Tag Archives: Food Waste

Biogas from Kitchen Waste at Akshaya Patra Foundation

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The Akshaya Patra Foundation, a not-for-profit organization, is focused on addressing two of the most important challenges in India – hunger and education. Established in year 2000, the Foundation began its work by providing quality mid-day meals to 1500 children in 5 schools in Bangalore with the understanding that the meal would attract children to schools, after which it would be easier to retain them and focus on their holistic development. 14 years later, the Foundation has expanded its footprint to cover over 1.4 million children in 10 states and 24 locations across India.

Akshaya-Patra-Kitchen-BioGas

The Foundation has centralised, automated kitchens that can cook close to 6,000 kilos of rice, 4.5 to 5 tonnes of vegetables and 6,000 litres of sambar, in only 4 hours. In order to make sustainable use of organic waste generated in their kitchens, Akshaya Patra Foundation has set up anaerobic digestion plants to produce biogas which is then used as a cooking fuel. The primary equipment used in the biogas plant includes size reduction equipment, feed preparation tank for hydrolysis of waste stream, anaerobic digester, H2S scrubber and biogas holder.

Working Principle

Vegetable peels, rejects and cooked food waste are shredded and soaked with cooked rice water (also known as ganji) in a feed preparation tank for preparation of homogeneous slurry and fermentative intermediates. The hydrolyzed products are then utilized by the microbial culture, anaerobically in the next stage. This pre-digestion step enables faster and better digestion of organics, making our process highly efficient.

The hydrolyzed organic slurry is fed to the anaerobic digester, exclusively for the high rate biomethanation of organic substrates like food waste. The digester is equipped with slurry distribution mechanism for uniform distribution of slurry over the bacterial culture.

Optimum solids are retained in the digester to maintain the required food-to-microorganism ratio in the digester with the help of a unique baffle arrangement. Mechanical slurry mixing and gas mixing provisions are also included in the AD design to felicitate maximum degradation of organic material for efficient biogas production.

After trapping moisture and scrubbing off hydrogen sulphide from the biogas, it is collected in a gas-holder and a pressurized gas tank. This biogas is piped to the kitchen to be used as a cooking fuel, replacing LPG.

Basic Design Data and Performance Projections

Waste handling capacity 1 ton per day cooked and uncooked food waste with 1 ton per day ganji water

Input Parameters                      

Amount of solid organic waste 1000 Kg/day
Amount of organic wastewater ~ 1000 liters/day ganji (cooked rice water)

Biogas Production

Biogas production ~ 120 – 135 m3/day

Output Parameters

Equivalent LPG to replace 50 – 55 Kg/day (> 2.5 commercial LPG cylinders)
Fertilizer (digested leachate) ~ 1500 – 2000 liters/day

Major Benefits

Modern biogas installations are providing Akshaya Patra, an ideal platform for managing organic waste on a daily basis. The major benefits are:

  • Solid waste disposal at the commercial kitchen site avoiding waste management costs
  • Immediate waste processing overcomes problems of flies, mosquitos etc.
  • Avoiding instances when the municipality does not pick up waste, creating nuisance, smell, spillage etc.
  • Anaerobic digestion of Ganji water instead of directly treating it in ETP, therefore reducing organic load on the ETPs and also contributing to additional biogas production.

The decentralized model of biogas based waste-to-energy plants at Akshaya Patra kitchens ensure waste destruction at source and also reduce the cost incurred by municipalities on waste collection and disposal.

akshayapatra-kitchen

An on-site system, converting food and vegetable waste into green energy is improving our operations and profits by delivering the heat needed to replace cooking LPG while supplying a rich liquid fertilizer as a by-product.  Replacement of fossil fuel with LPG highlights our organization’s commitment towards sustainable development and environment protection.

The typical ROI of a plug and play system (without considering waste disposal costs, subsidies and tax benifts) is around three years.

Future Plans

Our future strategy for kitchen-based biogas plant revolves around two major points:

  • Utilization of surplus biogas – After consumption of biogas for cooking purposes, Akshaya Patra will consider utilizing surplus biogas for other thermal applications. Additional biogas may be used to heat water before boiler operations, thereby reducing our briquette consumption.
  • Digested slurry to be used as a fertilizer – the digested slurry from biogas plant is a good soil amendment for landscaping purposes and we plan to use it in order to reduce the consumption of water for irrigation as well as consumption of chemical fertilizers.

