Newly-Launched Inventions That Can Help Homeowners Save Energy

Domestic energy efficiency has advanced a long way over the last few decades. Despite our overall energy consumption increasing by just over a third since 1980, on average our homes consume around 10% less overall. How can this be the case when we have so many more electrical appliances? Back in 1980, not many homes had more than a single TV, and computers and mobile phones were essentially non-existent. Yet somehow they used more electricity!

The answer to this question comes down to one simple principle. Energy efficiency. Government regulations and technical advances led by the private sector have resulted in appliances that are simply more sustainable. Throw in a better public understanding of the importance of reducing carbon emissions, and also the use of money expert comparison sites to track the expense of powering a home, and it the picture becomes a little clearer.

Expect to see this trend, become ever more prevalent in the near future, as sustainability has become a huge industry sector that continues to rapidly expand.

Here’s a selection of the most recent technologies that are already helping homeowners save money that we can expect to become common place over the coming years.

1. Smart Homes

At first glance, you may wonder what the point is in buying a new domestic appliance that is advertised as ‘internet connected/ready’. After all, who is going to need a web compatible refrigerator or air conditioning unit? It is increasingly common for newly released appliances to boast this feature because in the coming years, our homes are going to be much more connected than at present. Being able to monitor and control energy expenditure remotely via smartphone is a tech that is already with us – but these are still the early days.

The next big step forward is going to be the implementation of wireless sensors throughout the home. These will connect all the appliances in the home to a centralized control panel which will automatically instruct how they interact with the energy supply.

For instance, appliances not in use, but on ‘standby’ mode will be entirely disconnected from the power supply when nobody is at home. Heating and air conditioning use will be precisely measured according to the ambient temperature. Just these two examples – and there are many more in the pipeline – are set to shave a considerable amount of household energy consumption in the very near future.

2. Next Generation Home Insulation

The US Industrial Science & Technology Network takes the approach that heating and cooling costs can best be reduced by simply developing superior insulation. While still at the development stage, these are promised to be far more efficient at preventing heat from escaping.

As may be expected, they are also going to be environmentally sound and most likely comprised of recycled foam materials. Should these be proven to work, there is a very good chance they will become the industry norm for new build and redeveloped housing in the years to come.

3. Reflective Roofing Materials

While insulation is ideal for maintaining an ambient temperature what about those who live in warmer climes? Everyone knows how expensive it is to run air conditioning 24 hours a day, but there have been considerable recent advances in reflective rooftop materials. Currently, these work by using special pigments that are coated onto the roof in order to reflect sunlight and heat.

The next generation in development will use fluorescent pigments that look likely to be up to four times more efficient. So for those who reside in areas where effective air conditioning is essential around the year, these new materials may well be an absolute godsend.

4. Magnetocaloric Refrigerators

A fridge powered by magnets? Close, but not quite. Refrigeration technology has barely changed or advanced since they were first introduced. Modern fridges still rely on vapor compression, which unfortunately requires chemical coolants that are notoriously bad for the environment.

Next generation models are going to be able to make use of water-based coolants that make use of the magnetocaloric effect. In layperson’s terms, this is the use of magnets to alter the magnetic field which can provide an extremely energy efficient cooling effect. Expect this to become commonplace in the coming years, thanks to their potential in enormously reducing energy expenditure and carbon emissions.

5. Much More Efficient Heat Pumps

Considerable progress has been made by the US Building Technologies Office in developing heat pumps that essentially move heat throughout the home. There are three models in design that promise to considerably reduce expenditure on heating while also significantly reduce carbon emissions. Standard gas boilers/furnaces are notoriously expensive and inefficient.

  • A low-cost gas-based heating pump could massively increase efficiency and result in lowering heating costs by a staggering 45%.
  • Multiple function fuel based pumps designed for domestic use can still save an estimated 30% with the added bonus of also providing more efficient water heating.
  • Natural gas based heating pumps connected with air conditioners aim to use a very low emission boiler to cater for all domestic needs regardless of the season. Of all three options, this is the most complete package and the one most likely to become widespread in the coming years.

