Thursday, September 30, 2010

Utilization of Microalgae for Biofuels Production

As we know, modern society relies heavily on fossil fuels. 80-90% of all energy consumed in the world is from fossil fuels. Fossil fuels include oil, natural gas and coal. They originated from plants and animals that lived on the earth millions of years ago. The resources of fossil fuels are limited and non-renewable.

The first slide shows the history and the future prediction of worldly oil production. It is generally believed that worldly oil production will peak in less than 10 years. As you can see from the figure, USA and Russia passed their oil production peaks decades ago, in 1970s and 1990s respectively.

After world oil production peaks and declines, the world will face a severe situation. The situation is that the world simply cannot produce enough fossil oil to meet the demand from transportation.

This oil gap for transportation has to be filled. Biofuels are one of the candidates to fill this oil gap. Biofuels are derived from biomass. And biomass used for producing biofuels can be grains, hay, weeds, woods and others.

The first generation biofuels derived from crops. For example, in USA, corns are used for producing ethanol; in Brazil sugarcane are used for producing ethanol; and soybeans are widely used for producing biodiesel. But corn, sugarcane and soybean are crops. The main problem facing crop-derived biofuels is conflict between food production and biofuels production. Other problems concerning crop-based biofuels production include deforestation, high production cost and limited potential. Take the limited potential for example: Even if all the corn currently produced in the USA were used for producing ethanol, it could only replace about 15% of oil currently consumed in the USA.

Microalgae are single-celled lower plants that make seas, lakes and rivers green. When you walk around a natural pond in the spring and summer, you can find the surface of water is covered by green stuff. That are microalgae. Microalgae are "plants" because they can grow by using sunlight, CO2 and water.

There are several advantages of using micro-algae for biofuels production over crops.

First, microalgae grow much faster than land plants. It can grow 7 to 30 times faster than the next best crop. Under the optimum conditions, microalgae can double its biomass in several hours.

Second, cultivation of microalgae doesn’t compete for farmland. Algae can be grown on land that is not suitable for crops, for instance, arid land, land with excessively saline soil, and drought-stricken land. Moreover, 70.8% of the earth’s surface is cover by water. Microalgae can be cultivated in open ponds, and even in the sea.

Third, algae-based biofuels are CO2 neutral, which does not deteriorate Global Warming effect. Algae absorbs CO2 from atmospheres when it grows and the CO2 is released back into atmospheres when the biofuels is used.

Fourth, microalgae can be harvested daily or any time needed, not like crops that are limited by their long growth cycle.

The main challenges facing algae-based biofuels are lack of cost-effective technologies to cultivate, harvest microalgae and to process microalgae into biofuels. But this is not strange. Human Beings have been planting crops, such as corn, sugarcane and soybean, for at least five thousand years, but cultivating and processing microalgae for biofuels is still in experimental stage. There is a lot of space to develop an improve algal cultivation, harvesting and processing technologies.

Utilizing microalgae for biofuels production will bring many benefits to the society and the country, such as breaking the USA’s dependence on foreign oil, creating a new source of green energy and adding job opportunities.

Microalgae are one of the most promising sources for biofuels production. But to make it reality, renovation of technology in this area is needed. And to renovate the technology, more money and more human resources should be invested.


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The above is one of 8 - 10 min speeches I delivered in my Toastmasters club. The speech is based on AC#2: The Proposal.

Sunday, September 19, 2010

Helping Seedlings Grow by Pulling Them Upwards


"Helping seedlings grow by pulling them upwards” is an English Translation of a Chinese idiom “Ba Miao Zhu Zhang”. The idiom originated from a story and the story goes like this:

In ancient China, there was a farmer who grew rice. He hoped the rice seedlings would grow fast and was expecting a good harvest. So he went to the field to watch the rice seedlings every day. It seemed to him the seedlings were growing very slowly. He became anxious about the seedlings and said to himself: “I should do something to help the seedlings grow faster.”

He thought and thought and then had a great idea. "Why don’t I pull the seedlings upwards a little bit and that would help them grow faster.” After thinking of this, he went down to the field and pulled every seedling upward a little bit. After doing that, the seedlings did look taller.

Looking at the taller seedlings, he was happy though exhausted from the hard work. On his way back home, he couldn’t help thinking how smart and hardworking he was. He even couldn’t understand why people hadn’t discovered this method before.

However, several days later when he went back to field, he found all the seedlings had dried up and died.

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The basic meaning of “Helping seedlings grow by pulling them upwards” is spoiling things by excessive enthusiasm. It describes behaviors of people who are too eager to get things done only to make the things worse. I know I made such mistakes. Can you find examples of “Helping seedlings grow by pulling them upwards" in history and real life, for example, in some parents who want to help their children, in some religious groups that want to influence their followers, or in some governments that want to control their people?

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The above is a 4-6 minute speech I delivered in my Toastmasters club. The speech is based on a project titled "The Moral of a Story".

