Syngas is the main feedstock for methanol and synthetic liquid hydrocarbons production in the modern chemical industry. Reducing the cost of syngas production may significantly decrease the cost of final products. The high-temperature co-electrolysis of CO2 and H2O is a new and promising method of syngas production.
The price of syngas, which is produced by using this technology, mainly depends on the price of electricity and fossil fuel. Thus, optimization of hot utility sources may substantially reduce the cost of synthesis gas, as well as make this technology more cost-effective.
The aim of current research is to select the optimal type of fuel for the syngas production technology mentioned above, reducing the operating cost and carbon footprint.
Flue gases, produced by burning of various fuels (natural gas, liquefied petroleum gases (LPG), coal etc.), are considered as sources of hot utility. Using Pinch approach, it was found that the load on hot utilities varies within the range from 4110 to 4075 kW while exploiting different types of fuel. However, the flow rates change in a wide range from 2.6 to 4.4 thousand tons per year due to their different calorific value, respectively.
While comparing the prices of energy carriers, it can be found that despite the similar flow rate between natural gas and LPG, the cost of the latter is 6.5 times higher, but the cost of coal practically is identical to the price of natural gas that is 260 k$ per year with a two-fold difference in a flow rate. These flow rates were obtained for optimal heat exchange networks. An explicit tendency could be found towards its decrease from cheaper fuels to more expensive ones while estimating ΔTmin. Consequently, the high cost of LPG will add significant capital costs which are related to the big heat transfer area.
The smallest carbon footprint is achieved when using the natural gas and optimal configuration of the heat exchanger network; the final emissions equal to 5 ktCO2/y. Fuel oil has the largest carbon footprint, which is 9.7 ktCO2/y. The carbon footprint of the process that uses LPG and coal is practically the same, despite the significant difference in their heat exchange networks.
Thus, this technology is recommended for regions that have access to natural gas or coal. The use of LPG leads to a significant increase in the price of syngas.
|Affiliation of speaker||Tomsk Polytechnic University|
|Publication||Impact Factor journals|