These styles of heat pumps are also going to be used to significantly reduce the energy used by clothes drying machines. General Electric has been already near completing their first gas pump compatible dryer. This is intended to reduce the energy consumption of perhaps the least efficient appliance in the home by up to 60%.

6. Even Better LED Lighting

Energy saving lighting may have become the accepted norm in many households, and the good news is that it is set to become even better. At present these are up to 85% more efficient than old fashioned incandescent bulbs, but the next generation – scheduled for a few years time – promise to double their efficiency. An improvement up to 230 lumens (from the current 115) is forecast.

8% of all electricity consumption in the USA are due to lighting homes and businesses. Having that figure will make for a huge national saving and reduction of energy costs across the board. (Source:https://www.eia.gov/tools/faqs/faq.php?id=99&t=3)

7. Advanced Window Insulation

While still in development this may not sound like a huge advance, but could well result in enormous net energy savings down the line. Using microprocessors and sensors to measure sunlight and radiant heat, these are going to automatically provide shading to assist with providing ideal natural lighting and also assist with heating. Expect these to be integrated with the general smart home system outlined above in due course.

Final Thoughts

So there we have seven of the most exciting and interesting developments that we can expect to see in the home over the coming years. While some are already in production while others are just passing the prototype phase, the future is looking positive in terms of reducing emissions and better managing energy consumption. Energy efficiency is here to stay and these developments will likely only be the tip of the iceberg compared to what we can look forward to over coming decades.

Titanium – An Environmental Vanguard Among Metals

When titanium was first brought into widespread usage, it was lauded for its strong and weathering-resistant properties. Due to energy costs, production declined over the past 10 years; however, a new process established by the UK’s Dstl has reduced titanium processing time by 50%. The result? Cheap, low-energy titanium production.

Titanium is used in a startlingly diverse array of applications, too. From paint, to bikes, to eco friendly party glitter, you will likely encounter titanium in your day-to-day life more frequently than you’d notice. It’s good news, then, that titanium is being used to support positive environmental change in numerous ways.

Titanium taking over plastic

One of the foremost ways in which titanium is helping to improve our natural environment is through offering alternatives to polluting items. A great example of this is plastic replacement.

According to clean ocean advocates The Ocean Cleanup, there’s over 80m tonnes of plastic in the oceans. A large contributor to this is the plastic straw, which features at 11th in the list of Get Green’s most commonly littered plastics. Many manufacturers, by utilizing the non-rusting and sturdy quality of titanium tubes, have opted to replace drinking straws with titanium. Given the possibility of cheap, low energy tubes, this means ocean cleanliness can be improved and carbon emissions mitigated.

Taking titanium to the next level

The material properties of titanium are being taken to the next level by modern science. Another huge cause of carbon emissions and pollution is the plastic bottle. A key target for environmental plans, the reusable bottle industry grew to $7.6bn last year, according to Nielson.

Titanium has entered the market through a  clever flexible bottle, with titanium a key component. The metal has again been chosen due to its resistant quality and the improving environmental impact of producing it.

Tackling the oxides

Oxides have been the main use of titanium for a while. Paint, ink, sunscreen, medicines, paper – there are countless products that use titanium oxide. Historically, the process for oxide extraction has been environmentally damaging, as has the product itself; for example, the USA’s National Park Service states that various sunscreens with Ti oxide will damage coral.

Many manufacturers are replacing plastic drinking straws with titanium.

Now, Titanium Oxide is likely to be brought into the green sphere, too. A novel new study published in the Journal for Pharmaceutical Sciences found that titanium oxide can be synthesized using bacteria, and that this could spell a much brighter future for the historically damaging extraction.

