Zinc Oxide Desulfurization Adsorbent T306
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Introduction
Model | Zinc oxide desulfurization adsorbent T306 |
Color | White or light yellow |
Shape | extrude |
Normal size(mm) | 桅4脳4-15 |
Bulk Density(kg/L) | 1.0-1.3 |
Crushing strength(N/cm) | 鈮50 |
Loss on Attrition(%) | 鈮6 |
Breakthrough sulfur capacity, wt锛 | 鈮28(350鈩) 鈮15(220鈩) 鈮10(200鈩) |
Pressure, MPa | ambient to 4.0 |
Temperature 鈩 | 180-400 |
Space velocity, h锛1 | 1000-2000锛gas锛 |
Sulfur in feed gas, mg/m3 | 1-20 (鈮200鈩) 20-100 (鈮250鈩) |
Sulfur in treated stream, ppm | max0.1 |
Saturation sulfur capacity, wt% | min30(400鈩) |
Feature and Typical Application | T306 Zinc Oxide Desulfurization Adsorbent, developed by the Northwest Research Institute of Chemical Industry, is applicable to desulfurization of residue cracking gases or syngas and purification of feed gases for organic synthesis processes. It is suitable for both higher (350-408鈩) and lower(150-210鈩) temperature use. It can convert some simpler organic sulfur while absorbing inorganic sulfur in gas stream. Main reaction of the desulfurization process is as follows: (1) Reaction of zinc oxide with hydrogen sulfide H2S+ZnO=ZnS+H2O (2) Reaction of zinc oxide with some simpler sulfur compounds in two possible ways: a. Organic sulfur compounds, catalyzed by zinc oxide, react with hydrogen to form hydrogen sulfide: CS2 + 4H2 = CH4 + 2H2S C2H5SH + H2 = C2H6 + H2S Then hydrogen sulfide is absorbed by zinc oxide H2S+ZnO=ZnS+H2O b. Zinc oxide reacts directly with organic sulfur compounds COS + ZnO = ZnS + CO2 T306 is an ideal desulfurization adsorbent for deep purification cases, especially those at higher temperature (350-400鈩). |
Loading | Loading depth: Higher L/D (min3) is recommended. Configuration of two reactors in series can improve utilization efficiency of the adsorbent. Loading procedure: (1)Clean the reactor before loading; (2)Put two stainless grids with smaller mesh size than the adsorbent; (3)Load a 100mm layer of 桅10鈥20mm refractory spheres upon the stainless grids; (4)Screen the adsorbent to remove dust; (5)Use special tool to ensure evenly distribution of the adsorbent in the bed; (6)Inspect uniformity of the bed during loading. When inside-reactor operation is needed, A wood plate should be put on the adsorbent for the operator to stand upon. (7)Install A stainless grid with small mesh size than the adsorbent and a 100mm layer of 桅20鈥30mm refractory spheres at the top of the adsorbent bed so as to prevent entrainment of the adsorbent and ensure even distribution of the gas stream. Note: Evenly distribution of the adsorbent is essential to its efficient operation, which should be paid close attention to. |
Start-up | (1)Replace the system by nitrogen or other inert gases until oxygen concentration in the gas is less than 0.5%; (2)Preheat the feed stream with nitrogen or feed gas under ambient or elevated pressure; (3)Heating speed: 50鈩/h from room temperature to 150鈩 (with nitrogen) ; 150鈩 for 2h (when heating medium is shifted to feed gas ), 30鈩/h over 150鈩 until required temperature is attained. (4)Adjust the pressure steadily until the operation pressure is attained. (5)After pre-heating and pressure elevation, the system should first be operated at half load for 8h. Then raise the load steadily when operation becomes stable till full-scale operation. |
Shut-down | (1)Emergent shut-down Cut feed gas (oil) supply. Close inlet and outlet valves. Keep the temperature and pressure. If necessary ,use nitrogen or hydrogen-nitrogen gas to maintain the pressure to prevent negative pressure. (2 ) Change-over of desulfurization adsorbent Close inlet and outlet valves. Steadily lower the temperature and pressure to ambient condition. Then isolate the desulfurization reactor from the production system. Replace the reactor with air until oxygen concentration of锛20锛 is attained. Open the reactor and unload the adsorbent. (3) Equipment maintenance (overhaul) Observe the same procedure as shown above except that pressure should be lowered at 0.5MPa/10min and temperature lowered naturally. The unloaded adsorbent shall be stored in separate layers. Analyze the samples taken from each layer to determine status and service life of the adsorbent. |
Transportation and storage | (1)The adsorbent product is packed in plastic or iron barrels with plastic lining to prevent moisture and chemical contamination. (2)Tumbling, collision and violent vibration should be avoided during transportation to prevent pulverization of the adsorbent. (3)The adsorbent product should be prevented from contact with chemicals during transportation and storage. (4)The product can be stored for 3-5 years without deterioration of its properties if appropriately sealed. |
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