Hilaire Ananda Perera http://www.linkedin.com/in/hilaireperera

BIOMASS Based Power (Electrical & Thermal)

Electricity has today become a basic necessity for not just the developed world, but also for the

developing and underdeveloped countries. Diminishing supply and environmental concerns have

been brought to light in recent years, exposing fossil fuels, currently the world’s primary source

of energy, as unsustainable and potentially harmful to the environment. Because of this, clean

renewable energy sources are controlling more of the available market and Biomass is one of the

leading options on this front.

Biomass refers to a group of organic materials that can be used to generate electric and thermal

power. Sources of biomass are: herbaceous and woody plants, agriculture and forestry wastes

and residues, landfill gases, animal wastes, municipal wastes, and other organic material.

Biomass materials can reliably provide electricity, but due to their naturally high water content,

Biomass materials burn less efficiently than coal because they require more energy input to

produce a given amount of energy. Biomass producers can increase the energy efficiency of

Biomass materials by "densifying" them though so costly

Energy crops compete for land that would otherwise be used for food crops and wood, but

agricultural and forest residues can be a practical use of waste resources. The availability of

residues, however, can be unpredictable. In addition, residues can be expensive to collect.

Biomass can predictably generate electricity, differentiating it from other renewable electricity

sources, but its reliability can be affected by costs of Biomass materials and the ability of power

facilities to effectively use Biomass fuel.

Because of the variety of sources, there are a variety of ways that electricity can be generated

using Biomass.

Direct combustion is a process that involves burning Biomass, such as wood and solid waste

from forestry and agriculture. The burning Biomass creates heat that is used to boil water and

make steam. The steam turns a turbine to generate electricity.

Anaerobic digestion makes use of the microorganisms living in wastes that break down organic

matter and produce biogas. The Biogas that is created is a combustible fuel that can be used in an

electricity generation plant.

Co-firing refers to adding Biomass to coal-fired electricity generation plants. Burning Biomass

and coal together means less coal is used, minimizing the overall consumption of coal and its

environmental impact.

Pyrolysis is a process that converts solid Biomass into a liquid fuel. This is achieved through

heating Biomass in an oxygen-free tank to produce a gas. The gas is quickly cooled to create an

oil-like liquid rich in hydrocarbons. This liquid fuel can be used to generate electricity.

Hilaire Ananda Perera http://www.linkedin.com/in/hilaireperera

Gasification is a form of pyrolysis that uses more air during the heating process. It creates a

producer gas, which is burned to heat water and make steam. The steam turns turbines and

generates electricity.

Biomass power makes up only a small fraction of Canada's total electricity generation, but its use

in Ontario is expected to increase with Provincial incentives to make the price of Biomass power

comparable to traditional sources of electricity (fossil fuels and hydro). The use of Biomass will

increase as Ontario works to phase out coal: there are plans to co-fire Biomass and coal, and to

convert some coal-fired plants to Biomass-fired plants.

http://www.electricalindustry.ca/latest-news/778-opg-opens-north-america-s-largest-100-

biomass-fueled-power-plant

Biomass can reliably provide baseload power, unlike other renewable energy sources like wind

and solar, but the main drawback of biomass fuel is its inefficiency. Although Biomass can be

used to produce electricity to meet consumer demand, Biomass contains large amounts of water

per unit of weight, which means it does not contain as much energy potential as fossil fuels.

Additionally, transportation costs for Biomass are higher per unit of energy than fossil fuels

because of its low energy density.

Biomass Power Overview

Biomass power technologies convert renewable biomass fuels to heat and electricity using

processes similar to that used with fossil fuels. Next to hydropower, more electricity is generated

from Biomass than any other renewable energy resource in the United States. A key attribute of

Biomass is its availability upon demand - the energy is stored within the Biomass until it is

needed. Other forms of renewable energy are dependent on variable environmental conditions

such as wind speed or sunlight intensity. Today in parts of the developing world, Biomass is

primarily used to provide heat for cooking and comfort. Technologies have now been developed

which can generate electricity from the energy in Biomass fuels. Biomass technologies are

highly scaleable - small enough to be used on a farm or in remote villages, or large enough to

provide power for a small city.

