To carry out the generation of hydrogen, the principle of electrolysis was used. The design of this equipment (See Figure 1) was based mainly on the natural conditions of water and gases seeking optimization through the interaction of water-gas temperature and the relation of conductivity of hydrogen, electromagnetic field movement, tip-shape effect and electrification equipment, electric current intensity, accessibility to maintenance, suitable materials such as copper and stainless steel 316, plastics and borosilicate glass, industrial glues and tin-copper and silver-copper solders, arc welding, tic, blowtorch, tin, plastic welding. All these applications and combinations of materials are necessary to be able to design and build the gas generating equipment. The constrction material, was based in low cost comercial componentes (tanks, piping, tubes).
The flow chart presented in Figure 1 corresponds to the base scheme, since three prototypes were made changing the area of the gasifier that is presented in the diagram, in order to find the most feasible and viable production solution. The prototypes are described below:
2.1 Design s hydrogen generator and solar collector
The first point to be analyzed is the tip-shape effect. This consists of a natural condition of the current, which models the energy in a specific direction. This is focused on the tip of the electrical conductor which receives most of the energy, this effect was put to the test and it was discovered that the increase of 1.76 [cm3] to 11.6 [cm3] of H2 in 12 hours of electrification, not only generates the electrostatic wind produced by the tips, but also polarizes the water molecules and amplifies the production of hydrogen inside an electrode.
The electrifier-gasifier equipment specifically separator, is based on previous experiences in which the combination of the proximity of the poles in direct current, the metals that compose it as stainless steel 316 TI and copper, PVC (Polyvinyl Chloride) pipes with perforations in all its contour to bring the poles closer in function of a diaphragm and at the same time prevent them from coming into contact, acrylic that performs the same function as PVC but makes it visible to the observer, stainless steel meshes and to conserve the electrical conductivity it was necessary to weld the electrical connections with silver and argon.
2.1.1 Design of the gasifier
The gasifier stores the hydrogen coming from the electrifier in relation to what it produces. First, it is pre-stored in the suction cup storage (See Figure 2), once it is full it releases the gas to the gas seal and to the gasometer.
The gasometer together with sunlight prevents the hydrogen from mixing with air or oxygen maintaining the quality of the gas. The objective of this design is used in the accumulation of molecular hydrogen to subsequently store it temporarily in a water seal.
The water seal and the suction cup storage together are a single device and are an essential part of the hydrogen plant. In Figure 3, the gas outlet system is not installed, but it is in the design.
The criteria for obtaining a hydrogen gasifier begin with the characteristics of the gas itself. The H2 molecule is the smallest found in the table of chemical elements, since it is so small, special care must be taken so that no leakage occurs, all seals must be interchangeable, it should also be taken into account the ground inclination with respect to the gasifier, Henry's law, gasifier height, container material, sealant glues, water seal effect, safety conditions (distance from switches or sparks).
2.1.2 Solar collector design
The aim of the solar collector is to heat the water with the sun, which favors the dissociation of gas from water. These collectors are made of a material called boro-silicate which is transparent and black which allows the sun's rays to enter the collecting pipe, but does not let it come out which increases the temperature quickly. It´s design is shown in Figure 4.
Care must be taken that the water does not increase its temperature beyond 90 ° C due to its evaporation, which damages the concentration of hydrogen, so in the worst case it results in hydrogen with water vapor.
To increase the collection of solar rays it is necessary to install an aluminum mesh from which the beam of light bounces off, being projected into the solar collector, as shown below.
2.1.3 Gas compressor
Equipment sought in the market to meet the needs of the pilot solar hydrogen plant. The characteristics to select it were the maximum pressure that it reaches, 200 [psi], and an average temperature of 43ºC. In relation to the Van der Waals equation, storage should be at a maximum of 90 [psi] since hydrogen performs self-ignition at 530ºC. The compresor is recycled form domestic refrigerators.
2.1.4 Hydrogen gas storage cylinder
The hydrogen gas cylinder of the solar hydrogen plant is a reinforced stainless steel cylinder capable of safely storing 250 [psi]. This cylinder is from the AGA company in its special gases division.
This cylinder is ideal for the storage and transport of pressurized hydrogen gas, which is why it is used as a fundamental part of the pilot solar hydrogen plant. This cylinder has a capacity of 10 liters of gas at atmospheric pressure and 205 liters or 100 [psi] at maximum pressure as the maximum safety pressure.
2.1.5 Electrified water output
The output water of the equipment has a high concentration of iron oxide in it, so it is necessary to store it as industrial waste.
2.2 Prototype Nº2 Cylindrical plates of 2 mm thickness and H-Cut
This equipment does not separate hydrogen from oxygen so a gas called HHO (oxyhydrogen) is obtained with it. This gas has a trace of oxygen and one of hydrogen mixed, these can be pressurized and ignite a conical flame capable of reaching a temperature of 900°C. We can see the diagram of the prototype in the Figure 5.
2.2.1 Cylindrical electrified plates
This equipment has the facility of working with photovoltaic panels as well as with common batteries used in the automotive industry and it is more focused on the production of more efficient gas in a small predesigned cylindrical space. To start operating, it needs direct current and at an amperage of 0.1 [A] the electrolysis process begins to be observed. The design of the plates are shown in Figure 6.
2.3 Prototype Nº3 Rectangular plates of 1 [mm] thickness
This equipment has an efficiency of 0.07% with respect to natural energy, which complicates the option of storing hydrogen in a pressurized gas cylinder. The advantage of this configuration and geometrical shape is the contact area of the fluids since being the same size as the previous electrolyzers, it has a contact area of 0.286 [m²]. This area is much higher than the previous more efficient equipment that had an area of contact of 0.08 m2 so it needs a higher power intensity and a lower voltage. What does improve in this design is the continuity of the fluid that enters and exits.
Figure 7 shows the constituent parts of the gas generating plate equipment. It has a rubber composed of bi-teflon that performs the task of pressure seal and separator between plates. It has a stainless steel plate and a lid that has a fluid exchange system.
The equipment built is 25% smaller than the one in the 3D diagram, this is due to lack of materials with the ideal dimensions.
2.3.1 Design of a family plant
This plant is oriented to the villages of the interior, specifically to a family composed of four members, and the objective is to implement a substitute product to the LPG used in homes, namely pressurized gaseous H2.
For the calculation of the initial investment, the sums of the investments in civil works and pieces of equipment were taken. The sum of all of them results in a total investment of US$31,000 per family of four people.
Indirectly, as the demand for hydrogen grows, the carbon footprint of those who choose this technology for their home decreases proportionally. So in the best of scenarios it is possible to raise prices due to the reduction of the carbon footprint and the sale of carbon credits by our customers.
The carbon ratio that is no longer produced is 59% of the mass of LPG gas, so 70.8 kg of coal are no longer emitted per year, evaluated in US$310 and tradable emissions of US$30.
The location of the headquarters of the company would be in the city of Calama preferentially, due to its greater proximity to the towns of the interior and its great amount of solar electromagnetic energy.
Typical housing with three rooms for a family of four inhabitants, a bathroom and parking. In the backyard there are civil works for the installation of gas generation equipment for a household (Figure 8)
Unlike previous equipment, it has a water heater and electrifier in one single container, thus improving the commercial aesthetics of the possible equipment to be installed in the altiplanic zones of the province of El Loa.
