(245e) Achieving a More Sustainable Process Design for the Production of Methanol

Achieving a More Sustainable Process Design
for the Production of Methanol

Cristina Calvera Plaza, Marta Gonzalez Garcia, Ana
Diez Callau, Emmanouil Papadakis*

Department of Chemical and Biochemical
Engineering

Technical University of Denmark, DK-2800
Lyngby, Denmark

*empap@kt.dtu.dk

Methanol is an important chemical product
because it can be used as a raw material for the production of other chemicals (1), for example dimethyl carbonate, formaldehyde and methyl
tert-butyl ether and it is also one of the most produced bulk
chemicals with an annual global production of 100 million metric tonnes per
year (1).
Methanol can be produced using different reaction paths, for example natural
gas. If natural gas is used for methanol production then CO₂ is
produced, utilized and can be emitted. Therefore, achieving a more sustainable
design for the production of methanol is beneficial in order to reduce the
process CO₂ carbon footprint.

Using a 12 step, systematic task-based approach
for achieving sustainable process design, a process for the production of
methanol with an annual production of 300,000 metric tonnes of methanol per
year with minimum CO₂  emissions is analysed and designed. The
reaction path chosen for the production of methanol utilizes CO₂ as
raw material. The reactions are as
follows:

The process description that uses the above
reactions is explained. The first outlet stream from the reaction system is a
multi-component mixture that consists of methanol, water and unreacted gases.
First, the gases are separated using a flash and recycled to the reactor.
Second, the methanol is purified using two distillation columns. In the first
distillation, light components are separated and in the second one the water.
This design is analysed for improvements and is referred to as the base case
design.

The analysis consists of two parts, first
an economic analysis and second, a sustainability analysis. The economic
analysis provides the information in order to identify targets for improvement
related to heat integration and process optimization, while the sustainability
analysis (2) provides
information for identification of (design) targets for achieving sustainable
design, that is, for example, reduction in carbon footprint and LCA factors
(global warming potential, toxicity, etc.) (3). The sustainability analysis consists of a sustainability and LCA
analysis.

In this poster, the 12 task-based method
for achieving (sustainable) process design will be presented and its
application will be highlighted through the application of the production of
methanol. The input and output related to each step will be presented.

References

1. Methanex
Corporation: The Power of Agility. [on line] http://www.methanex.com.

2. SustainPro- A tool for systematic process
analysis, generation and evaluation of sustainable design alternatives. Carvalho,
A., Matos, H.A. y Gani, R. 8-27, s.l. : Computers & Chemical
Engineering, 2013, Vol. 50.

3. Integration of life cycle assessment software
with tools for economic and sustainability analyses and process simulation for
sustainable process design. Kalakul, S., y otros. 98-109,
s.l. : Journal of Cleaner Production, 2014, Vol. 71.