As an alternative energy source, hydrogen energy is considered to be a new code to solve the energy crisis and build a clean, low-carbon, safe and efficient modern energy system. The development and utilization of hydrogen energy is triggering a profound energy revolution. In the 2024 Government Work Report, the important task of "accelerating the development of frontier emerging hydrogen energy industries" was clarified.Proposed. It is predicted that by 2060, China's hydrogen energy consumption scale will reach nearly 86 million tons, and the industrial scale will reach 4.6 trillion billion yuan.

Hydrogen energy is a kind of secondary energy, which is produced by natural gas reforming, electrolysis of water, solar photosynthesis, biological hydrogen production and other energy sources, unlike coal, oil and natural gas, which can be directly mined from the ground and rely almost entirely on fossil fuels.

According to the different production methods and environmental impact, hydrogen can be divided into gray hydrogen, blue hydrogen and green hydrogen:

Ash hydrogen is hydrogen produced by direct combustion of fossil fuels (such as coal, oil, natural gas). This process is accompanied by a large amount of carbon dioxide emissions, so the carbon emission is large, but the preparation cost is low.

Blue hydrogen is also hydrogen produced using fossil fuels (mainly natural gas), but unlike gray hydrogen, blue hydrogen uses carbon capture and carbon sequestration technology in the production process, which helps reduce the carbon emission intensity, making blue hydrogen The carbon emission of hydrogen is lower than that of gray hydrogen.

Green hydrogen is completely different, it is through the use of renewable energy (such as solar energy, wind energy, water energy) to split water to produce hydrogen. In the production process, green hydrogen basically does not produce any carbon emissions, so it is considered to be the cleanest hydrogen energy source.

      Hydrogen appears in the scene of life

Industrial field: Hydrogen is an important raw material for chemical and steel industries, and can also be used in industrial processes such as oil refining, fertilizer, and metallurgy. With the requirement of carbon neutrality, hydrogen in the industrial field will gradually shift from fossil fuel production to renewable energy production to achieve low carbon.

Transportation: Hydrogen energy can be converted into power through fuel cells or hydrogen internal combustion engines to drive vehicles such as cars, buses, trucks, trains, ships, and airplanes. The advantages of hydrogen energy in the transportation field are clean and low-carbon, long cruising range, and short hydrogenation time.

Construction field: Hydrogen energy can be mixed with natural gas and transported to the building terminal through the existing natural gas pipeline network for heating, hot water, cooking, etc. Hydrogen can also provide electricity and heat to buildings through fuel cells, achieving combined heat and power, improving energy efficiency and reliability.

In the field of electricity, hydrogen energy can be used as a new form of energy storage to solve the intermittent and unstable problems of renewable energy. Hydrogen is produced by electrolysis of water and stored in the form of high-pressure gaseous, low-temperature liquid or solid materials; during peak power consumption or emergencies, the stored hydrogen is then used to generate electricity through fuel cells or hydrogen turbine devices and incorporated into the public power grid or distributed networks.

Currently more applications:

      Fuel Cell H2 Purity Test

Fuel cell is an energy conversion device. It is based on the electrochemical principle, that is, the working principle of the primary battery, and the chemical energy stored in the fuel and oxidant is directly converted into electrical energy isothermally. Therefore, the actual process is a redox reaction. In the practical application process, it is necessary to monitor the purity of H2 participating in the reaction to ensure the smooth progress of the reaction. We offer sensors with model number MTCS2601.

Description:

The MTCS2601 sensor consists of a micromachined thermal conductivity sensor with four Ni-Pt resistors implemented in MEMS technology. The sensor is mounted in a micro SMD package and is available in tape or tray packs. This MEMS TC sensor, combined with a simple low-power CMOS standard integrated circuit, is ideal for OEM gas detector applications that require ultra-low power, long service life and no maintenance. The device can measure the concentration of a gas in a mixture of two or three gases or a quasi-binary mixture in air, such as carbon dioxide, argon or freon in air, or gases with higher thermal conductivity, such as hydrogen, helium or methane.

Features:

1. 1. MEMS physical sensing principle is stable and reliable, no chemical reaction, based on thermal conductivity changes

2. 2. The range is 100 ppm to 100%, depending on the application and the thermal conductivity of the gas

3. 3. No chemical reaction, the linear signal that the concentration has no hysteresis

4. 4. Match the compensation with the heating resistor on the same silicon chip Excellent temperature compensation.

5. 5. Sensor volume is small to <0.1 cm3

6. 6. The physical resistance sensing principle works, the sensor is durable and the mean time between failures (MTBF) is long, and can withstand high-intensity shocks (>1000G)

7. 7. MEMS-based silicon sensors have large integrated resistance (such as 250 ohms) and low heating quality, so the working power consumption of the sensor is extremely low (<8mw)

8. 8. Fast response speed, large electronic bandwidth, short response time to <50 ms

      H2 Transport, Storage, In-Application Leak Detection

The hydrogen atom (H) is the lightest atom in the world. Commonly referred to as hydrogen is a gaseous hydrogen molecule (H2) formed by the combination of two hydrogen atoms. Because it is very small, it is easy to leak and spread, and colorless and tasteless, it is difficult to detect its leakage or not.

