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Independent Professional: Experienced educator and management consultant for engineering educational institutions, researcher, trainer, technical consultant on sustainable technologies, related to cement manufacturing and characterisation, using industrial and agricultural wastes in cement and concrete, durability of concrete and fuel cell power.

Monday, November 15, 2010

Five for sustainability

The International Council for Science has narrowed down the following five top challenges the world needs to meet in order to sustain our planet.

(1) Forecasting: We need to have pertinent & accurate forecasts of future environmental conditions and their consequences for people.

(2) Observing: We need to develop better observation systems to record global and regional environmental change.

(3) Confining: Anticipating and recognizing disruptive environmental change to quickly manage it.

(4) Responding: Determine those institutional, economic and behavioral responses that will make global sustainability possible.

(5) Innovating: Encourage innovation in technology and policy to achieve sustainability.


Tuesday, November 9, 2010

Competition between biofuel and food production: Brazilian experience

The Brazilian production of major food commodities increased fivefold between 1961 and 2008. In the same time, the area cropped with sugar cane increased with high growth rates, currently covering 3% of the area dedicated to agricultural production in Brazil. In order to assess a possible competition between biofuel and food production, the development of agricultural productivity and area expansion in the past was analysed.

Three scenarios were investigated, simulating possibilities of future changes in Brazilian agriculture. The results demonstrated that primary food production could be enhanced by 1.5 times while bioethanol production was enhanced simultaneously by 1.8 times over the years 2007/2008 and 2020. The generated bioethanol volumes would meet 38% of the total energy demand in Brazilian transport sector, applied to the year 2007. 

The second scenario evaluated an agricultural development with a higher focus on biofuels. It was projected that the production of bioethanol could be increased by 3.0 times to 76.7 million m3 of bioethanol, while increasing at the same time primary food production with the factor 1.4 aligned to the projected population growth. This bioethanol volume represents 67% of the total energy demand in Brazilian transport sector in the year 2007. 

A third scenario demonstrated that food production could be increased even with no area expansion higher than the projected population growth, due to a continued increase of productivity. At the same time bioethanol production would rise to 32 million m3 without occupying more area.

Ref: Martin Gauder et. al., "The impact of a growing bioethanol industry on food production in Brazil", Applied Energy, Volume 88, Issue 3, March 2011, Pages 672-679


Wednesday, September 22, 2010

Carbon dioxide to building materials

MIT biological engineers,  have found a way to convert carbon-dioxide emissions to useful building materials, using genetically altered yeast.

Every year, about 30 billion metric tons of carbon dioxide are pumped into the Earth’s atmosphere from power plants, cars and other industrial sources (such as cement plants) that rely on fossil fuels. Scientists who want to mitigate carbon dioxide’s effects on global climate have started experimenting with storing the gas underground, a process known as carbon sequestration. However, there are still many unknowns surrounding the safety and effectiveness of that strategy.

Genetically engineering ordinary baker’s yeast, Angela Belcher, the W.M. Keck Professor of Energy and two of her graduate students, Roberto Barbero and Elizabeth Wood, have created a process that can convert carbon dioxide into carbonates that could be used as building materials. Their process, which has been tested in the lab, can produce about two pounds of carbonate for every pound of carbon dioxide captured. Next, they hope to scale up the process so it could be used in a power plant or industrial factory.

The team plans to try scaling up the process to handle the huge volumes of carbon dioxide produced at fossil-fuel-burning power plants. If the process is successfully industrialized, a potential source for the mineral ions needed for the reaction could be the briny water produced as a byproduct of desalination.


Monday, September 20, 2010

Biomass for high-value chemicals

ScienceDaily (2010-09-02) -- Chemist Walter Trahanovsky was trying to produce sugar derivatives from biomass using high-temperature chemistry. He was surprised when his research also produced significant yields of high-value chemicals.

The biomass conversion process is based on the chemistry of supercritical fluids, fluids that are heated under pressure until their liquid and gas phases merge. In this case, Trahanovsky said the key results are significant yields of ethylene glycol, propylene glycol and other chemicals with low molecular weights. He said the process also produces alkyl glucosides and levoglucosan that can be converted into glucose for ethanol production or other uses.

