Biomass Resources from Rice Industry

The cultivation of rice results in two major types of biomass wastes – Straw and Husk –having attractive potential in terms of biomass energy. Although the technology for rice husk utilization is well-proven in industrialized countries of Europe and North America, such technologies are yet to be introduced in the developing world on commercial scale.

Rice-Biomass

The importance of Rice Husk and Rice Straw as an attractive source of energy can be gauged from the following statistics:

Rice Straw

  • 1 ton of Rice paddy produces 290 kg Rice Straw
  • 290 kg Rice Straw can produce 100 kWh of power
  • Calorific value = 2400 kcal/kg

Rice Husk

  • 1 ton of Rice paddy produces 220 kg Rice Husk
  • 1 ton Rice Husk is equivalent to 410- 570 kWh electricity
  • Calorific value = 3000 kcal/kg
  • Moisture content = 5 – 12%

Rice husk is the most prolific agricultural residue in rice producing countries around the world. It is one of the major by-products from the rice milling process and constitutes about 20% of paddy by weight. Rice husk, which consists mainly of lingo-cellulose and silica, is not utilized to any significant extent and has great potential as an energy source.

Rice husk can be used for power generation through either the steam or gasification route. For small scale power generation, the gasification route has attracted more attention as a small steam power plant is very inefficient and is very difficult to maintain due to the presence of a boiler. In addition for rice mills with diesel engines, the gas produced from rice husk can be used in the existing engine in a dual fuel operation.

The benefits of using rice husk conversion technology are numerous. Primarily, it provides electricity and serves as a way to dispose of agricultural waste. In addition, steam, a byproduct of power generation, can be used for paddy drying applications, thereby increasing local incomes and reducing the need to import fossil fuels. Rice husk ash, the byproduct of rice husk power plants, can be used in the cement and steel industries further decreasing the need to import these materials.

Rice straw can either be used alone or mixed with other biomass materials in direct combustion. In this technology, combustion boilers are used in combination with steam turbines to produce electricity and heat. The energy content of rice straw is around 14 MJ per kg at 10 percent moisture content.  The by-products are fly ash and bottom ash, which have an economic value and could be used in cement and/or brick manufacturing, construction of roads and embankments, etc.

Straw fuels have proved to be extremely difficult to burn in most combustion furnaces, especially those designed for power generation. The primary issue concerning the use of rice straw and other herbaceous biomass for power generation is fouling, slagging, and corrosion of the boiler due to alkaline and chlorine components in the ash. Europe, and in particular, Denmark, currently has the greatest experience with straw fired power and CHP plants.

Benefits of Wide Access Doors for Green Buildings

Are you considering green technology or green buildings? If you plan to incorporate designs that will help the environment, you should consider wide access doors in your planning! There are various ways to increase the energy efficiency of your commercial buildings to decrease damage to the environment. As the years progress, experts continue to create practical solutions to global warming, and they start with commercial buildings known to be one of the highest contributors to greenhouse gases in the world.

wide access doors for commercial buildings

Know More About Green Design

Green design is a term for sustainable architecture and structural designs. It incorporates simple yet helpful materials, designs, and technologies to minimize the effects of the building on the environment. It is still a progressing technique that not all commercial buildings are using, but to those that are, it is already a significant contribution to the environment.

Role of Wide Access Doors in Green Buildings

You might now be wondering what role doorways play in green buildings. It may not seem much, but if you want to attain that green building title and certification from LEED, you must consider everything, including the doors and hardware.

While you might not consider doors and other hardware as top contributors to the expenses of constructing a building, these components have a higher impact on lessening the energy consumption of your commercial building and improving the overall thermal performance.

Purpose of an Access Door

To understand how wide access doors contribute to green buildings, you must first understand the many uses of access doors. They can vary depending on their type and size, but the primary purpose of an access door is to conceal and protect essential components in a building. When it comes to commercial buildings, you can think of plumbing systems, HVAC systems, and even central wiring.

