the concentration exceeds 0.1 milligrams per liter, just a few breaths in can lead to sudden unconsciousness and death from asphyxiation. At temperatures above 260°C, H2S reacts with Fe to form FeS, which blocks the catalyst bed. In an H2 environment, H2S accelerates the corrosion of steel, causing the walls of equipment such as furnace tubes and reactors to thin out, reducing their ability to withstand pressure and leading to equipment failures such as overheating and leaks.
High concentrations of this dangerous substance can cause dizziness, headaches, fatigue, and confusion; extremely high levels can even lead to death
At low concentrations, inhalation can cause dizziness, headache, vomiting, general weakness, an odor similar to that of rotten eggs in the exhaled breath, constricted pupils, and slowed reaction times. When the concentration exceeds 0.1 milligrams per liter, just a few breaths in can lead to sudden unconsciousness and death from asphyxiation. At temperatures above 260°C, H2S reacts with Fe to form FeS, which blocks the catalyst bed. In an H2 environment, H2S accelerates the corrosion of steel, causing the walls of equipment such as furnace tubes and reactors to thin out, reducing their ability to withstand pressure and leading to equipment failures such as overheating and leaks
Harm to the human body: When hydrogen sulfide is inhaled, it first irritates the respiratory tract. Secondly, it stimulates the nervous system, causing dizziness, loss of balance, difficulty breathing, and an accelerated heart rate; in severe cases, it can lead to death due to oxygen deprivation in the heart. The damage of hydrogen sulfide to equipment materials: The corrosive effect of hydrogen sulfide on metal materials. Hydrogen sulfide dissolves in water to form a weak acid, and the forms of corrosion it causes in metals include electrochemical weight loss corrosion, hydrogen embrittlement, and sulfide stress corrosion cracking; the latter two are the most common, and they are generally referred to together as hydrogen embrittlement damage.
Hydrogen sulfide is a potent neurotoxin that also has a significant irritating effect on mucous membranes; it enters the body primarily through the respiratory tract, causing poisoning. At lower concentrations, it causes eye irritation, tearing, vomiting, and sometimes pneumonia or pulmonary edema. Inhaling high levels of hydrogen sulfide can lead to sudden loss of consciousness, coma, and death from asphyxiation. The sequelae of acute poisoning include headaches and reduced intelligence.