Uses for ethylene glycol include auto antifreeze, polyester fabrics and plastic bottles. Propylene glycol has many uses, including as a food additive, a solvent in pharmaceuticals, a moisturizer in cosmetics and as a coolant in liquid cooling systems.

The starting materials are cheap and the products are reasonably high-value chemicals.


Wednesday, September 1, 2010

Nanotechnology for water purification

ScienceDaily (2010-09-01) -- Researchers have developed a water-purifying filter that makes the process more than 80,000 times faster than existing filters. The key is coating the filter fabric -- ordinary cotton -- with nanotubes and silver nanowires, then electrifying it. The filter uses very little power, has no moving parts and could be used throughout the developing world.

Instead of physically trapping bacteria as most existing filters do, the new filter lets them flow on through with the water. But by the time the pathogens have passed through, they have also passed on, because the device kills them with an electrical field that runs through the highly conductive "nano-coated" cotton.
Cholera, typhoid and hepatitis are among the waterborne diseases that are a continuing problem in the developing world.

Read more


Sunday, June 27, 2010

US congress limits formaldehyde emissions from wood products

The US Congress has approved legislation to limit allowable emissions of formaldehyde from composite wood products, specifically hardwood plywood, particleboard and medium-density fiberboard sold in the United States. The new limits in are based on the levels established for the State of California in 2007 by the California Air Resources Board (CARB)

This is good news for reducing the serious toll that this known carcinogen takes on human health through widespread exposures in homes, offices and schools from building materials. The legislation should serve as a strong wake up call to the industry and help increase availability of low-formaldehyde and formaldehyde-free materials for the green designer. It is, however, only one piece of the puzzle in getting formaldehyde out of our buildings. 

Exemptions abound, including hardboard, structural plywood, structural composite lumber, OSB, glue-lams and wood I-joists, finger-jointed lumber, wood packaging, plus some exceptions for windows, exterior and garage doors, vehicles, boats and aircraft. 

Other important areas of formaldehyde use in building products, such as insulation and textiles, are not addressed by the legislation.

Finally, the new federal legislation reduces formaldehyde emissions but does not eliminate them.  The California Air Resources Board says bluntly that there is no known safe level for this carcinogen and avoidance is the best approach. There is a labeling option in the federal legislation for indicating “no-added formaldehyde-base binder,” but formaldehyde-based binders will still be widespread in products after this legislation goes into effect.


Monday, June 14, 2010

Beware, these five toxic chemicals are found everywhere

Five everyday chemicals linked to ailments including cancer, sexual problems, behavioral issues: Bisphenol A or BPA; phthalates; Perfluorooctanoic Acid or PFOA; formaldehyde; polybrominated diphenyl ethers, or PDBE. Tests reveal most of us now carry them in our bodies

BPA - Bisphenol A

It is found in water bottles, baby bottles, reusable food containers, plastic tableware, infant feeding cups, linings of infant formula cans and other cans, jar lids, CDs, electrical and electronic equipment, dental sealants.

The American Chemistry Council, an industry trade group, says exposure is so low there are no ill health effects. A new five-year Kaiser Permanente study of Chinese factory workers found higher BPA exposure linked to reduced male sexual function. This research joins a growing body of research on animals that suggests BPA poses a potential cancer risk and may mimic the female hormone estrogen and disrupt the extremely sensitive chemical signals in the body called the endocrine system. According to the Food and Drug Administration, BPA could affect the brain, behavior and prostate gland in fetuses, infants and young children.

To reduce exposure, buy stainless steel bottles and glass food storage containers. If you buy plastic, check for the recycle number on the bottom. If there is a number 7, assume the container contains BPA unless it explicitly says otherwise. Switch to fresh or frozen vegetables instead of canned. Other precautions include not microwaving or putting hot liquids in BPA plastic containers and throwing away baby bottles and feeding cups that are scratched.


They are found in shampoos, conditioners, body sprays, hair sprays, perfumes, colognes, soap, nail polish, shower curtains, medical tubing, IV bags, vinyl flooring and wall coverings, food packaging and coatings on time-release pharmaceuticals.

A new study by the Mount Sinai Center for Children's Environmental Health and Disease Prevention Research found a statistical association between prenatal exposure to phthalates and incidence of attention deficit hyperactivity disorder years later. Phthalates are considered endocrine disrupters, and studies have shown a statistical association between phthalate exposure and male sexual development. Research has also shown phthalates disrupt reproductive development of male laboratory animals.

