Since the beginning of time when humans had things they no longer needed, they either threw it to one side, buried it in a hole or burnt it. Considering the vast technological advances humankind has made in recent decades, let alone in recent centuries, why is it that not that much has changed to the way we treat waste? Compared to the progress that we have seen in computing power, medicines, telecommunications and living standards in general, why is it that much of the world still dumps its waste in a hole, waiting for it to rot and emit noxious gases? Admittedly some countries have landfills which are managed to try to capture some of the methane emissions (a 25x more potent GHG than CO2) but even the most advanced, wealthy and environmentally conscientious countries do little more than burn their residual waste to produce, by today’s standards, rather dirty electricity. The world seems to have moved on in so many other areas of life yet seems to be stuck in the past when it comes treating its waste. With so much of this so called rubbish being rich in energy it begs the question; why are we wasting our waste?
Historically speaking, the simple answer is that it didn’t matter. As long as waste was removed from the proximity of ones living area it was causing no harm - if it was out of sight it was out of mind. More progressive societies soon realised that rotting waste was damaging the environment and so open tips developed into landfills and eventually the industry adopted incineration which evolved into Energy from Waste facilities. EfW has of course become a big business and it would be wrong to suggest that it hasn’t advanced over the years with plants becoming cleaner and more efficient using only waste that has many of the recyclables removed. Yet what was originally promoted as a low carbon source of electricity, it is now clear that EfW facilities no longer fit that bill. In fact, in countries where coal is no longer used in power plants, electricity from EfW is the dirtiest on the grid. In the EU28 the average carbon intensity of electricity has been falling thanks principally to wind and solar and in 2018 it stood at 296g CO2eq/KWh. This compares with an average carbon intensity from EfW facilities of 580g CO2eq/KWh almost twice as high! What is more, even the best EfW technologies are tremendously inefficient, rarely converting more than 30% of the chemical energy in the waste into power.
Given these statistics, it is surprising that new EfW facilities are still being built. But the fact of the matter is that local authorities have had little alternative. EfWs may be inefficient and produce dirty electricity but they provide a clinical service in eliminating residual waste from our living space and for that reason they are tolerated, if not loved. Those dealing with waste – local authorities and waste management companies - are also incredibly risk averse. Long term contracts and the use of local tax payers’ money mean that adopting a step change in technology can be very difficult to justify both financially and politically, and some high profile disasters in alternative waste treatments has cemented industry’s mind-set to stick with what they know - even if it is well past its sell by date.
But the industry may soon be forced to change; competition from wind and solar generators and the threat of taxation on carbon emissions mean that the EfW business model may no longer be viable. With governments around the world committed to tackling climate change, heavy GHG emitters will increasingly be penalised; but the flip side of that coin is that those who can reduce their output are being helped by policy makers through grants, subsidies and other incentives. This opportunity should not be wasted by the managers of waste - but how can they seize it?
The petro-chemical industry has long used numerous processes to rearrange the hydrocarbon molecule to make products we actually need. The residual waste in our MSW - from plastics, paper, cardboard, wood, food and other organics - is full of carbon and hydrogen atoms which can also be rearranged to make useful products. The process of doing so may be slightly more complex than a simple distillation tower but nevertheless new systems are emerging that borrow heavily on existing technologies and can convert random waste into a consistent clean renewable fuel whilst simultaneously capturing the CO2 as part of the process.
Indeed, probably the easiest fuel to make from MSW is the simplest element of them all – hydrogen – and no subject is more topical amongst governments and industries who are falling over themselves trying to decarbonise our energy mix and build the new ‘Hydrogen Economy’.
OMNI Conversion Technologies of Canada is at the forefront of this transition with the launch of its fully integrated waste to hydrogen production unit. During the past two decades OMNI has invested over $400m in developing, testing and proving its unique gasification and plasma refining process to convert MSW into an ultra-clean syngas. From concept through to pilot plant and a full scale demonstration facility, its commitment in understanding the complexities of waste conversion is unparalleled. More recently it has joined forces with Texan EPC company KP Engineering to develop the syngas to hydrogen module. Whilst the concept is novel, the whole process has unashamedly borrowed best practices from established industry. For example, unlike other gasifiers the front end incorporates a moving grate, typically used in incineration, which gives far greater robustness in tackling truly random mixed waste. The gas clean-up and the hydrogen module all use tried and tested techniques that will be familiar to the petrochemical engineers but with modifications to suit the specification of the syngas.
The result is a process that can convert around 60% of the chemical energy in the waste into a useful product - twice that of a traditional EfW plant - whilst simultaneously capturing the CO2 for use or storage. Hydrogen from waste requires only a fifth of the electricity compared to hydrogen produced from electrolysis with the significant advantage of offering a negative carbon footprint. There are no emissions to atmosphere in the conversion of waste feedstock to syngas and even the inert materials in the waste can be used as they emerge from the process as a stable vitrified slag that can be used as a cement additive, abrasive material or aggregate.
Surely a much better solution than wasting our waste in landfills and incinerators.
Proud silver sponsors OMNI Conversion Technology will be attending Energy from Waste 2022 with senior representative Mark Redway, Managing Director UK & Norway, participating in the panel discussion 'Is hydrogen a viable path for waste to energy?'. This will be looking at the waste to hydrogen market alongside policy, commercial and technical issues.
Discover the full programme details and information on OMNI Conversion Technology's sponsorship of Energy from Waste here.