According to a recent report by the UN, factors like climate change and high demand for energy are the main reasons for switching to alternative sources, among which biogas is an essential one. The same report also indicates that increasingly higher shares of budgets are spent on biogas, solar and wind energy research.

What is Biogas?

Biogas is a mixture that is produced by microorganisms during the decomposition of vegetable and animal wastes in an oxygen-free environment. It consists of methane (60–70%), carbon dioxide (30–40%) and hydrogen-sulfide (0–2%). For its production, plant seeds that are rich in oil (e.g. sunflower), vegetables rich in carbohydrates (e.g. potato, wheat, corn, beet), fiber-rich plants (e.g. flax), other plant and tree remains (e.g. branches, hay, roots, bark), and animal remains can be utilized as raw material. Municipal and industrial waste can also be utilized on the condition that they are purified from inorganic materials like plastic and glass.

Biogas is an environmentally friendly energy source that is easy to produce almost anywhere. Biogas production capacity is directly proportional to the agricultural level of a country. Its ease of production and relatively higher efficiency compared to other renewable energy sources make it particularly important for countries which are not self-sufficient in energy production.

Biogas production in reactors

Biogas is produced by two main methods. In one case, the amount of biogas that can be extracted from the available organic waste is calculated. Then reactor tanks are designed according to the rate of production. In the other case, the energy requirement of a certain system (in terms of biogas energy) is calculated first, and then the reactors are built accordingly. The main concern in both designs is of course achieving the maximum efficiency and ease with minimum cost.

We can list the parameters in the design of a reactor tank as follows:

– Type and amount of organic material

– Type and amount of raw material

– Meeting the heat requirement of the chemical process

– Mixing various materials in appropriate proportions

Currently, reactors that are fed with raw materials on a daily basis are widely used in rural areas. This type of reactor is known as a continuous reactor. In cases where daily feeding is not possible, semi-continuous reactors are used instead. In this second type, re-feeding of the reactor is not necessary till the end of the first production cycle, but at the end of each cycle, the reactors have to be emptied and cleaned for the next cycle.

Keeping the temperature of the medium at the correct level is crucial. Solar energy can be used to manage this. It can help heat the liquid mixture up to the desired temperature and prevent the heat loss in certain designs by providing the green-house effect.

Implementing in daily use

How to implement biogas as an alternative source of energy in real life is surely an important subject. Currently, energy production from biogas is carried out either by direct burning or enriching and converting it into other forms of fuel to be used in industry.

One may wonder how good biogas really is compared to current energy sources. In terms of biogas production capacity, 440 lbs of food waste is equivalent to the daily manure production from 5 cows. From this much food waste or manure, 88 ft of biogas can be obtained. In terms of energy, this is equivalent to 9 lbs of wood, or 3 lbs of charcoal or 0.16 gallons of coal oil, 1.5 lbs of gasoline and finally 56.50 ft of natural gas. What can we really do with this much energy? Here is a small list of things we can do:

– cook 3 meals a day for a normal size family for 3 days

– run a 2-horsepower engine for an hour

– keep a 60–100 Watt lamp on for six hours, which is approximately 1.25kWh electrical energy

– heat two bedrooms daily

Humanitarian issues

Although when the western developed countries are considered, biogas is an excellent way of making use of waste food and other organic remains, it still calls for global thinking. In western countries, cutting food waste and turning it into useable energy is an advantage of biogas. Whether that energy is really needed is another issue to think about. People need to evaluate honestly how much energy they really need; they must consider the lights that are left on for no purpose, the heating and cooling systems that are over-used for extreme comfort, the excess of food they leave on plates and the pots of food dumped in the trash… Besides, in much of the rest of the world, there is malnutrition and a shortage of food. So, a straightforward question is, “Is it fair to consume edibles to make energy that we do not necessarily need, while there are people suffering from hunger?”

Biogas clearly holds promise to resolve both the energy problem and the environmental crisis of our modern days. However, will it ever be possible to find resources that can satisfy the consumption needs of a humanity that lacks virtues such as contentment and the desire to share?

Bekir Mugayitoğlu is an environmental engineer. He lives in West Virginia, USA.

