Biomass Conversion into Energy

Ancient way of converting biomass into energy is just to burn it for producing heat, as humans practiced it for thousands of years. Still this is the most common way for conversion of biomass into energy in United States and elsewhere also.

The heat generated from biomass can be used for heating, cooking, and industrial processes, or for producing electricity.

Using biomass for burning haves some problems regarding some energy waste and also some air pollution if it is not carefully controlled.

There is a process for enhancing biomass energy while burning it with coal in power plants; this is called “co-firing”. Biomass can reduce the use of coal in a boiler for up to 20 percent. Co firing of biomass with coal contains benefits like lower operating costs, reductions of harmful emissions and most of all greater energy security. Co-firing is capable of developing and surviving independently for increasing power generation today. In 2000, the co-firing of switchgrass with coal was tested at Alliant’s Ottumwa Generating Station in Iowa; this test was a jointly conducted by the Chariton Valley Biomass Project, Alliant Energy, The U.S Department of Energy, and local biomass groups.

This project got so much successful that in 2005 Alliant Energy got the permission to build a permanent biomass processing facility at the plant. That plant is capable of co-firing up to five percent of its energy with switchgrass.

For converting biomass into energy there are number of non-combustion methods. These methods haves the capability to convert raw biomass into gases, liquid fuels, or solid fuels so that it can be used directly in the power plants for generating electricity. Biomass usually contains carbohydrates, which are composition of oxygen, carbon, and hydrogen and that can be broke down into different types of chemicals from which some are very useful fuels.

This non-combustion conversion of biomass can be done in following three ways:

Thermochemical

When biomass in the plant is heated but hasn’t burned then it breaks into various gases, liquids, and solids. Then these processed products can be further refined into useful fuels such as methane and alcohol. When biomass convert into gas it captures methane released from the plants and then burn it in a gas turbine to produce electricity.

There is another method, which is to take these fuels and run them through fuel cells, converting hydrogen rich fuels into water and electricity. This process haves few or no emissions.

Biochemical

Bacteria, enzymes and yeasts are also capable of breaking down the carbohydrates of biomass. Such as process of fermentation, which is used to make wine, in this process biomass changes into alcohol, which is a useful combustible fuel.

There is another similar process like fermentation, which is used to turn corn into grain alcohol or ethanol, and then it’s mixed with gasoline to make gasohol.

When bacteria breaks down biomass it also produce methane and carbon dioxide. That methane can be captured from sewage treatment plants and landfills and can be used for heating and power.

Chemical

Biomass oils such as soybean and sunflower and canola oils are capable of being converted chemically into a liquid fuel similar like diesel fuel and also into gasoline additives. For example cooking oil used from restaurants can be used for making biodiesel for trucks. There is also a better way for making biodiesel by using algae as a source of oils.

There are many people who believe that biomass takes more energy to produce fuels from biomass than the fuels themselves contain. In simple word it can be said that it is a net energy loser.

But most of studies done in last 10 years had confirmed that the production of ethanol is a positive energy balance. U.S. Department of Agriculture made a study in 2002 regarding that matter and it shows that technological advances in ethanol conversion and efficiency increases in farm production have caused the net energy value (NEV) of corn ethanol to increase gradually over time. It also shows that every British thermal unit (BTU) of energy, which is used in the production of ethanol, leads to a 34 percent energy gain.

This is truth also that it can be done much better. Currently corn-based ethanol is gained from the corn plants, for producing ethanol only corn kernels are used but not the entire kernel.

To make ethanol from energy crops we can extract four or five times more energy than we had consumed on crops growing. And if we make electricity from that then the obtained energy ratio get high up to 10 times more than that.

For having a sustainable biomass energy system in the future its necessary to replace the fossil fuels with the biomass or other renewable fuels to plant and harvest the crops.

Another issue regarding biomass energy systems is that biomass contains less energy per pound than fossil fuels. So it means that raw biomass is not typically cost effective for shipping more than about 50 miles before it is converted into fuel or energy. This particular issue regarding biomass shows that biomass energy systems are likely to be smaller than their fossil fuel counterparts. Reason for making smaller biomass energy systems is that it’s hard to gather and process more than this quantity of fuel in one place.

But that is not the drawback of biomass energy it can be beneficial for the local, rural communities and even individual farms. So that they will be able to design energy systems that are self sufficient, sustainable, and perfectly adapted to their own needs.