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  • As inventions go, the Haber-Bosch process might be the most important for human survival.

  • It enabled mass production of nitrogen fertilizers,

  • which help our farms produce more than ever before.

  • "The object is to produce an early crop maturity and consequently more grain volume.”

  • Food is more affordable and billions of us have avoided starvation.

  • It’s been so instrumental to the existence of our species, it’s estimated half the

  • nitrogen in our bodies is made synthetically.

  • Around the beginning of the 19th century populations started to grow faster thanks

  • to the Industrial Revolution.

  • But it was hard to grow enough food.

  • Harvests are unpredictable and could take months to renew for the next planting.

  • It became clear to scientists that nitrogen was a key ingredient for growing crops.

  • In nature, when plants die the nitrogen they contain returns to the soil

  • and new ones grow using it.

  • But agriculture disrupts that cycle.

  • So farmers started using manure and compost which contain nitrogen.

  • But it was never enough.

  • By the mid 19th century the superpowers of the time went to extraordinary lengths to

  • get better fertilizer.

  • Hundreds of British, German and American ships travelled to islands off the coast of Peru,

  • to load up on bird droppings.

  • Guano has high nitrogen content.

  • So thousands of tonnes of the stuff were mined and shipped across the Atlantic.

  • But it ran out.

  • Luckily for the men mining it, something more plentiful and nitrogen-rich would come along.

  • In 1909 German chemist Fritz Haber managed something that had eluded scientists for decades.

  • He synthesized ammonia from nitrogen gas.

  • Even though 78% of air is nitrogen turning it into useful ammonia fertilizer

  • is extremely difficult.

  • Nitrogen doesn’t exist as a single atom, it exists in a largely unreactive form - as

  • two atoms coupled together with triple bonds - the strongest in nature.

  • Simply put, it’s incredibly hard to break down.

  • It happens naturally, but it’s rare - either by lightning pulsing through the air - or

  • bacteria slowly eating away at rotting vegetation in the earth.

  • Haber initially tried to mimic a thunderstorm to produce nitric acid

  • but he only got small amounts.

  • So he began to work with high temperature and high pressure.

  • Germany’s largest chemical company BASF had engineer Carl Bosch help Haber turn it

  • from a lab experiment into a commercial process.

  • The team had to invent much of their equipment to handle the extreme conditions and worked

  • in a concrete chamber away from other workers due to frequent explosions.

  • When completed, the Haber-Bosch machine stood nearly 8 metres tall and produced 90 kilos

  • of ammonia per hour.

  • But it wasn’t used to create fertilizer.

  • Not initially, anyway.

  • By 1914 the world was at war.

  • Germany was struggling to manufacture explosives due to shortages of nitric acid.

  • A proud patriot, Fritz Haber became involved in the war effort

  • and began to produce poison gas.

  • In 1915 chlorine and mustard gas at the Battle of Ypres would kill tens of thousands of troops,

  • Haber reportedly watched the field of battle as the gas was released on allied troops.

  • Haber’s wife Clara Immerwahr, a prominent chemist in her own right, was sickened by

  • his involvement and would commit suicide by shooting herself with Haber's army pistol.

  • Despite effectively becoming the father of chemical warfare, Fritz Haber’s achievements

  • in synthesizing ammonia would lead to the award of a Nobel prize.

  • Together with advances in breeding, synthetic nitrogen fertilizers more than tripled average

  • US wheat yields during the 20th Century.

  • The planet’s human population exploded from 1.6 billion in 1900 to nearly 8 billion today

  • as it became easier for people to secure food.

  • As fertilizer use ramped up after the Second World War, population growth accelerated.

  • It wasn’t just human life the Haber Bosch process supported, billions more animals were

  • farmed to satisfy human consumption.

  • Of course there is a price to pay.

  • A huge strain is placed on the environment by the number of mouths to feed.

  • A lot of the nitrogen in fertilizer fails to make it into the food chain

  • and pollutes our water.

  • So as our population continues to grow and the more we rely on the Haber-Bosch process,

  • the more nitrogen will leach into the environment.

  • That is unless we choose to reduce our meat-heavy diets.

  • It also takes a lot of energy to make ammonia out of nitrogen.

  • The Haber-Bosch process burns 3 percent of globally-produced natural gas and releases

  • another 3% of carbon emissions,

  • so it isn’t a guilt-free miracle.

  • With almost every meal that we eat, we benefit from the Haber Bosch process - providing the

  • world with easy and affordable access to nitrogen.

  • If crop yields remained at 1900 levels, we would need four times more land to farm on.

  • That’s nearly half of all ice-free continents, rather than the 15% it is today.

As inventions go, the Haber-Bosch process might be the most important for human survival.

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    林宜悉 posted on 2020/03/07
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