The explosive concentration range is wide, the lower explosive limit is 4.0vol%, and the upper explosive limit is 75.6vol%. The explosive range is four times that of ordinary flammable gases (methane, propane, isobutane), so hydrogen is very dangerous.

Industrial sites generally require an alarm signal when the gas reaches a certain content in the air. The low report generally requires 5% LEL ~ 25% LEL. If there is a high report, it is set at 50% LEL. (It is stated in 4.3.1.8 in the GB15322.1-2019 that 100%LEL of hydrogen corresponds to 4% vol).

There is another standard for the hydrogen generator, which requires an alarm signal when the hydrogen content in the air reaches 0.4 vol, and a shutdown when the hydrogen content reaches 1.6 vol. (GB/T31138-2022 6.4.9 has instructions)

Therefore, the alarm requirement for H2 leakage must be at least 4000PPM before the alarm!!!

In the whole process of using H2, the following sensors need to be added to detect and warn H2 leakage in a timely and effective manner to avoid safety accidents. For H2 leakage, we can provide a concentration detection scheme from several hundred ppm to tens of thousands ppm, and the following TGS6812 TGS2616 H2-BF can be realized.

     catalytic combustion TGS6812

Principle: The catalytic combustion type gas sensor is composed of two elements: a detection piece (D) that reacts with combustible gas and a compensation piece (C) that does not react with combustible gas. If a combustible gas is present, only the detection piece can be burned, so that the resistance of the detection piece is increased by the temperature rise of the detection piece.
On the contrary, because the compensation plate does not burn, its resistance does not change (Figure 1). These components form the Wheatstone bridge circuit (Figure 2). In an atmosphere where there is no combustible gas, the variable resistance (VR) can be adjusted to make the bridge circuit in a balanced state.
Then, when the gas sensor is exposed to the combustible gas, only the resistance of the detection plate rises, so that the balance of the bridge circuit is broken, and this change appears as an unbalanced voltage (Vout) and can be detected. Since the imbalance voltage and the gas concentration have a proportional relationship as shown in FIG. 3, the gas concentration can be detected by measuring the voltage.

TGS6812-D00 is a catalytic combustion type gas sensor, which can detect hydrogen at 100%LEL level. This sensor has the characteristics of high accuracy, good durability and stability, fast response and linear output. It can not only monitor hydrogen, but also detect methane and LP gas. This is an excellent solution for leak detection when a stationary fuel cell uses hydrogen as a combustible gas.

The cap of the TGS6812-D00 has an adsorbent and has very low cross sensitivity to organic vapors. In addition, the sensor is more resistant to silicon compounds and is more adaptable to harsh environments.

Features:

Linear output

Long service life

Low sensitivity to alcohol

High sensitivity to hydrogen, methane and LP

      Semiconductor TGS2616

Principle: When tin oxide particles are exposed to oxygen at a temperature of several hundred degrees, the oxygen captures electrons in the particles and then adsorbs on the surface of the particles. As a result, an electron depletion layer is formed in the tin oxide particles. Since the tin oxide particles used in the gas sensor are generally very small, the entire particles will enter the state of the electron depletion layer in the air. This state is called volume depletion. On the contrary, a state in which the center part of the particle fails to reach the depletion layer is called domain failure (regional depletion). When the oxygen partial pressure rises from zero (flat band) in the order of small ([O-](I))→ medium ([O-](II))→ large ([O-](III)), the changes in the band structure and electron conduction distribution are shown in the following figure ([O-]: adsorbed oxygen concentration). In the capacity depletion (volume depletion) state, the thickness change of the electron depletion layer ends, resulting in the Fermi level conversion pkT, the electron depletion state advances to the pkT increases, and the pkT decreases.

TGS2616-C00 gas sensors for detecting hydrogen

The TGS2616-C01 contains a newly developed sensitive element, which is very little affected by interference gases such as alcohol, and has a high selectivity to hydrogen.

Features:

High selectivity to hydrogen

Small size, low power consumption

Simple application circuit

      electrochemical H2-BF

Principle: hydrogen and oxygen in the working electrode and the corresponding oxidation-reduction reaction on the counter electrode and the release of charge to form a current, the resulting current size and hydrogen concentration is proportional to the size of the test current can determine the level of hydrogen concentration.

Features: low power consumption, high precision, high sensitivity, wide linear range, strong anti-interference ability, excellent repeatability and stability.

      Comparison of sensors with different principles

In the future, sensors for detecting low concentrations of oxygen in high concentrations of H2 will be developed, and this technical challenge will be realized in the near future.