GreenBizCafe Talking about all the changes happening in the world from a small business person's point of view Thu, 24 Oct 2019 21:46:35 +0000 en-US hourly 1 122688027 Feeding the World without Destroying the Environment Thu, 19 Sep 2019 06:27:41 +0000   Read more »]]> Worldwide, one in nine people are undernourished. More than 30 million children under the age of five are dangerously underweight and poor nutrition is responsible for the deaths of nearly 3.1 million children under five each year.

Researchers at the International Institute for Applied Systems Analysis together with the Ritsumeikan University and the National Institute for Environmental Studies in Japan have explored different ways to end hunger.

One option is a general increase in food production associated with sustained economic growth. This would lead, not only to a reduction in the prevalence of undernourishment but also to an increase in over-consumption. Many decades of economic growth would be necessary to achieve the required 20% or more growth in food production. It would require 48 million hectares of additional agricultural land and would increase greenhouse gas emissions by 550 million tonnes of carbon dioxide a year in 2030.

An alternative strategy is to introduce policies focused on bridging the nutrition gap of the undernourished population. This could be done, without the need to wait for economic growth, through targeted government support. Such a strategy would include food and nutrition programs that provide school-feeding programs, vouchers for food, income support programs and safety-nets.

A third strategy is to focus on producing more food for the undernourished only. Eradicating hunger by 2030, would mean providing sufficient food for an additional 410 million people who would otherwise remain undernourished under a business as usual scenario. The additional global agricultural production necessary to achieve this would only be 3%, with corresponding limited negative effects on the environment.

The researchers concluded that undernourishment is not a problem of agricultural production capacity but of the current economic and political system and that, if equity of food distribution is accompanied by a reduction in over-consumption and food waste, undernutrition could be eradicated while at the same time reducing agricultural production. So, to end hunger without pressuring the environment, we need not only policies that address hunger but also policies related to food waste and over-consumption.

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Microbes Take CO2 from Air to Make Plastic or Petrol Fri, 09 Aug 2019 04:01:34 +0000   Read more »]]> University of Colorado, Boulder researchers have developed nanobio-hybrid organisms capable of taking carbon dioxide from the air and converting it into products such as biodegradable plastic, petrol, ammonia and biodiesel.

The researchers used light-activated quantum dots, which are tiny semiconductors similar to those used in television sets, to activate particular enzymes within microbial cells.

Specially-tailored quantum dots were fired into the cells of common microbial species found in soil. After this, exposure to even small amounts of indirect sunlight activated the microbes’ CO2 appetite, without the need for any source of energy or food to carry out the biochemical conversions.

Different combinations of dots and light produce different products. For example, green wavelengths cause the bacteria to consume CO2 and nitrogen to produce ammonia while red wavelengths make the microbes consume CO2 to produce plastic. The microbes lie dormant in water and release their resulting product to the surface, where it can be skimmed off and harvested for manufacturing.

The researchers believe that the process will be able to operate at scale. They found that, even when the microbial factories were activated consistently for hours at a time, they showed few signs of exhaustion or depletion. But they acknowledge that they are “just getting started with the synthetic applications”.

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Geothermal Battery Could Supply Uninterrupted Electricity Wed, 17 Jul 2019 06:31:01 +0000   Read more »]]> Scientists at the Tokyo Institute of Technology and Sanoh Industrial have developed a very stable battery cell that can directly convert geothermal heat into electricity.

Currently electricity is generated from geothermal systems using water heated by hot rocks a few kilometers below the Earth’s surface. Hot water is either pumped to the surface or water is pumped down, heated and pumped back up. The heat is used to produce steam to drive a turbine. Such systems need high temperatures, over 180°C, to work

The Japanese researchers have made a battery of sensitized thermal cells which are able to generate electricity from heat at temperatures below 100°C without needing any water or steam.

The battery made up of three layers of material sandwiched between two electrodes – an electron transport layer, a semiconducting layer of germanium and a solid electrolyte layer that transports copper ions.

The battery is designed to be buried in the relatively low temperature hot ground such as exist in vast areas of Australia and the United States. The heat excites the electrons in the semiconductor, causing them to move to the electron transport layer which passes them, via the electrode, through an external circuit and eventually back to the other electrode and into the electrolyte. In the electrolyte, oxidation and reduction reactions carry the low-energy electrons back into the semiconductor, starting the cycle over again.