Renewable Energy from Food Residuals

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Food residuals are an untapped renewable energy source that mostly ends up rotting in landfills, thereby releasing greenhouse gases into the atmosphere. Food residuals are difficult to treat or recycle since it contains high levels of sodium salt and moisture, and is mixed with other waste during collection. Major generators of food wastes include hotels, restaurants, supermarkets, residential blocks, cafeterias, airline caterers, food processing industries, etc.

food-waste

According to EPA, about 63.1 million tons of food waste was thrown away into landfills or incinerators the United States in 2018. As far as United Kingdom is concerned, households threw away 6.6 million tons of food each year. These statistics are an indication of tremendous amount of food waste generated all over the world.

The proportion of food residuals in municipal waste stream is gradually increasing and hence a proper food waste management strategy needs to be devised to ensure its eco-friendly and sustainable disposal. Currently, only about 3 percent of food waste is recycled throughout U.S., mainly through composting. Composting provides an alternative to landfill disposal of food waste, however it requires large areas of land, produces volatile organic compounds and consumes energy. Consequently, there is an urgent need to explore better recycling alternatives.

Anaerobic digestion has been successfully used in several European and Asian countries to stabilize food wastes, and to provide beneficial end-products. Sweden, Austria, Denmark, Germany and England have led the way in developing new advanced biogas technologies and setting up new projects for conversion of food waste into energy.

Anaerobic Digestion of Food Waste

Anaerobic digestion is the most important method for the treatment of organic waste, such as food residuals, because of its techno-economic viability and environmental sustainability. Anaerobic digestion generates renewable energy from food waste  in the form of biogas and preserves the nutrients which are recycled back to the agricultural land in the form of slurry or solid fertilizer.

The relevance of biogas technology lies in the fact that it makes the best possible use of various organic wastes as a renewable source of clean energy. A biogas plant is a decentralized energy system, which can lead to self-sufficiency in heat and power needs, and at the same time reduces environmental pollution. Thus, anaerobic digestion of food waste can lead to climate change mitigation, economic benefits and landfill diversion opportunities.

Of the different types of organic wastes available, food waste holds the highest potential in terms of economic exploitation as it contains high amount of carbon and can be efficiently converted into biogas and organic fertilizer. Food waste can either be used as a single substrate in a biogas plant, or can be co-digested with organic wastes like cow manure, poultry litter, sewage, crop residues, slaughterhouse wastes, etc.

Renewable Energy from Food Residuals

The feedstock for the food waste-to-energy plant includes leftover food, vegetable refuse, stale cooked and uncooked food, meat, tea bags, napkins, extracted tea powder, milk products, etc. Raw waste is shredded to reduce to its particle size to less than 12 mm. The primary aim of shredding is to produce a uniform feed and reduce plant “down-time” due to pipe blockages by large food particles. It also improves mechanical action and digestibility and enables easy removal of any plastic bags or cling-film from waste.

Fresh waste and re-circulated digestate (or digested food waste) are mixed in a mixing tank. The digestate is added to adjust the solids content of the incoming waste stream from 20 to 25 percent (in the incoming waste) to the desired solids content of the waste stream entering the digestion system (10 to 12 percent total solids). The homogenized waste stream is pumped into the feeding tank, from which the anaerobic digestion system is continuously fed. Feeding tank also acts as a pre-digester and subjected to heat at 55º to 60º C to eliminate pathogens and to facilitate the growth of thermophilic microbes for faster degradation of waste.

From the predigestor tank, the slurry enters the main digester where it undergoes anaerobic degradation by a consortium of Archaebacteria belonging to Methanococcus group. The anaerobic digester is a CSTR reactor having average retention time of 15 to 20 days. The digester is operated in the mesophilic temperature range (33º to 38°C), with heating carried out within the digester. Food waste is highly biodegradable and has much higher volatile solids destruction rate (86 to 90 percent) than biosolids or livestock manure. As per conservative estimates, each ton of food waste produces 150 to 200 m3 of biogas, depending on reactor design, process conditions, waste composition, etc.

Biogas contains significant amount of hydrogen sulfide (H2S) gas that needs to be stripped off due to its corrosive nature. The removal of H2S takes place in a biological desulphurization unit in which a limited quantity of air is added to biogas in the presence of specialized aerobic bacteria that oxidizes H2S into elemental sulfur. The biogas produced as a result of anaerobic digestion of waste is sent to a gas holder for temporary storage. Biogas is eventually used in a combined heat and power (CHP) unit for its conversion into thermal and electrical energy in a co­generation power station of suitable capacity. The exhaust gases from the CHP unit are used for meeting process heat requirements.

