Environmental impacts of a processing operation (PHB) - Case Study Example

SUSTAINABILITY REPORT FOR PHB PRODUCTION 1. ENVIRONMENTAL SUSTAINABILITY Environmental impacts of a processing operation is worth considering in order to ascertain the environmental sustainability of the PHB plant. To maintain a sustainable environment, aspects of environment such as resource usage, raw materials, effluents and wastes, and energy consumption and environmental effects of the product have to be taken into account (Gavrilescua & Chisti, 2005). The plant must be operated in a way that it complies to the environmental policies and regulations set by the Local Government of Victoria. Some plant operations may cause detrimental effects to the environment, and for this reason, it is important to quantify these effects where possible and take mitigation measures. 1.1 Environmental Resource Usage Air Usage Air is a required component in various streams of the PHB production process. This is a natural resource that has to be considered in this industrial process as seen in Chapter 9 of the feasibility report (mass balance). The table below shows the air usage of the plant. Table 1: Air usage. Plant Section Stream number Air Inlet/Mass flow rate (kg/hr.) Air Outlet/Mass flow rate (kg/hr.) Fermentation 13 Oxygen/ 32,525 14 CO2/ 12757.17 N2/ 25694.75 The process requires 32, 525 kg of oxygen per hour. Assuming that oxygen takes only 21% of air, this is equivalent to 154.88 tonnes of air on hourly basis. Water Usage Water is one essential resource in the environment that is required in the process of PHB production. Every processing plant uses water at some point in the production process. The quantities of water required in the PHB production plant have been determined in the mass balance section of the feasibility report. Table 2 shows the water requirements of the plant. Table 2: Water usage Plant Section Stream number Water Inlet/Mass flow rate (kg/hr.) Water Outlet/Mass flow rate (kg/hr.) Pretreatment of molasses 2 17424.00 11 6305.00 Fermentation 14 6387.81 Centrifugation (1st pass) (2nd and 3rd pass) 15 6387.81 16 2427.37 17 3960.444 20 3960.44 21+25 2376.26 24 3877.97 TOTAL 40414.294 (40.41m3) 12692.81 = (12.70m3) The water requirement in one production season is 232,761.6 m3. The water outlet from the pretreatment and fermentation process in one production season is 73,152 m3. Land Usage The PHB plant is to utilize 33 tonnes of molasses per hour obtained from 165 tonnes of raw sugar, which equals to 190, 080 tonnes of molasses annually if the plant operates for 8 months a year, 24 hours a day. This is dependent on the sugar crushing capacity of Victoria Sugar Mill. According to Australian Sugar Milling Council, (2014), sugar production in Victoria is 80-97 tonnes per ha. On average, this is about 89 tonnes per ha. The sugar mill requires 950,400 tonnes of sugar per season, which is equivalent to 10,680 ha of land. This is also the land required for the PHB plant since it is dependent on the operation capacity of the sugar mill. The PHB plant will be an extension of the existing Victoria Sugar Mill. A land area of about 1000 m by 500 m is proposed to be occupied by equipment and facilities for the process and an effluent treatment and water land fill system. 1.2 Environmental Raw Materials Table 3 lists the raw materials required in the production of PHB. Table 3: Use of raw materials Raw Material Stream Quantity (kg/hour) Raw molasses (feeder) 1 33,000.00 Bacteria (E. coli cells) 12 3.36 Calcium hydroxide, Ca(OH)2 8 8.00 Concentrated sulphuric acid 6 10.00 HAZOP analyses of these raw materials reported in the feasibility study indicate that they are harmful not only to humans, but also to the environment if not handled carefully. Where possible, it is recommended to recycle raw materials in order to have an environmentally sustainable production process. For example, ethanol is used as a solvent to extract PHB at downstream. This material can be recovered by converting it back to the initial state. While it may be challenging to recover other materials, using them efficiently is key to reducing the environmental effects caused by products. 1.3 Environmental Products The main product of the bioprocess plant is 23,985 PHB. The main environmental issues associated with PHB include: land contamination, waste disposal, Life cycle assessment and biodegradability. From the HAZID and HAZOP analysis, the raw materials used in this process pose a great danger to the environmental if not handled properly. Land contamination may also occur if materials like sulphuric acid or untreated effluent water find their way into the land. Emissions of carbon (IV) oxide gas into the environment contribute to accumulation of greenhouse gases. The waste materials associated with the production of PHB are discussed in section 5. Biodegradable plastics have to exhibit, tensile strength, chemical resistance and gas permeability in order to be useful in food packaging. If biodegradable plastic is recycled, the material’s physical properties can change, allowing external contaminants and degraded chemical compounds to enter the packed food. In addition, it can be difficult to recycle plastics contaminated with food (Flint, 2013). 