14 Figure 6. Geographic Material Flows Diagram: Destilería
Transcription
14 Figure 6. Geographic Material Flows Diagram: Destilería
Figure 6. Geographic Material Flows Diagram: Destilería Serrallés Figure 7. Geographic Material Flows Diagram: Bacardi Corporation 14 4.1 Inputs: Raw Materials 4.1.1 Molasses Sugarcane molasses, also known as blackstrap cane molasses, is the principal raw material input for the manufacture of rum. Defined by U.S. Department of Agriculture regulations (24 FR 8365 § 52.3651), it is the “clean, sound, liquid product obtained by evaporating the juice of sugarcane and the removal of all or any part of the commercially crystallizable sugar.” Sugar is extracted from sugarcane by crushing the stems of the plant to create a juice and the byproduct bagasse. Calcium hydroxide is added to the sugar cane extract and the mixture is heated, filtered to remove impurities, and evaporated to form a concentrate. The mixture then is crystallized and centrifuged to separate the product, sugar, from the molasses byproduct. 3 to 4 tons of molasses is produced for ever 100 tons of sugar cane (McGee, 1999). World production of sugarcane molasses for 2001/2002 was an estimated 35.7 million tons (McGee, 1999). The quality and quantity of molasses produced is influenced by the technological efficiency of the producer and the market price of sugar respectively. The higher the international market price of sugar and the greater the efficiency of the producer, the more sugar cane is converted to refined sugar and the more sugar is extracted from the juice producing less and lower quality molasses as a function of sugar content (Szendrey, 2003; McGee, 1999). The sugar content of molasses processed at the Bacardi facility is typically 41-42% (Szendrey, 2003). The molasses used by Destilería Serrallés, Inc. and the Bacardi Corporation is mostly purchased from sugar producers in the Caribbean basin and transported to Puerto Rico via ship and to the facilities via tanker truck (Serrallés, 2003; Szendrey, 2003). The current market price of blackstrap cane molasses (43% sugar) at the commodities market in New Orleans as of April 28, 2003 is USD 55.00 – 60.00 per ton (USDA, 2003). The world molasses market demonstrates a strong downward price trend over the past decade (Roney, 2002). The current cost of molasses however has nearly doubled since 1999, when prices in New Orleans reached a low of USD 32.50 per ton and world sugar production hit a record output of 135.16 million tons (USDA, 1999; IFAP, 2003). Because sugar production has increased dramatically over the last 35 years, accommodating strong global demand, available quantity of molasses for rum production does not appear to be limited any time in the foreseeable future. However, because of recent increased price pressure and due to improvements in the efficiency of sugar production in lesser developed countries, the acquisition of high quality materials, in terms of sugar concentration, is becoming increasingly difficult for both firms (Serrallés, 2003; Szendrey, 2003). Last year, Destilería Serrallés used 90,000 metric tons of molasses to produce 10.5 million gallons of rum (Serrallés, 2003). 15 The most important constituent of molasses is sugar, predominantly sucrose with lesser concentrations of glucose and fructose. In addition to sugars, molasses is composed of a large number of organic and inorganic constituents including: water, other reducing sugars and carbohydrates, nitrogenous compounds (amino acids), non-nitrogenous acids, wax, sterols, phospholipids, and micronutrients such as calcium, phosphorous, sodium and potassium chlorides, magnesium, sulphur, copper, zinc, iron, and manganese (Kampen, 1975; McGee, 1999). As the principal raw material in rum manufacturing, it is intuitive that the production of high quality rums requires the use of high quality molasses. Kampen (1975, p.37) outlines the optimal qualities of molasses for the production of rum, stating that the material should be, …high in fermentable sugars; low in ash, because this acts as an inhibitor for the growth of yeast cells and also yields scaling of heat exchangers and distillation columns; low in gums, since this also acts as an inhibitor for yeast cells; high in assimilable inorganic N and in P3O5, since this is required for yeast growth; a ratio of total fermentable sugars over ash of 6.5; a pH value of 5.5 to 6.0 in a 1:1 dilution with neutral distilled water, The concentrations of these materials are highly influenced by the environmental conditions where the sugarcane was grown and the processing efficiency of the sugar producer, therefore exact concentrations of each chemical is variable (Szendrey, 2003). Aside from the sugars, organic nitrogenous compounds and phosphorous, the remaining materials are largely un-reactive in the production process and thus the chemical composition of the molasses should mimic the outgoing waste streams in the production process, particularly the mosto, also called vinasse. Tables 1 and 2 provide an example of the variation in sample values of chemical concentrations for molasses. Animal feed is the primary worldwide market for molasses, representing 51% of the total use. Secondary markets for molasses include fermentation and distillation industries, including rum production, and the bricketing industry. These industries produce products for consumer and industrial clients, such as ethanol for consumption and energy, yeast, amino acids, citric acids, boards and paper (McGee, 1999; IFAP, 2003). 4.1.2 Yeast Yeast is an essential ingredient in the manufacturing of rum. Schizosaccharomyces are the alcoholic fermentation agents used in rum which contain the enzyme sucranase that causes the sugars in the molasses to be converted to ethanol. The initial development of these yeasts began under the Puerto Rico Rum Pilot Plan to revitalize the industry. This project recovered 360 yeast strains from cane fields and developed the strains that were most efficient in fermentation. Both the Bacardi Corporation and Destilería Serrallés maintain and store their own proprietary strains of yeast which offer each the best fermentation efficiency and time, and rum quality for their process. Because more 16 yeast is created during each fermentation, each distillery is able to maintain their cultures at relatively low cost. Table 2. % Concentration of Proximates, Nutrients, and Amino Acids in Molasses % Concentration Component Water 28.7 Ash 8.2 Carbohydrate 60.8 Calcium, Ca 0.86 Iron, Fe 0.0175 Magnesium, Mg 0.215 Phosphorus, P 0.04 Potassium, K 2.492 Sodium, Na 0.055 Zinc, Zn 0.001 Copper, Cu 0.00204 Manganese, Mn 0.00261 Selenium, Se 0.0178 Thiamin 0.00033 Riboflavin 0.000052 Niacin 0.00108 Pantothenic acid 0.00088 Vitamin B-6 0.0007 Folate, total 0.001 Source: USDA National Nutrient Database for Standard Reference, Release 