The digested substrate leaving the reactor is rich in nutrients like nitrogen, potassium and phosphorus which are beneficial for plants as well as soil. The digested slurry is dewatered in a series of screw presses to remove the moisture from slurry. Solar drying and additives are used to enhance the market value and handling characteristics of the fertilizer.

Diverting Food from Landfills

Food residuals are one of the single largest constituents of municipal solid waste stream. Diversion of food waste from landfills can provide significant contribution towards climate change mitigation, apart from generating revenues and creating employment opportunities. Rising energy prices and increasing environmental pollution makes it more important to harness renewable energy from food scraps and create a sustainable food supply chain.

Anaerobic digestion technology is widely available worldwide and successful projects are already in place in several European as well as Asian countries that makes it imperative on waste generators and environmental agencies to root for a sustainable food waste management system.

The Role of Bioengineering in Sustainable Food Supply Chain

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Every year, the production of food around the world accounts for almost a third of all global emissions of greenhouse gases. Deforestation, grazing livestock, and the use of fertilizers all contribute to climate change. Finding ways to minimize the damage that food production causes is becoming a priority in the fight against global warming. In addition, the United Nations’ Food and Agriculture Organization has estimated that every year, the world produces enough food waste to feed 2 billion people.

To address these problems, the field of bioengineering has found ways to recycle scrap food, reduce the amount thrown away, and find alternative ways to produce sufficient food to feed the world more sustainably and with less waste.

sustainability-food-supply-chain

Engineering Sustainable Food

A degree in bioengineering, or a masters in biomedical engineering online, involves the study of a range of scientific fields from computational biology and physiological systems to mechanical engineering and material sciences. This multidisciplinary approach lends itself well to improving the sustainability of food production. For many years, the genetic engineering of plants has created the potential of increasing production in a sustainable and environmentally-friendly way, and more recently, progress has been made in creating synthetic meat.

Now, without the use of genetic engineering, biomedical engineers have created the first bioprinted steak from cattle cells. The qualities of real meat are replicated by allowing living cells to grow and interact in the same way as they would in nature. The result is the creation of an authentic-tasting steak produced without the extensive environmental damage caused by farming livestock.

Converting Food Into Fuel

Every year in the US alone, 80 billion pounds of food is thrown away without being eaten. An increasing number of scientific projects are working on harnessing the valuable energy from food waste and converting it into renewable fuel. This can then be used to power a range of vehicles from privately owned cars to planes and trains.

In communities where food waste is collected along with other recyclable materials, anaerobic digestion can also be used to convert the high fat content of food waste into green electricity, which is put back into the grid to power households.

food-waste-behavior

Reducing Food Waste

Some food scraps are unavoidable, but now bioengineering is being applied to reduce some of the waste from over consumerism. Shoppers often buy excess food and leave fresh fruit and vegetables to go mouldy before they are eaten. Using plant derived-technology, the protective peels of fruit and vegetables can now be enhanced, allowing them to stay fresh for triple the amount of time of regularly grown produce. As the freshness of the products is protected for longer, the logistical costs of a strictly controlled refrigerated supply chain are reduced, and in the long-term, food waste is minimized.

As it exists at the moment, the food supply chain is environmentally damaging. From growing meat in a lab to extending the lifespan of fresh food, bioengineers are now finding ways to improve sustainability in food production.

5 Ways to Shop For Food Responsibly

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Nowadays, we can get food from the four corners of the Earth. If you want tropical fruit during the winter, you can get it. You’ll never run out of oranges, mangoes, or bananas. While these fruits and other imported foods are delicious, it’s important to eat the foods local to your area.

Shopping for and eating locally grown food is stellar for the environment and your health. However, it’s a bit difficult to navigate these days when most common items are imported. Let’s go through some tips to become a responsible food consumer:

locally-grown-food

1. Research Food Local to Your Area

First things first, get to know what crops grow best in your area. Do some googling and go to the library to find resources. Talk to people at your local grocery store.

Figure out which foods grow during the specific seasons and tailor your diet to suit the standards. Buy some cookbooks that have recipes specific to your area if they’re available.

2. Go Into the Store With a Game Plan

Going into a grocery store can either be a terrible burden or a fun experience. Most of the time, we enter huge establishments that push certain products towards consumers due to profits. Those who consider grocery shopping burdensome should craft a plan of action.

locally-grown-food

You’ve already looked into local foods in your area. Now, you can craft recipes based on the ingredients. Plan what you’re going to cook for the week before you go shopping. Then, you can shop efficiently without succumbing to sales prices or food from far away.

