Final report

LETTER OF TRANSMITTAL

Dear Mr. Blackstone, 

                                                                                                

Re: Proposal for Implementation of Food Waste Recycling Technology in SIT Punggol 

This letter is prepared in response to the call for proposals regarding an engineering issue in Singapore to improve the recyclability of food waste. In this proposal, the team has identified that the new campus at SIT@Punggol, can be a test-bed for exploring the potential combination of technologies to further reduce food waste. This report has been prepared with the intention of implementing a food waste recycling machine that combines technologies of converting food waste into by-products such as reusable water and fertilizers. 

The report consists of a description of the current machines using recycling technologies, the rationale behind the proposed solutions, an evaluation of the benefits, and a detailed summary of all related primary and secondary research. As we aim to reduce the overall food wastage in Singapore, using SIT Punggol as a stepping stone, we have provided information on the integration of using these technologies and an analysis on how this machine can further reduce the amount of food wastage being sent for incineration.  

We would like to express our gratitude to you for taking the time to read this proposal. Your consideration of our suggestions in improving food waste practice in our future campus so as to help reduce food waste and conserve the environment. 

Yours sincerely,     

                                                                                           

Angela 

On behalf of Econopy 

Civil Engineering programme 

CVE1281 Effective Communication 

PERSONAL STATEMENT

Angela Hwee Sook Yee

Angela, a student from Singapore Institute of Technology (SIT), is currently pursuing her degree in Civil Engineering. She studied Material Science as her diploma during her polytechnic years. She sees the importance in recycling and reusing of materials and resources essential for conservation. This project allows her to understand the need to recycle food waste as well to value the importance of conserving food waste. Together with her team members, she strives to improve the current food waste issue and implement food waste recycling into their targeted platform. Angela has contributed in the evaluation and conclusion of the proposal.

 EXECUTIVE SUMMARY

This report was written in response to call for engineering problem-solution proposals. It focuses on the waste recycling technologies that are currently out in the market to combat the generation of food waste and discusses its capabilities against one another. The complication would be the difficulty to handle a overproduction of by-products and the productive use of them. This may result in squandering of by-products which reduces the tendency to use these machines which defeats the purpose of improving the recyclability of food waste. 

The objective of this report is to propose to the planning committee of SIT Punggol a more sophisticated system that improves and combines the technologies that are offered in the market currently. The team proposes a solution that allows the waste recycling machine to effectively produce the amount of by-products based on the input of the user. This will effectively provide the sufficient volume of fertilisers and reusable water so as to reduce the potential squander of useful products.  

1.    BACKGROUND 

Figure 1: Food waste percentage (Source: National Environment Agency 2015)

This report is prepared in response to the call for proposals regarding an engineering issue in Singapore to improve the recyclability of food waste. 

As Singapore’s population continues to grow, the amount of food disposal has been increasing at the incineration site. To counter the issue on the rapid growth in food disposal, this team proposed an idea to improve the situation of food disposal efficiency. Since the recycling rate in Singapore has increased gradually to 14% from 2006 to 2016 (NEA, 2016), our goal is to design a machine that incorporates the current food recycling machines starting from new campus at SIT Punggol.  

Our team feels the need to encourage and focus into recycling food waste as it has not yet been well-established enough in the current market due to certain factors. We believe that through the integration and improvement of existing technology can we only be able to further recycle food waste into reusable products. 

As of now, two waste recycling technologies are being used to produce two different byproducts. Currently, in the market, there are various machines such as Westcom, BioHitech and Eco-Wiz that recycle food waste into either fertilisers or reusable water. However, the organisation is required decide to between the two technologies to implement in their premises. Our solution is to incorporate two of these technologies into a single machine whereby the operator will select the preferred mode for the output of the byproducts. This way, it will generate the flexibility of installing the machine in a variety of facilities. 

Evaluating the current technologies of recycling food wastage, would help the planning community of SIT to understand that there are such machines in the current market. Through the implementation of a food waste recycling machine that decompose into two different by-products, it would increase efficiency and flexibility. Finally, food waste can both be recycled into fertilizers and reusable water. 

2.    PROBLEM STATEMENT 

Canteens at SIT Punggol campus should integrate the current technologies of recycling food waste into a single machine to increase the efficiency to produce high quality fertilizers/reusable water as by-products. However, amongst all the approaches in which food waste is decomposed, there has not been an integration of technology that incorporates producing fertilisers and reusable water as by-products in a single machine. Incorporating both technologies into a single system, it will benefit the new SIT campus canteen in adapting a food waste recycling habit that makes full use of the reusable by-products. 

