“Unless you add value to waste, it will not be considered important. This was one of the important aspects of our Indo German Project to establish correlation between waste management and carbon emission. A study tour was conducted to one of the Recycling Units located on Mysore Road in order to understand the application of new technology in the process of recycling. The Bruhat Bengaluru Mahanagara Palike (BBMP) model was taken as an example to understand the importance of avoiding and reducing the waste. It also led to our understanding of recycling and reusing the waste in the form of usable products. The sessions were beautifully taken up by the Engineers of the plant, step-wise with explanation and interactive discussions. There were wonderful 3D computer simulations shown to us that gave a holistic understanding of the entire process of recycling.
The process cycle of waste includes the following phases:
Primary Sedimentation, Bio Filtration, Secondary and Tertiary Filtering units. In these steps, oil and grease are removed from the waste water, microbial (Bacteria) activity cleanses the water by eating organic waste and the water thus treated through chemicals is finally released for public use like maintenance of gardens and parks. The residual waste generated form the above procees is used as manure and landfills.
The visit culminated by learning about water recycling process through Ion Exchange Method which includes the following stages: Filtration, Specific treatment, Ultrafiltration, Polishing and Combined treatment.
The Energy and Resources Institute (TERI)
TERI has created an environment that is enabling, dynamic and inspiring for the development of solutions to global problems in the fields of energy, environment and current patterns of development, which are largely unsustainable. The central element of TERI’s philosophy has been its reliance on entrepreneurial skills to create benefits for society through the development and dissemination of intellectual property.
Our visit focused on understanding research and development happening for sustainable energy. Various thematic sessions were taken up by different research wings some of which were green buildings, Industrial energy efficiency, Industrial biotechnology, environment-friendly plastics and clean and rural energy. Demonstration sessions on multiple uses of renewable energy were conducted along with the campus tour emphasizing on green concept in construction sector.
Novozymes is a biotech company with a strong focus on enzyme production. We are committed to changing the very foundations of our industrial system for the better by using industrial biotechnology.
Tanning enzymes help towards a better environment
An environmental comparison of chemical and enzyme-assisted soaking and unhairing/liming in a Chinese tannery indicates that, if all tanneries switched to the enzymatic processes, the carbon dioxide emissions saved would be equivalent to the annual load from 170,000 cars.
Enzymes have been used in the tanning industry for centuries because they are efficient at degrading protein and fat. In early times, the enzymes were derived from animal excrement, and later on from the pancreas of cattle. Nowadays, many of the enzymes are produced using microbial fermentation, and Novozymes is a major supplier of this type of enzyme.
One of the applications of microbial enzymes in the tanning industry is in soaking and unhairing processes. Enzymes can replace chemicals and shorten processing times, thereby reducing production costs. Other benefits can include increased area yield and improved quality of the final product. As part of Novozymes’ work with Life Cycle Assessment (LCA), the company collaborated with a Chinese tannery to assess the environmental implications of the application of enzymes in the soaking and unhairing of bovine hides.
True production data
The assessment is basically a comparison between two different ways of soaking and unhairing/liming bovine hides. An entirely chemical method was compared to an enzymatic method with reduced chemical consumption.
Life Cycle Assessment has been used as an environmental analytical tool to evaluate the changes in enzyme and chemical consumption that occur when switching from the chemical method to the enzyme-assisted method. The information has been derived from a major Chinese tannery that applies chemical as well as enzyme-assisted production methods.
The study was based as far as possible on true production records and refers to an enzymatic hair-saving process – where the hairs on the hides are not dissolved by the chemicals but removed intact.
The enzymes Greasex® 50 L and NovoCor® SG were used by the tannery for soaking to degrade fat and proteins. They reduced the soaking time, which leads to electricity savings in turning the drum. There were also savings in the tenside and soda requirements for the process.
The unhairing enzyme NUE 0.6 MPX was used to degrade proteins. It reduced the sulphide requirements for the process but did not influence processing time or temperature. The lower level of sulphides required reduces the sulphide content of the waste water and some manganese sulphide can be saved.
Savings in chemicals
Savings in chemicals as a result of the enzyme application show that a relatively small quantity of enzymes replaces quite a large quantity of chemicals.
The environmental impacts of producing and delivering the enzymes to the tannery on the one hand and savings in chemicals and electricity on the other hand have been evaluated. It shows that a small ‘investment’ in energy and carbon dioxide emissions in enzyme production results in considerable savings when these enzyme products are used to replace chemicals and electricity in the soaking and unhairing/liming processes. A small amount of enzyme products made from a biological production process replaces a relatively large amount of harsh chemicals made using a relatively large amount of energy derived mainly from coal.
Contributions to other environmental impacts (acidification, nutrient enrichment and smog formation) are also reduced. In fact, the environmental impacts resulting from enzyme production are at least 20 times lower than the impacts that are avoided by the savings in chemical and electricity consumption.
Sulphide savings in the unhairing/liming process are considerable compared with other chemicals. Since a large quantity of coal is used to produce sulphides and a large quantity of carbon dioxide is emitted during production, the savings in sulphides turn out to be the most important environmental effect of enzyme use.
A comparison of conventional and enzyme-assisted bovine soaking and unhairing/liming processes indicates that the application of enzymes in the tanning industry results in considerable reductions in the contribution to global warming. The environmental advantages of enzyme application are primarily due to savings in sulphides in the unhairing/liming process because a small quantity of enzyme replaces a considerable amount of sulphides, which have a relatively high environmental load.
Novozymes is continuously developing enzymatic solutions. In future, the company envisages that new, more efficient enzymes will be able to virtually replace conventional chemicals in the soaking and unhairing processes.
Global impact The global supply of bovine hides for leather production was about 8.8 million tons in 2005. Today, less than 10% of bovine hides are soaked and unhaired in enzyme-assisted processes. Assuming that the environmental improvements observed in this study by switching from conventional to enzyme-assisted soaking and unhairing/liming are applicable worldwide, the global potential saving is in the order of 8 million GJ of energy and 0.7 million tons of carbon dioxide per year. The saved carbon dioxide emissions are equivalent to the annual load from 75,000 average world citizens or 170,000 cars.