In hospitals, the purpose of access doors is not limited to concealment but also insulation, proper pressure control, and airflow control from one room to another. Knowing the different goals of access doors can help you determine what type of access door can be more useful to you and your green design. By choosing to install a wide access door, you are not only increasing accessibility but also convenience.

Why It Helps in Green Buildings

Depending on the material of your wide access door, you can help minimize its negative environmental impact. Bigger and broader access doors are not only for convenience, but they are also for safety. For example, if you choose to install oversized fire-rated access doors, it will increase protection during a fire and ensure that there would be no blockage when people access it to escape. These wide doors also come with insulation of their own, lessening the energy consumption of the building. Know more about the benefits of wide access doors below:

Wide Access Doors in Green Buildings

1. Insulation

Access doors can come with their insulation if you choose it. Access doors are often a requirement in most commercial buildings. Having one not only adheres to building codes but can also contribute to the energy efficiency of your structure. An access door can ensure that the air outside does not seep into the building and vice versa. It does not only contribute to energy efficiency and thermal control, but it also ensures the concealment of your building’s essential components.

2. Convenience and Accessibility

Another thing you can benefit from an access door that has its insulation is the convenience and accessibility it gives you. Compared to an ordinary door that does not come with insulation, the properties and features of an access door are worth the cost because of the additional benefits.

You do not have to create significant changes regarding green design immediately. Sometimes, starting with the small things like your doors and windows can help with the overall green rating of your building. Green building is still a progressing idea that not everyone can immediately follow. If you have the means, starting small can already create an impact.

The Benefits of Green Building

Each year, we see the effects of global warming drastically increase. The World Meteorological Organization reported that in the last 50 years, the number of climate-change-driven weather calamities increased by five. With this information coming to light, we must act now to prevent these disasters from worsening.

One simple step is to integrate sustainable practices into your establishment. While this may seem like an expensive proposition at first glance, did you know that going green also benefits your bottom line?

In this article, you’ll see a few benefits of green buildings:

advantages of green buildings

1. Healthier Environment

Unsurprisingly, we spend a large portion of our time indoors when working in an office. In these cases, you may experience exposure to several air pollutants, such as mold, volatile organic compounds from air fresheners, and even secondhand smoke from cigarettes. Regular contact with these air pollutants poses a significant health concern leading to decreased performance and absenteeism.

Introducing steps to improve indoor air quality to combat these health risks is essential. One source of air pollutants is mold growth due to moisture build-up in areas such as behind walls. One of the ways you can reduce mold growth in these areas is to have gasketed access doors like those from Elmdor Access Doors and Panels.

Harvard also studied how effective green buildings are at improving cognitive functions. The result was that workers had a 61 percent higher performance when in green building conditions. You can trust that you and your officemates will make more intelligent decisions when breathing cleaner air.

Economic Benefits

You may have seen the words “LEED certification” thrown around the industry in the past few years. For a bit of context, LEED Certification is one of the best frameworks to follow if you want an environmentally conscious building. Compared to traditional buildings, LEED Certified buildings are proven to use less energy, less water, and lower overall operational costs. Lower operating expenses and utility bills ensure you can focus on growing your business to become a leader in the industry.

With lower maintenance costs and massive health benefits, you could enjoy a 6.6% increase in property asset valuation by going green. Additionally, laws have been getting stricter over the past years as we get closer to the 2030 sustainable development goal. Slowly introducing eco-friendly features to your building today can save thousands in fines and expensive overhauls in the future.

Better Infrastructure

With concrete being our primary building material of choice, it’s no surprise that the market for one of the most versatile construction materials has also grown. This demand comes at the cost of our environment, though, as cement is the third-highest producer of carbon dioxide. Because of this, you need to start thinking of ways to incorporate sustainability in your next construction project.

solar-leasing

What if there was some way to use other materials in concrete? You’ll be glad to know that some companies have already begun offering such products. From using Fly Ash (found in coal-fired powerplants) to capturing the carbon dioxide from the air directly, it’ll be easy to find low-carbon concrete for you to use.