3.    PURPOSE STATEMENT 

This report proposes to the planning committee of SIT Punggol an integration of waste recycling technologies into one machine that can be implemented into SIT Punggol campus’ canteens through the analysis of both technologies that currently exists in the market. 

4.    CURRENT IMPLEMENTATION 

In the last 10 years, NEA (2016) stated that food waste has been increasing from about 500,000 tonnes to close to 700,000 tonnes in 2016. This increment of food waste is due to two main factors. The increase in population and commercial activity. Efforts has been taken place to reduce food waste. Starting from the source, food wastage efforts has been carried out in terms of posters to encourage buying what is only needed as food wastage due to expired foods were the main contributors to food wastage. The next effort was to redistribute excess food to food organizations through donations to reduce the need to throw food waste when it passes the date of expiry. The last and least recommended effort would be to dispose waste to waste-to-energy (WTE) plants to recover energy from waste and to reduce them down to ten percent from its original size to be disposed into incineration plants (NEA, 2018). 

Food waste machines are implemented with the main purpose to reduce the dependency of incineration plants and landfills. Currently, there are two different types of food disposal technology that breaks down food waste. One of which, breaks down the food waste into fertilisers using anaerobic digestion, where micro-organisms breaks down food waste without the presence of oxygen. The other technology that produces reusable water uses a process call aerobic digestion, where food waste is broken down in the presence of oxygen. The fertilisers that are produced can then be used for agriculture or any green spaces and the reusable water can then be used for watering plants or cleaning of premises. 

 

4.1  WASTE TO FERTILISER RECYCLING TECHNOLOGY

Figure 2: Food Waste Recycling Machine (Westcom)

Illustration 1: Mechanism of Food Waste into Fertilizers

According to BioHiTech video entitled “The Science of Digestion” (2015), these machines operate through the breakdown of food waste by micro-organism in the system. As waste is introduced into the system, micro-organisms start to feed and break down on food particles, ultimately reducing its size. 

In this machine, rotating shafts would mix the bio media (which houses micro-organism) as well as the food waste to ensure homogeneous mix of materials. There is a heating element that provides a warm condition for micro-organism to thrive. Fertilisers are produced as by-products through anaerobic conditions. As the chamber is closed and sealed off, waste will first get its water vapour evaporated off through an exhaust. According to Ecoman FOODIE video entailed “How FOODIE works? Waste decomposing process!” (2014), waste is then reduced by 70 percent. Ecoman FOODIE further stated that Micro-organisms will further reduce the volume of the waste to 10 percent of its original volume, turning it into useful fertiliser compost which can be used on spaces. 

4.2  WASTE TO LIQUID RECYCLING TECHNOLOGY 

Figure 3: Ecodigester (Eco-Wiz)

Illustration 2: Mechanism of Food Waste into Reusable Water

To produce waste water as a by-product, micro-organisms need an aerobic condition and hence, air is introduced through inlets (BioHiTech entitled “The Science of Digestion,” 2015). Food waste are then broken down till it would be small enough to pass through digester screens. According to Joe Liu video entailed “Eco-Wiz Coporate Video,” (2016), a 2-step filtration system will then be used to remove grease and certain microbials which may cause diseases or fermentation before it is passed off as reusable water.   

Similar to the technology mentioned previously, rotating shafts would mix the bio media as well as the food waste to ensure homogeneous mix of materials. However, there is a heater present to evaporate the water content in food waste. Then, the leftover sludge produced will pass through filter screens such as a grease filter and a microbial treatment. This reusable water that can then be used around the school premises.  

5.    PROPOSED SOLUTION 

Clients would often face difficulty in deciding which machine works best on their specific environment they are in due to the variance of by-products produced. Most commercial companies prefer the food waste machine to produce reusable water as they do not have green spaces and would prefer a full reduction of waste to ultimately reduce manpower. Educational, eco-friendly parties may choose a food waste machine to produce fertilizers as the compost produced would save the company money. The compost can be applied on most soil media and hence its versatility encourages more interested parties to use the product. 