15, 2002 Table 3. % Mean Concentration & % Concentration Range of Components of Molasses Water % Concentration (mean) 20 % Concentration (range) 17 – 25 Sucrose 35 30 – 40 Glucose 7 4–9 Fructose Other reducing substances Other carbohydrates 9 5 – 12 3 1–5 4 2–5 Ash 12 7 – 15 Nitrogenous compounds 4.5 2–6 Non-nitrogenous acids 5 2–8 Wax,Sterols and Phospholipids 0.4 0.1 – 1 Component 17 Source: McGee (1999) 4.1.3 Oak barrels As stated in Section 3, the alcohol produced by distillation must be aged in Puerto Rico for one year to be legally labeled “Puerto Rican Rum”. The barrels used in rum production at Destilería Serrallés and the Bacardi Corporation are sourced as byproducts the from the whiskey industry in the United States (Serrallés, 2003; Szendrey, 2003). United States Federal law requires that all bourbon whiskey be aged in charred new white oak barrels (Emission Factor Documentation for AP-KIR Sec. 9.12.13). Therefore, whiskey manufacturers in the United States can only use their casks once, producing a large stream of residual solid waste in form of used barrels. These used barrels are purchased on a secondary market for $20-$30 per unit, depending on the quantity, from the whisky distilleries by other alcohol manufactures, such as wineries and the rum industry (Serrallés, 2003). Destilería Serrallés and the Bacardi Corporation get approx. 20 years use out of each barrel before they reach their end of life (Serrallés, 2003; Szendrey, 2003). Therefore, as long as the whiskey industry is strong, this material should be readily available due to the cheap cost, long use period and abundant supply. 4.1.4 Nutrients Destilería Serrallés utilizes sulfuric acid (H2SO4) and ammonium sulfate ((NH4)2SO4) to optimize conditions for yeast colony growth in the fermentation process. Sulfuric acid is used to maintain the solution’s pH at 4.7 because one of yeast’s primary enzymes, sucranase, functions optimally at this level of acidity. Ammonium sulfate is added because cane sugar molasses doesn’t contain all the necessary growth factors to 18 facilitate yeast growth. Molasses is often deficient in nitrogen and phosphorus that needs to be compensated for by adding these elements to the mash in a suitable form. Destilería Serrallés uses small quantities of (NH4)2SO4 to provide a source of nitrogen and to serve as a buffering conjugate base for the sulfuric acid. No phosphorus containing nutrients are supplied by Serrallés, but the mosto has a 258 mg/ kg phosphorus concentration which may be sufficient for fermentation reactions to take place. Supplies of (NH4)2SO4 and H2SO4 both come from local distributors. The ammonium sulfate comes from Ochoa Fertilizer and is supplied from Louisiana, Texas, Colombia, or Venezuela depending on the price. Manuel Del Valle, Inc. is the supplier for the sulfuric acid. This chemical is also produced in Puerto Rico. Both sulfuric acid and ammonium sulfate are abundantly available. H2SO4 was the most highly produced chemical in the US in 2000 (39.62 x 109 kg), while (NH4)2SO4 was the 19th highest produced chemical in the US in 2000 (2.6 x 109 kg) (Chemical & Engineering News, 2001). Since both of these chemicals are widely available, the major variable is pricing. The cost of H2SO4 can vary any where from $15-$30 per liter (18M-concentrated acid) depending on the quantity purchased and the dilution rate (Chemical & Engineering News, 2001). The cost of (NH4)2SO4 is approximately $12 per 100 lbs. if purchased from fertilizer companies (MSU Extension Service, 2003). The Bacardi Corporation uses an additive mixture that provides macronutrients in the following ratio, 100 carbon: 5 nitrogen: 1 phosphorus. 4.2 Inputs: Water 4.2.1 Water The production of rum requires large volumes of water for fermentation, distillation, dilution, washing and in the form of energy as steam. Water is the largest productive input, as a function of mass, in the manufacturing process. As an example, Destilería Serrallés uses over 6.5 L of water per unit of productive output, one 750 ml bottle of rum (see Section 5). The availability of water is a high concern for the island. Puerto Rico has 1814 m3 per year of water available per person ranking it 135 out of 180 countries and territories surveyed by UNESCO (UNESCO, 2003). Periods of drought in the 1990’s created several problems for the island, including water rationing and over USD 100 million in agricultural losses. During the 1990's, annual rainfall reached the lowest levels of the 20th century at over half of the meteorological stations on the island, with the remaining stations recording levels that were the second lowest of the century (USGS, 1999). A complex and challenging topography that couples a relatively high relief and a short distance between the hydrological divide and the ocean represents the major physical limiter of water availability on Puerto Rico. Anthropogenic factors such as a high population density of 440 people per sq km, rapid urbanization, increased use across all 19 sectors and an aging distribution infrastructure are significant drivers of water scarcity as well (USGS, 1999). These factors have contributed to overuse of existing water supplies, filling of reservoirs with sediment from erosion during heavy storm events, and contamination of groundwater and surface water (USGCRP, 2001). In general, Puerto Rico has abundant ground and surface water resources due to relatively high rainfall in the mountainous regions and porous rocks along the northern regions that form a large aquifer system. Ground water accounts for 30% of the total amount of water used in Puerto Rico, with surface water accounting for the remaining 70% (USGCRP, 2001). A significant portion of surface waters in Puerto Rico are impaired, 19% of surface waters do not support aquatic life and 21% are impaired for swimming (USGS, 1999). The major sources of ground water contamination are septic tanks, livestock operations, agriculture, storage tanks, and landfills (USGS, 1999). As population and growth pressures persist, it is conceivable that water will become less available and natural disturbance such as drought and storm events will further impair service delivery. Destilería Serrallés receives its’ water from a source in the mountains. The water is extracted from wells and transported to the facility by pipes via gravity flow at a rate of 600,000 gallons per day where it is treated using sand filtration and activated carbon for process use and additionally deionized for product dilution. Roughly 500,000 gallons per day is used as process water and 100,000 gallons per day is used for dilution (Serrallés, 2003). The rights to this water source were granted by Crown of Spain prior to the arrival of the U.S. in Puerto Rico, therefore an extraction permit from DNER is not necessary (Huertas, 2003). The Bacardi Corporation receives its’ water from two sources, the municipal water supply provided by PRASA and wells. The municipal water is received at the facility via pipes and used for steam and product dilution. The steam water is treated via ion exchange and an additional treatment of activated carbon is employed for product dilution. The steam is directly injected into the distillation columns and is not recovered. The well water is used in the fermentation process. Prior to use, the water is treated using reverse osmosis. (Szendrey, 2003). 