Synthetic Natural Gas (SNG) has essentially the same properties like natural gas and LNG. With a strong demand of LNG e.g. in Asia SNG is a valuable alternative which is based on resources such as low rank coal and thus is looking more and more attractive. This product is especially attractive in locations where natural resources are scarce.
SNG can furthermore be easily produced e.g. mine mouth and then transferred with the usual natural gas pipelines to industrial and private customers. Essentially the same products produced from natural gas can be obtained from SNG such as electricity and chemicals such as ammonia.
The production steps for SNG are shown in a block flow diagram. After the gasification process the sulphur is removed from the process with a gas treatment process such as Genosorb. Downstream of these units the main reaction to SNG takes place. A shift reaction to produce additional hydrogen is needed to satisfy the boundary conditions for the methanation process. The product is then purified and is shipped to battery limits. It is worth noting that the process chain is overall exothermic and it is recommended to use the heat produced to produce electricity.
The PRENFLO® PSG process is very well suited for this application since it is a highly efficient process reducing the feedstock amount to a minimum. The steam produced in the gasification section is used for electricity production as well. To give an impression of the size of the production plants, please note that SNG production from one gasifier of over 350,000 t/y (over 700,000 t/y production from 2 PRENFLO® PSG gasifier) is possible.
KEPCO-Uhde works together with the other KEPCO fleet members on the optimization of the overall process of SNG production.