Gas hydrates are inclusion compounds of gases in a lattice of water molecules. Hugeamounts of methane are stored around the world under the sea floor in the form of solidmethane hydrates. Methane hydrates, represent a new and completely untappedreservoir of fossil fuel, because they contain, immense amounts of methane, which is themain component of natural gas. Methane hydrates belong to a group of substances calledClathrates - substances in which one molecule type forms a crystal-like cage structure andencloses another type of molecule. If the cage-forming molecule is water, it is called ahydrate. If the molecule trapped in the water cage is a gas, it is a gas hydrate, like methanehydrate. Methane hydrate also poses problems during transportation of natural gas.Temperature and pressure conditions in pipelines especially in cold areas allow theformation of hydrates. These hydrates form agglomerates and tend to clog valves, pumps,pipelines and other parts. It is desirable to avoid the formation of hydrates rather thanremoval of existing hydrate due to economical and safety reasons. The production as wellas study of artificial gas hydrates are done in special autoclaves like the gas hydrateautoclave System, under specific pressure and temperature conditions. At roomtemperature and normal atmospheric pressure, methane hydrate is unstable dissociatinginto water and gas. Pipeline conditions can be simulated in the gas hydrate autoclavesto check the effectiveness & optimization of hydrate-inhibitors. Pressure-resistantborosilicate / quartz / sapphire-glass windows in the gas hydrate autoclaves allows the useof one or multiple boroscope-cameras for observing or recording the processes of gashydrate formation inside the autoclave. The autoclaves can also be provided with magneticstirrer to simulate turbulent mixing conditions. Overhead stirrer can be connected to atorque sensor to perform torque measurements to study viscosity changes. Refer page 42for 25 ltr gas hydrate system.
Amar manufactures & supplies systems for Hydrogen Induced Disbonding (HID) tests as perASTM G146. These tests are used to simulate & study the effects of hydrogen environmentunder very high pressures from 150 - 250 bar & temperatures from 400 - 500°C onbimetallic plates that are to be used under similar conditions in refineries. The resultsindicate the resistance of bimetallic steels & its alloy to hydrogen induced disbonding. Suchtests can be used to decide the material metallurgy, its heat treatment, manufacturing &fabrication technology for use in refineries in similar environments. The system can bemanually operated or completely automated.
Initially the test samples are put inside the vessel, pressurized with hydrogen to very highpressure upto 150 - 200 bar & then heated to desired temperature of around 400 - 500°Cfor a period of around 48 hrs. After the test is over, the vessel is cooled at a pre-defined rateof around 150°C/hr till the temperature reaches 200°C. The vessel pressure is then releasedcompletely & cooled further to remove the test samples.