4.2.2 Activated charcoal, Chlorine, and Polyaluminium chloride Polyaluminum chloride (AlCl3), chlorine (Cl2), and activated carbon are chemicals used in water pretreatment. AlCl3 reacts with solids in water, causing them to become heavier and sink to the bottom of the suspension. After the AlCl3 application, a very small quantity of chlorine is added to the water to kill bacteria. After passing through a sand filter, activated carbon is then added in the next step to remove the chlorine from the water. Activated carbon can be produced from organic based materials such as coconut shells, palm-kernel shells, wood chips, sawdust, pecan shells, corn cobs and seeds (NMSU, 2000). These materials can be grinded down into a fine powder and then carbonized to 20 obtain the carbonaceous material, which is activated to yield the highly porous final product. The most widely used methods for the activation process are zinc chloride, magnesium chloride, calcium chloride, and phosphoric acid. 4.3 Inputs: Energy 4.3.1 No. 6 Oil No. 6 oil is burned in a boiler to generate heat to convert water to steam for use throughout the distillation columns. No. 6 oil is a complex of heavy petroleum hydrocarbons with variable quantities of sulfur. The No. 6 oil used at Destilería Serrallés is bought from a local vendor, Western Petroleum, at a cost of $0.75/ gallon and contains about 1.7% sulfur (Huertas, 2003). Because Puerto Rico has no domestic petroleum reserves, the fuel must be imported. There are a number of environmental challenges associated with the use of No. 6 oil. Hydrogen sulfide may be present in trace quantities and can accumulate to levels which can be toxic. The combustion of fuel oil results in the production of trace amounts of nickel, vanadium and other metals in ash which are carcinogenic and toxic, respectively. No. 6 oil is listed on the EPA Toxic Substance Control Act TSCA Inventory, and spills, which can cause human and ecological damage, must be reported to a number of agencies including the Environmental Quality Board, Department of Natural Resources and the EPA National Response Center. 4.3.2 Electricity All the electricity used in Puerto Rico is provided by the Puerto Rico Electric Power Authority (PREPA), a public corporation and government agency (US DOE RFQ-00004, 2001). PREPA supplies the electrical power to both the Bacardi Corporation and Destilería Serrallés for lighting and powering for electrical equipment, and all systems that do not function with steam as the energy input such as the computer systems employed at the Bacardi Corporation that monitor and control the different flows and parameters of the production process. Another electrical energy need is pumping the aqueous raw materials, such as the highly viscous molasses. Destilería Serrallés uses a positive displacement pump for pumping the raw molasses into the mixing tank where it is diluted with water and heated with steam, the higher temperature further reducing the viscosity. The diluted mixture is then pumped to the fermentation tank with a centrifugal pump (Serrallés, 2003). 4.4 Inputs: Packaging 4.4.1 Glass bottles Both the Bacardi Corporation and Destilería Serrallés primarily package their rum in glass bottles. The Bacardi Corporation uses about 30 million glass bottles a year, and Destilería Serrallés uses a little less than that number. Glass is often used for its 21 durability and its aesthetic appeal. It is a $28.8 billion industry in the US (O’Rourke, 2003) and blown glass, the type of glass used to make bottles, accounts for more than 50% of US glass production. The glass container industry is currently experiencing increased growth resulting from the introduction of flavored alcoholic drinks onto the beverage market (Cattaneo, 2001). Blown glass is produced from silica which is then melted. Materials such as lime, dolomite, soda, and cullet may also be added to the melt. The melting furnace is fueled by natural gas, fuel oil, and petroleum gas. Many times, furnaces run on electricity as well. After melting, the glass is refined and then processed into a bottle shape. The Bacardi Corporation and Destilería Serrallés both receive their glass from producers in Mexico and Puerto Rico (World Bank, 1998; Szendrey, 2003; Huertas, 2003). The primary environmental concerns associated with glass production are that the process is extremely energy-intensive and releases gas and liquid residues. The energy-intensive nature of glass manufacturing is largely due to the melting stage of production. A 100% efficient melting process would require 2.3 million BTUs to melt a ton of glass (Sandia, 2002). And because of problems like heat loss and furnace inefficiency, the actual energy needed to melt glass is much higher (DOE, 2003). Also contributing to the high energy usage is the rum companies’ transport of glass from Mexico. This transport requires travel by ship as well as by tanker truck when the glass reaches the island. Gas residues are also released during the transportation of glass. Both ship and truck release pollutants to the atmosphere. Glass manufacturing releases significant levels of SOX, NOX, and particulate matter (EPA, 1986). Glassmaking also releases liquid residue with harmful contaminants (World Bank, 1998). 4.4.2 Box-board After the rum is bottled, the bottles are placed in boxboard cases, usually each holding 12 bottles. Some products however, like Bacardi Silver, are placed in six pack boxboard holders which in turn are placed in other boxes. Corrugated boxboard is used for packaging rum bottles because it is a very light and cheap material, and highly functional for protecting the product and packaging (glass bottle) during shipment. The price of corrugated boxboard is affected by seasonal and cyclical changes. Prices rise when demand increases during the Christmas season and cyclical changes are tied to the overall economy, since the supply of boxboard rises when the economy is doing well, which drives prices down (Solid Waste Department, 1995). The supplier for the boxboard cases for the Bacardi Corporation is Castleton Beverage Corporation, a subsidiary of the Bacardi Corporation based in Jacksonville, Florida. The Castleton Beverage Corporation have managed to make a collapsible partition for the bottles inside the box, allowing for half the bottles to be shipped without any packaging, and the other six can have individual boxes for special seasons, during the summer or holidays. At the same time, it can also be used for regular shipments of 12 bare bottles, without increasing the amount of material used. This new fiberboard partition replaced 22 the corrugated one which was twice as thick, while testing has proved that it provides the same protection to the precious contents of the bottles (Packaging Digest, 1996). 