Robert McClure has just published an article entitled ” The Forever Debate: Is Burning Wood for Electricity a Good Idea?” https://undark.org/article/woody–biomass–electricity–powerclimate/ May 3 2017.
In it he discusses the historical cycle of the debate around woody biomass as a source of power. In the end it is a very mixed article that leaves us wondering where is the biomass power industry going? My interpretation of his position is that it is not good. I don’t necessarily agree.
So much of the public information, at least here in North America, on this debate comes from politicians and academics. The press seems to rely on them for their information rather than operating companies. While a company operating these facilities is definitely going to give you a biased opinion so are politicians and academics if it suits their platform at the time. Politicians and academics are also typically the more vocal about any particular subject.
This source of information and the ability to have this put into the public forum is excellent and we need this. However, we often see a specific aspect of the overall process figure predominantly in any one of their current arguments.
- they do not require emissions monitoring on these facilities
- the numbers do not include the fuel spent in the logging and forestry operations
Etc…
Often a minor attribute of the overall argument or a number that someone has fixated on and no clear indication as to where this came from.
If the alternate is coal or petroleum based or even natural gas then my vote is for the biomass. Call it a circular carbon cycle rather than one of taking already sequestered carbon from the ground.
Comments like a 100-year carbon debt due to harvesting a tree and burning it for power generation are misleading. Yes, if you cut down a 100 year old tree and burn it and plant another tree to replace it. The recapture of the carbon in that specific tree that was just planted to replace the one harvested may take 100 years to recapture the same amount of carbon that was in the original tree. However, the carbon recapture starts immediately. What if we were to adopt Sweden’s practice where they plant 3 trees for every tree harvested? What about the infinite carbon debt of burning coal, or oil?
The reality is that the land owners and forestry companies plant more trees than anyone. They know that they rely on multiple growths to sustain their business and properties.
This question has been bounced around for the last 10 Years and if you have seen my last article on LinkedIn you know I stand on the pro side of this debate. That is the Pro side of using woody biomass as a power source but with a caveat. The caveat being that the burning of the wood is done efficiently and effectively.
Just like those land owners maintaining that resource, the consumers… the power generation facilities and biorefineries must utilize that resource to the best of their abilities as well.
The more effective the heat capture within the furnace from burning biomass the lower the emissions per unit of energy produced.
Not only does this make sense environmentally but economically as well.
Reduce the tonnage of biomass consumed per MWh or increase production by 1 gallon of ethanol or chemical per ton of feedstock then the payback is a very short term.
A reduction of 0.10 tons per MWh at a 25 MW plant at $ 25.00 per ton fuel cost can result in over $400,000 annual savings for a power facility. With a one gallon per ton increase in output from a biorefinery would potentially result a greater economic return.
What are the indicators that savings can be achieved?
For a Biomass Power or Heating facility it is:
- High O2 readings
- High CO Levels
- Unburnt wood or too much char or carbon in the ash which includes bottom ash, multiclone ash and fly ash.
- And / Or just poor production numbers.
You may believe that the process is running well but it may not be as good as it can get.
Production numbers and output can be very consistent and the facility can look like it is operating at optimum levels. However you may be throwing money away either up the stack in lost heat or in your ash in unburnt fuel. Either a case of “this is how it runs “, or “I can’t be everywhere at once ” attitude.
This is not necessarily the operators fault.
Often this is a case of asking the operator to take care of too many disparate items at once. Plus have one incident that takes their focus away for a couple of minutes or even an hour either an operational or administrative issue and they are going to set parameters to where they cause them the least amount of problems. It its not causing issues guess where the next shift is going to run things? Not necessarily at the optimum operating level. This is just human nature, its not broke so don’t fix it.
The How!
There are other options. We have developed control systems and processes that can make the operator’s job easier and the production process more efficient.
Our supervisory control system runs in conjunction with most current process control system assisting the operator by making minor adjustments to the control parameters and sustaining the system at optimum levels. Through the use of control algorithms developed specifically for the site along with nonlinear modeling and genetic algorithms our system continuously seeks the optimum levels based upon the current conditions and reactions within the process. Monitoring for unusual operational parameters and warning the operators in advance of potential upcoming issues.
Often the advance warnings are issues that the operator would not recognize until greater levels of impact to the overall operation occurs. Example would be a fuel hang up. All level indicators would remain in the green while other parameters within the furnace dependent upon the furnace configuration would indicate the lack of fuel being fed. The earlier the operator is aware of the issue the earlier he can react and rectify the situation before major impacts are experienced.
Without the early warning system the operator may not realize that he has an issue until his production starts to drop off and then he scrambles to try to figure out what is going on.
Reactions in the process can change. Variations in the fuel can cause reactions to vary and be delayed and the timing of the delay can also vary. The increased feed of wet or low quality fuel may not be seen as an increase in heat for a delay that is measured in minutes, there may even be a slight quench effect where the wet fuel is reducing the heat output from the grate. Increase the fuel feed too fast and you will have an overloaded grate and a mess. Feed it too slow and you have a longer period of lost production. When the process parameters and reactions are continuously monitored and responded to accordingly then the process runs more consistently and with increased productivity.
This process implementation starts with defining the goals of the business unit, determining where the opportunities lie and developing a team approach to the implementation and change management.
We also use a staged approach so that as our system is implemented we monitor the savings returned to the client. Until the system has paid for each stage no further payments are due.
It takes a cohesive team with proper leadership and the correct equipment to make this process work effectively. Take away any of these components and you will struggle with mediocrity.
Contact us to discuss the potential unrealized capacity your facility may have.