You’ll be glad to know that it won’t just be the environment that’ll benefit from using low-carbon concrete. For example, concrete that utilizes fly ash in its mixture has high compressive strength and better sulfate resistance. You aren’t just using concrete that can bear heavier loads; you’re also set to enjoy it for longer than traditional Portland cement.

It Takes All Of Us

Hopefully, these points have convinced you of the potential benefits of having a sustainable building. Clean air and clear skies don’t need to only exist in far-away lands. You can also enjoy them in your city as soon as we have done our part in having an eco-friendly society.

We get the better living environment we want through concerted and unified efforts towards this goal, and it all starts with your choice in taking the first step.

Pet Waste Management in the UK – Prospects and Challenges

Pet waste is a growing public health and environmental risk. According to a report commissioned by the Pet Food Manufacturers’ Association, 13 million UK households (45%) keep pets of some kind. Cats and dogs are each kept by 8.5 million households (these numbers are not additive, as some will of course keep both).

pet-wastes

Can those of us who want both the joys of animal companionship and waste minimisation, find ways to cut down, or better manage, the huge amount of pet waste generated in the UK every year? With so many cats and dogs in the UK, pet waste must represent a significant mass of organic matter within the residual waste stream.

Does this waste represent a floater in the residual waste stream by necessity—due to inherently unpleasant and possibly dangerous characteristics of the waste—or is it only there out of convention and squeamishness?

I’ve written before about the relationship between waste management and squeamishness, and talking about faeces really brings the point home. There are some undoubtedly nasty pathogens present in pet faeces, notably the parasites Toxocariasis and Toxoplasmosis. But might these be safely killed off by the temperatures reached in anaerobic digestion (AD). If so, provided any litter and bags were made of organic matter, might pet waste be collected along with food waste?

I began by contacting a local authority waste officer, but was told that no one had asked this question before, and that I might be better off talking to AD plant operators. This I did, but most seemed similarly baffled by my query. However, one mentioned that AD digestate goes through a pasteurisation process, where it is heated to a temperature of 70oC for one hour, in order to make it safe for land application. I also attempted to contact some technical specialists in the field, but to no avail.

There are some theoretical indications that this pasteurisation should be sufficient. Hanna Mizgajska-Wiktor and Shoji Uga’s essay Exposure and Environmental Contamination states: “Anaerobic waste treatment kills Toxocara spp. eggs at temperatures in excess of 45oC”, well below the 70oC mentioned by my operator. The susceptibility of Toxoplasma to heat is less clear, although numerous internet sources suggest this can be killed in meat by cooking at 66oC. So far, then, I haven’t confirmed or falsified my initial inkling, and so the collection of pet waste in the municipal organic stream remains a theoretical possibility.

Motivated dog owners can already turn their pet’s waste into a resource within their own home. The website London Worms explains how you can turn your dog’s poo into rich and useful vermicompost, although it warns that the results will only be suitable for use on non-edible plants.

Foul Pay

Household pet droppings may still be largely fated for disposal, but even when binned this waste is at least moving through proper waste management channels. Unfortunately, not all pet poo is binned, and we have real data measuring public perceptions of the disamenity resulting from dog fouling. For most, the presence of this unwelcome waste in our streets, parks and footpaths is of much higher concern than its diversion from landfill. Therefore, it is necessary to make use of biodegradable dog poop bags to keep our environment clean.

A 2011 Defra-funded study on local residents’ willingness-to-pay — via an increase in council tax — for improvements across a range of environmental factors found that dog fouling was the third most important issue out of the presented range (with litter and fly-tipping taking first and second place). Surveys were conducted in inner-city, suburban and rural/semi-rural areas around London, Manchester and Coventry.

