Question

What is the most important method for the industrial production of hydrogen? Write balanced equations for the reactions involved.

Short answer

The most important industrial method for hydrogen is steam methane reforming, involving reactions: 1) \(\text{CH}_4 + \text{H}_2\text{O} \rightarrow \text{CO} + 3\text{H}_2\); 2) \(\text{CO} + \text{H}_2\text{O} \rightarrow \text{CO}_2 + \text{H}_2\).

Step-by-step solution

Identify the Industrial Method

The most important method for the industrial production of hydrogen is steam methane reforming (SMR). This process uses natural gas, primarily methane, as a feedstock to produce hydrogen.

Write the Initial Reaction Equation

In steam methane reforming, methane reacts with steam under high pressure and temperature to produce hydrogen and carbon monoxide. The chemical equation for this reaction is: \[ \text{CH}_4 + \text{H}_2\text{O} \rightarrow \text{CO} + 3\text{H}_2 \]

Convert Carbon Monoxide to Carbon Dioxide

The carbon monoxide produced in the initial reaction is further reacted with steam in a process known as the water-gas shift reaction, producing more hydrogen and converting carbon monoxide into carbon dioxide. The equation is: \[ \text{CO} + \text{H}_2\text{O} \rightarrow \text{CO}_2 + \text{H}_2 \]

Combine Overall Equations

Combining the two equations from steam methane reforming and the water-gas shift reaction gives the overall chemical process: \[ \text{CH}_4 + 2\text{H}_2\text{O} \rightarrow \text{CO}_2 + 4\text{H}_2 \] This is the overall balanced equation for the industrial production of hydrogen via steam methane reforming.

Key concepts

Industrial Production of Hydrogen

Hydrogen is an essential gas used in many industrial applications. Its clean and efficient energy properties make it especially valuable. One of the primary methods for producing hydrogen on an industrial scale is Steam Methane Reforming (SMR). This process is cost-effective and highly efficient.
In SMR, natural gas, which is mainly composed of methane (CH}_4), is used as the starting material. Methane reacts with water vapor (steam) under high temperatures and pressures. This reaction breaks down methane molecules to free up hydrogen.
During the initial step of the SMR process, methane reacts with steam to form carbon monoxide (CO) and hydrogen (H}_2). This reaction can be represented by the following equation: \[ \text{CH}_4 + \text{H}_2\text{O} \rightarrow \text{CO} + 3\text{H}_2\]This method is widely used due to an abundance of natural gas and the relatively straightforward operation of the process.

Balanced Chemical Equations

Chemical reactions are best understood through balanced equations. These equations show the relationship between the reactants and products based on the conservation of mass. In the context of steam methane reforming (SMR), it's crucial to balance the equations to illustrate how substances change during the reaction.
Initially, methane reacts with water, yielding three hydrogen molecules and one carbon monoxide molecule. To ensure both sides of the reaction are balanced, make sure the number of each type of atom is the same: \[ \text{CH}_4 + \text{H}_2\text{O} \rightarrow \text{CO} + 3\text{H}_2\]Afterward, the carbon monoxide produced undergoes further reaction in the water-gas shift stage. This balance is maintained by converting carbon monoxide into carbon dioxide, while producing additional hydrogen: \[ \text{CO} + \text{H}_2\text{O} \rightarrow \text{CO}_2 + \text{H}_2\]The overall balanced chemical equation for the entire process is critical for understanding the complete hydrogen production cycle: \[ \text{CH}_4 + 2\text{H}_2\text{O} \rightarrow \text{CO}_2 + 4\text{H}_2\]Learning how to balance chemical equations is a crucial skill for visualizing these transformations and verifying their accuracy.

Water-Gas Shift Reaction

The water-gas shift reaction is an essential part of the hydrogen production process through steam methane reforming (SMR). After the initial reaction where methane and steam produce hydrogen and carbon monoxide, the latter undergoes further transformation.
In the water-gas shift stage, carbon monoxide (CO) reacts with more water (H}_2O) to yield carbon dioxide (CO}_2) and additional hydrogen (H}_2). This can be represented by the balanced equation: \[ \text{CO} + \text{H}_2\text{O} \rightarrow \text{CO}_2 + \text{H}_2\]This reaction is crucial because it not only increases the amount of hydrogen produced but also reduces carbon monoxide levels.
Carbon monoxide removal is important due to its toxic nature and the need to minimize emissions. Producing more hydrogen from the same starting materials showcases the efficiency of this reaction. This step is a fine example of utilizing chemical reactions to achieve maximum production efficiency and environmental compliance in industrial settings.