Rural electrification via biomass gasification

Prof Zainal Alimuddin

Universiti Sains Malaysia

Problem Statement

• Many parts of Malaysia is still not connected to the grid and thus deprive the rural folks from a good standard of living

• The rural folks depends on diesel generator sets for their limited electrical use

• (Diesel consumption for 50kW engine per hour is about 15liters per hour. For one day of 8 hours, diesel consumption is about 120 liters per day @ RM240 per day)

• Other types of renewable energy options are available such as solar photovoltaic panels.

Solution

• The rural areas have abundant supply of biomass resources

• The rural folks are farmers and produce agricultural residues.

• Biomass is a viable source of energy for power generation and rural electrification

• Technology is available to convert the biomass into electrical power- BIOMASS GASIFICATION

Biomass gasification

• Thermochemical conversion of biomass into combustible gas (producer gas or wood gas) through an endothermic reaction in the presence of limited supply of gasifying agent (air, O2, Steam, CO2,H2)

• Biomass gasification occurs in reactors called gasifiers

BIOENERGY LAB

Types of biomass

Gasifier

Producer

gas exit

Air

supply

Grate

Biomass

feed

Ash

Reduction

zone

Combustion

Pyrolysis

Drying zone

600-800oC

1g/m3 tar

5kW BIOMASS GASIFICATION SYSTEM

20 KW BIOMASS GASIFICATION

200kW BIOMASS GASIFICATION SYSTEM

Gasifier efficiency

70%

Gas cooling and Cleaning sytem

Diesel generator efficiency 25%

20 kWe

69kW (17 kg/h)

48kWt

32kWt diesel

Biomass consumption 1 kg/kWh Overall efficiency 20% Diesel saving 60%

20KWe BIOMASS GASIFICATION SYTEM WITH DIESEL ENGINE GEN SET

Gasifier 70%

Gas cooling and cleaning system

100%

Petrol engine Gen set 25%

20 kWe

115kW (28 kg/h)

80kWt

Biomass consumption 1.4 kg/kWh Overall efficiency 17.4% Petrol saving 100%

20KWe BIOMASS GASIFICATION WITH PETROL ENGINE GEN SET

Proposal A

• For village that is already using a diesel generator set.

• Using the existing diesel generator set and incorporate a biomass gasifier system comprising of a gasifier and a gas and cooling system.

• Diesel saving 60% ( diesel consumption 0.15L/kWh)

• Investment on gasifier system with gas cooling and cleaning is about RM1500/kW

• The power plant can still operate with diesel in case there is shortage of biomass supply.

Proposal B

• For village that is not using any electrical generating device

• Based on a the village population a Biomass gasifier system with diesel engine generator is proposed.

• Investment will be RM3000/kW

• Diesel consumption 0.15 L/kWh

• The power plant can still operate with diesel in case there is shortage of biomass supply.

Proposal C

• For village that is not using any electrical generating device

• Based on a the village population a Biomass gasifier system with petrol engine generator is proposed

• Investment RM3000/kW

• Diesel consumption for start up only.

• The power plant will be operate if there is shortage of biomass supply

FINANCIAL COST FOR PROPOSAL C

• A typical rural village has about 50 houses

• Each house uses about 1000 W per day.

• Total power requirement is 50kW for a typical village

• Nominal cost RM 3000/kW

• Total cost for development of a Biomass energy system is RM150,000.00 (including a small shed for the system)

FINANCIAL COST (breakdown)

• Petrol gen set RM50,000 (with modification)

• Gasifier RM50,000 (manual loading of biomass)

• Gas cleaning and cooling system RM 20,000 (cyclone separator, condenser and filter)

• Electrical connection to houses RM20,000 (cables)

• Transportation RM10,000 (depends on location)

• 5kWe diesel gen set RM 5,000

PAY BACK PERIOD

• For 50kW power generation the operating cost is RM240/day.

• Proposal A cost is RM75,000. Saving in diesel fuel is RM120/day. The pay back period is 1.8years. Diesel fuel cost RM120/day

• Proposal B cost is RM150,000. Saving in diesel fuel is RM120/day. The pay back period is 3.5 years. Diesel fuel cost RM120/day

• Proposal C cost is RM150,000. Saving in diesel fuel is RM240/day. The pay back period is 1.8 years. No fuel cost .

Requirement

• Use a 5kW diesel gen set for start up process.

• Use a 50kW petrol engine with 100% producer gas (no petrol consumption)

• Unskilled operators (villagers) for biomass pretreatment

• One skilled operator for operating the system.

• One skilled operator for maintenance of the system

THANK YOU