Conclusion

Titanium is a versatile and well renowned metal used in a huge range of applications. As such it’s not an easy proposition to remove it from the market on the grounds of environmentalism. However, through determined scientific study and consumer action, it’s becoming a figurehead in helping the public to use its quality and simultaneously protect the planet.

Biomethane from Food Waste: A Window of Opportunity

food-waste-behaviorFor most of the world, reusing our food waste is limited to a compost pile and a home garden. While this isn’t a bad thing – it can be a great way to provide natural fertilizer for our home-grown produce and flower beds – it is fairly limited in its execution. Biomethane from food waste is an interesting idea which can be implemented in communities notorious for generating food wastes on a massive scale. Infact, the European Union is looking for a new way to reuse the millions of tons of food waste that are produced ever year in its member countries – and biomethane could be the way to go.

Bin2Grid

The Bin2Grid project is designed to make use of the 88 million tons of food waste that are produced in the European Union every year. For the past two years, the program has focused on collecting the food waste and unwanted or unsold produce, and converting it, first to biogas and then later to biomethane. This biomethane was used to supply fueling stations in the program’s pilot cities – Paris, Malaga, Zagreb and Skopje.

Biomethane could potentially replace fossil fuels, but how viable is it when so many people still have cars that run on gasoline?

The Benefits of Biomethane

Harvesting fossil fuels is naturally detrimental to the environment. The crude oil needs to be pulled from the earth, transported and processed before it can be used.  It is a finite resource and experts estimate that we will exhaust all of our oil, gas and coal deposits by 2088.

Biomethane, on the other hand, is a sustainable and renewable resource – there is a nearly endless supply of food waste across the globe and by converting it to biomethane, we could potentially eliminate our dependence on our ever-shrinking supply of fossil fuels. Some companies, like ABP Food Group, even have anaerobic digestion facilities to convert waste into heat, power and biomethane.

Neutral Waste

While it is true that biomethane still releases CO2 into the atmosphere while burned, it is a neutral kind of waste. Just hear us out. The biggest difference between burning fossil fuels and burning biomethane is that the CO2 that was trapped in fossil fuels was trapped there millions of years ago.  The CO2 in biomethane is just the CO2 that was trapped while the plants that make up the fuel were alive.

Biofuel in all its forms has a bit of a negative reputation – namely, farmers deforesting areas and removing trees that store and convert CO2 in favor of planting crops specifically for conversion into biofuel or biomethane. This is one way that anti-biofuel and pro-fossil fuel lobbyists argue against the implementation of these sort of biomethane projects – but they couldn’t be more wrong, especially with the use of food waste for conversion into useful and clean energy.

Using biogas is a great way to reduce your fuel costs as well as reuse materials that would otherwise be wasted or introduced into the environment. Upgrading biogas into biomethane isn’t possible at home at this point, but it could be in the future.

If the test cities in the European Union prove successful, biomethane made from food wastes could potentially change the way we think of fuel sources.  It could also provide alternative fuel sources for areas where fossil fuels are too expensive or unavailable. We’ve got our fingers crossed that it works out well – if for no other reason that it could help us get away from our dependence on finite fossil fuel resources.

The Impact of Smart Homes on Generations

America is already feeling the impact of smart homes. A large industry based on this technology is forming. But, what is the effect of it on the different generations? Here you can find a brief discussion of the impact of smart homes on generations.

What is a Smart Home?

Smart homes consist of all the different smart products owned by the user. These products are interconnected. It makes use of the internet to connect to other products. This technical feature is called the Internet of Things (IoT).

There are all kinds of products. Every room or space in a home can be automated by smart home products. You can even install smart devices into your backyard like smart lawnmowers and irrigation systems.

Benefits for all generations

Smart home products are designed to benefit its users. The technology is developed for all generations. So there are benefits to its use that applies to everyone.

These benefits include:

  • An increase in comfort of the user’s lifestyle.
  • Increased life expectancy caused by the usage of these products (i.e. smart security products).

Impacts on different generations

Three larger generation groups have been defined for the purpose of this discussion. It’s been split into the retirees, the working force, and the youth.