4.5 Product Output: Rum Rum is the product of this manufacturing process. It is defined by U.S. labeling regulations (27CFR5.22) as the “alcoholic distillate from the fermented juice of sugar cane, sugar cane syrup, sugar cane molasses, or other sugar cane by-products, produced at less than 190 deg. proof in such manner that the distillate possesses the taste, aroma and characteristics generally attributed to rum, and bottled at not less than 80 deg. proof; and also includes mixtures solely of such distillates.” 4.6 Non-Product Output: Solid Residue 4.6.1 Mosto The residues from the beer column of the distillation process are known as mosto (see Section 3). This waste stream, organic in nature, is a mixture of sugars (5 to 8% by weight), organic acids, amino acids, proteins, polysaccharides, and inorganic salt complexes (Caribbean Rum Study, 1979). The composition of the mosto depends on the composition of the molasses, which varies by batch (see Section 4.1.1). The mosto stream is estimated to constitute 65% of the volume of the rum effluent and contains over 95% of the pollutants with high concentrations of potassium, chloride and sulfate ions along with low pH (Caribbean Rum Study, 1979; Gottfried, 1986). The present operations at Destilería Serrallés result in the production of 200,000 MGD of mosto per day, which is combined with sludge and wastewater. Destilería Serrallés possesses a land application permit which allows for the disposal of this waste to a leased parcel of land. Destilería Serrallés monitors the soil and groundwater quality on this property for contamination. With the building of a wastewater treatment works underway at the facility, Destilería Serrallés is in a position to consider options for use of the mosto that will eliminate soil degradation which is presently occurring and yield economic benefits. The mosto produced at the Bacardi Corporation is also combined with other waste streams of sludge and wastewater which is then sent to the facilities wastewater treatment plant. After passing through the treatment works, the effluent is discharged to Boca Vieja Bay via a deep ocean outfall. The high biological oxygen demand (“BOD”) is considered to be potentially harmful to marine life. Laboratory analyses performed by the Center for Environment and Energy Research determined that mosto has an 23 adverse effect on low intertidal organisms, though the effect was not noticeable at low concentrations (Gottfried, 1986). The present NPDES permit issued by EPA to the Bacardi Corporation has set stringent standards for the concentration of contaminants in the effluent. On January 25, 2002, the EPA and the Bacardi Corporation reached a $112,500 settlement resulting in an enforcement action taken by EPA Region 2 for failure to seek a permit and the discharge of storm water associated with industrial activity, the discharge of mosto without a permit, and exceeding effluent limits of its current discharge permit. Therefore, finding uses for the mosto will not only yield economic benefits in terms of environmental compliance, but also reduce the environmental harm presently occurring. Bacardi is presently researching opportunities to use the mosto and is operating a pilot project which uses the mosto in the manufacture of animal feed and fertilizers. 4.6.2 End-of-life oak barrels At the end of the 20 year average life span of the oak barrel, both companies sell the residue as a product back into the local economy. Destilería Serrallés sells their end-oflife barrels for $1 each for uses such as landscaping (Huertas, 2003). This transaction improves the economic and environmental performance to the company by defraying the cost of disposing of the material. 4.7 Non-Product Output: Aqueous Residue 4.7.1 Fermentation wastewater (with spent yeast) A sludge waste stream is generated from the fermentation tanks, containing about 9% aledehydes, 0.2% sugars, unfermentable solids and spent yeast. The Caribbean Rum Study (1979) refers to this waste as the “heal of yeast” which must be washed out of the fermentation tanks before the next batch is started. The waste stream therefore contains wash water as well. Destilería Serrallés generates 13,000 gallons per day of this waste stream which is sent along with the mosto and wastewater for land disposal. This waste stream from Bacardi is sent to the wastewater treatment facility, treated and release as effluent via the ocean outfall. 4.7.2 Distillation byproducts: wastewater, fusel oils & aldehydes As detailed in Section 3.2, aqueous organic waste is a significant byproduct of the distillation process. Water is recovered from the stripping column, fusel oil (which can foul the rum) is a by product of both the stripping and rectifying columns, and aldehydes are a byproduct of the rectifying column. 24 The water recovered in the distillation process is co-mingled by both Destilería Serrallés and Bacardi Corporation with its aqueous waste streams and disposed of accordingly. As discussed previously, Bacardi Corporation utilizes and advanced anaerobic wastewater treatment system to abate its waste streams and Destilería Serrallés disposes of its combined waste stream through land application of the residue. Fusel oil and aldehydes are handled differently by the two companies respectively. Fusel oil, a composition of mixed amyl alcohols, is handled in the aqueous waste stream by Destilería Serrallés and captured and sold for artificial flavorings and scents by Bacardi. Bacardi Corporation currently sends its aldehydes to its wastewater treatment works, while Destilería Serrallés collects this material and burns it in its boiler. 4.8 Non-Product Output: Gaseous Residue 4.8.1 Methane Methane (CH4) gas is produced during anaerobic digestion of the aqueous waste streams. Bacardi Corporation currently employs a piping system that re-routes the CH4 back to the boiler to be used as energy. This biogas provides 55-60% of Bacardi’s total energy input (Szendrey, 2003). Destilería Serrallés is currently in the process of building a WWTP to process their mosto and aqueous waste streams. 