Every year, roughly one-third of the food produced in the world for consumption is thrown away. That’s approximately 1.3 billion tonnes of food wastage. This project aims to examine the magnitude of the problem and what chemical processes can be utilized to combat this problem, and to see what the future holds. While there are several areas of green chemistry worth studying, this project focuses on the the issue of food waste and on the chemical processes of turning food waste to biofuel. Turning food waste into biofuel contributes to the reduction, recycling and reuse of the food waste by making high-value products out of it. However, there are challenges ahead to scale up the chemical processes on an industrial level, and the science in this area is still at a nascent stage requiring further improvements. Fossil fuel depletion is a reality, and the potential to use biofuels from food waste as a substitute is something worth investigating.

To examine the issue and proposed solutions, a few research papers have been reviewed to understand the impacts, the current trend, and future prospects of chemical processes to convert food waste into biofuels. Through the literature review, I discovered that statistics on food wastage is astounding and creates huge burdens to our environment, something that must be changed. Food is lost or wasted at every point along the food chain: on farms and fishing boats, during processing, packaging, during distribution, in retail stores, in restaurants and at home. The United Nations has set a clear target to reduce food wastage by half by 2030, and many governments and businesses are rising to meet the challenge. Therefore, throughout this project I hope to make clear the severity of this issue as well as the chemistry behind such a necessary solution for our environment.

The traditional waste disposal methods, either sending to incinerators for burning or sending to landfill for burying, are increasingly being criticized given the negative impacts they bring to our environment and to human health. Scientists and engineers all over the world are working to take advantage of untapped energy resources like food waste. The current chemical proposals are to use different chemical processes along the way to produce biofuels out of food waste. First, it is the pyrolysis which applies heat to dehydrate the food waste to get the first bio oil. Another process is hydrolysis, during which the food waste is mixed with water to make slurry, and the obtained hydrolytic mixture goes through a centrifugation process to separate the lipid rich biomass (or crude oil), from the food hydrolysate. The obtained food hydrolysate is subjected to fermentation using some specially-selected microorganisms, and finally distillation is done to obtain pure ethanol. The obtained crude oil is subjected to transesterification using the selected catalyst to become the biodiesel that can be used for cars, boats, plants, and airplanes. Given the much scientific nature of these processes, my project presents a simplified version of the process flow, so that it is more understandable to people outside of chemistry.

It is worth noting that although the technology is still in nascent stages, it holds the key to the optimum utilisation of waste and natural resources. While the continuation of the field of green chemistry will help reduce the harm we inflict upon our planet, a major part of being environmentally friendly still lies on individual effort. The onus is not only on governments and corporates to support the research and scale up of the conversion processes at commercial level, but also on ourselves to maintain habits like composting to reduce our carbon footprint. This way, food waste can be truly reused as a valuable source of energy.

Here are two primary research articles I found particularly interesting that would be helpful for people wanting to learn more:
1. https://www.sciencedirect.com/science/article/abs/pii/S1364032115010114

2. https://pubmed.ncbi.nlm.nih.gov/31683456/

Florance Wu 2021 Chemistry DYO