Cleaner Use and Management of Agricultural Waste for Biogas Fuelled Power Generation and Biofertilizers Production

Miro R. Susta

IMTE AG

Power Consulting Engineers

Switzerland

MALAYSIA POWER 2004 CONFERENCE, KUALA LUMPUR, MALAYSIA

April 2004

ABSTRACT

Electrical power is an essential element in all productive processes of agricultural enterprises; but its irreplaceable importance is in many countries very often underrated.

However, after last year’s serious blackouts in USA, Canada, England, Denmark, Sweden and Italy also governments of high developed countries realized that lack of electrical power may:-

Ø      Cripple country economics;

Ø      Cause chaos in the cities;

Ø      Have a significant impact on production costs, and

Ø      Pose important technical problems to key consumers.

A study measuring the economic impact of the North American power blackout in August 2003 has concluded that the blackout will have far-reaching, long term economic implications in the affected region.

Among others, one key finding of the study was:-

§         38% of the business surveyed said that they would be likely to invest in the alternate power generation systems.

The main questions related to electrical power supply and to the choice of appropriate power generating technology are usually concentrated to the following main criteria:-

Ø      Grid availability;

Ø      Fuel availability;

Ø      Consumers structure;

Ø      Production reliability and costs.

Most of the time the major power consumer centres, like townships and large industrial enterprises have good access to reliable and safe electrical power.

On the other side, rural agricultural communities and small enterprises are very often facing problems related to unsafe electrical power supply.

This is either due to non availability of power transmission and distribution network or because the electrical power supply from existing grid is not reliable.

Another constraint in the way to reliable power supply is the availability of necessary primary energy (fuel) at affordable price.

The complete absence of electrical power supply means that self-sufficient alternate solutions should be considered and the use of traditional fuel sources (coal, natural gas or oil) versus renewable resources (solar, wind, geothermal, hydro, ocean or biomass) for power generation has to be evaluated.

The availability of reliable renewable ocean, geothermal or wind energy is rather limited in Malaysia. On the other hand, Malaysia has considerable hydro and solar energy potential as well as abundant biomass resources.

Hydro energy, which is already highly developed power generation technology in Malaysia, is not subject of this paper.

The solar energy for power generation is still considered high cost technology, not affordable for small and medium size agricultural enterprises.

Biomass waste is well available and accessible throughout the country. Major biomass energy resources for power generation include:

Ø      The Forest Residue _{PRODUCTION OF}^à Steam (Direct Combustion-DC) & Syngas

Ø      Free Field Residue  _{PRODUCTION OF}^à Steam (DC) & Syngas

Ø      Waste from Wood Processing Industry _{PRODUCTION OF}^à Steam (DC) & Syngas

Ø      Urban Wood, Paper & Cardboard  Waste _{PRODUCTION OF}^à  Steam (DC) & Syngas

Ø       Waste from Agricultural Products Processing Industry _{PRODUCTION OF}^à Biogas & Syngas

Ø      Organic Components in Town Waste _{PRODUCTION OF}^à  Syngas & Biogas

Ø      Solid & Liquid Animal Manure _{PRODUCTION OF}^à  Syngas & Biogas

Ø       Agricultural Plant Waste _{PRODUCTION OF}^à  Steam (DC), Biogas, Syngas, Methanol & Ethanol

Ø      Waste Waters _{PRODUCTION OF}^à  Biogas

Ø      Landfills _{PRODUCTION OF}^à  Biogas (Landfill gas)

Unlike any other energy resources, biomass use for energy production is often a way to dispose biomass waste materials that otherwise would create environmental risks.

Almost all biomass products can be converted either into thermal energy or into commercial fuels, suitable to substitute for fossil fuels.

These can be used for electricity and heat generation and anything else fossil fuels are used for.

The conversion is accomplished through the use of the following distinct processes:-

Ø      Direct Combustion _PRODUCTà Steam, Hot Water;

Ø      Thermo-Chemical Conversion _PRODUCTà Pyrolysis, Charcoal, Syngas;

Ø      Bio-Chemical Conversion _PRODUCTà Methanol, Ethanol, Biogas.

There are a number of challenges that inhibit the development of biomass energy.

In this regard, formulation of sustainable energy policy and strategies in addressing these challenges is indeed a pre-requisite for the development and promotion of biomass energy.

This paper describes utilization of biomass waste for biogas production and power & heat generation with the following topics:

Ø      Demonstration pilot project for biogas production for power and heat generation;

Ø      Project planning equipment, design, digestion process;

Ø      Using the effluents;

Ø      Project economics;

Ø      Application possibilities in Malaysia;

Ø      Benefit & constraints;

Ø      Conclusions.