Energy Crops – Biomass Generation
Photosynthesis
Photosynthesis in C3 plants (such as trees) and C4 plants (such as Energy Cane and Sugarcane) involves the conversion of radiant energy from the sun into chemical energy in the form of glucose and other sugars.
The initial process in photosynthesis involves the decomposition of water (H2O) into oxygen, which is released, and hydrogen. This process requires direct light.
The carbon and oxygen from carbon dioxide (CO2) and hydrogen are then converted into a series of increasingly complex compounds, ultimately resulting in a stable organic compound, glucose (C6H12O6), and water. This phase of photosynthesis utilizes stored energy and can therefore proceed in the dark.
There are three main types of photosynthesis: C3, C4, and CAM. C3 photosynthesis is the most common type and is found in woody, round-leafed plants, which account for approximately 95% of all plant species. In contrast, C4 and CAM photosynthesis are more efficient in terms of water and energy use. C4 plants have a distinct advantage when it comes to photosynthesis under high heat and light conditions, outperforming C3 plants in these environments.
C4 photosynthesis provides a competitive advantage in environments with high temperatures and intense sunlight. This type of photosynthesis enables plants to thrive in conditions that would be challenging for C3 plants. Notably, C4 plants possess more competitive advantages in high temperature and light conditions than C3 plants. Additionally, C4 plants utilize water more efficiently.
In the context of climate change, where rising CO2 levels in the atmosphere are associated with an average temperature increase and water scarcity, C4 type plants have been found to be more adaptable to these new climate conditions.
Global Biomass Generation
Terrestrial and oceanic biological processes have a significant impact on the global carbon cycle across all time scales. In these components of the biosphere, photosynthesis is responsible for virtually all the production of organic matter through biochemical processes.
Solar energy reaching the biosphere is approximately three quintillion megajoules (MJ) per year, or 3 x 10^24 Joules. This energy is captured and converted into biomass and carbon content by terrestrial and aquatic ecosystems. The efficiency of this process is approximately 0.1 percent. As a result, the energy captured by these ecosystems is approximately three quadrillion megajoules (MJ) per year, or 3 x 10^21 Joules. This energy is stored in approximately 200 gigatons of biomass per year. The amount of biomass produced is directly related to the amount of solar energy. Specifically, approximately 30 gigajoules are required for the synthesis of 2 tons of biomass.
On the other hand, the solar energy incorporated into the plant kingdom is approximately 10 times greater than the energy consumed by humanity. This energy is roughly 300 trillion megajoules (MJ) or 3 x 10^20 Joules per year. Furthermore, it is about 200 times greater than the energy consumed as food, which is approximately 15 trillion megajoules (MJ) or 1.5 x 10^19 Joules per year.
Although the aquatic ecosystem covers approximately two-thirds of the Earth’s surface, it produces roughly the same amount of biomass as the terrestrial ecosystem due to its relatively low efficiency. This is achieved through the conversion of approximately 100 million megajoules (MJ) per year, or 1 x 10^14 Joules annually.
The Earth has a diameter of approximately 12,756 kilometers, or around 7,926 miles. It encompasses an area of roughly 510.1 million square kilometers, which is equivalent to approximately 196.9 million square miles. Alternatively, this area can be expressed in hectares as 51 billion, or in acres as 126 billion.
The average dry biomass production can be estimated to fall within a range of 4 to 6 tons per hectare per year. This production level varies across different ecosystems. Specifically, the terrestrial ecosystem is capable of producing at least 6 tons per hectare per year, whereas the aquatic ecosystem produces approximately 3 tons per hectare per year.
Studies using satellite measurements of ocean and terrestrial ecosystems have found that tropical regions have the highest Net Primary Production (NPP). Net
Primary Production refers to the amount of biomass or organic matter created by plants through photosynthesis, minus the energy they use for their own metabolism. It is typically expressed in grams of dry matter produced during a year per square meter of vegetation exposed to sunlight.
Plant biomass productivity can vary significantly depending on the specific type of crop. The productivity rates are as follows: Forests have productivity rates of 10 to 40 tons per hectare per equivalent year; Corn productivity rates range from 20 to 50 tons per hectare per year; Conventional sugar cane productivity rates are between 35 and 60 tons per hectare per year; New varieties of Energy Cane have significantly higher productivity rates, ranging from 80 to 160 tons per hectare per year.
Algae exhibit a wide range of productivity, typically between 50 and 200 tons per hectare per year. However, commercial productivity tends to be relatively low and is often linked with high production costs.
The most competitive and sustainable raw material will be one that possesses the best and most efficient photosynthetic process. It should also have the lowest production costs and be supported by strong and well-established breeding programs. Furthermore, it should be located in regions with favorable edaphoclimatic conditions, providing abundant solar irradiation. This will help to optimize biomass production and atmospheric carbon conversion/absorption