1.4 Environmental Energy Victoria Sugar Mill burns about 881, 000 tonnes of bagasse annually to provide 24 MW of power for the plant use. The company exports 55% of the total power generated to the grid (Rural Industries Research and Development Corporation, 2013). As the PHB plant will be located proximal to the sugar mill, it will utilize this power in its processes. Power consumption should be minimized to reduce greenhouse gas emissions and production costs. From the feasibility report on process energy balance, the energy required to produce PHB is shown in table 4 below: Table 4: Usage Energy Process section Energy Requirement (kilowatts/tonne) Fermentation 179.3 Centrifugation 30 Drying 28.01 TOTAL 237.31 Efficient use of energy can be achieved through improvement of the fermentation process, improvement of the product recovery steps, and betterment in processing steps at downstream (Bharti & Swetha, 2016). For instance, considering energy balance, 856.321 kW of energy is produced as a result of exothermic reaction in the fermenter – which could be utilized in the drier section. These handling techniques can substantially reduce the cost of production. 1.5 Environmental Emissions/Effluent Identification & Treatment Table 5 summarizes the effluents generated in each step of the process. Process step Effluent Quantity (kg/hr.) Feed pre-treatment Molasses, E. coli, Sulphuric acid 26343.5 Fermentation Carbon dioxide, Molasses, E. coli, water 51336.36 Centrifugation Nitrogen, Carbon dioxide 13323.12 Drying Nitrogen, Carbon dioxide, water 12614.94 TOTAL 103617.92 2. ECONOMIC SUSTAINABILITY Economic sustainability is an organization’s capacity to operate efficiently using the available resources while gaining profits out of its operations. It creates an economic friendly environment where investor financial returns contribute to economic growth, not only for the processing company, but also the national economy. The main factors that will largely affect the economic sustainability of PHB are cost of raw materials, cost of energy consumption, and product supply and demand. The economic cost of goods, value added and gross margin are the three important indicators used to quantify economic sustainability (Dewulf, et al., 2016). 2.1 Economic Cost of Goods The cost of goods is the total of direct costs incurred in the production of one unit of PHB. This cost includes the cost of raw materials, utilities and labour, and it excludes the cost of product distribution. The feasibility study done on the initial techno-economic evaluations of the production process indicated that it costs an average of $ 5.85 to produce a kilogram of PHB. This is equivalent to $ 5850.00 per tonne. 2.2 Economic Value Added Value addition is the sales revenue obtained from product sales, excluding the cost of manufacturing, labour cost and depreciation cost. This value contributes to the country’s GDP and is the basis on which VAT is calculated. Initial techno-economic evaluations in the feasibility report indicate that the average selling price of PHB is $ 15.00. This means that the economic value added to a kilogram of PHB is $ 9.15, equivalent to $ 9150.00 per tonne. 2.3 Economic Gross Margin Economic gross margin is useful in the determination of the value of incremental sales and is considered when pricing a product in the market. It is obtained by finding the difference between the total sales revenue and the total cost of manufacturing and expressing as a percentage. The percentage of gross margin of PHB is calculated as follows: } 3. SOCIAL SUSTAINABILITY Social responsibility refers to the ability of an organization or company to maintain or improve the socio-economic status of the community around it through provision of employment opportunities, participation in community development activities, education, public health and safety, cultural activities, and environmental care programs. Social sustainability helps a company to integrate its operations into the community and benefit from social support from the community (Haynes, et al., 2012). 3.1 Social Employment The construction of the PHB production plant will bring numerous employment opportunities ranging from skilled, semi-skilled and unskilled labour. During the implementation, construction workers will be required to run the actual construction of the plant. Many unit processes are involved in the PHB production including Rotary vacuum filtration, Membrane filtration, Flotation, Pressure filtration, Candle filtration among others. These operations require different skills to run which offers excellent employment opportunities. The community will be incorporated in the employment cycle. Unskilled labour should be provided by the community. Semi-skilled labour and skilled labour might be imported to supplement the gaps that cannot be filled by the community. Since the PHB production is a new venture in the township of Ingham, it is expected to offer competitive positions ranging from management positions, supervisory and other position due to the opportunity to grow start and develop a career. The employment opportunities created will be beneficial to the local communities, government and the company. Employing of locals will greatly foster a good relationship between the company and community. For PHB production to be effective and efficient, extensive training and skill development will have to be conducted to employees. The training will increase the employees’ confidence which is very important to the company. While employing it is important to take into consideration equity in terms of gender. It is also important to consider already skilled community members for employment. So as to attract locals with strong desire to achieve, incentives e.g. scholarship, this also helps foster a good relationship. Production of PHB is a long term continuous project. Having high qualified employees’ and retaining them is important since they will be mentors for future new employees or even become trainers when the company opens other branches. 