What goes around comes around
By Paul Wormald, Director – Planning for Waste and Energy
Hopefully in 50 years’ time, when we have sorted the whole “waste” issue out, we will look upon the present day as a transitional stage and avoid waste production altogether.
Some things are easier said than done, though – and a number of the advanced treatment technologies that we have been seeking to deploy, at least in Britain, appear to have fallen at the final hurdle.
Anaerobic Digestion (AD), on the other hand, has been around for a very long time: anecdotal evidence suggests that a digester was operational in Bombay in the mid-nineteenth century, producing cooking fuel at a medical facility, and also that Exeter had a methane-powered street lighting system towards the end of that century.
Sir Humphry Davy determined that methane was produced by the breakdown of cattle manure, and today the water industry in the UK uses digesters to generate over 110 MW of electrical energy from human waste, whilst other non-water industry businesses produce over 35 MWe.
I recently read an article about waste from cheese manufacturing being utilised in an Anaerobic Digestion (AD) process, which made me smile as it seemed like some real success was being had in “closing the loop” and putting waste-derived gas back into the gas grid.
Waste markets abroad may be encountering issues that we have already faced, and for which we can provide some answers. Some people in India, for example, wonder why energy from waste is not more widespread there. I suspect that the general Indian household waste stream is wetter and therefore more difficult to utilise in conventional EfW, but conventional EfW, but if waste streams were better managed and segregated then a range of complementary technologies, such as AD, could probably be utilised.
Increasingly, comment is being made about the levels of air pollution in Indian and Chinese cities linked to the growth of fossil fuel usage, and this makes me pause and reflect. Unfortunately, in our pursuit of fashions, trends, and the latest gizmos, the market has responded by exporting production and also, it seems, pollution, to other countries.
The historic British reaction to air pollution was a series of public health reforms – and more recently, we have sought to decarbonise our economy in response to climate change. Unfortunately, people will segregate their own waste in this country, but give little thought to the effect that buying a new television or mobile every two years is having elsewhere in the world due to unsustainable power production for industry.
What concerns me is that cheap power and labour gives comparative advantage to other countries in production terms, so unless we pressure governments to adopt global sustainability standards, not Victorian ones, we are merely rearranging the deck chairs on the Titanic. No amount of recovery, recycling or solar panels in Britain will make any difference if we buy consumer goods from abroad manufactured using carbon-heavy power production.
It must be the case that simple, reliable waste sorting and fuel or power production technology could have a role to play in helping countries to become more sustainable. We could export common sense and the experience we have gained in this country in transitioning from landfill to a more circular economy, and help countries like India to rediscover some of the technologies, like AD, that they have been using in the past.