Purification Technology Edition: Daily Question [2017-11-17]
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What is the impact of excessive ammonia levels in methanol solutions on the system? Answer: Raw coal contains amino organic compounds, which decompose in the gasifier to produce ammonia. Most of this ammonia is decomposed, with only a small portion remaining undecomposed, which is further removed in the ammonia washing tower. Trace amounts of ammonia enter the low-temperature methanol washing system and dissolve in the methanol solution; it is difficult to separate them. Over time, as an excessive amount accumulates, ammonium carbonate crystals form in the water cooler at the top of the regeneration tower. The general requirement for ammonia content is that it should remain below 5–10 mg/l in the methanol returning to the top of the thermal regeneration tower; accordingly, the ammonia content in the methanol after thermal regeneration should be less than 20 mg/l, while the ammonia content in the rich methanol stream in the system should be between 100–200 ppm. Excess pressure in the carbon ammonium crystal regeneration tower is generated; the pipeline valve to prevent carbon ammonium crystal formation is opened promptly to eliminate it. Furthermore, excessive ammonia levels lead to the formation of thiourea, which decomposes at the top of the scrubber, resulting in elevated hydrogen sulfide levels in the purified gas.
Raw coal contains amino organic compounds, which decompose in the gasifier to produce ammonia. Most of this ammonia is decomposed, with only a small portion remaining undecomposed and being further removed in the ammonia washing tower. Trace amounts of ammonia enter the low-temperature methanol washing system and dissolve in the methanol solution; it is difficult to separate them. Over time, as an excessive amount accumulates, ammonium carbonate crystals form in the water cooler at the top of the regeneration tower. The general requirement for ammonia content is that it should remain below 5–10 mg/l in the methanol returning to the top of the thermal regeneration tower; accordingly, the ammonia content in the methanol after thermal regeneration should be less than 20 mg/l, while the ammonia content in the rich methanol stream in the system should be between 100–200 ppm. Excess pressure in the carbon ammonium crystal regeneration tower is generated; the pipeline valve to prevent carbon ammonium crystal formation is opened promptly to eliminate it. Furthermore, excessive ammonia levels lead to the formation of thiourea, which decomposes at the top of the scrubber, resulting in elevated hydrogen sulfide levels in the purified gas
The ammonia level in the system was too high, which resulted in inadequate regeneration of the methanol-depleted stream. As the ammonia level in the system increased, so did the ammonia content in the methanol-depleted stream; this led to the formation of sulfurous acid, which then decomposed into hydrogen sulfide at the top of the scrubber tower, causing the hydrogen sulfide level in the purified gas to exceed the allowable limits.
Raw coal contains amino organic compounds, which decompose in the gasifier to produce ammonia. Most of this ammonia is decomposed, with only a small portion remaining undecomposed and being further removed in the ammonia washing tower. Trace amounts of ammonia enter the low-temperature methanol washing system and dissolve in the methanol solution; it is difficult to separate them. Over time, as an excessive amount accumulates, ammonium carbonate crystals form in the water cooler at the top of the regeneration tower. The general requirement for ammonia content is that it should remain below 5–10 mg/l in the methanol returning to the top of the thermal regeneration tower; accordingly, the ammonia content in the methanol after thermal regeneration should be less than 20 mg/l, while the ammonia content in the rich methanol stream in the system should be between 100–200 ppm. Excess pressure in the carbon ammonium crystal regeneration tower is generated; the pipeline valve to prevent carbon ammonium crystal formation is opened promptly to eliminate it. Furthermore, excessive ammonia levels lead to the formation of thiourea, which decomposes at the top of the scrubber, resulting in elevated hydrogen sulfide levels in the purified gas.
Raw coal contains amino organic compounds, which decompose in the gasifier to produce ammonia. Most of this ammonia is decomposed, with only a small portion remaining undecomposed and being further removed in the ammonia washing tower. Trace amounts of ammonia enter the low-temperature methanol washing system and dissolve in the methanol solution; it is difficult to separate them. Over time, as an excessive amount accumulates, ammonium carbonate crystals form in the water cooler at the top of the regeneration tower. The general requirement for ammonia content is that it should remain below 5–10 mg/l in the methanol returning to the top of the thermal regeneration tower; accordingly, the ammonia content in the methanol after thermal regeneration should be less than 20 mg/l, while the ammonia content in the rich methanol stream in the system should be between 100–200 ppm. Excess pressure in the carbon ammonium crystal regeneration tower is generated; the pipeline valve to prevent carbon ammonium crystal formation is opened promptly to eliminate it. Furthermore, excessive ammonia levels lead to the formation of thiourea, which decomposes at the top of the scrubber, resulting in elevated hydrogen sulfide levels in the purified gas.
