hydrogen our clean energy edge - technip · 3 steam methane reformer 1 feedstock pretreatment 2 4...
TRANSCRIPT
Steam methane reformer3Feedstock1
Pretreatment 2 Shift conversion4
PSA unit5
H2
H2
H2
H2H2
H2
H2
H2
H2
H2
Methane
Propane
Ethane
Methane
Propane
Ethane
Sulphurs
Chlorides
MethaneSteam
Carbondioxide
Carbonmonoxide
Catalystpellets
Hydrogen
CatalystVessel
H2O
H2
CO2
CO
350°C
20°C 850°C 350°C
Cylindricaltubes
Catalyst pellets
HYDROGEN
With a 35% share of the market, Technip is a global leader in refinery hydrogen units, thanks to our Steam Methane Reforming (SMR) technology the world’s most widely used hydrogen production process.
Pure hydrogen does not exist in nature, but is present in combination with other elements in the form of water, hydrocarbons and biomass.There are two main methods used to produce
this gas: electrolysis of water and the reforming of hydrocarbon feeds, which accounts for 95% of production worldwide. As a pioneer in this industry, Technip has its own proprietary technology called Steam Methane Reforming (SMR). This process encourages natural gas – and other light hydrocarbons – to react with water vapor at high temperature in the presence of a catalyst to release hydrogen from the hydrocarbon and from part of the water.Demand for hydrogen, which is seen as a clean energy source, is increasing at an annual rate of 3.5%, most of which is met by refinery applications using SMR technology. Since 1960, Technip’s hydrogen portfolio covers close to 300 plants.
1Feedstock (also called feed) is a mix of lighter hydrocarbons such as methane, ethane, propane and/or heavier hydrocarbons as naphtha. In case of natural gas or refinery gas as feed, it may come from a pipe grid, or in the case of light naphtha or LPG, from a nearby storage tank.
2The feed may be contaminated with sulphur and/or chlorides which are poisons in the following process steps. After heating-up, the gaseous feedstock is fed into a feed treatment unit to remove unwanted feed contaminants. Feed is then mixed with steam and further heated to temperature of typically 550-600°C before entering the Steam Methane Reforming (SMR) section.
5To deliver ultra-pure hydrogen (up to 99.9999%) as most of the hydrocracking and some chemical processes now require, all undesired components are removed from the hydrogen through Pressure Swing Adsorption (PSA). Layers of different adsorbent beds are pressurized and depressurized in a cyclic manner in order to adsorb and release carbon dioxide, residual steam, the remaining unconverted methane and the residual carbon monoxide while letting hydrogen pass through because of its different molecular structure.
Actually this is a physical process and not a chemical process. The PSA unit contains 4 to 16 vessels, each for a different stage of the cycle to ensure a continuous flow of the hydrogen product.
4The shift reaction converts carbon monoxide and water into carbon dioxide and hydrogen thereby increasing the hydrogen yields and decreasing the by-product carbon monoxide. After shift conversion, the reformed gas now contains hydrogen but also carbon dioxide, some unconverted methane, traces of carbon monoxide and steam.
3In the tubes filled with catalyst pelletsThe feed enters into a number of parallel cylindrical vertical tubes filled with catalyst pellets.The catalyst pellets trigger the chemical reaction. It converts the feed and part of the steam into a mixture of hydrogen, carbon monoxide and carbon dioxide together with some remaining unconverted feed in the form of methane and remaining steam (the reformed gas). The reformed gas leaves the SMR section at around 860-900°C and is then
cooled down to a temperature of 350°C to make it suitable for the next step: shift conversion.
At a temperature up to 1,200°CThe chemical reaction requires a lot heat. The cylindrical tubes are heated from the outside. The heat is generated by a series of burners that mix fuel gas with air. Burners and tubes are contained in a box called the Firebox. The tubes are made of special Nickel-Chromium alloy materials that tolerate temperatures up to 1,200°C. Combustion gases leave the firebox and enter into the convection section to cool then down and recover the remaining heat.
SMR: and the hydrogen is revealed the firebox
Our clean energy edge
Lubricating oils,waxes, polishes
Bitumenfor roads
Liquifiedpetroleum gas
ChemicalsDiesel fuels
Fuel fo ships, factoriesand central heating
Fuel for vehicles Jet fuel, paraffin forlighting and heating
The feedstock
THE DIFFERENT APPLICATIONS
Feed pretreatment PSA, to a pure hydrogenShift Conversion