Flow Instrumentation Solution for the Oil & Gas Industry (Ethylene)
Application Description
Ethylene is the core of the petrochemical industry, and its output is a key indicator of a country's petrochemical development. Feedstock such as naphtha, light hydrocarbons and refinery off-gas is cracked at high temperature in cracking furnaces to form cracked gas, which is then purified, compressed, cryogenically separated and fractionated into methane, ethane, ethylene, propylene and other products.
Application Focus
1. Cracking unit: feedstock oil and cracked gas contain hydrogen and hydrogen sulfide at above 830 °C, causing severe corrosion; heavy components condense in the quench section and readily block passages; accurate measurement of fuel gas and dilution steam (about 600 °C) directly affects furnace temperature and cracking efficiency.
2. Purification unit: caustic-wash yellow oil is viscous and easily blocks columns, and the caustic solution is highly corrosive; the hydrogen used for acetylene hydrogenation has low density and a high risk of hydrogen embrittlement, making meter selection difficult.
3. Compression unit: hydrogen and methane reach −132 to −144 °C; combined with high pressure and hydrogen embrittlement, this is a major challenge for materials and selection.
4. Separation and fractionation unit: methane, ethane and other media operate below −100 °C, limiting the choice of instrument types.
Solution Overview
1. Cracking Unit
(1)Feedstock oil / cracked gas (high viscosity, high abrasion, sulfur-bearing): wedge flowmeter in 316L with NACE-compliant treatment and dual-flange pressure tapping to prevent blockage.
(2)Fuel gas (hydrogen + methane, DN200–300, 60 °C, 0.4 MPa): standard orifice plate or Venturi tube (316SS, hydrogen-embrittlement resistant).
(3)Dilution steam (300–600 °C, 0.5–13 MPa): conventional orifice plate, or Venturi tube where pressure loss must be reduced; nozzle flowmeters (15CrMo) for high-temperature, high-pressure steam and feedwater.
2. Purification Unit
(1)Flushing oil / water / inhibitor (small bore, viscous, non-conductive): metal-tube rotameter (RFC Series) or standard orifice plate.
(2)Caustic solution (about 50 °C, strongly alkaline): electromagnetic flowmeter with PTFE lining and Ti electrodes, accuracy ±0.2%.
(3)Hydrogen (acetylene hydrogenation): Coriolis mass flowmeter (MFM-T Series, ±0.1% to 0.15%, 316L/Hastelloy C, hydrogen-embrittlement resistant).
3. Compression Unit
Hydrogen embrittlement + high pressure (up to 10 MPa) + cryogenic temperature + flammable and explosive medium: use 316L seamless pipe for the metering tube to reduce welds and seals, and select a standard orifice plate or Venturi tube (316L, solution annealed).
4. Separation and Fractionation Unit
Cryogenic media such as methane, ethane and C2/C3/C4 fractions: integrated orifice plates and vortex flowmeters (VFD/VFE/VFT Series) safeguard dealkanizer separation efficiency and ethylene quality.
Customer Value
1. Engineered for high-temperature corrosion, hydrogen service and cryogenic duty, it delivers trustworthy measurement and reduces the process risk of instrument failure.
2. Reliable measurement inputs for cracking furnaces, hydrogenation and fractionation units support closed-loop control, stabilising ethylene quality and reducing material consumption.
3. Addressing common issues such as blockage, corrosion and hydrogen embrittlement, it reduces instrument interventions and supports long plant runs.
4. Stable process data feeds the DCS/APC platform, supporting process analysis and predictive maintenance.
Related Products
1. DF Series differential pressure flowmeters: standard orifice plates, multi-hole balancing orifice plates, nozzles, wedge elements, V-cone, Venturi tubes and integrated orifice plates, covering feedstock oil, fuel gas, high-temperature steam and cryogenic separation.
2. MFM Series Coriolis mass flowmeters: high-accuracy hydrogen metering for hydrogenation and custody transfer of ethylene and propylene.
3. MF Series electromagnetic flowmeters: caustic solution for caustic washing, plus sulfur-bearing process water and wastewater.
4. VF Series vortex flowmeters: cryogenic hydrocarbons, dealkanizer and fractionation columns, fuel gas and cracked gas.
5. RFC Series metal-tube rotameters: small-bore metering of flushing oil, water and inhibitor.
