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PROCESS & TECHNOLOGY FOR METHANOL AND DME

2.3 METHANOL FROM CARBON DIOXIDE

This is another very interesting development in methanol/DME production. Large numbers of
publications have appeared in literature where new catalysts are reported to convert carbon
dioxide and hydrogen into methanol/DME. There are several approaches such as use of
concentrated or dilute carbon dioxide from atmosphere, use of Solid Oxide Fuel Cell with
biogas or syngas avoiding direct use of hydrogen, direct conversion of carbon dioxide to
carbon monoxide with solar energy or conversion of carbon dioxide and natural gas to form
syngas, and even direct conversion of hydrogen and carbon dioxide to methane by Sabatier
Reaction. [28, 94, 95, 96, 97]
Methanol can also be produced from carbon dioxide via carbon monoxide formation with coal
or directly converted to methanol with [38, 98, 99, 100]. Recently, a commercial plant started
operating in Iceland. The name of the plant honors George Olah, Nobel Prize Laureate in
chemistry and co-author of the book “Beyond Oil and Gas: The Methanol Economy”. In 2015
CRI expanded the plant from a capacity of 1.3 million litres per year to more than 5 million
litres a year. The plant now recycles 5.5 thousand tons of carbon dioxide a year, which would
otherwise be released into the atmosphere. All energy used in the plant comes from the
Icelandic grid, which is generated from hydro and geothermal energy. Germany also operates
a similar plant [101].
Since this route offers dual advantage of fixing carbon by creating value added products, this
technology requires special attention. Shown below are the possibilities of producing different
chemicals using carbon dioxide as feedstock. Different possible products from carbon dioxide
is shown in Fig. 6.

FIG. 8

Different Products from Carbon dioxide [141]

CO
HCOOH CH
4

R NH
HCONR 2 CO +H Hydrocarbons
2 2 2

CH OCH Higher alcohols
3 3
CH OH
3

The three major reactions are: methane, carbon monoxide and methanol formation as shown
below:
CO + 4H ↔ CH + 2H O ∆ H 298 K = - 252.9 kJ mol - 1
2 2 4 2
CO + H ↔ CO + H O ∆ H 298 K = 41.2 kJ mol - 1
2
2
2
CO + 3H ↔ CH OH + H O ∆ H 298 K = - 49.5 kJ mol - 1
2 2 3 2

Methanol and DME Production: Survey and Roadmap | 2017 43