Since our community meeting with Creatively United for the Planet and other community groups concerned with the CRD’s proposed massive landfill expansion plan at Hartland Landfill (and announced agreement in principle with FortisBC which financially motivates CRD to continue to dump garbage into the ground), we have received many questions about gasification and its merits. This is exciting – it is promising to see so many in our region engaging in this important conversation about how to better manage our waste while directly addressing climate action.
The following has been put together with the help of Creatively United and Graeme Bethell, Pivotal IRM Ltd. – Graeme has a Master’s Degree in Combustion Engineering and Atmospheric Chemistry, Leeds University, England.
Q. Shouldn’t we focus on upstream and upcycling strategies, such as reuse/repair/sharing, upcycling, recycling, composting and reducing consumption of new materials?
A. Yes, gasification addresses recycling, composting (better than) and should be a component of any waste management plan going forward.
First off, gasification does not burn (or incinerate) the waste as there is no oxygen in the process. Simply put, if there is no air (or oxygen) there cannot be a fire to burn the waste. Incinerators that can burn waste need lots and lots of oxygen to keep the fire burning. Gasification is NOT incineration!
Gasification can be thought of as a manufacturing process where waste materials (including plastics) are heated to a high temperature with only steam and the molecules in the solid waste are pulled apart and undergo a series of specific chemical reactions to make simple gases comprised of hydrogen, carbon monoxide, methane and carbon dioxide. This gas mixture is called Synthesis Gas (or syngas) which can be burned just like natural gas. In a gasification system the syngas is burned in a specialized combustion chamber called a “thermal oxidizer” and the emissions are treated to remove possible contaminants so that none is released into the atmosphere. This is what makes gasification such a good technology for recovering resources from waste.
In addition, the production of complex hydrocarbon contaminants (such as dioxins-furans) found in incineration cannot even form in the gasification process because there is no oxygen and because the temperature of the gasifier is lower than what is required for the atmospheric complex hydrocarbon contaminants to be formed in the first place. The temperature and duration of combustion in the thermal oxidizer is far above the point at which they are destroyed.
Q. From a circular economy perspective, gasification does not appear to utilize material streams at their highest value. Does it not perpetuate the make waste model?
A. Based in CRD analysis of waste it is 77% organic (paper, food scraps, wood, fabrics etc), plastics and other non-organic material represents only 11% (and the Ministry of Energy Mines and Petroleum Resources has approved energy from waste as a renewable energy because of the small percentage and difficulty of separating composite materials). Based on this and in regards to a circular economy perspective – gasification is possibly the most uniquely environmentally friendly technology available to support a circular economy.
First, it only uses residual wastes after all recycling has been accomplished, plus it can improve recycling by separating recyclables before gasification.
Second, in addition to recovering energy from the residual wastes we also produce biochar which can return carbon to the soil in the form of biochar sequestering carbon for up to 1000 years vs compost material which stimulates this carbon directly back into the active carbon cycle.
Third, gasifiers can be scaled down to small communities giving it wide application to all communities in BC and across Canada.
Q. What about the gases produced and energy involved in the process?
A. Gasification systems are always two stage processes – the first is gasification and the second is combustion. In the gasification stage there is no air emissions. The air emissions are produced during the thermal oxidation stage which has integrated air emissions treatment systems to remove contaminants to levels equivalent to burning natural gas to heat one’s home. CO2 produced is about 1% of the amount if it were landfilled.
The toxicity associated with biochar is predominantly associated with heavy metals imbedded in the waste material. These are determined before uses are determined. These metals are strongly bonded to the carbon and are not known to leach out. Obviously, biochar that is highly contaminated with heavy metals cannot be used on agricultural and food soils (we have standards for this) but it can be sequestered away in things like concrete or safely stored for future refining. There are solutions to make this sustainable.
Q. If the source of landfill emissions is decomposing organics – plastics are relatively stable long term – and wet organics are difficult to process with gasification, isn’t gasification better suited to plastics which were stable in the landfill? However, wouldn’t emissions go up dramatically from both the organics and plastics released by burning the syngas?
A. Correct, plastics all convert to energy and wet organics are first dried and then gasified to produce energy and biochar. The argument still stands – gasification is a great approach to lowering landfill emissions. As stated the amount of CO2 released from gasification is about 1% of what a landfill would release.
Q. Wouldn’t a move to this waste to energy gasification system serve to perpetuate the underlying problem – that we generate waste in the first place (and too much of it)? The way to deal with materials that cannot be easily reused/recycled indefinitely is to not produce them in the first place – studies have shown that when materials are designed for reuse/recycling the costs can be one third for the re-processing and can be done without the environmental hazards associated with many of the current materials.
A. This is what we all who work in environmental protection want, but it’s idealistic too. Economics will drive how products are packaged for transportation around the world and subsequently the waste that is produced. If anything, history tells us it will not go away. Can we do a better job at packaging, yes I think so but this doesn’t negate a technology like gasification.
Q. Gasification requires a substantial cash investment that could be spent funding other initiatives, for example: local entrepreneurs to develop zero waste ventures – designing better, locally made products; repurposing and salvaging materials; supporting reuse and repair; etc.
A. Gasification, if implemented properly, pays for itself from the recovered resources! All of the things suggested can also be done, creating a win/win.
Q. The hazards of gasification need to be weighed against the benefits. Is there any literature about this?
A. See Esquimalt project documents at www.esquimalt.ca/IRM
Q. Europe has been testing gasification, but don’t they have limited experience with it?
A. They have limited experience with Municipal Solid Waste (MSW), but extensive experience with gasification using agricultural and forestry wastes only because all of the solid waste was contracted to large municipal incinerators for 40-50 years following the Kyoto Protocol signing in the early 1990’s.
Many countries in Europe built their waste incinerators as a measure to lower GHG emissions from coal-fired power production – many European countries are now zero waste and they all thermally convert wastes to lower GHG emissions!
Q. Currently, it sounds like the syngas produced in Europe is typically burned onsite as it is typically too contaminated to use as a feedstock for material production (and is too expensive to clean it to make it an ideal feedstock). Whether we make fuels directly from hydrocarbons out of the ground or from plastics that were derived from hydrocarbons from the ground – aren’t we taking hydrocarbons out of the ground and releasing it to the atmosphere?
A. Only for a maximum of 11% of the material gasified in the capital region! Economics is going to be the most significant driver for a zero waste society and converting waste residuals to energy is viable under the current economic conditions and will improve if the price of carbon increases to $50/tonne and upward. Gasification is something concrete that can be done today to reduce ghg’s which can then be improved upon as better approaches are developed.