3. Use Online Marketplaces Run by Farmers

While being responsible for your food choices involves eating mostly locally, some imported delicacies are hard to resist. Go easy on yourself. While you should avoid going into huge grocery chains and buying exclusively imported foods, you can splurge every once in a while.

If you want to buy certain foods that need to be imported, consider using online marketplaces. These stores are partnered directly with farmers. That way, you can enjoy imported foods while supporting farmers directly.

4. Go to Your Local Farmers Market

While grocery chains are great for certain products, there’s nothing like a farmers’ market. At a farmers market, you are directly exposed to the foods grown in your area. While farmers maintain a huge presence in these markets, you’ll also see other vendors as well.

food-waste-college

Organic food is a modern, healthy part of a sustainable lifestyle.

You’ll be able to buy locally made dips, chips, and other snacks. Plus, you can also buy crops or plants from certain individuals if you have a green thumb.

5. Buy Less

When transitioning to the life of a responsible food consumer, you’ll have to adjust to buying less every week. A responsible consumer does not overbuy. The individual buys what they need, whether that can be accomplished in one trip to the store or several.

The more you minimize food waste, the better you’ll feel. However, take baby steps and don’t feel too down if you have waste.

Become a Responsible Food Consumer

The task of being a responsible food consumer seems impossible, but it isn’t. The journey will take a while since you’re changing your habits and mindset, but it’s worth it. When you follow the steps to be more responsible, your body, mind, and the earth will thank you.

Take your time, make small changes every day, and have fun in the process. Maybe a love for cooking or baking will pop up while you are in the process.

Top 5 Tips For Reducing Waste in Your Home

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Reducing waste in your home is more important now than ever. As the environment is becoming more in danger because of greenhouse gases, climate change, and pollution, the need for humans to reduce their carbon footprint is imperative. However, even if people want to make an effort to save the environment, many people don’t know where to start and how to go about changing their everyday lives in order to become more eco-friendly.

Starting in your home is a great way to begin working towards an eco-friendly lifestyle. A custom home builder in Cherry Hill New Jersey, said, “Making your home environmentally savvy can mean installing something as large as solar panels or it can mean something much smaller; like using reusable shopping bags at the grocery store and not buying plastic products. Either way, making your home eco-friendly is important.”

Reducing waste in your home is easy and will have an outstanding impact on the environment. Here are some quick and easy tips to keep in mind that will help you reduce waste in your home:

1. Start Composting

Starting a compost pile creates less trash by recycling leftover food that would otherwise go in the trash. The point of a compost pile is to put the leftover, and even expired, food back into the earth rather than letting it sit in the garbage or in landfills.

benefits-composting

 

A compost pile is easy to start, all you need is a bin and some extra space. After you’re done eating something (as long as it isn’t meat, a milk product, or greasy processed food), you can put it in this bin and then incorporate it into your garden or yard every few weeks. Your food won’t go to waste and your garden/yard will get the nutrients it needs.

2. DIY Beauty and Household Products

Buying less plastic products is another great way to reduce waste in your home. However, most beauty and household products are packaged in plastic containers which makes reducing plastic in this way a major obstacle.

A possible solution to this issue is making your own beauty and household products like floor cleaner, and toothpaste. Making your own natural deodorant is also a great way to reduce waste generation.

Though buying the ingredients to make these products may create a small amount of waste, the ingredients are easier to buy in bulk so you will have to buy them less frequently and will be able to create ample amounts of beauty and household products.

office-cleaning

Creating homemade products is also a great way to ensure you aren’t getting chemicals in your products that are damaging to the environment and will create waste or harmful toxins.

3. Meal Plan

Food waste is a huge issue in households. Often, between ¼ to ½  of a household’s weekly produce, meats, and milk products are thrown out at the end of the week. This is preventable with the incorporation of meal planning and meal prepping in your life. By starting a meal plan, you will only buy what you need and will be less likely to waste products because they expired.

food-waste-management

This will generate less waste in terms of food that will end up sitting in a landfill but also in terms of plastic packaging waste that food is packaged in.

4. Repair Instead of Replace

This is an easy way to create little waste in your home that many people don’t think about. When something in your home breaks, whether it is a small kitchen appliance or something large like a heater or part of a couch, take the time to repair it instead of getting a new one. If you repair an item, the original one won’t make its way to a landfill and you will get more life out of your products.