Avoid shampoos, conditioners and other personal care products that list "fragrance" as an ingredient. These may contain phthalates. (Companies are not required to disclose the ingredients in their scents, and the industry says this phthalate is safe.) The federal government recently ended one source of exposure, banning the sale of toys containing any of six phthalates.

Perfluorooctanoic acid, PFOA

PFOA is present in Teflon and other nonstick or stain- and water-repellent coatings as a trace impurity. These coatings are used on cookware, waterproof breathable clothing, furniture and carpets and in a myriad of industrial applications. PFOA can also be produced by the breakdown of these products.

Almost everyone has PFOA in his or her blood. PFOA causes cancer and developmental problems in laboratory animals. The EPA concludes PFOA is suggestive of carcinogenicity but not sufficient to assess human carcinogenic potential.

You can reduce potential exposure by using stainless steel or cast iron cookware. If you use nonstick cookware, do not overheat, which releases toxic gas.


It is found in pressed wood products such as particle board, plywood, paneling and fiberboard; also, glues and adhesives and durable press fabrics like drapes.

Formaldehyde is a known human carcinogen, causing cancers of the respiratory or gastrointestinal tract. Formaldehyde fumes can also cause nausea, skin irritation, watery eyes, or burning eyes, nose and throat.

Buy furniture free from formaldehyde eliminates much of the exposure we face from the chemical. One option to reduce "off-gassing": purchase "exterior grade" pressed-wood products, which emit formaldehyde at significantly lower rates. If you have wood products containing formaldehyde, increase ventilation, reduce humidity with air conditioning or dehumidifiers and keep your home cool.

Polybrominated diphenyl ethers, PBDE

PBDEs are found in televisions, computers and wire insulation, and furniture foam. Over time, televisions and other products shed PBDEs, which accumulate in dust. More than 124 million pounds of PBDEs are produced annually worldwide and they do not break down easily.

PBDEs accumulate in the body. Toxicology tests show PDBEs may damage the liver and kidneys and affect the brain and behavior, according to the EPA.

Try to find products without PBDE flame retardants and be sure to sweep up dust.


Friday, June 4, 2010

Converting CO2 into BPA-free plastics

Researchers say they have identified several classes of organic chemicals that can capture carbon dioxide from the atmosphere and then be used to make more environmentally benign plastics. Researchers at the Institute of Bioengineering and Nanotechnology in Singapore used chemicals called imidazoliums and N-heterocyclic carbenes to couple CO2 with “epoxide” molecules to create polycarbonate plastics that can be used in a variety of applications, from drinking bottles to compact discs. Significantly, in addition to finding a use for carbon dioxide, these polycarbonates do not contain bisphenol A (BPA), a potentially harmful chemical found in most commercial polycarbonate plastics in use today. The imidazolium salts are stable enough that they can repeatedly “grab” CO2 molecules and incorporate them into larger molecules in the plastic-making process, according to a study published in the journal Energy & Environmental Science. The process also eliminates the need for petroleum in the manufacture of plastics.

Ref:  Zhang, Y and J Young Gerentt Chan. 2010. Sustainable chemistry: imidazolium salts in biomass conversion and CO2 fixation. Energy and Environmental Science http://dx.doi.org/10.1039/b914206a.


Tuesday, January 19, 2010

Eat vegetables

On consuming more fresh vegetables and fewer or no processed foods, our body consequently responds better with cleaner and unclogged arteries, balanced blood sugar and a lower toxic overload in our bodies.

Taking advantage of the seasonal availability of vegetables and the flexibility in purchasing power of the same, sneak in vegetables in every meal. One reason we do not get enough vegetables is because many of us consider them merely a side dish to lunch and dinner. Sneak in leaves as purees in chapatti/parantha dough, fill in veggies in spaghetti or pasta sauce, drop finely chopped veggies into whisked eggs for your egg breakfast. Carrot and celery sticks, cucumber and raddish slices, string beans, peas, tomatoes, colourful bell pepper strips are healthy and contain virtually no calories. Served on a platter, they furnish antioxidants and micro-nutrients at the same time provide their unique taste and a satisfying crunch. Eaten before or along with the main course, they help substantially cut the consumption of calorie dense main course dishes.