Green engineering and green chemistry Chapters 11 and 12 Cleaner production book Presentation: by Dalia Jankunaite BUP Teachers Conference on Environmental Management

Green Engineering  Green Design  Corporate Strategies  The Strategies of Green Engineering

Industrial Ecology  The Kalundborg Case  Energy Cooperative Systems  Water Recycling in Kalundborg  Gas and Inorganic Material Recycling  Biomass Recycling

Product Design  Eco-design or Design for Environment  Dematerialising Products and Services  Extending the Life of a Product  Making Products Recyclable  Reduce Impact During Use

Materials Management  Choosing Material  Recycled Materials

Production Design  Cleaner Production Strategies  Distribution and Transport  Supply Chain Management  Optimizing the End-of-life System

Green design  Material and energy in our economy flows in one direction only – from raw materials towards final disposal as industrial or municipal waste.  Sustainable development requires a change in these flow patterns. Cyclic flows of material needs to be established. The focus is on the efficient use of materials and energy, reduction of waste toxicity, and reuse and recycling of materials.

Influence of product design on materials flows

Strategies of green engineering  Green engineering practice requires that concerns about environmental quality include not only production and product use but also useful materials or potential energy embedded in products.  Product becomes input to several product cycles instead of merely ending up as waste ready for landfilling after one life cycle.

Sustainability strategies Sustainability strategies can be used in production on several levels: level of the industrial system level of the product level of material management level of the production system

Industrial Symbiosis  Industrial Symbiosis mimics the natural ecosystem by setting up a system of recirculation of residual materials from industrial processes or discarded products from consumer matter.  Industrial Symbiosis typically is pursued in a limited area, in a municipality or industrial area in a municipality.

The Kalundborg Case  Kalundborg municipality;  power plant and an oil refinery,  gypsum board manufacturing plant,  pharmaceuticals plant;  biotechnical plant for production of enzymes;  plant for remediation of polluted soil;  waste handling company, fish farm and the surrounding farming community.

Energy Cooperative Systems  In Kalundborg, the Power Station produces heat for the city of Kalundborg and process steam for the oil refinery and for the enzymes factory.  The combination of heat and power production results in a 30% improvement of fuel utilization compared to a separate production of heat and power.  District heat has replaced approx. 3,500 small oil-fired units.

Water Recycling in Kalundborg  The Kalundborg Region, as well as its industrial companies, is a large consumer of water. This is why the Symbiosis companies are seeking to recycle as much water as possible.  The Power Station has, for example, reduced its total water consumption by 60%.  The consumption of lake water has been reduced by 50% by recycling of the wastewater from the power plant.

Gas and Inorganic Material Recycling  The desulphurisation plant of the Power Station removes sulfur dioxide (SO 2 ) from the flue gas, producing about 200,000 tones of gypsum on a yearly basis.  The gypsum is sold to the gypsum company that manufactures gypsum board products for the construction industry.

Biomass Recycling  The use of residual biological material is worldwide the most typical kind of industrial symbiosis. A plant that has biological material as a residual product tries to sell it rather than pay for its destruction.  Sludge is a major residual product stemming from the municipal water treatment plant in Kalundborg. The sludge is utilized at the soil-remediation plant as a nutrient in the bioremediation process.

The Principles of Green Chemistry  What is Green Chemistry  The History of Green Chemistry  Green Chemistry Methodologies

Selecting Raw Materials  Criteria for Green Chemicals  Selecting Raw Materials  Hydrogen and Fuel Cells vs Fossil Fuels and Combustion  Production of Hydrogen based on Fossil Raw Materials  Hydrogen Production using Renewable Raw Materials  Alternatives to Heavy Metals.

Auxiliary Materials & Reaction Pathways  Solvents  Finding Alternatives to Chemical Reactions  Finding Alternatives for Chemical Processes

Biotechnology  The Promises of Biotechnology  The Components of Biotechnology  Textiles and Leather – Chromium vs Enzymatic Tanning  Use of Enzymes for Leather Tanning

What is Green chemistry  Green chemistry, refers to the design of chemical products and processes that reduce or eliminate the use and generation of hazardous and polluting substances.  The identification of environmentally preferable chemical processes requires extensive chemical and process knowledge and creativity.