If an appliance or piece of furniture is unable to be repaired, make an effort to recycle some of the important parts; or, if you are in the market to buy a replacement, look online for used products or go to a secondhand store. This will create less waste and will also save you money.

5. Cancel and/or Recycle Junk Mail

Easy and free, by canceling and recycling junk mail will immediately reduce waste in your home. Most people don’t even look at the junk mail and toss it right in the garbage can. Canceling subscriptions only requires a phone call or email and will significantly cut back the waste that is generated in your home.

If you receive junk mail that is not sent to you via subscription and you are unable to cancel it, make sure to at least recycle it.

Eliminating junk mail will also help with decluttering your coffee tables and countertops, an added benefit to helping the environment.

Bottom Line

There is always room for improvement when trying to improve your lifestyle in terms of creating less waste. These tips are a great way to start making an impact on saving the environment before it’s too late. Reduce the waste in your life with minimal effort and small, simple changes.

Popular Feedstock for Biogas Plants

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Anaerobic digestion is the natural biological process which stabilizes organic waste in the absence of air and transforms it into biofertilizer and biogas. Almost any organic material can be processed with anaerobic digestion.

Biogas_Plant

Anaerobic digestion is particularly suited to wet organic material and is commonly used for effluent and sewage treatment.  The popular feedstock for biogas production includes biodegradable waste materials such as waste paper, grass clippings, leftover food, sewage and animal waste.

Large quantity of waste, in both solid and liquid forms, is generated by the industrial sector like breweries, sugar mills, distilleries, food processing industries, tanneries, and paper and pulp industries. Poultry waste has the highest per ton energy potential of electricity per ton but livestock have the greatest potential for energy generation in the agricultural sector.

1. Agricultural Feedstock

2. Community-Based Feedstock

  • Organic fraction of MSW (OFMSW)
  • MSW
  • Sewage sludge
  • Grass clippings/garden waste
  • Food wastes
  • Institutional wastes etc.

 3. Industrial Feedstock

  • Food/beverage processing
  • Dairy
  • Starch industry
  • Sugar industry
  • Pharmaceutical industry
  • Cosmetic industry
  • Biochemical industry
  • Pulp and paper
  • Slaughterhouse/rendering plant etc.

Anaerobic digestion is particularly suited to wet organic material and is commonly used for effluent and sewage treatment. Almost any organic material can be processed with anaerobic digestion process. This includes biodegradable waste materials such as waste paper, grass clippings, leftover food, sewage and animal waste. The exception to this is woody wastes that are largely unaffected by digestion as most anaerobic microorganisms are unable to degrade lignin.

Anaerobic digesters can also be fed with specially grown energy crops such as silage for dedicated biogas production. A wide range of crops, especially C-4 plants, demonstrate good biogas potentials. Corn is one of the most popular co-substrate in Germany while Sudan grass is grown as an energy crop for co-digestion in Austria. Crops like maize, sunflower, grass, beets etc., are finding increasing use in agricultural digesters as co-substrates as well as single substrate.

biogas-energy-crop

A wide range of organic substances are anaerobically easily degradable without major pretreatment. Among these are leachates, slops, sludges, oils, fats or whey. Some wastes can form inhibiting metabolites (e.g.NH3) during anaerobic digestion which require higher dilutions with substrates like manure or sewage sludge. A number of other waste materials often require pre-treatment steps (e.g. source separated municipal organic waste, food residuals, expired food, market wastes and crop residues).

Composting in Qatar: An Overview

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Composting in Qatar is mainly done at the Domestic Solid Waste Management Centre (DSWMC) in Mesaieed, which houses the largest composting facility in the country and one of the largest in the world.  The waste that enters the plant initially goes through anaerobic digestion, which produces biogas that can power the facility’s gas engine and generators, followed by aerobic treatment which yields the final product.

Two types of compost are generated: Grade A (compost that comes from green waste, such as yard/park trimmings, leftovers from kitchen or catering services, and wastes from markets) and Grade B (compost produced from MSW).  The plant started its operation in 2011 and when run at full capacity is able to process 750 tons of waste and produce 52 tons of Grade A compost, 377 tons of Grade B compost, liquid fertilizer which is composed of 51 tons of Grade A compost and 204 tons of Grade B compost, and 129 tons of biogas.

benefits-composting

This is a significant and commendable development in Qatar’s implementation of its solid waste management plan, which is to reduce, reuse, recycle and recover from waste, and to avoid disposing in landfills as much as possible.  However, the large influx of workers to Qatar in the coming years as the country prepares to host the World Cup in 2022 is expected to substantially increase solid waste generation and apart from its investments in facilities like the composting plant and in DSWMC in general, the government may have to tap into the efforts of organizations and communities to implement its waste management strategy.

