Biomass Full Scale Model
MHESA Sdn Bhd - Demonstrating the successful implementation of a Biomass
Renewable Energy Project
BACKGROUND
The demonstration project undertaken by MHES Asia Sdn Bhd to produce renewable
energy for grid connection is a brave move. This is one of the first two Full
Scale Model initiatives (FSM) of the Biomass-based Power Generation and
Cogeneration in the Malaysian Palm Oil Industry (BioGen) project. This project
shows that it is possible to convert the energy stored in palm oil mill biomass
into electricity thereby reducing an equivalent amount of fossil fuel that is
fast depleting. A day will come when there will be no more fossil fuel for power
generation. So we need a substitute fuel and the palm oil mill waste is one of
the fuels that is readily available in abundance, coming to our rescue.
The main objective of the BioGen project is to
mitigate GHG emissions from the power producing sector of Malaysia
by undertaking biomass based power production to replace part of the fossil fuel
currently used for power production. You may wonder in what way the use of
biomass would reduce GHG emission as it too would produce carbon dioxide, no
different from that emitted by fossil fuels. Yes, that is true however the
effect of palm trees consuming carbon dioxide during the process of
photosynthesis can be deemed to contra the production of carbon dioxide during
the combustion of biomass. We should also appreciate the fact that biomass will
be replaced daily being exactly the reason why it is called renewable energy
whereas it takes thousands of years to produce fossil fuel.
Although biomass based energy production is a noble
deed, its implementation on a large scale seem to face considerable barriers as
can be expected- the fear of something new. Developed countries seem to have
overcome most of the barriers but we are still at the infancy trying to figure
out how to get it moving. The government in its effort to remove these barriers
has offered a number of incentives to facilitate the implementation of RE
projects in the country including soft loans and tax holidays. In addition, the
BioGen project being a government supported project, was especially designed to
remove barriers and implement demonstration projects so that investors can gain
confidence in undertaking RE power projects.
While the Serting FSM project uses biogas as its fuel,
the MHES project will utilize biomass. However, the implementation of both these
projects will be subjected to similar administrative, regulatory, legal and
financial steps before being transformed into a full scale project.
PROJECT OVERVIEW
The MHES project as with the Serting Biogas Project
was also selected through the tendering exercise carried out by the BioGen team.
On 21st September, 2006 a Memorandum of Agreement (MoA) was
signed between MHES and Pusat Tenaga Malaysia (PTM) witnessed by YB Dato’ Seri
Dr. Lim Keng Yaik, Minister of Energy, Water & Communications (KTAK).
The MOA signing ceremony between
PTM and MHES Sdn Bhd
The Host Site
The anticipated capacity of the selected host site for the biomass power plant,
located in Bahau, Negeri Sembilan is 13 MW and it will utilize empty palm fruit
bunches (EFB) as the fuel. The Plant expects to sell 10MW electricity [maximum
eligible limit under the Small Renewable Energy Power (SREP) Programme] to
Tenaga Nasional Berhad (TNB) for 21 years at a price RM0.21/kWh as agreed in the
Renewable Energy Power Purchase Agreement (REPPA). The power plant, which is
expected to be completed in 2008, will apply a two-stage burning system using
EFB as the main fuel.
MHES Asia Sdn Bhd has appointed Ramunia Fabricators Sdn Bhd. as the Engineering,
Procurement, Construction & Commissioning (EPCC) contractor for their RE power
plant. The contract value for the EPCC is RM60 Million and the contract duration
is 18 months.
TABLE 1: A ROUGH FINACIAL
ANALYSIS OF THE PROJECT
(without revenue from Clean Development Mechanism-CDM)
|
Project cost ( Capital )
|
RM 79,000,000
|
|
Actual power dispatch , energy exported
|
66,551,000 kWh
|
|
Revenue at the rate of 21 sen /kWh
|
RM 14 million
|
|
Average Net Profit per year
|
RM 1.176 million
|
|
Internal rate of returns (IRR) –
after tax
|
5.87 %
|
|
Pay back period as a rough estimate
|
11.3 years
|
To ensure the security of the fuel/ EFB supply a long term Fuel Supply Agreement
(FSA) has already been signed with a palm oil miller and negotiation with a few
others are in progress.