4.8.2 Sulfur Sulfur escapes in gaseous form as sulfur oxides (SOx), most of which is sulfur dioxide (SO2). This gas is very harmful and can result in respiratory illness, asthma, cardiovascular disease, and chronic lung disease (EPA, 1995). This gas can also combine with other compounds in the atmosphere to form sulfuric acid (H2SO4) that returns to earth as acid rain. The EPA’s health-based national air quality standard for SO2 is 0.03 parts per million (ppm), measured yearly, and 0.14ppm when measured daily. Destilería Serrallés uses fuel No.6 in their boiler, and this fuel contains 1.7% sulfur. Since they use about 2.2 million gallons per year (Serrallés, 2003), that translates to 9700kg/year, of which the 1.7%, or 165kg/year, would be sulfur resulting in 115,000 liters per year of sulfur oxides. The Bacardi Corporation burns both No. 6 oil and methane in their boiler. The methane, or biogas, can contain traces of sulfur as well. Although there is no data on the exact concentration of sulfur in the biogas used at the Bacardi facility, the magnitude of the operation at Bacardi results in the emission of approx. hundreds of thousands to millions of liters per year of sulfur oxides. 4.8.3 Carbon dioxide 25 The CO2 is a byproduct of fossil fuel combustion, such as No. 6 oil and biogas. CO2 and other trace gases are considered by the United Nations Intergovernmental Panel on Climate Change as the primary contributors to global climate change, representing a significant threat to the sustainability of current life on the planet. In addition to the CO2 that is released to the atmosphere as a byproduct of combustion, there is a significant amount of CO2 produced as a byproduct of yeast metabolism during the fermentation process. This gas is collected by both companies. Destilería Serrallés compresses the gas and the Bacardi Corporation liquefies the CO2 where it is then sold to the beverage manufacturing industry. The gas produced by Destilería Serrallés is first sold to a local gas manufacturer distributor, Aga Gas, prior to use for carbonated beverage manufacture. Destilería Serrallés produces about 45,000 pounds of CO2 per day, and Bacardi 140,000 pounds per day. 4.8.4 Carbon monoxide Carbon monoxide is a poisonous compound that results from the incomplete combustion of fuel. It is a colorless and odorless gas, so it can go undetected even in high concentrations, causing nausea and headaches, or more serious health problems and even death (Consumer Product Safety Commission, 2003). The EPA health-based national air quality standard is 9ppm measured as an annual second-maximum 8-hour average concentration (EPA, 1995). The amount of CO produced is dependent on temperature and operating conditions during combustion, such as mixing of air with the fuel during burning. 4.8.5 Nitrous oxides The nitrous oxide gases (NOx) include nitric monoxide (NO) and nitrogen dioxide (NO2), both of which are in the gaseous form at atmospheric pressure and temperature. NOx gases are highly poisonous and potentially deadly in high concentrations (Environmental Defense, 2002). They also play an important role in the creation of smog, react with other compounds to form acids, resulting in acid rain and facilitate the formation of ozone, which is also poisonous (EPA, 1995). NOx gases are created when fuels are burned at high temperatures. However, by changing operating conditions and lower temperatures, these emissions can be reduced. 5.0 Life Cycle Analysis 5.1 Streamlined Life Cycle Analysis: Bacardi Corporation A Streamlined Life Cycle Analysis (SLCA) was performed to analyze the rum production process at the Bacardi Corporation facility in Cataño, Puerto Rico. This SLCA is designed to prioritize the aspects of the production process that could be improved from 26 an environmental standpoint. The life cycle stages in the SLCA are: pre-manufacture, product manufacture, product packaging, product use, and recycle disposal. The environmental concerns are: material choice, energy use, solid residue, liquid residue, and gaseous residue. All grid elements in the SLCA therefore describe an environmental concern for the product at a particular point in the product life cycle. When assessing of a product’s environmental performance, each grid element is rated on an integer scale of 0 to 4, with 0 representing a very negative environmental impact and 4 representing a very low environmental impact. 5.1.1 Pre-Manufacture The pre-manufacturing stage received mixed scores for environmental performance. For evaluation of material choice, four major inputs to rum production were identified: glass, molasses, yeast, and water. The choice of material is fixed. Rum distilleries must use molasses, yeast, and water to create the final rum product; there are no alternate forms of these materials that can be used which could be more environmentally sound. The only input which could be optimized is the container packaging, which is currently made from glass. Because the materials currently used as inputs in rum production are the best of available choices, this box is scored a 4 indicating a low environmental impact. Energy use is scored a 2 because glass production is energy intensive and many input materials are transported from sources overseas (DOE, 2002). Other inputs, such as water and yeast, require relatively little energy. The solid residue aspect of the pre-manufacturing stage is scored a 4 because little solid residues are produced from the production of glass, molasses, yeast, nutrients or water use. Liquid residues associated with pre-manufacture are scored a 3. A World Bank report on the glass industry states: “In blowing and pressing, pollutants in effluents are generated by finishing processes such as cutting, grinding, polishing and etching. The pollutants include suspended solids, fluorides, lead, and variations in pH (World Bank, 1998). Molasses production produces wastewater, with a minor contribution from yeast. Gaseous residue was scored a 2 and is a point of concern in pre-manufacture. Glass production produces particulate residue at the rate of 17.4 lbs./ton, and SOx and NOx at the rates of 5.6 and 8.5 lbs./ton, respectively, with most glass facilities producing between 50 and 300 tons of glass per day (World Bank, 1998). In addition, glass shipment to the Bacardi facility by both ship and tanker truck produces a lot of gaseous residue. Molasses production also creates gaseous residue (Packaging Digest, 2002). The other two inputs, water and yeast, contribute very little gaseous residue. 5.1.2 Product Manufacture Product manufacturing was, on the whole, a source of environmental concern with most boxes scored a 2. For every gallon of alcohol produced, Bacardi generates 14-15 gallons of waste (Szendrey, 2003). The first environmental concern is material choice, which is more or less dictated by the nature of the product. As stated in the premanufacturing section, rum distilleries must use certain ingredients to achieve the desired product. There is little room to choose different materials. The next 27 environmental concern is energy use. The Bacardi distillery must use a large amount of energy to operate its numerous distillation tanks, boilers, fermentation tanks, control rooms, etc. Energy use is therefore very intensive and is rated with a 2. Solid residue is a great concern for Bacardi. Most solid residue results from the generation of mosto, a byproduct of the fermentation. Mosto has high BOD, meaning that it can significantly reduce dissolved oxygen levels in receiving waters. Therefore, the “solid residue” box is labeled with a 2. Liquid residue results from the fermentation and distillation processes. Finally, major gaseous residues take the form of CO2, NOx, and SOx. The “gaseous residues” box was labeled with a 2. 