Future Outlook

Thankfully, several organizations recognize the importance of composting in waste management and are raising awareness on its benefits.  Qatar Green Building Council (QGBC) has been actively promoting composting through its Solid Waste Interest Group.  Last year, they were one of the implementers of the Baytna project, the first Passivhaus experiment in the country.

This project entails the construction of an energy-efficient villa and a comparative study will be performed as to how the carbon footprint of this structure would compare to a conventional villa.  The occupants of the Passivhaus villa will also be made to implement a sustainable waste management system which includes composting of food waste and garden waste, which is meant to lower greenhouse gas emissions compared to landfilling.

Qatar Foundation is also currently developing an integrated waste management system for the entire Education City and the Food Services group is pushing for composting to be included as a method to treat food and other organic waste.  And many may not know this but composting can be and has been done by individuals in their own backyard and can even be done indoors with the right equipment.

Katrin Scholz-Barth, previous president of SustainableQatar, a volunteer-based organization that fosters sustainable culture through awareness, skills and knowledge, is an advocate of composting and has some great resources on how to start and maintain your own composting bin as she has been doing it herself.

A simple internet search will also reveal that producing compost at home is a relatively simple process that can be achieved with minimal tools.  At present, very few families in Qatar are producing their own compost and Scholz-Barth believes there is much room for improvement.

As part of its solid waste management plan as stated in the National Development Strategy for 2011-2016, Qatar aims to maintain domestic waste generation at 1.6 kg per capita per day.  This will probably involve encouraging greater recycling and reuse efforts and the reduction of waste from its source.

It would also be worthwhile to include programs that will promote and boost composting efforts among institutions, organizations and individuals, encouraging them with the fact that apart from its capability of significant waste diversion from landfills, composting can also be an attractive source of income.

Note: The article is being republished with the permission of our collaborative partner EcoMENA. The original article can be viewed at this link.

The Role of Biomass Energy in Net-Zero Buildings

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The concept of biomass energy is still in its infancy in most parts of the world, but nevertheless, it does have an important role to play in terms of sustainability in general and net-zero buildings in particular. Once processed, biomass is a renewable source of energy that has amazing potential. But there is a lot of work to be done to exploit even a fraction of the possibilities that would play a significant role in providing our homes and commercial buildings with renewable energy.

According to the U.S. Energy Information Administration (EIA), only about 5% of the total primary energy usage in the U.S. comes from biomass fuels. So there really is a way to go.

The Concept of Biomass Energy

Generally regarded as any carbon-based material including plants, food waste, industrial waste, reclaimed woody materials, algae, and even human and animal waste, biomass is processed to produce effective organic fuels.

The main sources of biomass include wood mills and furniture factories, landfill sites, horticultural centers, wastewater treatment plants, and areas where invasive and alien tree and grass species grow.

Whether converted into biogas or liquid biofuels, or burned as is, the biomass releases its chemical energy in the form of heat. Of course, it depends on what kind of material the biomass is. For instance, solid types including wood and suitable garbage can be burned without any need for processing. This makes up more than half the biomass fuels used in the U.S. Other types can be converted into biodiesel and ethanol.

Generally:

  • Biogas forms naturally in landfills when yard waste, food scraps, paper and so on decompose. It is composed mainly of carbon dioxide
  • Biogas can also be produced by processing animal manure and human sewage in digesters.
  • Biodiesel is produced from animal fats and vegetable oils including soybeans and palm oil.
  • Ethanol is made from various crops including sugar cane and corn that are fermented.

How Biomass Fuels Are Used

Ethanol has been used in vehicles for decades and ethanol-gasoline blends are now quite common. In fact, some racing drivers opt for high ethanol blends because they lower costs and improve quality. While the percentage of ethanol is substantially lower, it is now found in most gasoline sold in the U.S. Biodiesel can also be used in vehicles and it is also used as heating oil.

But in terms of their role in net-zero buildings:

  • Biomass waste is burned to heat buildings and to generate electricity.
  • In addition to being converted to liquid biofuels, various waste materials including some crops like sugar cane and corn can also be burned as fuel.
  • Garbage, in the form of yard, food, and wood waste, can be converted to biogas in landfills and anaerobic digesters. It can also be burned to generate electricity.
  • Human sewage and animal manure can be converted to biogas and burned as heating fuel.