The project will collect 222,000 tonnes
of EFB from seven nearby plantations owned by FELDA (Federal Land Development
Authority) and 50,000 tonnes from one more mill owned by Prosper Palm Oil Mill
Sdn Bhd. Therefore, the project will use a total of 272,000 tonnes of EFB per
year.o:p>
Schematic Diagram of Biomass Power Generation Facility
The Basic Principles Involved In
This Technology
The Process
The Biomass Power Generation Facility
(BPGF) is a complex system; nevertheless a simple description of the facility
will be explained here. The BPGF consist of 3 main units namely the 2 stage
combustion unit ‘Envirocycler’, the
Heat Recovery Steam Generation (HRSG) unit
and finally the turbine.
The process in the BPGF starts with the
pretreatment of the EFB which contains about 65-70% moisture considered high
even for biomass which must be press dried before it can be converted in the
boiler into steam. Another reason for its pretreatment is the fact that it
produces huge amounts of potassium that causes costly boiler parts to corrode
rapidly.
The pre-treatment of the EFB also entails its shredding and storage for an
average of two days before it passes through the Envirocycler which is subjected
to updraft gasification in the 1st stage followed by vigorous, double
vortex cyclonic combustion in the second stage. In the Envirocycler air for
combustion is admitted from four sources as follows:
·
Under-fire air which gasifies biomass in the 1st
stage
·
Over-fire air that preheats 1st stage producer
gas to ensure ignition in the 2nd stage
·
Primary combustion air ignites the preheated
producer gas at the bottom of the 2nd stage
·
Secondary combustion air completes combustion of
producer gas also in the 2nd stage.
The wet combustor Envirocycler can combust almost any biomass
residue in an environmentally friendly manner. Using biomass residues as fuel,
it meets the following limits directly from its 1100°C (2,000°F) stack: 0.05
gr/dscf (120 mg/Nm3) particulate, 1.5 ppm CO, 15 ppm NOx . It also recovers
energy from its exhaust to displace power and/or process heat. Heuristic Engineering Inc. of Canada
will provide the technology of the 2-stage wet combustors. This technology will
be transferred from Canada
and the fabrication will take place in Malaysia through Meridien Utilities Sdn Bhd.
The advantage of the technology is that it can burn biomass with moisture
content of up to 65%.
Once the above process is completed, the Heat Recovery Steam
Generation (HRSG) recovers the heat produced by the Envirocycler to produce
steam for use in the turbo-alternator to generate electricity. The condensed
steam will then go through a cooling tower and then will be reconnected to the
HRSG unit. The exhausted low pressure steam will be reused in the dearator that
will remove the dissolved gases from the exhausted steam. With a capacity to
produce 60 tonnes/hr of steam, operating 24 hours per day regime (except for
downtime periods) the boiler will consume about 34 tonnes/hr of EFB, operating
approximately 7,600 hours/year at full capacity.
The final process in the BPGF is the working of the steam
turbine which produces 13 MWe at a steam consumption rate of 4.3 kg/kWh.
The turbine will be supplied and
installed by NG Metalurgica, one of the largest and more experienced Brazilian
manufacturers of Industrial Steam Turbines, with more than 80 years of
experience in various industrial sectors.
Scheduled Maintenance
The plant will also have two scheduled maintenance shut down
periods every year. One is estimated to last for one week and the other for
three weeks. During these two periods, the maintenance and calibration of all
the equipment will be carried out. To re-start the boilers, it is anticipated
that a small amount of electricity from the grid will be used. This electricity
used will be captured within the monitoring plan and taken into account. No
standby fossil fuel generators will be installed as a backup and no fossil fuels
will be used during the downtime.
Ash-Removal
Particulate matter carried up into the Envirocycler's 2nd stage
is removed centrifugally out of its walls for deposition into the 1st
stage. It is removed from the first stage by the built-in ash removal
system. Shredding the fuel before admission produces fine ash and its
continuous removal also poses no problems in the absence of clinkers.
Conclusion
The implementation of the demonstration project play an important role as a
support for the targeted RE installed capacity of 350 MW planned in the 9th
Malaysia Plan. It is also a showcase for the technology viability and
bankability of renewable energy projects especially in Peninsular Malaysia since
there are no such projects being implemented successfully. Furthermore as the
implementing agency, PTM has the duty to monitor the performance of the Full
Scale Model (FSM) project from the date of its commissioning up to a period of
five (5) years during which time data and information gained could be used for
PTM’s research or promotional activities. The FSM also could be replicated by
other potential RE developers in achieving RE target for
Malaysia.