The synthesis of ammonia makes the most important method for humans to produce nitrogenous compounds from nature. Nitrogen is the most important raw material for the further synthesis of nitrogen-containing compounds.
Nitrogen-containing compounds are essential in people's lives.
In addition to being used as fertilizer itself, ammonia is a raw material for further production of various nitrogen fertilizers. Nitrogen fertilizer is an indispensable part of modern agricultural production
There are nitrogen fertilizers made of ammonia, the most important of which are urea, ammonium nitrate, ammonium sulfate, ammonium bicarbonate, ammonium phosphate, etc.
Ammonia can be used to make inorganic substances such as nitric acid, nitrate, ammonium salt, cyanide, etc., and can also be used to make organic substances such as amines, sulfonamides, and nitriles. Ammonia and this
Some nitrogenous compounds are raw materials for the production of fuels, explosives, medicines, synthetic fibers, plastics, etc.
Ammonia is synthesized from hydrogen and nitrogen, so the direct raw materials for ammonia synthesis are hydrogen and nitrogen
More than 60% of the factories use natural gas and oilfield gas as raw materials. This is followed by light oil and refinery gas that are close to natural gas. With coal
Only 10% of the raw materials are
The production process of ammonia can be roughly divided into four steps: the production of raw materials; purification of raw gas; synthesis of ammonia; Separation of ammonia. In addition to the synthesis of ammonia,
The conversion and separation rates of other processes are relatively high. Due to the low conversion rate of ammonia synthesis, the reactive gas is separated by ammonia and circulated back to the synthesis tower.
Principle process of ammonia production:
The raw material for ammonia synthesis, whether it is coal, natural gas or oilfield gas, will cause fire and explosion once it leaks.
In the synthesis of ammonia, a catalyst with iron as the main body is used, the catalyst is more prone to poisoning, and the presence of a small amount of oxygen and oxides will oxidize the active iron
Inactive. However, when oxygen or oxides are removed, the activity can still be restored, so this is called temporary poisoning. sulfur (H2S), phosphorus (such as PH3) and other citations
Catalyst poisoning is irreversible, so it is called permanent poisoning. Raw gas made from raw materials contains components that can cause catalyst poisoning.
Mainly sulfur-containing compounds and oxides of carbon. They undergo a purification process of desulfurization and decarbonization. This process produces carbon dioxide, carbon monoxide,
Toxic gases such as hydrogen sulfide.
The semi-hydrated gas produced in the gas production cycle using coal and coke as raw materials contains hydrogen, carbon monoxide, nitrogen, carbon dioxide, and more
Contains a small amount of methane, oxygen, hydrogen sulfide, sulfur, etc.
The raw materials of light hydrocarbons are mainly natural gas, oilfield gas, refinery gas, light oil, etc. The most used is natural gas, the main component of which is methane.
Ammonia synthesis from natural gas is a gas produced from a two-stage conversion furnace, and its compositions are methane, carbon dioxide, carbon monoxide, hydrogen, and nitrogen.
In addition, the raw gas of light hydrocarbons contains a small amount of sulfur, which is toxic to nickel catalysts, and hydrogen reaction needs to be added to produce hydrogen sulfide when removing sulfur.
The partial oxidation method of ammonia synthesis using heavy hydrocarbons as raw materials is to let oxygen, water vapor and heavy hydrocarbons burn in the gasifier to release heat and heat up the system.
At the same time, the gasified oil cracks and reforms. After that, the combustion material undergoes a conversion reaction to obtain synthetic ammonia mainly composed of hydrogen and carbon monoxide
Raw gas. The side reaction products will contain carbon monoxide, carbon dioxide, and hydrogen.
Gas to be detected for raw material storage and transportation: hydrocarbon flammable gas.
Decarbonization and desulfurization gases to be detected: carbon monoxide, carbon dioxide, hydrogen sulfide, oxygen.
Gases to be detected in the process of ammonia synthesis and separation: carbon monoxide, hydrogen sulfide, hydrogen, sulfur dioxide, oxygen and other toxic gases, hydrocarbonization
Complex flammable gas.
Monitoring System Function Introduction:
When the on-site detector detects that the corresponding gas concentration exceeds the standard, it will immediately output the corresponding alarm switch to the corresponding sound and light alarm to trigger no
Alarm signals of the same level to inform the on-site personnel. At the same time, the controller receives a value that exceeds the alarm limit, which triggers the relevant relay action and goes up
to DCS to trigger a linkage.
Optima Plus Combustible Gas Detector:
The Optima Plus combustible gas detector adopts the infrared compensation detection principle of "dual light source, dual beam", which has fast response speed and high accuracy.
Low maintenance, long service life (typical service life of 15 years) and other advantages. The Optima Plus is made of full 316 stainless steel for good corrosion resistance.
Optima Plus also has SIL2 safety certification, as well as BV, ABS and other multinational classification societies certifications, making it a high safety level and maintenance-free
Instrumentation.
XCD Flammable/Toxic Gas Detector:
As Honeywell's next-generation universal gas detector platform, XCD features intelligent sensors with multiple detection and principles for detection
All kinds of flammable gases and toxic and harmful gases. XCD has a shell made of aluminum alloy and 316 stainless steel, and a unique three-color backlit LCD
The display function, the standard relay signal output, and the patented "SurecellTM" technology make the XCD suitable for any working environment. At the same time,
XCD's cost-effectiveness makes it a more economical gas detection solution especially for intensive companies such as refineries.
System57 Controller:
The System57 controller, installed in the central control room safe area alarm cabinet, is compatible with all fixedHoneywell industrial gas detectors
controller, its specific functions are as follows:
Provides 24V power to detectors in the field.
The 4-20mA current analog signal from the field detector is received, and the corresponding gas concentration is accurately converted into a display panel.
Its single-channel independent loop design can provide three types of alarm uploads: A1, A2 and fault for each detector connected to it.
Upload analog signals, Modbus signals and three alarm switches to output to DCS.
XCD Flammable/Toxic Gas Detector (see page 39 for details)
Optima Plus combustible gas detector (see page 42 for details)
System57 controller (see page 45 for details)