Biomass as a Viable Clean Energy Source for Net-Zero Energy Buildings

Don’t rely on what I say, let’s look at some research, specifically, a study published just last year (2018) that deals with the development of net-zero energy buildings in Florida. It looked at the capacity of biomass, geothermal, hydrokinetic, hydropower, marine, solar, and wind power (in alphabetical order) to deliver renewable energy resources. More specifically, the study evaluated Florida’s potential to utilize various renewable energy resources.

Generating electricity from wind isn’t feasible in Florida because the average wind speeds are slow. The topography and hydrology requirements are inadequate and both hydrokinetic and marine energy resources are limited. But both solar and biomass offer “abundant resources” in Florida. Unlike most other renewable resources, the infrastructure and equipment required are minimal and suitable for use within building areas, and they are both compatible with the needs of net-zero energy.

The concept of net-zero buildings has, of course, been established by the World Green Building Council (GBC), which has set timelines of 2030 and 2050 respectively for new and all buildings to achieve net-zero carbon goals. Simplistically, what this means is that buildings, including our homes, will need to become carbon neutral, using only as much renewable energy as they can produce on site.

But nothing is simplistic when it comes to net-zero energy buildings (ZEB) ). Rather, different categories offer different boundaries in terms of how renewable energy strategies are utilized. These show that net-zero energy buildings are not all the same:

  • ZEB A buildings utilize strategies within the building footprint
  • ZEB B within the site of the property
  • ZEB C within the site but from off-site resources
  • ZEB D generate renewable energy off-site

While solar works for ZEB A and both solar and wind work for ZEB B buildings, biomass and biofuels are suitable for ZEB C and D buildings, particularly in Florida.

Even though this particular study is Florida-specific, it indicates the probability that the role of biomass energy will ultimately be limited, but that it can certainly help buildings reach a net-zero status.

There will be different requirements and benefits in different areas, but certainly professionals offering engineering solutions in Chicago, New York, London (Canada and the UK), and all the other large cities in the world will be in a position to advise whether it is feasible to use biomass rather than other forms of eco-friendly energy for specific buildings.

Biomass might offer a more powerful solution than many people imagine.

Food Waste Management

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The waste management hierarchy suggests that reduce, reuse and recycling should always be given preference in a typical waste management system. However, these options cannot be applied uniformly for all kinds of wastes. For examples, food waste is quite difficult to deal with using the conventional 3R strategy.

food_waste

Of the different types of organic wastes available, food waste holds the highest potential in terms of economic exploitation as it contains high amount of carbon and can be efficiently converted into biogas and organic fertilizer.

There are numerous places which are the sources of large amounts of food waste and hence a proper food waste management strategy needs to be devised for them to make sure that either they are disposed off in a safe manner or utilized efficiently. These places include hotels, restaurants, malls, residential societies, college/school/office canteens, religious mass cooking places, communal kitchens, airline caterers, food and meat processing industries and vegetable markets which generate food residuals of considerable quantum on a daily basis.

anaerobic_digestion_plant

The anaerobic digestion technology is highly apt in dealing with the chronic problem of food waste management in urban societies. Although the technology is commercially viable in the longer run, the high initial capital cost is a major hurdle towards its proliferation.

The onus is on the governments to create awareness and promote such technologies in a sustainable manner. At the same time, entrepreneurs, non-governmental organizations and environmental agencies should also take inspiration from successful food waste-to-energy projects in Western countries and try to set up such facilities in cities and towns.

Behavioral Drivers Behind Food Wastes

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By 2075, the United Nations estimates the global population will peak at 9.5 billion, an extra 3 billion mouths to feed by the end of the century. Meanwhile, while we produce about four billion tonnes of food annually, it is estimated that 30-50% of this never reaches our plates. Of the food that does reach us, some western societies throw away up to a third of all food purchased. This has enormous implications for the global environment, from wasting the water used to grow the food to adverse effects on climate, land and biodiversity.

food-waste-behavior

The drivers behind the phenomenal levels of food waste are complex and include public behavior, food pricing, logistical and storage issues. However, given the significant level of waste that happens within the households of societies like the UK and US, it is useful and informative to consider those behaviours that drive this level of waste.

The quality of data around food waste, as with much of waste data, has historically been poor. To this end, WRAP commissioned groundbreaking research in the UK in 2006/7 to act as a baseline to their Love Food Hate Waste campaign. This came up with the alarming statistic that 1/3 of food bought by a UK household was thrown away. Until this time, there had been no comprehensive research, either by food manufacturers, retailers or interest groups, suggesting the importance of government, or some other dis-interested party, taking a lead on the issue.

