No, it’s not something out of the next series of Doctor Who. Biomass originates from living, or recently living organisms. It is thus a biological material and when talking about biomass in terms of energy, it usually means vegetable material, although biomass strictly can mean animal material as well.

And for you chemists out there, it is carbon based and is made up of organic molecules which contain hydrogen, usually including oxygen and nitrogen. Other atoms are also present and these might include heavy metals, alkaline earth and alkali.

The carbon that it used to build biomass comes from the atmosphere by plants absorbing carbon dioxide (CO2), deriving the necessary energy from the sun.

Now biomass has a number of fates. It might be eaten by animals, when it becomes animal biomass, or it might be eaten by micro-organisms and released back into the atmosphere as CO2, or methane. If it is burned, it’s released straight back into the atmosphere as CO2.

All these processes have been occurring since the start of the earth and it is called the carbon cycle.

Now, to understand the difference between biomass fuels and fossil fuels, is to understand that the biomass process will have happened recently. The plant will have absorbed the carbon dioxide as it grows and will then release it as it burns, creating what’s known as a closed carbon cycle.

The problem with fossil fuels (oil, coal and gas) which is also made up of biological material, is that the carbon was captured in these materials many millions of years ago and basically represents a store of harmful CO2 which, ideally, should not be released up into the atmosphere.

Biomass crops can therefore be regarded as a sustainable source of fuel, constantly absorbing and then releasing carbon in a replenishing cycle.

Okay, all good so far. But the problem is that creating enough sustainable biomass crops requires a huge change in the human mindset. In the human view, mining a provable fuel source such as oil, is a far simpler and more economic solution to satisfying the worlds energy needs.

So, people need to think a little harder and embrace the numerous sources of sustainable biomass fuels that already exist.

And for convenience, it has been established that biomass fuels originate from around five different sources.

Firstly, energy crops, which include high yielding crops which are grown specifically for fuel. Secondly, food waste, which is in abundance and mainly comes from consumer waste. Thirdly, virgin wood which can be sustainably harvested from a number of activities. Fourthly, products from industrial processes, such as manufacturing. And finally, the fifth source, agricultural residues which arrive from the normal process of agriculture and the harvesting of crops.

So, it’s hurray for biomass crops and boo for fossil fuels. The big question is, will the human population be able to make the switch from relying on fossil fuels, to harnessing the full potential of biomass fuels. And indeed, is there enough biomass for us to wean ourselves completely off fossil fuels.

Of course, only time will tell.

Biomass Worries

There are however, safety concerns over new biomass boilers which are preventing their use in Edinburgh schools, despite their promotion by the Scottish Government.

Biomass fuel is regarded as a sustainable source of fuel, constantly absorbing and releasing carbon in a replenishing cycle. They are far better for the environment than fossil fuels. But new fears have been raised over the production of particulates in the emissions from biomass boilers. And these particulates have worried scientists who think they may cause people breathing problems, especially children.

So new biomass boiler systems destined for seven Edinburgh schools have been put on hold whilst further reports are studied.

But Scottish Government scientists are adamant the new biomass boilers are safe, as long as they are used together with technology that removes any particulates from the emissions. This depends on filters and the correct type of chimneys being installed.

Thus a stalemate has been reached between the council chiefs of the authority where the schools are situated and the Scottish Government. But cynics have pointed out that the decision to install the boilers is actually down to worries over costs and that health screens are a convenient excuse to delay the project.

Supporters of the biomass boilers point that it has always been known their installation has depended on emission cleaning technology which ensures their safety.

Biomass Boilers May Not Be The Answer

As many companies and householders consider the option of an eco-friendly biomass boiler, the Environmental Agency has warned they could actually be harmful to the environment.

But it’s not so much the process of burning wood and similar fuels that is the problem. It comes down to the planting and growing of the biomass crops in the first place. The main issue centred on the fact that the ploughing up of pasture for the energy crops would create more CO2 than their actual use would save.

The report, called ‘Biomass: Carbon Sink or Carbon Sinner’ also stated the gas emissions from different types of biomass fuels varied enormously. Some of the best fuels represented a huge advance over say coal, producing 98% less emissions of CO2 per megawatt hour. But other biomass fuels faired less well; some even worse than fossil fuels.

Waste wood and MDF were some of the best performers; oil seed rape, poplar and willow, not so good.

And the report called on producers to take into account the effect of emissions from all stages of the process, from ploughing to growing, to cropping and use; not just the final stage, in order to get an accurate picture.

With the popularity of biomass boilers increasing daily, there are also worries about the sustainability of the fuel source. The agency further warned that by 2030, the production of biomass fuels will have to be as efficient and as low in emissions as possible, otherwise the good work achieved will have been wasted.

It reiterated the fact biomass fuels are a limited resource and their use should not be wasted without thought for the future.

Guest Article by Neil Camp