In order to move from the current level of dog fouling to the best possible scenario, it was found that inner-city residents would on average be willing to pay £8.87 per month, suburban residents £7.79 per month, and rural residents £2.72. Combining these figures with population statistics allows us to place a disamenity value on dog fouling. National statistics only allow for an urban-rural split, but based on a 2012 Defra rurality study which found that 18.9% of the population lives in rural areas, we can calculate that across England we would collectively be willing to pay £462m per year to achieve best case scenario improvements in dog fouling.

This somewhat crude calculation gives an indication of the perceived disamenity of dog fouling. Presenting the matter in terms such as these may allow economically minded policy makers a means of engaging with this important street scene issue and evaluating the costs and benefits of interventions.

Food for Thought

Let’s wash our hands of poo (with plenty of soap and warm water) and look to the other end of the pet waste problem. According to a report published by WRAP, the UK uses around 75,000 tonnes of primary packaging annually. This holds 1,263,000 tonnes of wet and dry cat and dog food, of which 9,000 uneaten tonnes are thrown away. Although this wasted food constitutes less than 1% of the total sold (if only we were as careful with food for human consumption) the estimated cost to the consumer is still £21m a year.

WRAP examined a number of designs intended to cut to down on the amounts of both pet food and packaging thrown away. A major problem with packaging design is the need to account for portion sizes, which vary from animal to animal and change depending on age and level of activity. Single serve packaging may actually lead to regular food wastage if the portion provided is too big for a particular pet; indeed, this is a problem I am experiencing with my own cat, whose appetite seems to fluctuate wildly. Re-sealable packaging that allows owners to dish out meals in accordance with the changing appetites of their pets is therefore preferable.

The material that packaging is made of is also significant: for example, relatively heavy tins are recyclable, whereas lightweight plasticised plastic foil packets are not. Pet food and its packaging can be pushed up the waste hierarchy by simply choosing a recyclable and resealable container which will allow them to adequately provide for the appetite of their pet. However, these issues are likely to be given less weight compared with health, convenience and cost in the minds of most householders. The onus has to be on manufacturers to develop packaging which is both low cost and easily recyclable. A recent development in this area for cat owners includes durable stainless steel litter boxes, which eliminates the need to purchase and replace plastic boxes.

Love pets, hate waste?

People love animals, but are rather less keen to engage with pets as an environmental issue. Leaving aside questions of whether it is sustainable for so many of us to have pets at all, there are clearly ways in which we can reduce their impact. The convenience of single serving pouches of pet food seems to win out over more recyclable and waste-avoiding alternatives, although pet owners might be willing to change their choices if presented with a better option.

While worrying about recovery options for cat poo might seem somewhat academic, it may be easier to tackle than dog fouling. It might even help to tackle the common psycho-social root of both issues. Cultural distaste perhaps lies behind the lack of information available on dealing with household pet waste, and the persistence of dog fouling as a street scene issue.

Things were very different in Victorian London when “pure finders” earned a living by seeking out doggie doo to supply the tanning trade. But for us this kind of waste is a disagreeable fact of life which we deal with as simply and with as little thought as possible. But as a nation of animal lovers, it’s our responsibility to engage with the waste management issues our pets present.

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

Waste Management in the Food Processing Industry

Food processing industry around the world is making serious efforts to minimize by-products, compost organic waste, recycle processing and packaging materials, and save energy and water. The three R’s of waste management – Reduce, Reuse and Recycle – can help food manufacturers in reducing the amount of waste sent to landfill and reusing waste.

EPA’s Food Recovery Hierarchy

EPA’s Food Recovery Hierarchy is an excellent resource to follow for food processors and beverage producers as it provides the guidance to start a program that will provide the most benefits for the environment, society and the food manufacturer.

Notably, landfill is the least favored disposal option for waste generated in food and beverage producers worldwide. There are sustainable, effective and profitable waste management options including:

  • making animal feed,
  • composting to create nutrient-rich fertilizer,
  • anaerobic digestion to produce energy-rich biogas,
  • recycling/reusing waste for utilization by other industries,
  • feeding surplus food to needy people

Waste Management Options

Food manufacturers has a unique problem – excess product usually has a relatively short shelf life while most of the waste is organic in nature. Food waste created during the production process can be turned into animal feed and sold to goat farms, chicken farms etc. As far as WWTP sludge is concerned, top food manufacturers are recycling/reusing it through land application, anaerobic digestion and composting alternatives.