Combining the two respective technologies together into a machine, increases the efficiency of food waste recycling. With the flexibility of functions in the system, it allows the user to have the ability to select the amount of fertiliser or reusable water produced from the food waste. Loading the waste into the respective input of the machine, fertilizer or liquid. Estimated time for food waste digestion will be show on the digital panel of the machine. Overtime, the by-products will be churned into bits and fine particles. The breaking own of by-products will be ready after 24 hours. Leaving it untouched for a prolonged time, the system will be “smart” to shut down itself. This is to greatly save the electricity cost from the power supply.  

6.    METHODOLOGY 

Before implementing a new type of technology, our team had to fully understand the current efforts Singapore is practicing tackling food waste. Our team decided to focus on the food waste treatment system that organisations around the nation may have adopted and further narrow down to the various technologies.  

6.1  PRIMARY RESEARCH

Apart from conducting research to determine the different types of waste recycling methods there are available, Dr. Ng, who has a major in civil engineering and a PH.D. in water microbiology studies. He agreed that having a waste recycling system that produces fertilizers not only helps in reducing overall food waste but justifies that the compost would be able to be stored and used for a later date, increasing the flexibility in using the output. Moreover, the team emailed the two main companies, ECOwiz and Westcom Solutions, to acquire about the prices and products. In addition to that, we conducted a survey to review on the need of recycling food waste and the importance to implement a technology that will be able to satisfy the users need.   

6.2  SECONDARY RESEARCH 

Based on our observations, a food waste treatment system under Westcom Solution is placed at the back of our school’s canteen. The system converts the food waste to soil fertilizer. Our team further researched on possible by-products that may be produced by the treatment systems supplied by the other suppliers. According to Eco-wiz, one of the suppliers, its webpage mentioned that its product, ecoDigester, could convert solid food waste to reusable water. After further discussion among our team, we conclude that these fertilizers and reusable water could be used around the school premises itself.  

7.    BENEFITS 

These are the benefits that this dual system can operate to increase the food waste recycling efficiency. 

7.1  VERSATILITY 

The main benefit for implementing the dual digestion system is to fully expand the possibilities and further enhance the versatility of the machine. Selecting the amount of by-products needed, would further prompt the user to utilise the machine and prevent an overproduction of by-products which may be thrown due to its lack of use.  

7.2  COST OF MANPOWER 

These machines will also encourage savings in the long run. According to Violia (2016), the cost of disposing a large waste bin that is between 660 to 1100 kg, which carries a maximum capacity of about 440 kg is $720.82. This would in turn provide savings of $8,649.84 a year. Working out the initial costs of the machine, the turnover of the cost of the machine will take roughly 4 years.  

7.3  GOAL IN RECYCLING 

The goal towards recycling food is being taken place as users can make use of this machine and collect the by-products that they needed to. Moreover, this practice will further prompt users to use this machine whenever they needed to. This increases the percentage of food waste recycling at SIT Punggol as a starting platform. 

8.    EVALUATION 

However, with potential benefits, there ought to be challenges as well. Our team has evaluated the possible challenges that can happen and making sure that they would not overweigh the benefits. 

8.1  MAINTENANCE 

With the incorporation of both technologies, there is a high maintenance to operate the system's quality and functionality. To countermeasure this challenge, frequent routine checks must be implemented to make sure the machine faces no defects and difficulties. Therefore, proper instructions must be placed near the machine to properly educate users on the operation

8.2  COST OF MACHINE 

The estimated average cost of this system is S$30,000 to S$50,000. Although this is very costly, comparing with the cost in manpower that was calculated within a year, this challenge can be overlooked as it is only a one-time payment. 

 

8.3  RESOURCE 

As this machine relies vastly on the usage of micro-organisms, there is a need to refill after the product finishes in the machine. Additionally, the refill will depend on how frequent the machine will be used during the months. 

9.    CONCLUSION 

In conclusion, our team proposes to implement a technology which integrates two different types of technology that produces soil fertilizers and reusable water into a single system or machine. Having two different form of by-products, reassures the school that there will not be an overproduction of a certain type of by-product. These by-products can be used around the school’s premises. For example, the soil fertilisers can be used any agriculture around the vicinity and the reusable water can be used to wash the canteen floors or toilets. Based on our team’s research, this machine will have an estimated cost of S$30,000 to S$50,000. This may be a huge sum; however, statistics have shown that the cost saved from food waste recycling will compensate for the estimated cost of the proposed system. 

We wish to implement this system into SIT@Punggol university campus canteens as a test-bed for innovation that improves overall food waste recycling in Singapore. Our team sees the viable opportunity to create possibilities of reducing food waste through the new Punggol campus.