Valve Operability During a Fire

Fire and explosion are a major cause of concern for refinery, gas processing, petrochemical, and gas installations. The safest way to deal with a fire is to prevent it. However, fire prevention strategies are not always successful, and fires can happen. Therefore, valves should be designed and tested to be fire-safe. This paper reviews valve design features that can help prevent fires, including secondary sealing between the ball and body in case of losing a soft seat, a graphite fire-safe ring design for stem and seat sealing, antistatic devices, and antistatic tests to ensure that the valve is fire-safe. In addition to design considerations, a fire-safe design should be validated through tests defined in standards such as API 607, API RP 6FA, and ISO 10497. The API RP 6FA tests reviewed in this paper include seven tests that check the operability of the valve from closed to open position. A case study was done to prove the operability of a fail close 38″ pipeline ball valve on an oil export pipeline in case of fire during the first 20 s from the open to the closed position. Thermal analysis on the body of the valve proved that there was no thermal expansion inside the valve after 150 s of fire. Additionally, the maximum radial displacement on the valve body after 150 s of fire was 0.34 mm which is negligible. Thus, the valve thermal expansion did not disturb the operation of the valve after 20 s.

Advanced Control Solution for a Refinery Gas Sweetening Process

Gas sweetening unit, also known as acid gas removal unit, is a wide used unit in refineries and petrochemical plants and refers to a group of processes that use different amines such DiEthanolAmine (DEA) to remove the hydrogen sulfide (H2S) from gases, in order to use them as fuel to different furnaces from other processing units. If the hydrogen sulfide is not well removed, will lead to furnaces tubular corrosion and therefore will generate loss in refractory properties. Also, the emission values of the exhaust gases will not be in accordance with the environmental regulations. The paper outlines the main results obtained by authors concerning the advanced control solution for a refinery gas sweetening unit and contains three parts. The first part outlines the results of the dynamic gas sweetening process investigation using HYSYS� simulation software. The second part presents the proposed structure of the advanced control system and the third part outlines the results obtained using the control structure in order to remove as good as possible the H2S content from residual gases.

Optimized NOX Control by Injection of Fine Water Spray Into Compressor Discharge

The Watson Cogeneration Plant (WCP) is situated within Los Angeles Refinery Complex. A portion of generated power and steam is sent to Refinery. Major power producers are the combustion gas turbines, GE-made, Frame No 7, Model EA. These turbines are furnished with diffusion-type combustors which can burn mixture of treated refinery gas and natural gas from the pipe line. These combustors are capable of burning pure butane gas too, as required. The NOX control is achieved by injection of DE-NOX steam into the combustors. The Refinery change in processes was reflected in the refinery gas composition where the percentage of Hydrogen grew. Hydrogen combustion generates more NOX, at the same firing temperature and additional steam injection is necessary. During the years, since 1987, startup of WCP, steam demand from Refinery steadily grew. This Paper describes the efforts to curtail further DE-NOX demands and instead of additional DE-NOX steam, use water injection into gas turbine housing element called the “wrapper”.

Co-processing of bio-oil from de-oiled Jatropha curcas seed cake with refinery gas–oil over sulfided CoMoP/Al2O3 catalyst

Schematic representation of Co-processing of bio-oil from de-oiled Jatropha curcas seed cake with refinery gas–oil over sulfided CoMoP/Al2O3 catalyst.