5.1.3 Product Packaging The packaging of rum has two components to consider, the bottles, including labels and caps, and the boxboard cases, which usually contain 12 bottles each. The bottles are made of glass, and are provided by local manufacturers in Puerto Rico and from nearby Mexico, and the caps are made of metal. The cases are made of recycled boxboard, and bottle partitions are made of a new generation of fiberboard which protects the bottles while using half the material than ordinary partitions (Hartman, 2002). Bacardi has switched to a new bottle and a more expensive pressure-sensitive label which require more energy and thus more money (Packaging Digest, 2002). Therefore, material choice is scored a 4 and energy use is scored a 3 for packaging. The packaging process also involves some solid residues from the waste boxboard and glass, and negligible liquid or gaseous residues, so solid waste is scored a 3 and liquid and gaseous residues scored a 4. 5.1.4 Product Use The product use of rum is the act of consumption or drinking, by people. The resultant waste is from the human body is mostly liquid in addition to the bottles and boxboard packaging that must be disposed of. The material choice or energy use is negligible at this stage and are scored a 4. The solid residues are mostly the empty containers, which can be either recycled or discarded. Because they can have some negative impact, especially since the rate of recycling is comparatively low in both Puerto Rico and in the United States to other developed economies, solid residues are scored a 3. The liquid residues are the liquid body waste, which having no large impact, get a 4, and there are no gaseous residues, so we give the same score for them as well. 5.1.5 Recycling The materials left after the consumption of the rum, mostly glass and boxboard, are both easily recyclable, scoring a 4 for material choice. However, some problems arise in both cases. The glass recycling process requires a high input of energy, but that is less than the energy required to make the glass originally. Recycling boxboard does not require much energy, but it is important to remove any contaminants before doing so. The overall energy use for recycling turns out to be important, but not excessive scoring a 3. These processes also create some waste. In terms of solid waste, some 28 parts of the bottles, especially the caps, or bottles contaminated with chemicals, have to be removed, and discarded. Contaminated boxboard is also discarded scoring a 3 for solid residues. The boxboard recycling process also involves using some chemicals, such as bleach for whitening, which can be very harmful. Glass recycling does not have any significant liquid wastes, but the high environmental impact from the boxboard recycling process scores a 2. Finally, some gaseous residues are formed in the combustion gases for melting the glass, as well as small quantities of noxious fumes, but less so than when new glass is being made, scoring a 3 for gaseous residues, while boxboard recycling does not produce any gaseous residues. 5.2 Life Cycle Analysis: Destilería Serrallés A Life Cycle Analysis (LCA) was performed for the ‘Production’ and ‘Use’ stages of Destilería Serrallés rum life cycle. Because the processes at both the Destilería Serrallés and Bacardi Corporation facilities are similar, Section 5.1 provides a strong overview of the materials and impacts associated with the life cycle of rum in general. For Destilería Serrallés specifically, the data is normalized so that the amounts of material recorded (Tables 1) represent the required inputs and outputs generated for one glass 750 mL bottle of Serrallés dark rum. This analysis assesses masses and volumes of inputs and outputs using either measurement where appropriate. The methodology and calculations are available in Appendix A. Solids are represented by the letter (s), aqueous solutions by (aq), gases by (g), and ND means “no data”. Solids are measured in grams (except for the yeast and mosto being that the density of these materials is unknown), while aqueous solutions and gases are measured in liters (except for Cl2 gas because the density and storage pressure are unknown). Based on the outcome of the SLCA for Bacardi Corporation indicating that the production stage is the largest contributor in terms of materials and environmental impact, the “Use” and “End-of-Life” stages are not included in this assessment. For a discussion of these stages in life cycle of rum, see Sections 5.1.4 and 5.1.5. 5.2.1 Production Inputs For input solid flows, ammonium sulfate and glass are the largest contributors, representing over 90% of all inputs to production, as measured by mass. For aqueous solutions, water is 93.1% of the flow followed by molasses at about 6.7%. Chlorine is the only gaseous input. Across all inputs, water is the largest contributor as a function of volume or mass (density = 1 g per ml). 5.2.2 Production Outputs For output solid flows, mosto and wood are the dominant contributors (assuming the mosto is at least as dense as the molasses). For aqueous solutions, wastewater occupies about 73.6% of the outflow while the final product, rum, occuppies 26.4%. The 29 largest gaseous output is CO2. Across all outputs, mosto and aqueous wastewater are roughly equal as the largest contributors in terms of volume or mass. For each 750 mL bottle produced, 2 L each of mosto and aqueous wastewater are produced. Table 4. Input and Output Flows of Materials in Production Stage of Rum Life Cycle Inputs Type (aq) molasses (s) yeast (aq) H2SO4 (s) (NH4)2SO4 (s) oak barrels (s) glass (s) boxboard (s) plastic bottle caps electricity (aq) no. 6 Oil (aq) water: filtered (aq) water: filtered & deionized (s) polyaluminum chloride (s) activated charcoal (g) Cl2 landuse 5.3 Qty .48 L .24 L 0.0011 L 4.19 g 2.28E-5 g 403.7 g ND ND ND .067 L 5.55 L 1.11 L 1.88E-16 g 0.002 g 0.0066 g 206,000 m2 Outputs Type (s) mosto (s) wood (s) metal (aq) waste water (aq) rum (g) S (g) CO (g) CO2 (g) NOx Qty 2L 2.26E-5 g 2.28E-7 g 2.09 L 0.75 L .001 L ND .75 L ND SLCA/LCA Priorities for Industrial Symbiosis Combining the outcomes of the SLCA and LCA provide an excellent means of prioritizing opportunities for industrial