Choosing Steam Generator Pressure

[Basil_sa]

Hi,

I am a new engineer in my first job and have been tasked with the design of a steam generator. The company is a very small start-up so I am the only one working on this. The fuel I have available is a pyro-gas produced from the pyrolysis of bamboo powder, the details of the fuel are listed below. I am looking into a steam boiler for producing electricity, as the fuel has a high tar content hence I didn't think an IC engine would be appropriate.
There are a number of things I am clueless about, so any advice would be much appreciated. My main questions are:

1) How do I choose a pressure for the boiler to operate at? Does increasing operating pressure increase efficiency and if so why would you choose a lower pressure boiler?
2) Is it best to have a single turbine or multiple turbines? Should these turbines be condensing turbines?
3) Is the rate at which steam will be outputted by the boiler calculated by using the rate at which thermal energy is supplied to the boiler and dividing this by the latent heat of vaporisation at that temperature, or do I have to take other things into account?
4) To calculate the electrical output, do I just have to find the change in enthalpy across the turbines or is there other things I need to take into account?

Sorry about the newbie questions... thanks in advance for your help! Basil

Technical details:
mass flow of fuel = 7990 kg/hr
HHV of fuel = 20MJ/kg
Energy available from fuel = 176,728 MJ/hr
Fuel mass fractions -
H2 - 0.012
CO - 0.44
CO2 - 0.25
CH4 - 0.03
Phenol - 0.26

 

[chicopee]

First, I would contact a boiler manufacturer in the USA and pause the question to them if the type of fuel that you have can be adapted to there burners. Then they would propose a particular boiler for your application. I am favoring USA manufacturers because they will follow up on any problem that you may have with their equipment. Product liability in the USA is a big deal whereas Asian manufacturers for example would be leaving dangling with problems.

 

[Basil_sa]

Thanks for the reply, problem is the plant is being built in China so it will save heaps of money on the product and the shipping to buy a boiler made in China