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PROCESS & TECHNOLOGY FOR METHANOL AND DME

2.1.2.7
GASIFICATION OF BIOMASS TO SYNGAS

Biomass such as corn, sugar beet, wheat etc. is traditionally converted to ethyl alcohol by
fermentation. More recently, lignocellulosic materials such as straw, wood, rice husk, cereal
plants, wood scraps etc. are converted to ethanol by enzyme digestion and hydrolysis. In
addition to this biochemical route, these lignocellulosic materials could be burnt for energy
recovery. In India this is the most common usage of the surplus lignocellulosic materials after
direct utilization as cattle feed whenever possible. The combustion and power generation of
course comes with lower GHG penalty, while gasification and conversion to bio fuels such as
methanol or DME is more rewarding even the investment is higher, particularly for too small a
scale.

The wide variation in types of biomass, with high volume and moisture content, is a major issue
for their use far away from the source. Fig.4 shows different biomass gasification products and
their uses.

FIG. 4

Biomass Gasification Products & their Uses [63]

Biomass

Inputs Air Steam Oxygen Hydrogen

Air Steam Oxygen Hydrogen
Gasifier type
Gasifier Gasifier Gasifier Gasifier

Intermediate Low Medium
Products Energy Gas N 2 Energy Gas N 2

Synthetic
Final Products Power Steam Gas
Liquids

Medium & High Methanol
Examples/uses Spark and Diesel Process Heat & Energy for Ammonia
of Products Engines Power Pipelines Gasoline

Gasification, Producer Gas and Syngas, by Samy Sadaka
The problem of collection, transportation prevents construction of large size biomass gasification
plants for methanol/DME production. The problem is handled in several ways:
1. Breaking away from the concept that only Mega Scale Syngas and methanol plants are
feasible. In fact today many skid mounted gasification and methanol/DME plants are
operating in the world, successfully.
2. Preliminary treatment of the biomass at the point of origin to reduce its weight.
3. Design of the gasifier for processing multiple types of biomass feedstocks

4. Use of available biomass in the large gasifiers for coal or solid residues to the extent possible.
5. To locate the plant closer to the source where sustained supply of adequate quantity

Methanol and DME Production: Survey and Roadmap | 2017 35