Back to Basics

There may be a link between the amount of time spent preparing food, and the skill and effort that goes into this, and the amount of food waste produced. This has led to a loss of confidence in the kitchen, with individuals losing basic skills that allow them to cook with leftovers, understand food labeling, including Best Before and Use By, even basic storing. WRAP had found little evidence of best practice storage advice so carried out the research themselves – leading the (surprising for many) conclusion that fruit such as apples and pears are best stored in the fridge wrapped in a plastic cover.

However, this has masked a larger trend of less time spent in the kitchen, due to demographic changes. This of course begs the question – how should we use this when trying to reduce food waste? Should we encourage people to cook from scratch as a principle?

Although waste prevention and recycling are clearly separated within the waste hierarchy, there are apparent links between the two when considering food waste. There is an urgent need for legislation to enforce separate food waste collections, not only to ensure it was diverted to anaerobic digestion or composting, but also as it led to greater self awareness around food waste. WRAP research has clearly showed a fall in food waste when separate food waste collections were introduced.

Role of Packaging

Historically, packaging has always been a high priority to the public when asked about priorities for reducing waste. However, as awareness of food waste has grown, a more nuanced position has developed among waste managers. While excess packaging is clearly undesirable, and, within the UK for instance, the Courtauld Commitment  has helped reduced grocery packaging by 2.9 million tonnes of waste so far, there is a realization of the importance of food packaging in preserving food and hence reducing food waste.

food-packaging

Making food easily accessible and affordable by many, it could be argued, is one of the crowning achievements of our age. Over the last century, the proportion of household income that is spent on food has plummeted, and there is a direct link to malnutrition and food prices, particularly for children. But does cheap food mean that it is less valued and hence greater wastage? Is the answer expensive food? The evidence from WRAP in the UK is that food waste is still a serious economic issue for households, and underlining the economic case for reducing food waste a major incentive for households, especially as food prices are not entering an era of increase and instability, providing added economic urgency

Political Persuasions

Different political persuasions often differ in the approaches they take to changing behaviours and food waste is no different. In the UK, the Courtauld Commitment is a voluntary agreement aimed at encouraging major retailers to take responsibility mainly for packaging, later growing to encompass food waste, voluntary and so far has seen a 21% reduction in food waste post-consumer.

Meanwhile Wales (in the UK) effectively banned food waste from landfill. Scotland has ensured that businesses make food waste available for separate collection – again it’s only once you see it, you can manage it. Campaigns like the UK’s Love Food Hate Waste have been successful but measuring food waste prevention, as with all waste prevention, is notoriously difficult. But, people are now widely aware of food waste as an issue – we even see celebrity chefs actively talking about food waste reduction and recipes involving leftovers or food that is about to go off.

Food-Waste-UK

There is clearly a balance between food waste and food safety, with a commitment to reducing food waste throughout the retail and catering world, not just at home. By engaging environmental health officers to help deliver this, a potentially conflicting message can be delivered in a nuanced and balanced way. Indeed, environmental health officers in Scotland will be responsible for ensuring that Scottish food businesses present their food waste for separate collection.

Role of Communication

It is worth considering how the message should be communicated, and by whom. The community sector are more trusted by the public than government and the private sector are more effective at imparting personal, deeply held beliefs – the sort of beliefs that need to change if we are to see long term changes in attitudes towards consumption and hence waste production.

Furthermore, communications can engage wider audiences that hold an interest in reducing food waste that is perhaps not primarily environmental. The health and economic benefits of issues and behaviours that also result in food waste prevention may be the prevalent message that fits with a particular audience. So whilst the main aim of a training session might be food waste prevention, this is may not be the external message. And this has wider implications for waste prevention, and how we engage audiences around it.

Municipal authorities tasked with waste prevention will need to engage with new groups, in new ways. They will have to consider approaches previously considered to be beyond their powers to engage new audiences – should they be partnering with public health authorities with an interest in nutrition, or social housing providers that are focused on financial inclusion.

Should waste prevention even be a discipline in itself? After all, across material streams it is a motley assortment of behaviours with different drivers. Furthermore, with the knots that one can tie oneself in trying to measure waste that doesn’t get generated, – therefore doesn’t exist – should we integrate waste prevention in to other socio-economic programmes and position it as an “added benefit” to them?

Note: The article is being republished with the permission of our collaborative partner be Waste Wise.