Viking I was launched from earth orbit in August 1975. It traced seven hundred million kilometres in an interplanetary spiral to reach Martian orbit the following June. In July 1976 a car size tripod lander, dropped from the space craft, alighted on the rocky surface of Mars some 1200 miles from the Martian Mariner canyon system. This was the location of man’s first on-site search for life on another planet.

The successful Viking missions to Mars supplied us with most valuable scientific information. Although Mars is a rock-strewn desert, its rocks are enriched with minerals that may support life forms with water, air, and raw materials. This was the verdict of the Viking 1 and 2 missions to Mars. Mars may once have had rivers and lakes, but now the temperatures and the atmospheric pressures are so low that water can only exist in the form of vapour or ice. Scientists also suspect that the planet’s giant volcano, Olympus Mons, overlies a hot spot. Although this volcano may still erupt every 10,000 years, the red planet has essentially been frozen to death. However, there is still hope, because the experiments conducted with Martian soil produced significant results. During the experiments, Martian soil was fed with nutrients and water. The results were most surprising. Unlike the lunar dust, Martian soil consumed the nutrients. Not only did apparent consumption of the nutrients give ‘rise to a steady rate of carbon dioxide production but the introduction of water vapour resulted in a most unexpected surge in oxygen levels.

Eighteen years have passed since these experiments and mankind has not taken a step on Mars yet. Will it ever be possible for man to achieve a settlement on Mars in the future? Firstly, such settlements on the planet need to be as self-sufficient as possible. The first Mars invaders will need to begin a search for crucial supplies such as water and oxygen. Since Mars has little nitrogen in its soil to sustain plants, scientists would need to inject the soil with earthly micro-organisms to free up the crucial element. A base independent from earth is impossible without these necessities of life, particularly water and power sources and raw materials for building an ecosystem. Although the atmosphere is only 0.03 % water, the air is saturated with water most of the time, due to the low temperature. However, rain is impossible because the atmosphere is too thin and it is generally cloudless.

A Martian day is 24 hours and 37 minutes, which is very close to earth’s. The fact that gravity is one third of earth’s, is also an advantage. However, what is important is to produce resources like ammonia (a plant nutrient), hydrazine (for rocket fuel), formic acid (for storing electricity), nitric acid (for oxygen storage) and methane (natural gas). We do not know what will actually be found on Mars when it is completely explored, but the important fact about Mars is that, unlike the moon, it contains all the raw materials that are crucial for a Martian base.

At present the planet is an Arctic wasteland, but scientists say this has not always been the case. Much can be learned from a small core sample of the planet’s polar ice. Scientists need to know what happened to its climate, if it resembled the earth’s in the distant past. The topographical features and the river channels suggest that a few million years ago Mars was a warm planet and probably had a thick atmosphere. The Viking findings and the analysis of some of the data suggest that Mars contains more water than once thought. We must also keep in mind that the Viking probes did not completely rule out the possibility of life on the planet. It might still be possible that Mars supports some kind of microbes. It may be that we have not yet looked in the right place. There are many questions about Mars that remain to be answered. For example: we do not know anything about the interior of the planet, whether its core is liquid or frozen or maybe an earth-like core or if the largest volcanoes in the solar system are still alive. A manned mission to Mars and building bases on its surface is quite possible but we are not sure when it will actually take place.

When we think about the planets in our solar system and their conditions, it is impossible to overlook the fact that the earth was designed purposely for life forms to exist. One has to be out of one’s mind to assume that all this order and harmony is completely coincidental. One important thing we have to understand is that we (living organisms) need the earth and its conditions to survive. It is the only planet in the solar system that could support us. For all we know, it might even be the only one in the galaxy. It is obvious that the earth was specifically designed for human beings, because all other life forms on earth serve mankind. By this token we can even claim that the whole universe was created for the benefit of man. The only reason for this claim is that everything would be completely meaningless without an intelligent thinking being.

Our neighbour, the red planet, might be a hope for the future. Whether we will indeed be able to build bases, grow plants, produce valuable gases and materials, begin settlements and colonies or maybe even achieve the birth of the first human being on Mars, remains to be seen, but until then we have to take care of this blue planet of ours and its inhabitants, since we are its trustees.