BIOFUEL PRODUCTION FROM FOODWASTE

Abstract

According to the FAO of UN, 33% of the production of food items all over the world for humans is wasted in the Food Supply Chain. In addition to this, with increasing population demand for fuel as energy source also increasing day by day and as we know fossil fuels are limited and their combustion leads to pollution and global warming by emission of greenhouse gases. The alternative for the above problems is to generate a sustainable energy source by food waste (FW) which decreases pollution, reduces our dependency on fossil fuels, and is easily replenished. Biofuels obtained from the fermentation of FW is a suitable option in front of us to meet the requirements of energy demand and environment safety issue. Bioethanol and biodiesel are abundantly produced over the world. Currently, in most countries, the wasted food is either filled in the land or incinerated along with the other municipal waste to recover the possible amount of energy. But the problem with these two efforts is that they are very costly and facing environmental problems. So, we can go with the other kinds of approaches to recover the energy from the food waste. As we know, the FW has an organic and nutrient-rich composition that is why we can use it as a good feedstock for biofuel production. we focus on the current techniques and procedures that are used around the world.

In 2010, biofuel production reaches up to 105 billion litres across the world. Biofuel production technology improving and increasing day by day. There are a few kinds of biofuels are manufactured around the world and this report including bioethanol, biogas, biohydrogen and biodiesel. Bioethanol production includes high carbohydrate-rich feedstock like sugarcane residues and corn and food wastes from kitchens. Steps followed in bioethanol production are pretreatment, saccharification or hydrolysis, fermentation (mostly by

P a g e | v S. cerevisiae), and distillation of ethanol. Pretreatment is done to delignification of biomass and to separate cellulose parts from lignin and hemicellulose so enzymes can work efficiently in later stages of the process. Saccharification is done to break down cellulose into simpler sugars like glucose, galactose, ribose and xylose. Then sugars are fermented by S. cerevisiae to get acids, gases, and ethanol.

Biogas is produced through an anaerobic process. This can be done by 2 ways: single- stage anaerobic digestion which includes, hydrolysis, acidogenesis, acetogenesis, and

methanogenesis. Another way is two-stage anaerobic digestion in which the first stage yields hydrogen and VFAs and the second stage yields biogas and carbon dioxide. Biogas yield improved in second stage anaerobic digestion by 37%. Biodiesel is a monoalkyl ester of unsaturated fats. It will reduce about 75% of the overall emissions of engines and acts as lubricants. Biodiesel production from oils and lipids is done by transesterification. Water and pigment residues in the oil sample can act as inhibitors in the process of transesterification.