Ideal chemical reactions  Simple and safe  High yield and selectivity  Energy efficient  Use renewable and recyclable raw and auxiliary materials  Use raw materials with no or low content of impurities

Green Chemistry Methodologies A qualitative approach to chemical process design involves raw material selection, selection of auxiliary materials such as solvents, catalysts and other materials and the selection of reaction pathways and conditions. It is important to: avoid pollution use renewable resources use biological or biologically inspired conditions

Criteria for Green Chemicals  Persistence in the environment  Bioaccumulation potential  Eco-toxicity and human toxicity  The scarcity of the material, and whether it is a renewable or non-renewable resource  The environmental impacts associated with creating the raw material should also be considered.

Selecting Raw Materials  Chemical industry is today dominated by oil products, petrochemicals.  About 10% of all petroleum products are used as raw materials in chemical industry.  To replace this with materials from renewable resources is difficult and will take time.  Biological sources include forest products and cultivated crops.

Replacement  Different crops (corn, sugar cane, wheat etc.) are used for the production of ethanol through fermentation  Organic waste is used for the production of methane, biogas, through fermentation  Wood can be used for the production of methanol  Extraction of metals is combined with environmental impacts. The alternative is to use recycled metals.

Hydrogen and Fuel Cells vs Fossil Fuels and Combustion  Fossil oil products are totally dominating as fuel, that is energy carrier, for many purposes especially transport.  Alternatives now on the market include ethanol and biogas.  In the long term hydrogen appears to be an even more interesting alternative energy carrier, as it may be used in fuel cells.

Alternatives to Heavy Metals  Organic lead (tetraethyl lead, PbEt 4 ) as anti-knocking agents in petrol was replaced with other compounds.  Replacement of lead with alloys between tin and one or more other metals in soldering of metals.  Replacement of copper wires with optical fibers in various electric equipments.  Mercury has also been replaced in a series of other products. Thus amalgamates for repair of teeth, can today be replaced with either plastics or ceramics.

Alternatives to Chemical Reactions (1)  As an example of how it is possible to rethink a reaction pathway the production of carbaryl in an alternative way is described as a case study.  The classical way of synthesis involves very toxic compounds. It is this production that led to the disaster in Bophal in India in 1984.

Classical way of synthesis

Alternative reaction routes

Alternatives to Chemical Reactions (2)  The world production of ibuprofen exceeds 13,500 tons per year.  The traditional process consists of a six- step synthesis with an atom efficiency of 40%, remaining 60% are undesired by- products and waste.  The new process has only three catalytic steps and an approximately 80% atom utilization. In addition the new process saves 20-40% of the total energy required in the traditional process.

Alternatives for Chemical Processes  A chlorine alkali industry uses hundreds of tones of mercury in mercuric method.  Today alternative methods are used for production of chlorine and sodium hydroxides have found increased use.  The most common are the diaphragm method and the membrane method which both are mercury free.  A disadvantage is that the caustic soda produced is less concentrated.

Biotechnology  Biotechnical alternatives to traditional chemical processes are being developed and more and more introduced in large scale production processes.  Micro-organisms are being used in industrial production to produce many important chemicals, antibiotics, organic compounds and pharmaceuticals.

Components of Biotechnology  Cultivation of biological cells for technical purposes  Genetic change of cells, also referred to as genetic engineering  Use of isolated bio-molecules, especially enzymes, for technical purposes

Enzymes for Leather Tanning  The chemicals mainly responsible for pollution in the pre-tanning are lime, sodium sulfide, caustic soda as well as salt and degreasing solvents.  By introducing enzymatic treatment of the hides in the pre-tanning stages substantial reduction of hazardous pollutants is achieved.