This document presents a case study on biomass gasification. It provides background on biomass gasification, including that it is a process that converts solid biomass into a combustible gas through thermo-chemical reactions. It then details the specific case study conducted, which analyzed the thermoneutral points of downdraft gasification of rice husk at temperatures from 500-1000°C. The study found the reaction and process thermoneutral points, and analyzed gas composition and energy parameters at these points, both with and without a heat exchanger.

1. CASE STUDY ON BIOMASS
GASIFICATION
PRESENTED
BY
Ms.SHABAANA M
19PEF006
II M.E FOOD TECHNOLOGY
DEPARTMENT OF FOOD PROCESSING AND PRESERVATION TECHNOLOGY
Mrs.R.CHITRA A.P(SS)
DEPARTMENT OF ECE
SCHOOL OF ENGINEERING
AVINASHILINGAM INSTITUTE OF HOME SCIENCE AND HIGHER EDUCATION
FOR WOMEN
WASTE TO ENERGY

2. Introduction
 Biomass gasification is a process of converting
solid biomass fuel into a gaseous combustible gas
(called producer gas) through a sequence of
thermo-chemical reactions.
 The gas is a low-heating value fuel, with a calorific
value between 1000- 1200 kcal/Nm3 (kilo calorie
per normal cubic metre).

3.  Gasification is a process that converts organic or
fossil based carbonaceous materials mainly into
carbon monoxide, hydrogen and carbon dioxide
 Today there is a huge demand for fuel because of
the increasing population.
 Biomass is renewable resource and is available
very easily.

4. History
 Gasification has been in use for over 180 years,
with coal being the primary feedstock.
 Over the course of its development gasification
technology has resulted in three general types of
reactors: moving bed gasifiers, fluidized bed
gasifiers, and entrained bed gasifiers.
 The current unsustainable use trends of
petrochemical fuels has increased the demand for
renewable energy alternatives, and thermochemical
processes such as gasification will be required to
meet these demands.

5.  Moving bed gasifiers employ a fixed bed of fuel
that moves downward under gravity while
contacting an oxidant in either counter-current or
co-current flow.
 Fluidized bed gasifiers use a bubbling fluidized bed
of inert particles as a heat transfer medium while
the oxidant serves as the source of fluidization.

6. Gasification process

7.  It is the third among the primary energy sources
after coal and oil.
 The gasification of biomass allows the production
of a synthesis gas or “syngas”, consisting primarily
of H2, CO, CH4, CO2 and N2, which further has a
variety of uses.

8. Biomass Selection
 Rice husk as the biomass to be gasified.
Composition by weight: 47.8% C, 5.1% H, 38.9%
O, 0.1% N.
 Weight for 1 mole of rice husk is calculated to be
25.105 grams.
 Temperature range considered in this study is 500-
1000 °C.

9. Energy production

10. WORKING OF DOWNDRAFT
GASIFICATION

11. Advancement in biomass
gasification
 Cutting-edge, innovative and economical
gasification techniques with high efficiencies are a
prerequisite for the development of this technology.
 The fundamentals such as feedstock types, the
impact of different operating parameters, tar
formation and cracking, and modelling approaches
for biomass gasification.

12.  The comparatively various conventional
mechanisms for gasification as well as recent
advances in biomass gasification.
 Unique gasifiers along with multi-generation
strategies are discussed as a means to promote this
technology into alternative applications, which
require higher flexibility and greater efficiency.

13.  A strategy to improve the feasibility and
sustainability of biomass gasification
is via technological advancement and the
minimization of socio-environmental effects.
 The sheds light on diverse areas of biomass
gasification as a potentially sustainable and
environmentally friendly technology.

14. Gasification process

15. Current status in biomass
production in India
 Ministry of New and Renewable Energy has
realised the potential and role of biomass energy in
the Indian context and hence has initiated a number
of programmes for promotion of efficient
technologies for its use in various sectors of the
economy to ensure derivation of maximum
benefits.
 For efficient utilization of biomass, bagasse based
cogeneration in sugar mills and biomass power
generation have been taken up under biomass
power and cogeneration programme.

16.  The current availability of biomass in India is
estimated at about 500 million metric tonnes per
year.
 Studies sponsored by the Ministry has estimated
surplus biomass availability at about 120-150
million metric tonnes per annum covering
agricultural and forestry residues corresponding to
a potential of about 18,000 MW.

17.  By gasification, about 7000 MW additional power
could be generated through bagasse based
cogeneration in the country’s 550 Sugar mills, if
these sugar mills were to adopt technically and
economically optimal levels of cogeneration for
extracting power from the bagasse produced by
them.

18. Case study
Heat integrated heat pumping for biomass
gasification processing
 It deals with an application of a heat pump in
energy systems for biomass gasification in a wood
processing plant.
 Process integration methodology is applied to deal
with complex design interactions as many streams
requiring heating and cooling are involved in the
energy recovery.

19. Thermo-neutral Points (TNP’s)
 A thermodynamic analysis of the process of
biomass gasification was conducted to find the
Thermoneutral Points (TNP’s) for different
gasifying agents for different compositions of the
input streams to the gasifier,
 Reaction TNP’s (R-TNP’s)
 Process TNP’s (P-TNP’s).

20. Methodology
 PART A : R-TNP Analysis
 For a particular feed condition, we calculated the
output composition of the reactor using
'Equilibrium Compositions' at temperatures ranging
from 500 to 1000 °C, with intervals of 50 °C and
constant pressure of 1 bar.
 Using those compositions and 'Reaction Equations'
the reaction enthalpy at respective temperatures
was calculated .

21.  Reaction TNP’s (R-TNP’s), Process TNP’s (P-
TNP’s) with and without Heat Exchanger were
calculated and product gas compositions at TNP’s
were analysed for syngas production, syngas ratio,
%CO2 conversion and heat utilities.

22.  the R-TNP's of the reaction:
 The product gas compositions at the R-TNP's and
analysed the parameters:
 Syngas, Syngas Ratio, %CO2 Conversion, Heat
utility (without Heat exchanger), Reduced Heat
Utility (with Heat exchanger).

23. Process TNP Analysis
 PART B: Process TNP Analysis (without Heat
exchanger).
 The Biomass preheating value for temperatures
between 500 to 1000 °C, with intervals of 50 °C.
Cp value of Rice husk was taken as 2.094 J/gK.
 The preheating value of gasifying agents (CO2 and
H2O) for respective temperatures.

24.  The Process enthalpy (without Heat Exchanger) as
the sum of Reaction enthalpy, Biomass preheating
and Gasifying Agents preheating.

25.  Process TNP Analysis (without Heat exchanger).
 The P-TNP's without Heat exchanger.
 The product gas compositions at the P-TNP's and
analysed the parameters: Syngas, Syngas Ratio,
%CO2 Conversion, Reaction Enthalpy at P-TNP's.

26. REFERENCES
1. https://mnre.gov.in/bio-energy/current-status
2. https://pubs.rsc.org/en/content/articlelanding/2016
/ee/c6ee00935b#!divAbstract
3. https://www.researchgate.net/publication/2892005
46_Biomass_gasification_Process_overview_hist
ory_and_development

27. 4. https://www.sciencedirect.com/science/article/abs/
pii/S0956053X16300836
5. https://www.nationalgeographic.org/encyclopedia/
biomass-
energy/#:~:text=Biomass%20energy%20is%20en
ergy%20generated,heat%20or%20converted%20i
nto%20electricity

28. Thank you