Eventually, the cycle stops working because different types of ions end up in different places. But the researchers have found that turning on an external circuit recharges the battery – meaning that it can supply power “semi-permanently”.

The system still needs further refinement but it has the potential to supply electricity without burning fossil fuels and without the interruptions experienced with solar or wind power.

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“Game-changing” Desalination Method Sun, 16 Jun 2019 05:32:50 +0000   Read more »]]> Researchers from Columbia University believe they’ve found a way to quickly and easily desalinate water.

The process, called Temperature Swing Solvent Extraction, is designed to purify hypersaline brines (water that contains a high concentration of salts up to seven times as salty as seawater). This kind of waste water is produced by industrial processes and poses a major pollution risk to groundwater.

As is shown in the video below, the research team mixed a solvent (dyed red) in with a sample of hypersaline brine (dyed blue). The liquids appear to stay separated in the jar, but after heating and then decanting the red solvent into another jar to be heated separately, the team is left with a layer of clear water.

The team was able to remove up to 98.4% of the salt, which is comparable to the current “gold standard” process, reverse osmosis. But unlike reverse osmosis or other methods of desalination, this process doesn’t require high temperatures or high pressures – just a low-grade heat of less than 70ºC.

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Refrigeration without Greenhouse Gases Thu, 16 May 2019 23:58:29 +0000   Read more »]]> An international team of scientists, led by Bing Li from the Chinese Academy of Sciences, has reported that they have discovered that crystals of a plastic, called neopentyl glycol, have the potential to replace harmful greenhouse gas refrigerants in refrigerators, air conditioners, computer cooling systems and the like.

Between 25 and 30% of the world’s electricity is used for cooling. It is estimated that one kilogram of the refrigerants currently in use contribute as much to the greenhouse effect as two tonnes of carbon dioxide. These gases are released to the atmosphere when the refrigerator or air conditioner is disposed of.

The newly discovered crystal works in a similar way to the gas cooling system used in current refrigerators but does so at the atomic level. Instead of using pressure to change the refrigerant from a gas to a liquid, releasing heat, pressure is used to change the structure of the crystal.

Normally, the atoms of the crystal spin randomly around points within a lattice. Under pressure, the atoms become highly ordered and line up in a crystalline structure. When the pressure is removed, the structure reverts back to the random state, releasing heat.

The cooling performance to comparable to using a gas refrigerant. The plastic crystals can be made cheaply and are able to endure a large number of cooling cycles.

The technology has been demonstrated in the laboratory. The next stage is to develop it for practical use.

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Solar Panel Produces Hydrogen from Air Tue, 16 Apr 2019 06:15:39 +0000   Read more »]]> Researchers at Katholieke Universiteit Leuven in Belgium say that they have developed a solar panel that converts sunlight directly into hydrogen using the moisture in the air.

Hydrogen can easily be stored and transported and converted into either electricity or heat. Hydrogen doesn’t release any greenhouse gases or toxic substances. 

The panel takes the water vapor and splits it into hydrogen and oxygen molecules. It can produce 250 litres of hydrogen a day. Twenty panels could produce enough hydrogen to heat house in Belgium throughout winter.

The device, which looks like an ordinary solar panel measuring 1.65 meters long, has a rated power output of about 210 watts. The system can convert 15% of the solar energy it receives into hydrogen.

The researchers plan to field test their prototype on a house. The hydrogen would be stored in a small, underground pressure vessel during the summer months, then pumped throughout the house during the winter.

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Improving Solar Cell Efficiency with a Bucket of Water Wed, 13 Feb 2019 06:48:27 +0000   Read more »]]> Associate Professor Beth Sparks, during a Fullbright Scholarship in Uganda, developed an amazingly simple way to significantly improve the efficiency of solar cells in developing countries and other remote areas.

In Uganda, between 20 to 25% of people have no access to electricity. One solar cell supplies enough energy to power lights and charge cell phones and radios giving a huge quality-of-life improvement.

Solar panels are typically mounted on a fixed frame and only optimally oriented toward the sun during specific hours of the day.

Professor Sparks worked with students at the Mbarara University of Science and Technology to design a frame, using cheap metal tubing that a local welder could easily obtain and assemble, that allows the solar panels to track the arc of the sun throughout the day.

