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CURRENT STATUS OF TECHNOLOGY AND TRENDS

area including Johnson Matthey, Clariant, Haldor Topsøe etc. For mercury and sulfur removal,
technologies are readily available.

Many small and medium capacity plasma gasifiers are operating in the world but most of them
are deployed for power generation rather than methanol/DME production [6]. This technology
is particularly suitable for biomass and low grade renewable carbon source as well as for low
grade coal gasification, for effective ash control. However, commercial operation at a scale
suitable for methanol/DME production as standalone unit for low grade source is still far off.

3.9 Synthesis for methanol/ DME from Syngas

The next step for methanol / DME production is to bring both H and CO together in a methanol
2
reactor. Typically this reaction is carried out in vapour phase at about 30 to 50 bar pressure
and 130 - 150 C. The technology for methanol synthesis from syngas is well established and
0
several reputed licensors can supply the technology. However, DME is a relatively new product.
Although it involves simple dehydration of methanol, technologies have not been perfected yet
in large commercial scale, and not many large operating plants exist.

There are a few pilot plants/demonstration plants operating with liquid phase slurry reactors,
where the syngas containing carbon dioxide can be easily handled. It is worth looking into this
technology, since it will reduce the cost of methanol / DME production significantly. A small
scale methanol plant could be economically feasible, where the separation of carbon dioxide
is not required, and methanol or DME can be produced in a slurry reactor [34].
Haldor Topsøe A/S (HT) has developed and demonstrated an integrated process for the
direct production of DME from synthesis gas on a pilot plant scale. Based on their extensive
experience in syngas production, methanol synthesis, and DME-related pilot plant work, HT
and BP Amoco have identified proven technology for the construction of Greenfield DME plants
with capacities in the range of 8-10 thousand tons per day.
NKK Corporation (Tokyo) and the Centre for coal utilization of Japan have jointly developed a
new process for DME by utilizing sub bituminous coal. They have demonstrated this technology
in a pilot plant of 5 tons per day capacity.
Biomass based syngas production units are typically smaller scale than coal or natural
gas based units. Therefore, these plants are normally designed for a single product, either
methanol or DME. There are several demonstration plants for direct conversion of syngas to
DME in liquid or slurry phase reactors. In 2006, JEE group reported the operation of a 100 TPD
direct DME plant using biomass derived syngas. The DME synthesis is carried out in slurry
bed reactor at a temperature of about 260 C and pressure of 5 MPa. This is essentially a low
0
cost technology, and the most important part is the dual function of the catalyst, where both the
methanol synthesis and dehydration takes place in the single reactor. Both the catalysts and
the technology are being developed by several groups such as Haldor Topsøe, Air Products
and many others [19]. Another study was reported in 2009, where HZSM-5 zeolite based
catalyst was used to convert biomass derived syngas directly in a 100 TPA pilot plant with fixed
bed reactor [20]. Unitel Technologies reported operation of a demonstration plant of 10 TPD for
direct synthesis of syngas to DME for a Korean Group, Korea Gas (KOGAS). After successful
demonstration, a 900 TPD plant is being considered [43]. They have also built and successfully
commissioned a demo plant in early 2014 in Southern California, USA, where high-purity DME
stream was produced. They offer the technology for natural gas or biogas based plants with
reformer and synthesis to methanol and to DME by catalytic distillation. According to their
claim 300 TPD DME plant is feasible and economical [22].

As it appears, there is not much commercial experience in direct synthesis of DME, but there
is strong interest in having a viable technology for single step DME synthesis in medium scale
from biomass sources.

Methanol and DME Production: Survey and Roadmap | 2017 55