Organic waste at any food processing plant can be composted in a modern in-vessel composting and the resultant fertilizer can be used for in-house landscaping or sold as organic fertilizer as attractive prices.

Another plausible way of managing organic waste at the food manufacturing plant is to biologically degrade it in an anaerobic digester leading to the formation of energy-rich biogas and digestate. Biogas can be used as a heating fuel in the plant itself or converted into electricity by using a CHP unit while digestate can be used as a soil conditioner. Biogas can also be converted into biomethane or bio-CNG for its use as vehicle fuel.

Items such as cardboard, clean plastic, metal and paper are all commodities that can be sold to recyclers Lots of cardboard boxes are used by food manufacturers for supplies which can be broken down into flat pieces and sold to recyclers.

Cardboard boxes can also be reused to temporarily store chip packages before putting them into retail distribution boxes. Packaging can be separated in-house and recovered using “jet shredder” waste technologies which separate film, carton and foodstuffs, all of which can then be recycled separately.

Organizing a Zero Landfill Program

How do you develop a plan to create a zero landfill program or zero waste program in food and beverage producing company? The best way to begin is to start at a small-level and doing what you can. Perfect those programs and set goals each year to improve. Creation of a core team is an essential step in order to explore different ways to reduce waste, energy and utilities.

Measuring different waste streams and setting a benchmark is the initial step in the zero landfill program. Once the data has been collected, we should break these numbers down into categories, according to the EPA’s Food Recovery Challenge and identify the potential opportunities.

For example, inorganic materials can be categorized based on their end lives (reuse, recycle or landfill).  The food and beverage industry should perform a waste sort exercise (or dumpster dive) to identify its key streams.

Nestlé USA – A Case Study

In April 2015, Nestlé USA announced all 23 of its facilities were landfill free. As part of its sustainability effort, Nestlé USA is continually looking for new ways to reuse, recycle and recover energy, such as composting, recycling, energy production and the provision of safe products for animal feed, when disposing of manufacturing by-products.

Employees also work to minimize by-products and engage in recycling programs and partnerships with credible waste vendors that dispose of manufacturing by-products in line with Nestlé’s environmental sustainability guidelines and standards. All Nestlé facilities employ ISO 14001-certified environmental management systems to minimize their environmental impact.

Recommended Reading: Renewable Energy from Food Recycling

Investing In Green Commercial Real Estate: How to Get Started With Little Money

It’s often debated whether a capitalist world can truly go green. If you have the time and money to develop green commercial real estate (complete with green hosting servers), then our planet could see a greener future. But is it possible to invest in commercial real estate with no money?

Yes, there are plenty of ways to finance green commercial projects before you have a significant amount of cash flow. If you manage your developments properly, you can invest even more.

investing in green commercial real estate

How to Manage Green Commercial Property Development

It can be intimidating to invest in or develop a commercial property for the first time. Your first purchase could make or break your operation. However, you can mitigate risks while improving your return on investment (ROI) by using real estate development software like Northspyre.

As you start developing and investing in more real estate properties, you’ll be able to draw a data-backed conclusion on what works (and what doesn’t). Once data starts to drive your decision-making process, you’ll start to achieve predictable outcomes for all of your projects.

Not only will software eliminate errors caused by complex formulas or spreadsheets, but you’ll also have more time to spend on the parts of development that earn you the most money.

How to Start Investing in Green Commercial Properties 

Whether you’re looking to invest in or develop a commercial property, there are plenty of ways to build a solid portfolio with little money.

Here are 3 ways to finance your commercial projects.

