CH 4 → C + 2H 2
CO recirculation
Boudouard Reaction : The reaction products from the Plasma Zone are fed into the middle chamber. Here, in the Boudouard Zone, CO 2 is introduced to promote the Boudouard Reaction when C reacts with CO 2 to produce CO. This is a reversible, temperature-dependent reaction, wherein the thermodynamically favoured product is CO at temperatures over 900°C. It is a fully understood phenomenon that has been successfully employed in the fertiliser, refining, and petrochemical industries for more than 100 years. C + CO 2 → 2CO Heterogeneous Water-Gas reaction: In the next heterogeneous Water-Gas (hetWG) Zone, treated demineralised water is introduced into the reactor, which is first converted into steam in a coil located in the waste heat recovery section below. The steam reacts with the remaining red-hot carbon particles to form CO and H 2, producing syngas (H2 and CO) that helps regulate the desired H 2 -to-CO ratio. This is a process that has been known to humanity for ~200 years, and the kinetics are well understood. C + H 2 O → CO + H 2 Net reaction: 3CH 4 + CO 2 + 2H 2 O → 4CO + 8H 2 (syngas H 2/CO ratio 2:1) After passing through the hetWG Zone in the 3-in-1 PBR, the syngas still has a temperature of ~900°C. This thermal energy is recovered in heat exchange coils by preheating the feedstock gases (CH4 and CO 2) and evaporating the water into steam, whereby the process achieves an overall efficiency of ~86%. The last process step includes the so-called water quench. Here, the syngas is rapidly quenched to quickly traverse the temperature range in which reversible reactions (such as methanation) are favoured, thus preventing any such reactions from occurring. The unique plasma process, with its intellectual property rights protected in all relevant global markets, breaks down biogas into its components C and H 2 in the presence of CO 2 and water to produce syngas using renewable power. As both CH 4 and CO 2 are processed simultaneously, the removal of CO 2 from biogas is not essential. Raw biogas, typically containing 50-70%v CH4, 25-
CO
Methane
ReCarbon PCCU
Heat exchange & a mine unit
Plasma Carbon C onversion U nit
Industrial carbon emissions
CO -free s yngas (H + CO)
Figure 3 Plasma Carbon Conversion Unit
45%v CO2, and 5%v N2 +O 2 +H 2 O, can be used directly with little or no additional requirement of captured CO 2. No green H2 is required, and no byproducts are produced. The desired H 2-to-CO ratio in syngas can be controlled by adjusting reactant flows, making the technology suitable for production of a wide range of fuels and chemicals. The USP lies in the proprietary 3-in-1 PBR, which is a technological innovation based on the novel combination of three well-known sub-processes. This allows chemical reactions to be controlled in a targeted manner to produce syngas, as opposed to conventional processes that require many reactors and units. The TRL of this technology is assessed to be 6/7 with an industrial-scale plant under commissioning. Another start-up company, ReCarbon, has developed a compact microwave Plasma Carbon Conversion Unit (PCCU) in standard containerised modules to transform biogas and CO2 into syngas and carbon-negative H2 using renewable power, as shown in Figure 3 . For example, with 70 Emission Blades – a patented microwave-plasma generation device – configured in a standard 40ft container, each PCCU module can produce up to 900kg of H2 per day. The PCCU is scalable and stackable, providing flexibility and accessibility for projects of any size. SYNSPIRE is a mark of BASF. ShiftMax is a mark of Clariant. HyCOgen is a mark of Johnson Matthey. Rigel and GHG e-Reforming Modular Reactor are marks of Syzygy Plasmonics. DRYREF is a mark of Linde. eREACT and ReShift are marks of Topsoe.
VIEW REFERENCES Ajay Misra arsim.yaja@gmail.com
Refining India
49
Powered by FlippingBook