symbiosis in the rum industry. An overview of the SLCA indicates that the highest priority materials are related to: energy use and gaseous residues associated with the manufacture and transportation of the glass packaging; energy use, solid, aqueous and gaseous residue associated with the rum manufacturing; and the environmental impact associated with boxboard recycling. An overview of the LCA indicates that the highest priorities within the manufacturing process are: glass; input water; mosto; wastewater; and carbon dioxide. Tables 4 and 5 provide a comprehensive ranking of these materials based on the SLCA/LCA outcomes with materials scored either (H) high, (M) medium, or (L) low priority based on the following criteria. In terms of the SLCA, all aspects of the life cycle that scored a 2 or below are ranked a (H) high priority. A score of 3 is ranked (M) medium priority and a score of 4 or higher is ranked a (L) low priority. In terms of the LCA, all materials that represented over 50% of input or output type is ranked a (H) high priority for industrial symbiosis. All materials with negligible proportions of the inputs or outputs are ranked (L) priority, while the remainder is ranked (M) medium priority. The summary rank is assessed by taking material choice into consideration. 30 6.0 Industrial Symbiosis Opportunities The combined SLCA/LCA methodology provides the basis for investigating opportunities for industrial symbiosis in the rum industry in Puerto Rico. These assessments highlight materials of concern in production inputs and outputs where industrial symbiosis may provide a direct benefit to the firms. Figure 8 shows the current and proposed industrial symbiosis opportunities discussed below. 6.1 High Priority: Inputs 6.1.1 Water Industrial symbiotic linkages from other firms that have treated water as an output of their process or from their waste treatment facilities can provide water to the rum industry the process. The treated water may also be sourced from the wastewater treatment operations of the rum industry. Input of water from these sources will decrease the demand on the municipal and well supply. Figure 8. Current and Proposed Industrial Symbiosis Relationships 31 6.1.2 Glass Recycled glass has lower energy input requirements than glass manufactured from raw materials, therefore closing the recycling loop across the whole island could yield potentially positive environmental and economic benefits due to the costs associated with the manufacture and transportation of glass from off the island. Because the recycling rate in Puerto Rico is low, as compared to the U.S. as a whole, potential business opportunities exist for companies such as Owens Illinois in Vega Baja to facilitate the collection of glass for recycling at their facility for the Puerto Rican market, particularly the rum industry. Potential cost savings could be offset by the high price of energy in Puerto Rico, however a net environmental benefit would still exist. Nonconforming glass discovered during bottling can also be sent to recycling facilities on the island. 32 6.2 High Priority: Outputs 6.2.1 Mosto The organic nature of the mosto renders it useful for fertilizers, animal feeds and industrial waxes. The dried solid can be used as an organic fertilizer, a useful byproduct for which symbiotic linkages with other industries such as agriculture can be developed. Research sponsored by the Bacardi Corporation has shown that the material, can improve pH, fertility, porosity and structure of soil (Szendrey, 2003). The environmental benefits of using this material as fertilizer include its pest control properties. The use of this material therefore can decrease the need for chemical pesticides, known to degrade surface and groundwater quality proving both an economic and environmental benefit to the farmer. As the primary market for molasses is animal feed (see Section 4.1.1), it would follow that the mosto could be useful for this purpose as well. The dried solid contains approx. 45% protein and contains vitamins and minerals that make the byproduct useful as animal feed for aquaculture, poultry and sheep diets. The production of animal feed from mosto is approved by the Department of Agriculture and can be produced at a lower cost than soymeal in Puerto Rico (Szendrey, 2003). The economic benefits of using the dried solids as feed include a 15% tax credit on the value of the import soymeal replaced (Szendrey, 2003). After the usable sugars have been removed from the molasses to make the rum, the solid waste generated contains sugarcane waxes which have industrial applications, in particular for the cosmetic and pharmaceutical industry (Nuissier et al, 2002). The waxes present can serve as a substitute for costly carnauba wax which is presently widely used in cosmetic, foods and pharmaceuticals. The isolation and sale of these waxes represents a potential industrial symbiotic opportunity which can create a new market and add to the revenue of the rum company. 6.2.2 Waste water Ideally, the wastewater can be treated to remove mosto to reclaim water which can be rerouted for purposes including landscaping, irrigation, and use at fire stations. Destilería Serrallés is presently considering using this water to irrigate a nearby golf course they own. For both Bacardi Corporation and Destilería Serrallés, the treated water can also be reused as an input into the process reducing the demand from their wells and closing the loop on this input and output in the production process. Expensive capital improvements in the water treatment systems would be necessary to treat the water to the standards both companies currently have for input water. 33 6.2.3 CO2 CO2 is presently being sold to drink manufacturers, and this material exchange is an example of an existing industrial symbiotic linkage that both Bacardi Corporation and Destilería Serrallés employ. This is further discussed in Section 4.8.3. Other potential uses for this material include use as refrigerator coolant; fire suppression; and in welding operations and cement companies. 6.3 Medium Priority: Inputs 6.3.1 No.6 oil Substitution of this material with a cleaner and more environmentally benign fuel is a potential opportunity to offset environmental issues related to the use of this fuel. One byproduct of the anaerobic wastewater treatment system, currently employed at Bacardi Corporation and soon to be in use at Destilería Serrallés, is methane gas (see Section 4.8.1). Maximizing the treatment process for methane production is one avenue of substituting for this material. 6.3.2 Boxboard Boxboard is a significant contributor of landfill waste of Puerto Rico. Similar to the potential opportunity explored for glass (see Section 6.1.2), the rum industry could obtain its boxboard from local suppliers of recycled materials and close the loop on boxboard in Puerto Rico while expanding business opportunities on the island. 