1. Commercial Property REITs

A real estate investment trust (REIT) describes a company that invests in all sorts of real estate types, from homes to businesses. While REITs are often associated with residential properties, like homes, you can absolutely invest in commercial property development using REITs

REITs invest in all commercial real estate types, such as hotels, office buildings, and storage facilities. But you have to watch out for high fees that typically come from upfront sales loads.

If you’re someone who wants to become a commercial real estate developer but you don’t have a lot of cash flow, time, or knowledge of the market, REITs can help you dip your toe in. As a highly liquid asset, publicly traded REITs can be sold on the stock market when convenient. 

Investing in Green Real Estate

2. Loans and Hard Lending

Hard money lending is the best way to fund a commercial property development project with little money. After all, you’re not going to find commercial assets for cheap. Unfortunately, hard money lenders often have strict payment schedules that ask borrowers to pay up quickly.

Unless you can come up with thousands of dollars in a 6 to 24-month period, consider taking out a commercial real estate mortgage, working capital loan, line of credit, or a demand loan.

Alternatively, you could convince the land or building owner to consider seller’s financing. With seller’s financing, the owner finances a portion of the purchase price. You’re required to pay that amount back over a period, which can be negotiated when you both set your financing terms.

3. Commercial Crowdfunding 

Crowdfunding is the practice of funding a project by raising money from multiple people at once. While commercial real estate crowdfunding sites aren’t a new concept, new laws have allowed non-accredited investors to take part in the action for the purpose of building their portfolios. 

If you’re interested in green properties, you can search for green projects specifically. There are plenty of options to choose from because green developments see a high capitalization rate.

Commercial crowdfunding websites, like Fundrise, give low-income investors or developers the option to get in on the ground floor. Fundrise specifically allows non-accredited investors to spend a minimum of $10 on plenty of commercial opportunities at every stage of development.

Renewable Energy from Food Residuals

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

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.

Incineration of Medical Waste: An Introduction

Incineration is a thermal process that transforms medical wastes into inorganic, incombustible matter thus leading to significant reduction in waste volume and weight. The main purpose of any medical waste incinerator is to eliminate pathogens from waste and reduce the waste to ashes. However, certain types of medical wastes, such as pharmaceutical or chemical wastes, require higher temperatures for complete destruction.

Medical waste incinerators typically operate at high temperatures between 900 and 1200°C. Developing countries of Asia and Africa usually use low-cost, high-temperature incinerators of simple design for stabilization of healthcare wastes.

The most reliable and predominant medical waste incineration technology is pyrolytic incineration, also known as controlled air incineration or double-chamber incineration. The pyrolytic incinerator comprises a pyrolytic chamber and a post-combustion chamber.

Medical waste is thermally decomposed in the pyrolytic chamber through an oxygen-deficient, medium-temperature combustion process (800– 900°C), producing solid ashes and gases. The gases produced in the pyrolytic chamber are burned at high temperature (900– 1200°C) by a fuel burner in the post-combustion chamber, using an excess of air to minimize smoke and odours.

Small-scale decentralized incinerators used in hospitals, of capacity 200–1000kg/day, are operated on demand in developing countries, such as India. On the other hand, off-site regional facilities have large-scale incinerators of capacity 1–8 tonnes/day, operating continuously and equipped with automatic loading and de-ashing devices.

In recent years, mobile incinerators are getting attraction in the developing world as such units permit on-site waste treatment in hospitals and clinics, thus avoiding the need to transport infectious waste across the city.

However, the WHO policy paper of 2004 and the Stockholm Convention, has stressed the need to consider the risks associated with the incineration of healthcare waste in the form of particulate matter, heavy metals, acid gases, carbon monoxide, organic compounds, pathogens etc.

In addition, leachable organic compounds, like dioxins and heavy metals, are usually present in bottom ash residues. Due to these factors, many industrialized countries are phasing out healthcare waste incinerators and exploring technologies that do not produce any dioxins. Countries like United States, Ireland, Portugal, Canada and Germany have completely shut down or put a moratorium on medical waste incinerators.