Raw coal contains amino organic compounds, which decompose in the gasifier to produce ammonia. Most of this ammonia is decomposed, with only a small portion remaining undecomposed and being further removed in the ammonia washing tower. Trace amounts of ammonia enter the low-temperature methanol washing system and dissolve in the methanol solution; it is difficult to separate them. Over time, as an excessive amount accumulates, ammonium carbonate crystals form in the water cooler at the top of the regeneration tower. The general requirement for ammonia content is that it should remain below 5–10 mg/l in the methanol returning to the top of the thermal regeneration tower; accordingly, the ammonia content in the methanol after thermal regeneration should be less than 20 mg/l, while the ammonia content in the rich methanol stream in the system should be between 100–200 ppm. Excess pressure in the carbon ammonium crystal regeneration tower is generated; the pipeline valve to prevent carbon ammonium crystal formation is opened promptly to eliminate it. Furthermore, excessive ammonia levels lead to the formation of thiourea, which decomposes at the top of the scrubber, resulting in elevated hydrogen sulfide levels in the purified gas
Thiamine crystals are formed and cannot be absorbed by methanol; they decompose into H2S and ammonia at the top of the CO2 absorption tower, resulting in excess levels
Raw coal contains amino organic compounds, which decompose in the gasifier to produce ammonia. Most of this ammonia is decomposed, with only a small portion remaining undecomposed and being further removed in the ammonia washing tower. Trace amounts of ammonia enter the low-temperature methanol washing system and dissolve in the methanol solution; it is difficult to separate them. Over time, as an excessive amount accumulates, ammonium carbonate crystals form in the water cooler at the top of the regeneration tower. The general requirement for ammonia content is that it should remain below 5–10 mg/l in the methanol returning to the top of the thermal regeneration tower; accordingly, the ammonia content in the methanol after thermal regeneration should be less than 20 mg/l, while the ammonia content in the rich methanol stream in the system should be between 100–200 ppm. Excess pressure in the carbon ammonium crystal regeneration tower is generated; the pipeline valve to prevent carbon ammonium crystal formation is opened promptly to eliminate it. Furthermore, excessive ammonia levels lead to the formation of thiourea, which decomposes at the top of the scrubber, resulting in elevated hydrogen sulfide levels in the purified gas.
Raw coal contains amino organic compounds, which decompose in the gasifier to produce ammonia. Most of this ammonia is decomposed, with only a small portion remaining undecomposed and being further removed in the ammonia washing tower. Trace amounts of ammonia enter the low-temperature methanol washing system and dissolve in the methanol solution; it is difficult to separate them. Over time, as an excessive amount accumulates, ammonium carbonate crystals form in the water cooler at the top of the regeneration tower. The general requirement for ammonia content is that it should remain below 5–10 mg/l in the methanol returning to the top of the thermal regeneration tower; accordingly, the ammonia content in the methanol after thermal regeneration should be less than 20 mg/l, while the ammonia content in the rich methanol stream in the system should be between 100–200 ppm. Excess pressure in the carbon ammonium crystal regeneration tower is generated; the pipeline valve to prevent carbon ammonium crystal formation is opened promptly to eliminate it. Furthermore, excessive ammonia levels lead to the formation of thiourea, which decomposes at the top of the scrubber, resulting in elevated hydrogen sulfide levels in the purified gas
Raw coal contains amino organic compounds, which decompose in the gasifier to produce ammonia. Most of this ammonia is decomposed, with only a small portion remaining undecomposed and being further removed in the ammonia washing tower. Trace amounts of ammonia enter the low-temperature methanol washing system and dissolve in the methanol solution; it is difficult to separate them. Over time, as an excessive amount accumulates, ammonium carbonate crystals form in the water cooler at the top of the regeneration tower. The general requirement for ammonia content is that it should remain below 5–10 mg/l in the methanol returning to the top of the thermal regeneration tower; accordingly, the ammonia content in the methanol after thermal regeneration should be less than 20 mg/l, while the ammonia content in the rich methanol stream in the system should be between 100–200 ppm. Excess pressure in the carbon ammonium crystal regeneration tower is generated; the pipeline valve to prevent carbon ammonium crystal formation is opened promptly to eliminate it. Furthermore, excessive ammonia levels lead to the formation of thiourea, which decomposes at the top of the scrubber, resulting in elevated hydrogen sulfide levels in the purified gas.
Raw coal contains amino organic compounds, which decompose in the gasifier to produce ammonia. Most of this ammonia is decomposed, with only a small portion remaining undecomposed and being further removed in the ammonia washing tower. Trace amounts of ammonia enter the low-temperature methanol washing system and dissolve in the methanol solution; it is difficult to separate them. Over time, as an excessive amount accumulates, ammonium carbonate crystals form in the water cooler at the top of the regeneration tower. The general requirement for ammonia content is that it should remain below 5–10 mg/l in the methanol returning to the top of the thermal regeneration tower; accordingly, the ammonia content in the methanol after thermal regeneration should be less than 20 mg/l, while the ammonia content in the rich methanol stream in the system should be between 100–200 ppm. Excess pressure in the carbon ammonium crystal regeneration tower is generated; the pipeline valve to prevent carbon ammonium crystal formation is opened promptly to eliminate it. Furthermore, excessive ammonia levels lead to the formation of thiourea, which decomposes at the top of the scrubber, resulting in elevated hydrogen sulfide levels in the purified gas.