6.4 Medium Priority: Outputs 6.4.1 NOx Since NOx is formed as a function of the heat of the combustion reaction, controlling for NOx emissions can be difficult. This is especially the case because lower combustion temperatures can increase opacity and CO in stack emissions. 6.4.2. Fusel Oils Fusel oils can be isolated and sold as flavorings. This is presently being done by Bacardi Corporation and exhibits a material exchange from which revenue is generated. Destilería Serrallés can make use of this fusel oil by recovering it and selling it to food manufacturing industries, creating an industrial symbiosis linkage. 6.5 Low Priority: Inputs and Outputs These materials identified by the LCA and the SLCA as low priorities for industrial symbiosis have not been investigated thoroughly. The existing industrial symbiotic 34 relationships for materials that are in this category include purchasing of oak barrels from the whiskey industry and the purchasing of molasses as a byproduct of the sugar industry. Table 5. Recommendations for Industrial symbiosis opportunities in the rum industry Material Type Recommendations Firm IS Type LCA Priority Environmental Performance Economic Performance NPO Isolation of waxes from mosto for cosmetics and pharmaceuticals B, S 4 H H M NPO Use dried solids from mosto waste stream as animal feed B, S 4 H H H NPO Use dried solids from mosto waste stream as fertilizer B,S 4 H H H NPO Separate fusel oils and sell as Flavorings and artificial scents S 4 - H H NPO Send dried mosto to wasteto-energy facility B, S 4 H M L Energy Use methane generated from anaerobic digester for steam generation B, S 2 M H H Energy Use captured CO2 for filling onsite fire extinguishers B 2 H H L B 2 H H M B, S 2,4 H H M Use treated water for fire extinguishing at onsite station Use treated water for non potable uses such as landscaping Water Water Water Use treated water back in the processing of rum B,S 2 H H H Packaging Send non-conforming glass bottles to glass recycling facility B, S 4 H H L Packaging Use recycled boxboard B,S 4 M H H Packaging Use recycled glass B, S 4 H H H Legend IS Type B S NPO Types 1, 2, 3,4 as defined in Section 1.1 Bacardi Corporation Destilería Serrallés Non product output 35 6.6 Evaluation of the Proposed Industrial Symbiosis Opportunities The application of industrial symbiosis to the rum industry can be seen in improvements in both economic and environmental performance. Recommendations that can aid in the realization of this goal of improved performance are listed in the table below. For LCA priority, environmental performance and economic performance the recommendations are rated on a scale of high, medium, and low. The rating for the LCA priority is described in section 5.3. Recommendations that offer at least three environmental performance improvements including reduction of pollution and environmental damage, reduction of consumption of natural resources and approaching sustainability are rated as high. Those that offer less performance improvements are scored medium and low subjectively. Recommendations that can realize economic improvements by saving the company money on resource input through closing loops, increasing company revenue through by-product sales, and creation of new markets are scored high. Medium and low economic performances are scored in relation to high scoring recommendations. The recommendations are also diagrammed on the 3x3 matrix. The matrix is useful in visually representing where the efforts for industrial symbiosis can begin. Recommendations considered ideal for the present situation fall in the upper right hand corner with high environmental performance and high economic performance. 36 Figure 9. Criteria Matrix for Industrial Symbiosis Recommendations 37 7.0 Conclusion This research of the rum industry revealed that industrial symbiosis is presently being used to improve the economic and environmental performance, through revenue generated from the sale of by-products carbon dioxide, fusel oils and reuse of methane. Both Bacardi Corporation and Destilería Serrallés are in a position to take advantage of further industrial symbiotic linkages. Bacardi Corporation, with greater financial resources and a larger scale of operations than Destilería Serrallés, can move from the pilot project stage of mosto research to implementation of operations that allow for the sale of the dried mosto. With the development of the wastewater treatment facility, Destilería Serrallés can position itself to generate numerous by-products sales and close loops in their process, thus increasing their revenue and environmental performance. It is proposed that both Bacardi Corporation and Destilería Serrallés implement a system that creates industrial symbiotic linkages that focuses on both short term and long term opportunities that will eventually allow the operations of the rum industry in Puerto Rico to achieve sustainability. Such a system uses continuous life cycle assessments to target areas that industrial symbiosis can greatly benefit using the model described in this report in Sections 5, identifies opportunities through research and information sharing (a potential symbiotic linkage itself), and implements them based on available financial resources and market opportunities. The existing symbiotic opportunities should be maintained as long as it is feasible. The recommendations, such as those proposed by the research team should be carefully evaluated for economic feasibility and environmental improvement using ranking methods such as the one described in Section 6.0, and then move to the implementation phase. Constraints to implementing ideas such as political/ legal impediments must be considered as these may render them infeasible. The recommendations proposed in Table 5 are a good starting point for both Bacardi Corporation and Destilería Serrallés. It is important that the rum industry continue to do life cycle assessments after implementation of ideas so that it can track its progress on the road to sustainability and also reveal new areas that can be addressed. While engaging in short tem symbiotic linkages, the rum industry must consider long term opportunities for industrial symbiosis as the industry is a significant sector in Puerto Rico’s economy and cultural history, and can be a key player as the island aims to achieve sustainability. The development of eco-industrial parks, similar to the Kalundborg example, can allow for the creation of new businesses such as recycling glass and boxboard, strengthen existing ones, and increase the interconnectedness of industrial sectors in Puerto Rico. This will allow environmental and economic benefits for the rum industry, while positively contributing to the sustainability of Puerto Rico. 38