There are four primary classes of biopower systems: direct-fired, co-fired, gasification, and

modular systems. Most of today's biopower plants are direct-fired systems that are similar to

most fossil-fuel fired power plants. The Biomass fuel is burned in a boiler to produce high-

pressure steam. This steam is introduced into a steam turbine, where it flows over a series of

aerodynamic turbine blades, causing the turbine to rotate. The turbine is connected to an electric

generator, so as the steam flow causes the turbine to rotate, the electric generator turns and

electricity is produced. Biomass power boilers are typically in the 20-50 MW range, compared to

coal-fired plants in the 100-1500 MW range. The small capacity plants tend to be lower in

efficiency because of economic trade-offs; efficiency-enhancing equipment cannot pay for itself

in small plants. Although techniques exist to push Biomass steam generation efficiency over

40%, actual plant efficiencies are often in the low 20% range.

Hilaire Ananda Perera http://www.linkedin.com/in/hilaireperera

.

Great to get

Heat &

Electricity from

the Same Plant

for Other Use

* Fischer–Tropsch process is a collection of chemical reactions that

converts a mixture of carbon monoxide and hydrogen into liquid

hydrocarbons. It was first developed by Franz Fischer and Hans Tropsch

at the Kaiser-Wilhelm-Institut für Kohlenforschung in Mülheim an der

Ruhr, Germany, in 1925. The process, a key component of gas to liquids

technology, produces a synthetic lubrication oil and synthetic fuel,

typically from coal, natural gas, or biomass.

Hilaire Ananda Perera http://www.linkedin.com/in/hilaireperera

The above figure illustrates the advantages of operating a CHP system. The Sankey diagram

clearly depicts the vastly superior efficiency and subsequent cost savings inherent to operating a

CHP system in place of individual and separate power and boiler plants. .

Combined heat and power (CHP) is an efficient and clean approach to generating electric power

and useful thermal energy from a single fuel source. CHP places power production at or near

the end-user’s site so that the heat released from power production can be used to meet the

user’s thermal requirements while the power generated meets all or a portion of the site

electricity needs. Applications with steady demand for electricity and thermal energy are

potentially good economic targets for CHP deployment. Industrial applications particularly in

industries with continuous processing and high steam requirements are very economic and

represent a large share of existing CHP capacity today. Commercial applications such as

hospitals, nursing homes, laundries, and hotels with large hot water needs are well suited for

CHP. Institutional applications such as colleges and schools, prisons, and residential and

recreational facilities are also excellent prospects for CHP.

Combined Heat and Power (CHP) is the simultaneous generation of two or more forms of

energy from a single fuel source. By recycling valuable heat from the combustion process, CHP

results in far greater efficiencies than centralized power generation. The recovered thermal

energy may be used for industrial processes, space heating, and refrigeration or space cooling

through an absorption chiller. CHP is considered the most viable and economical use of

distributed generation (DG) when implemented at or near the point of use.

This Evaluation of Combined Heat and Power Technologies was for Wastewater

Treatment Facilities, and prepared for Columbus Water Works, Georgia, Dec 20, 2010

Hilaire Ananda Perera http://www.linkedin.com/in/hilaireperera

CHP offers a number of benefits compared to conventional electricity and thermal energy

production, including:

Efficiency Benefits CHP requires less fuel to produce a given energy output and avoids transmission and distribution

losses that occur when electricity travels over power lines.

Environmental Benefits Because less fuel is burned to produce each unit of energy output and because transmission and

distribution losses are avoided, CHP reduces emissions of greenhouse gases and other air

pollutants.

Economic Benefits CHP can save facilities considerable money on their energy bills due to its high efficiency, and it

can provide a hedge against electricity cost increases.

Reliability Benefits Unreliable electricity service represents a quantifiable business, safety, and health risk for some

companies and organizations. CHP is an on-site generation resource and can be designed to

support continued operations in the event of a disaster or grid disruption by continuing to provide

reliable electricity.

Catalog of CHP Technologies provides an overview of how combined heat and power systems

work and the key concepts of efficiency and power-to-heat ratios. It also provides information

and performance characteristics of five commercially available CHP prime movers.

https://www.epa.gov/chp/catalog-chp-technologies

Hilaire Ananda Perera http://www.linkedin.com/in/hilaireperera

The CHP Plant is designed to receive and process different types of segregated clean and treated

biomass and wood-waste fuels. The plant can operate on a single source feedstock basis or on a

variable and mixed feedstock basis where differently source feedstock is blended together, which

will allow for maximum feedstock flexibility now and in the future.