Monday, September 6, 2010

The Sun and the Solar Energy

If you are interested in mythologies of sun god or goddess, you will be able to find numerous versions in different cultures including Chinese, Korean, Japanese, Egyptian, Greek, Indian and many others.

The first slide shows the Indian sun god and Greek sun god. I personally like the story of Greek sun god, Apollo, very much. I think the story of Apollo is comparable to the best of William Shakespeare’s plays.

However everyone here knows that the sun is the only star in our solar system. Comparison between the sun, the earth and other planets in size is shown in the second slide. The sun is much larger than the earth and other planets. Actually the volume of the sun is over one million times larger than that of the earth.

The sun is an enormous ball of burning gases. The main elements of the sun are hydrogen and helium. Since there is no oxygen on the sun, the energy of the sun does not come from general sense of burning hydrogen, but from hydrogen nuclear fusion, a process similar to that happening in a hydrogen bomb when it explodes.

The sun produces enormous light per second and it has been doing that for billions of years. Up to now, the largest power plant in the world is the Chinese Three Gorge power plant, which can produce 18,000 Megawatts (one million) of power per year. However, the sun puts out the same amount of energy in the form of light per second as a billion of the largest power plant in the world would put out in a year. This number is enormous, even difficult to imagine.

The sun light absorbed by the earth atmosphere, oceans and land is called solar energy. The solar energy the earth receives per hour is equivalent to all the energy humans currently consume in a year.

About 0.1% of the solar energy has been captured by photosynthesis, transferring the light energy into chemical energy. Plants make their own food by Photosynthesis, and animals and humans have to eat plants or other animals to obtain their energy. So the energy to sustain almost all the life on the earth comes from the Sun.

Here lists the energy sources originally from the sun. Currently, 86% of energy we are using are form fossil fuels: coal, oil and natural gas. Fossil fuels were solar energy fixed by plants millions of years ago; and bioenergy, hydropower, solar power, wave power, wind power are all originally from solar energy. The only exceptions are nuclear power, tidal energy, and Geothermal energy.

Without the sun, life on the earth simply wouldn’t exist. We are so blessed that the sun provides us with free and clean energy. How can we be grateful enough for the Sun? The only thing we can do is to make good use of the solar energy.







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The above is one of 5-7 min speeches I delivered in my Toastmasters Club.

Liang and Zhu, Chinese Romeo and Juliet

It is said about one thousand and six hundred years ago, in east of China, there was a beautiful and intelligent girl. Her name was Zhu. At that time, females couldn’t go to school but Zhu was eager to study.

She managed to convince her family to allow her to go to school in disguise as a man.

On her journey to school, Zhu met Liang, a young man who was going to the same school as her. They became friends at first meeting. In the next three years, they studied together and behaved like "brothers". Gradually, Zhu fell in love with Liang.

One day, Zhu received a letter from her family, asking her to return home. Zhu had no choice but leave school and Liang. However, in her heart, she was deeply in love with Liang and was determined to be with him forever.

So she went to her teacher’s wife for help. The teacher’s wife actually recognized her to be a girl long time ago, and promised to help her.

On the way Liang saw Zhu off. Zhu hinted to Liang that she was a girl, but Liang was somehow a bookworm and didn’t understand Zhu’s hint. Finally Zhu came up with an idea and told Liang that she had a beautiful sister and would like to introduce her sister to be Liang’s wife. Liang was very happy and looked forward to meeting Zhu’s sister.

However, when Zhu went home, her family had already arranged a marriage for her. The man Zhu was arranged to marry was from a very rich and powerful family.

Zhu confessed her love with Liang to her parents and resisted to the arranged marriage. She even vowed that she would kill herself rather than marry another man. But his father didn’t agree to the possible marriage between Liang and Zhu, and threatened that if she didn’t agree to the arranged marriage, Liang’s life would be at risk if the powerful family got angry with her breaking the arranged marriage. Since Zhu loved Liang and didn’t want Liang to be hurt, she finally decided to submit herself to the arranged marriage.

At school, with the reminding of the teacher’s wife, Liang finally realized that Zhu was a girl and the sister Zhu wanted to introduce to him was actually Zhu herself. After knowing this, Liang was very happy and couldn’t wait any more to see Zhu again.

However, when Liang arrived at Zhu’s home, he was heartbroken to learn that Zhu had to marry another man. There was no way for them to break the feudal customs or rules set at that time.

Since then, Liang got sick and died later.

On the day Zhu was sent for wedding, a mysterious wind brought the team passing by Liang’s grave. When Zhu saw Liang's grave, she cried in bitter despair and begged for the grave to open up.

Suddenly, the grave opened with a strike of thunder. Without any hesitation, Zhu threw herself into the grave and united with Liang.

Their spirits turned into a pair of beautiful butterflies. They flied together and never separated again.









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The above is a 6 - 8 min speech I delivered in my Toastmasters club (AC#4 Tell a story)