Waste coffee processing

Caffeine can he extracted from coffee, tea, and kola plants hy one of three methods. These methods are used primarily to produce the decaffeinated counterparts of the products decaffeinated coffee, decaffeinated tea, or decaffeinated soft drinks. A commercial variation of these procedures is to treat the waste products of tea or coffee processing, such as the dust and sweepings collected from factories, for the extraction of caffeine. 

Other mold-based SCP processes that have been iavestigated iaclude utilization of sulfite waste Hquor by I aecilomyces varioti conversion of carob bean waste yg Jispergillus niger com- and pea-processiag wastes by Giotrichium sp. and coffee-processiag wastes by Trichoderma har anum (62). However, none of these processes is practiced commercially. 

The most volatile aliphatic compounds are largely lost at some stage of the roasting process. For example, acetaldehyde was among 12 volatile compounds evolved after an 8-min roast of coffee beans at 220°C.23 Waste... 

Orecchio, S. Recovery and Reutilization of Waste Matter from Coffee Preparation. An Experiment for Environmental Science Courses, J. Chem. Educ. 2001, 78, 1669-1671. van Wyk, J. P. H. Conversion of Used Paper Materials into Sugars A Biochemical Process to Limit Environmental Pollution, Chem. Educ. 2000,5,315-316. 

The industrial research efforts on coffee decaffeination, spice extraction, and flavors concentration are, to a great extent, shrouded by the cloak of proprietary security, but the investigations of the use of supercritical fluids to treat various waste streams is reasonably well publicized. Most familiar, perhaps, is the supercritical waste water detoxification process developed by Modar Inc. This is potentially attractive for detoxifying refractory chemicals such as polychlorinated biphenyls, dioxin, and other toxic materials (Anon., 1982 Modell, 1982). In the Modar process, the toxic chemicals are homogeneously reacted with oxygen in supercritical water, the solvent for the organics and the oxygen. The main feature of the process is a chemical reaction discussed in more detail in chapter 11. 

EXPOSURE ROUTES Inhalation (present in natural environment as a product of plant respiration, incomplete wood combustion in fireplaces and woodstoves, coffee roasting, burning of tobacco, vehicle exhaust fumes, coal refining and waste processing) absorption. 

The use of supercritical fluids as alternatives to organic solvents is revolutionising a huge number of important science areas (24). Scientific applications vary from established processes, such as the decaffeination of coffee and the extraction and synthesis of active compounds, to the destruction of toxic waste in supercritical water, the production of nanoparticles and new materials, to novel emerging clean technologies for chemical reactions and extraction. 

Xylan-degrading enzymes, especially xylanases, have considerable potential in several biotechnological applications. In some processes, the use of purified enzymes is required. However, in other applications, the presence of additional enzyme activities is desired. Commercial applications suggested for xylanases involve the conversion of xylan, which is present in wastes from the agricultural and food industry, into xylose (2). Similarly, xylanases could be used for the clarification of juices, for the extraction of coffee, plant oils and starch and for the production of fuel and chemical feedstocks (3). 

HPE may also be applied in multistage processes with countercurrent phase flow. Different products are obtained by a stage-wise pressure release of the enriched solvent in the gaseous state (separation of oleic acid and stearic acid in a multistage process using supercritical ethylene as a solvent [6.93], sweet oil extraction and raffination [6.94], removal of caffeine from raw coffee [6.95], treatment of waste oil [6.96], etc.). 

Uses Defoamer for fermentation process, instant coffee, paper coatings and sizes, latex, adhesives, textiles, ink, petroleum processing, waste treatment Properties Amber liq. si. odor si. disp. in water sp.gr. 0,96 vise, 50-175 pour pt. 8-11 C 100% act. 

Nevertheless, the environmentalist criticism is just as extreme as the industry position it condemns. There is indeed a rising trend in industrial research and development that takes into account the environmental impact of all sorts of chemical processes and is aimed at waste reduction and biodegradability, but this approach is a long way from dictating industrial production policy. While it is no doubt a good idea to replace plastic coffee cups with cardboard ones in drinks dispensers, this does not represent a global solution to the problems posed by the synthetic chemistry industry. 

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