3.2 Social Education For a successful project implementation the community in which the project is to be situated has to have a positive impression of the project. It is of great importance to educate the community about the general expectation and changes that will occur due to the presence of the project. Project background, people involved in the project and exact location to build the plant should be well understood by the community. For a good relationship between the company and the community, it is necessary for the community to be educated on the short term and long term benefits of having PHB production plant within their locality. The PHB production plant is to be located as near as possible to Victoria Mill sugar cane plant in the township of Ingham (from feasibility study). This will not be perceived as a new project but an extension of the existing one. The community will be educated on the benefits they will reap from the establishment of the plant. Education enables the community to own the project and this fosters a positive beneficial relationship. Education on safety operations for those who will be employed is important in ensuring that unnecessary accidents and delays are eliminated. Safety education should be conducted. Information on effluent disposal and how shared community resources e.g. water will be protected must be clearly dealt with. To ensure the community does not hesitate or have divided opinion about the project, workshops and seminars should be conducted around the community. Concern raised should be enlisted and cleared to ensure production will not be halted or disrupted due to future community resistance. Community education should not stop after project implementation but it should be continuous since there will be changes as production continues, e.g. technology, waste management and possibility of expansion. 3.4 Social Health Social health is the general wellbeing of a group of people. PHB is a biodegradable product hence its disposal is not a health concern. The raw material used to manufacture PHB is molasses which is food to the E-coli microorganism. E-coli is a pathogenic bacterium that causes infection of the large intestine when it makes its way into the body from vector born transmission such as touching un-sanitized, surfaces leading to gastroenteritis and diarrhea (from feasibility study).Safety precaution must be put in place to ensure people in contact are fully protected. Protective gear must be provided to employees handling this process. Any leakage spill over must be cleaned and surfaces sterilized. The use of sulfuric acid for pretreatment of molasses is a health and environmental concern. Sulfuric acid is a strong acid with high corrosion effect on living tissues e.g. skin. Sulfuric acid causes chemical burns when it comes into contact with the skin by the process of hydrolysis; it also causes thermal burns by the process of dehydration. When it is ingested the damage caused is irreversible and might lead to death. It should never get into contact with the eye since it might cause blindness. Prolonged exposure to sulfuric acid vapour may lead to respiratory problems. When working in environment containing sulfuric acid, safety goggles must always be put on; acid resistant clothing complete with boots must also be worn. As an emergency precaution a shower must be installed within the vicinity of the working location. Employees must be trained on safety precautions from time to time. It is also important to provide medical cover to employees and their dependents. 3.5 Social Culture This is the general acceptable belief, knowledge, language, customs, morals and habits of a given group of people. Every community has a unique culture that guides its associations. Understanding the culturally accepted norms is important in avoiding community conflict with the project. It is also important to protect and the traditions throughout the project cycle and life. Decisions that directly affect the community should be critically analyzed. PHB production is an extension of Victoria Mill sugar cane plant hence it may not offer great cultural resistance since the mother project is in existence. The location of the project must be carefully selected (from feasibility study) to ensure that it doesn’t infringe into regions that are of cultural importance to the community, government and the country. This location is intended to be as close to the sugar milling plant as possible, so that the two plants operate almost in the same way. Failure to take into consideration culture may result into the community being hostile, uncooperative and this will negatively affect the production process or even halt production. References Read More

