I am looking for some direction in the equations required to calculate the heat energy required to heat gas in a pipeline from 20 to 25 degrees Celsius. The reason is to calculate what the best means of heat exchange would be to surround the pipe that would allow the bio gas to heat up to a minimum of 25 degrees before it enters a dehumdifier unit. Before I get into this I first need to calculate the heat capacity required to raise the temperature of the gas internally before I look to find a means to create this heat.

For you to solve this problem, you need to know the mass flow rate of the gas and the properties of the gas. if its a biogas, I'm sure it contains methane and other gases such as hydrogen sulphide and the rest. you need this information so that you can calculate the specific heat capacity of the gas before thinking of any further calculations. You can use ASpen Hysys to obtain the value.