The device uses a bucket of rocks is placed on the west side of the frame and a bucket of water is placed on the east side. Using a controlled leak from the water bucket, the weight shifts and the panel slowly rotates from east to west throughout the day.

Tracking solar panel

The solar cell on the movable frame captured 30% more sunlight than the stationary solar cell at the same location.

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Air Conditioning without Electricity Wed, 30 Jan 2019 05:40:33 +0000   Read more »]]> SoundEnergy, a Dutch company, has demonstrated a thermal acoustic engine which takes heat from any source and produces a powerful cooling effect without requiring power from any other source – potentially providing air conditioning or refrigeration from industrial waste heat or solar energy.

The device combines two technologies which have been understood for a long time but, to date, have had only niche application.

The ability of heat to produce sound was noted by glassblowers centuries ago. In the 1850s experiments showed that a temperature differential drove the phenomenon.

In 1859, the Dutch physicist, Pieter Rijke, demonstrated that a heated wire mesh placed at the point of greatest air pressure greatly magnified the sound. The effect is the result of heat convention from the mesh interfering with sound wave in the tube.

The SoundEnergy device sets up a sound wave in argon gas in a closed loop and applies heat, which can come from any source, at the appropriate points to greatly amplify the sound.

The other technology employed by SoundEnergy is the Stirling cycle which was first used in an engine patented by the Scottish inventor, Robert Stirling, in 1816. There are various types of Stirling Engine but, basically, they use the differential between the hot and cold ends of a closed cylinder to expand and contract a gas within the cylinder. This expansion and contraction is used to drive a cylinder and do work.

Unlike other heat engines, the Stirling cycle is completely reversible. That is, the motion of the piston can be used to produce hot and cold.

The SoundEnergy device uses the vibrations of the amplified sound wave to drive a reverse Stirling cycle and produce cooling.

The system has no mechanical moving parts, uses no refrigerants, no precious metals or expensive materials. It uses argon gas, which is plentiful and has no global warming effect. The company says that the device makes about as much noise as a running shower, is scalable and can produce cooling temperatures as low as -25°C. It requires no maintenance and has and has an estimated lifespan of 20 to 30 years.

The first large units, which currently cost about $us50,000, have been sold including to Dubai.  SoundEnergy says that smaller units for residential purposes are possible at much lower prices.

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Inexpensive Flexible Material to Convert Waste Heat to Electricity Wed, 02 Jan 2019 20:01:48 +0000   Read more »]]> Scientists at Osaka University have reported that they have developed an inexpensive, large-scale and flexible thermoelectric generator that has high mechanical reliability and can convert waste heat into electricity efficiently.

Thermoelectric conversion is one of the most promising techniques for converting waste heat at temperatures below 150°C into electric power.

However, widespread adoption of this technology has been hampered by high cost and lack of suitable packaging techniques for thermoelectric generation modules.

Now, the scientists at Osaka University have developed a method to manufacture the modules in a cost-efficient manner while preserving their conversion efficiency. Their process is based on conventional semiconductor packaging techniques, allowing mass production and lowering the cost of the modules.

The new process involves mounting small thermoelectric semiconductor chips on a flexible thin plastic substrate on which the researchers were able to achieve reliable and stable adhesion of the electrical contacts between the chips and the substrate.

A unique feature of their module is the parallel integration of electrodes, which allows the module to be bent in any direction. The researchers believe that this gives their material great potential for applications in portable, wearable, or implantable electronic devices.

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Using Superconducting Tape Could Dramatically Lower Wind Turbine Costs Mon, 26 Nov 2018 03:32:43 +0000   Read more »]]> The EcoSwing project, funded by the European Union, is aiming to demonstrate a dramatically lower cost, lightweight wind turbine drivetrain using superconducting ceramic tape instead of rare earth elements.

The tape is made using a ceramic superconducting layer with gadolinium-barium-copper oxide, with a steel ribbon at its back and protection against metal poisoning through layers of magnesium oxide and silver. It is cooled using the same sort of cryo-cooling currently used in MRI scanners.

A conventional wind turbine uses up to tonne of rare earth elements. Using the superconducting tape reduces this to as little a one kilogram. The resulting turbine is about half the size and weight of a conventional turbine with the same output.

The technology is currently being tested in a 3.6MW wind turbine at a demanding site at Thyborøn, Denmark. The test phase is expected to last for 12 months.

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