Biodegradable plastics have to exhibit, tensile strength, chemical resistance and gas permeability in order to be useful in food packaging. If biodegradable plastic is recycled, the material’s physical properties can change, allowing external contaminants and degraded chemical compounds to enter the packed food. In addition, it can be difficult to recycle plastics contaminated with food (Flint, 2013). 1.4 Environmental Energy Victoria Sugar Mill burns about 881, 000 tonnes of bagasse annually to provide 24 MW of power for the plant use.

The company exports 55% of the total power generated to the grid (Rural Industries Research and Development Corporation, 2013). As the PHB plant will be located proximal to the sugar mill, it will utilize this power in its processes. Power consumption should be minimized to reduce greenhouse gas emissions and production costs. From the feasibility report on process energy balance, the energy required to produce PHB is shown in table 4 below: Table 4: Usage Energy Process section Energy Requirement (kilowatts/tonne) Fermentation 179.

3 Centrifugation 30 Drying 28.01 TOTAL 237.31 Efficient use of energy can be achieved through improvement of the fermentation process, improvement of the product recovery steps, and betterment in processing steps at downstream (Bharti & Swetha, 2016). For instance, considering energy balance, 856.321 kW of energy is produced as a result of exothermic reaction in the fermenter – which could be utilized in the drier section. These handling techniques can substantially reduce the cost of production. 1.5 Environmental Emissions/Effluent Identification & Treatment Table 5 summarizes the effluents generated in each step of the process.

Process step Effluent Quantity (kg/hr.) Feed pre-treatment Molasses, E. coli, Sulphuric acid 26343.5 Fermentation Carbon dioxide, Molasses, E. coli, water 51336.36 Centrifugation Nitrogen, Carbon dioxide 13323.12 Drying Nitrogen, Carbon dioxide, water 12614.94 TOTAL 103617.92 2. ECONOMIC SUSTAINABILITY Economic sustainability is an organization’s capacity to operate efficiently using the available resources while gaining profits out of its operations. It creates an economic friendly environment where investor financial returns contribute to economic growth, not only for the processing company, but also the national economy.

The main factors that will largely affect the economic sustainability of PHB are cost of raw materials, cost of energy consumption, and product supply and demand. The economic cost of goods, value added and gross margin are the three important indicators used to quantify economic sustainability (Dewulf, et al., 2016). 2.1 Economic Cost of Goods The cost of goods is the total of direct costs incurred in the production of one unit of PHB. This cost includes the cost of raw materials, utilities and labour, and it excludes the cost of product distribution.

The feasibility study done on the initial techno-economic evaluations of the production process indicated that it costs an average of $ 5.85 to produce a kilogram of PHB. This is equivalent to $ 5850.00 per tonne. 2.2 Economic Value Added Value addition is the sales revenue obtained from product sales, excluding the cost of manufacturing, labour cost and depreciation cost. This value contributes to the country’s GDP and is the basis on which VAT is calculated. Initial techno-economic evaluations in the feasibility report indicate that the average selling price of PHB is $ 15.00. This means that the economic value added to a kilogram of PHB is $ 9.

15, equivalent to $ 9150.00 per tonne. 2.3 Economic Gross Margin Economic gross margin is useful in the determination of the value of incremental sales and is considered when pricing a product in the market. It is obtained by finding the difference between the total sales revenue and the total cost of manufacturing and expressing as a percentage. The percentage of gross margin of PHB is calculated as follows: } 3.

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