Retirees

Smart home products can connect to all kinds of services and devices. Elderly people can enjoy minor medical check-ups from the comfort of their homes. Video calls and domestic smart medical equipment can supply all the information a doctor needs. Doctors can keep an eye on patients that are too far from their offices.

Retired people can make use of smart home technology to automate simple tasks. Grocery shopping and other basic services are accessible through these products. Retirees will enjoy the improved elderly care and greater access to basic services caused by smart homes.

The working force

Smart home products like smart thermostats have been known to save its users an average of 20% in yearly warming and cooling costs. According to a study conducted by SafeAtLast, 57% of American smart home owners save about 30 minutes per day. Automating your home will save you lots of time and effort in the process.

The working force who owns smart home products will be more productive. They will also have more cash on hand due to extra savings. Smart homes can help to create a wealthier economy by assisting the working force.

The youth

The youth of today is the promise for tomorrow. Smart home technology is indirectly designed to increase the life expectancy of its user. All these benefits will help to cultivate a better tomorrow. The youth who grow up with smart home technology will have an advantage over their lesser privileged youths. Though, the psychological effects of this technology (over the long term) is yet to be studied.

Conclusion

This technology wants to make your life better. It will benefit every generation. Give it a try to experience the benefits yourself. Read on to for interesting facts on smart homes.

Zena Fly- Feeding the World on Insect

Meeting an ever increasing demand for food/feed/energy and managing waste have become two of the major global challenges. The global world population is estimated to increase from 7.3 billion in 2015 to 9.7 billion in 2050. Approximately one third of the global food produced for human composition is wasted. Currently, approximately 1.3 billion metric tons of waste are disposed with significant environmental impact as far as greenhouse gases and economic footprints and the current waste management practices are not costly sustainable.

Increase in Global Energy Demand

Global energy demand is estimated to increase from 524 Quadrillion btu in 2010, to 820 Quadrillion btu by 2040 (a 56% increase). Similarly, global demand of food and animal products are projected to increase by 70-100% and 50-70%, respectively, by 2050. To cope up with the demand for animal products, a substantial increase in nutritious animal feed is needed.

On one hand, the production of conventional feedstuff such as soybean meal and fish meal is reported as the major contributor to land occupation, ocean depletion, climate change, water and energy consumption. Moreover, such conventional animal feedstuff are not only limited in supply but also are becoming more expensive over the years. Additionally, there is an already strong and increasing competition for resources such as food, feed and biofuel production.

Need for alternative non-conventional source of food, feed, and fuel

Thus there is a pressing need for identifying and exploring the potential of alternative non-conventional source of food, feed, and fuel, which are economically viable, environmentally friendly, and socially acceptable.

By 2030 the Bio-based Economy is expected to have grown significantly. A pillar of this is biorefining, the sustainable processing of biomass into a spectrum of marketable products and energy. To satisfy this demand biorefineries need to be better integrated, flexible and operating more substantially. This means that a major yield, more efficient use of nutrients and water and greater pest and disease resistance should be achieve.

Zena Fly: A Startup Worth Watching

In this context an Italian-based start-up, Zena Fly, designed an innovative process for the future integrated bio-refinery by mimicking nature’s ability. In fact, Zena Fly utilizes the natural insect life cycle to manage large quantity of organic waste produced in urban and industrial context, in order to generate sustainable and valuable by-products. The project of three young entrepreneurs foresees a combined bio-refinery where waste is turned into high-quality by-products by the anaerobic insect digestion.

The Concept

The basic concept is to convert waste into high-valuable products utilizing the black soldier flies (H. illucens), a now globally distributed insect. With a modern technique, the typical insect life cycle of these insects can be utilized in order to manage urban and industrial waste. The voracious larvae can reduce by more than 40-70% (based on the nature of the substrate-waste) the substrate where reared (waste) within 12-14 days.

