Please read the document: https://www.epa.gov/.../documents/stationaryemissions_3_2016.

I think that the question is incomplete as there must be some quantification or a measurable quantity for the comparison to be held. Like what concentration of biomass compared to how many kilograms of coal?

As you know, coal is a compressed forest (compressed by nature) containing far more carbon, sulphur, etc than (uncompressed) biomass. Therefore, coal is far more deadly, unless emissions are extracted and not released onto the air (but this process is costly).

Sir, Jorge Morales pedraza, I tried checking the page but got this always: https://www.epa.gov/home/page-not-found. May be you can help  mewith the correct link, Dr Nabeel, quantity of biomass required for any coal-based operation will definitely be more than coal but assume we target equal output like say in terms of Electricity generation (an equal MWh), will biomass still be deadlier in terms of its GHG emissions? Sir Micheal, does compression cause sequestered C, S and other deleterious elements in coal to be deadlier than biomass? 

Burning biomass emits more CO2 than fossil fuels per megawatt energy generated:

  1. Wood inherently emits more carbon per Btu than other fuels

Natural gas: 117.8 lb CO2/mmbtu

Bituminous coal: 205.3 lb CO2/mmbtu

Wood: 213 lb CO2/mmbtu (bone dry)

 2.  Wood is often wet and dirty, which degrades heating value Typical moisture content of wood is 45 – 50%, which means its btu content per pound is about half that of bone dry wood. Before “useful” energy can be derived from burning wood, some of the wood’s btu’s are required to evaporate all that water.

3.  Biomass boilers operate less efficiently than fossil fuel boilers (data from air plant permit reviews and the Energy Information Administration)

Utility-scale biomass boiler: 24%

Average efficiency US coal fleet: 33%

Average gas plant: 43%

http://www.pfpi.net/carbon-emissions

This is the title of the document: Direct Emissions from Stationary Combustion Sources

I think the question as presented is unanswarabel. What scenario are we assuming here? Home heating?  Transportation? Electricity production?

Different uses will give different numbers. At least for transportation biomass based biofuels seem to emit much less then gasoline under most scenarios.

Thanks Sir Jorge Morales, the pdf is much informing even though I have read other argument giving higher figures to coal emissions than biomass. Yoram Mam, please can you help with some figures or publication for that claim and properbaly with different areas of applications

. Thanks to all for your contributions

Read this report.

www.aol.co.uk/.../burning-of-woody-biomass-more-harmful-than-coal-says-report/

Depends on if you count the carbon in Biomass as having been fixed from atmosphere and that will be replaced in carbon cycle and therefore less harmful. Emissions from coal will not re-enter the earth in the same way as before as most of the conditions for its formation in bulk no longer exist - in particular the evolution of fungi mean carbon sequestration is greatly reduced compared to carboniferous era when decay was much slower so fallen trees would be buried..

In UK our main coal stations converted to burn wood chips from USA forests - hard to see this as anything other than a big scam, on carbon accounting and financial accounting bases. But allowed last Friday to be declared first day for 150 years that UK burned no coal for power generation.

I have a wood burner at home (in rural Sussex, UK), with controlled slow burn of logs. Heats house in winter, fuel is from the surrounding woodlands which I manage sustainably. However the smoke, creosote and soot emissions from this are pretty bad. if in a city would be unacceptable.  A small scale such unregulated combustion is ok but if everybody heated this way it would be a major problem.

What do you mean with GHGs are deadly?

They give climate change or rather an increase in the temperature of the globe