Bloom Box Reviews

Fuel Cells as the Heart of a Bloom Box

By definition, a fuel cell is a device that uses hydrogen and oxygen to generate electricity by means of chemical reaction. Since hydrogen and oxygen when combined produces another byproduct which is very common to us, water, the fuel cell causes very small pollution. In addition, using chemical reaction in extracting energy from fuels is more efficient than using a process called combustion. Usually, fuel cells are used in large numbers because one cell can only produce a very small amount of direct current.

A single fuel cell has two electrodes, positive electrode or the anode, and a negative electrode or the cathode. Chemical reaction takes place in these electrodes. A basic fuel cell also includes an electrolyte and a catalyst that are responsible for transferring electrically charged particles from one electrode to another and speeding up chemical reactions at the electrode, respectively.

Fuel Cells Producing Electricity

So how does a fuel cell work? Hydrogen is supplied at the positive electrode of the fuel cell. The chemical reaction then takes place when the hydrogen atom enters the electrode. The process called “ionization” takes place wherein the positive charged particles are separated from the negative charged electrons. These negative charged electrons produces electric current needed to do work, lighting a bulb for example. At the cathode of the fuel cell, oxygen is supplied to have a complete electrical path. Another chemical reaction takes place where the ionized hydrogen atom that passed through the electrolyte, oxygen atoms and negative charged electrons from the circuit are combined. This produces water and leaks from the fuel cell. The fuel cell will continue to generate electricity as long as there is a supply of oxygen and hydrogen.

Another factor that must be considered in fuel cells is the electrolyte. The electrolyte used must only allow sufficient amount of ionized atoms to pass from electrodes, and also not allow other substances to enter the electrolyte because this may cause problems in chemical reaction. The materials, design of electrodes as well as fuel used depends on the electrolyte used. Furthermore, the operating temperature is also affected by the electrolyte.

Fuel cells can be categorized based on the electrolyte, either liquid or solid. Liquid electrolytes are alkali, molten carbonate and phosphoric acid. Alkali fuel cell operates at 150-200 degrees Celsius. Molten carbonate has efficiency of 60-80% and can output up to 100 megawatts. Phosphoric acid uses phosphoric acid as its electrolyte. Disadvantage of liquid electrolyte is the possibility of leakage and may require pumps.

Proton exchange membrane and solid oxide are examples of solid electrolyte fuel cells. Proton exchange membrane is suitable for home and car because it can operate at low temperatures. Solid oxide on the other hand produces waste which can be recycled for further electrical use. Disadvantage is that it is big in size and may crack because it operates at high temperature energy provider.