The thermal energy created by combusting Biomass is turned into electricity via the CHP plant.

This works by using some of the heat created to drive a turbine and the excess thermal energy is

then used to provide either process heat or distinct heating

The design of a Biomass CHP plant should focus on meeting the thermal load requirements, as

any plant will produce roughly 5 times more than electricity. The size of the biomass boiler will

typically be 6 times the electrical output. This means that a 6MW Biomass boiler can produce

roughly 5MW of heat and 1MW of electricity.

The traditional technology used in thermal power plants involves the production of superheated

steam. Pressure is produced at 28 to 36 bar at temperatures between 320 and 260 deg C. This

steam then drives the turbine which transfers the energy to the generator via gears and coupling

With the single-stage turbine used in small power plants, it is possible to obtain an electrical

efficiency of 12-14% of the input energy. The steam turbines are generally suitable for Biomass

CHP plants with an electrical output of greater than 2MW.

Hilaire Ananda Perera http://www.linkedin.com/in/hilaireperera

What are the benefits of Biomass? What are its drawbacks and environmental impact?

BENEFITS

Biomass is a carbon-neutral source

The amount of carbon dioxide (a greenhouse gas) released when Biomass is burned to

generate electricity is less than the amount it captured through photosynthesis when it was a

living plant. For this reason, it's considered carbon-neutral.

It makes use of wastes

Biomass power uses organic wastes and residues from the forestry and agriculture

industries, as well as gases produced by landfills, and animal and human wastes to generate

electricity.

It's a renewable source of electricity

Organic materials are replenished by natural plant growth cycles.

DRAWBACKS AND ENVIRONMENTAL IMPACT

Meanwhile, the forestry and agriculture industries continue to produce organic wastes and

municipalities generate their own wastes. All can be used for Biomass power.

Biomass power needs a constant supply of organic materials

There are worries that tracts of land will be used to grow Biomass rather than food, and that

natural environments will be converted to monoculture Biomass crops, destroying habitats

and biodiversity in order to meet the supply needs of Biomass electricity generation.

It involves collection and transportation challenges

It is difficult to collect enough Biomass to generate electricity. Large quantities are needed,

and they typically come from a variety of places.

It releases pollutants when burned

Although Biomass is considered carbon-neutral, it still releases Green House Gases and

other air pollutants when burned to generate electricity. Its emissions are far less than those

caused by burning fossil fuels, but they are still harmful.

Ash is created by burning Biomass and can contain the same metals and other harmful

substances present in the original waste.

Hilaire Ananda Perera http://www.linkedin.com/in/hilaireperera

COST REDUCTION POTENTIALS FOR BIOMASS-FIRED ELECTRICITY

GENERATION

Analysing the potential for cost reductions in biomass power generation equipment is

complicated by the range of technologies available, from the mature to those still at the pilot or

R&D stage, and by the often significant variations in local technology solutions. However, some

analysis has examined potential cost reductions in the future.

There is currently little discussion about learning curves for biomass power generation. This is in

part due to the range of technologies available and to their different states of commercialisation

but also due to a lack of authoritative time series cost data.

Combustion technologies are well-established and are generally bankable if the project

economics are solid. Gasification with low gas energy content and internal combustion engines

are an established niche technology in India, but shifting from these simple gasifiers to ones with

greater efficiency, using oxygen as a reactive agent, gas clean-up and gas turbines to scale-up

this technology to larger power plants still requires more demonstration, especially because it

requires expensive gas clean-up, which is currently the main focus of gasification technology

improvements. In anaerobic systems, the main technological development needed is linked to the

digesters (as better control of the process: enzymes, pH, temperature) and the clean-up of the

biogas before combustion.

The main question regarding the viability of biomass power plants lies in the development of a

reliable feedstock supply chain, especially because long-term feedstock agreements are essential

for financing any biomass project. Predicting biomass cost reduction potentials is challenging

because many factors are involved, such as the local supply chain, resource potential, land

availability, competitive industrial uses (e.g. biochemical), risks of deforestation, sustainability

criteria, etc.