From the anaerobic waste digestion, large quantity of fine protein meal for feed composition (more than 50-60% in protein), fat, fertilizing oil and other by-products of great interest such as chitin, and high-quality biofuel are then extracted.

Since the adult fly do not feed, and do not fly around for feeding, these animals are exceptionally valuable from a sanitary perspective (larvae has been demonstrate to reduce/eliminate E.coli and Salmonella).

Business Model

Zena Fly business model foresees to replicate their integrated biorefineries next to any waste management companies or industrial production areas where large quantity of waste need to be reduced and transformed. This is a win/win operation, where the waste management cost would be cut in half and the process will generate appealing opportunities for investments in a market where the increasing demand is already way higher than the products availability.

Zena Fly is now seeking for the right partner-investor in order to scale up quickly. For more information, please visit www.zena-fly.com or email us on info@zena-fly.com

Anaerobic Digestion of Tannery Wastes

The conventional leather tanning technology is highly polluting as it produces large amounts of organic and chemical pollutants. Wastes generated by tanneries pose a major challenge to the environment. Anaerobic digestion of tannery wastes is an attractive method to recover energy from tannery wastes.

According to conservative estimates, more than 600,000 tons per year of solid waste are generated worldwide by leather industry and approximately 40–50% of the hides are lost to shavings and trimmings. Everyday a huge quantity of solid waste, including trimmings of finished leather, shaving dusts, hair, fleshing, trimming of raw hides and skins, are being produced from the industries. Chromium, sulphur, oils and noxious gas (methane, ammonia, and hydrogen sulphide) are the elements of liquid, gas and solid waste of tannery industries.

Biogas from Tannery Wastes

Anaerobic digestion (or biomethanation) systems are mature and proven processes that have the potential to convert tannery wastes into energy efficiently, and achieve the goals of pollution prevention/reduction, elimination of uncontrolled methane emissions and odour, recovery of biomass energy potential as biogas, production of stabilized residue for use as low grade fertilizer.

Anaerobic digestion of tannery wastes is an attractive method to recover energy from tannery wastes. This method degrades a substantial part of the organic matter contained in the sludge and tannery solid wastes, generating valuable biogas, contributing to alleviate the environmental problem, giving time to set-up more sustainable treatment and disposal routes. Digested solid waste is biologically stabilized and can be reused in agriculture.

Until now, biogas generation from tannery wastewater was considered that the complexity of the waste water stream originating from tanneries in combination with the presence of chroming would result in the poisoning of the process in a high loaded anaerobic reactor.

When the locally available industrial wastewater treatment plant is not provided by anaerobic digester, a large scale digestion can be planned in regions accommodating a big cluster of tanneries, if there is enough waste to make the facility economically attractive.

In this circumstance, an anaerobic co-digestion plant based on sludge and tanneries may be a recommendable option, which reduces the quantity of landfilled waste and recovers its energy potential. It can also incorporate any other domestic, industrial or agricultural wastes. Chrome-free digested tannery sludge also has a definite value as a fertilizer based on its nutrient content.

Potential Applications of Biogas

Biogas produced in anaerobic digesters consists of methane (50%–80%), carbon dioxide (20%–50%), and trace levels of other gases such as hydrogen, carbon monoxide, nitrogen, oxygen, and hydrogen sulfide.  Biogas can be used for producing electricity and heat, as a natural gas substitute and also a transportation fuel. A combined heat and power plant (CHP) not only generates power but also produces heat for in-house requirements to maintain desired temperature level in the digester during cold season.

CHP systems cover a range of technologies but indicative energy outputs per m3 of biogas are approximately 1.7 kWh electricity and 2.5kWh heat. The combined production of electricity and heat is highly desirable because it displaces non-renewable energy demand elsewhere and therefore reduces the amount of carbon dioxide released into the atmosphere.

AD Plant at ECCO’s Tannery (Netherlands)

A highly advanced wastewater treatment plant and biogas system became fully operational in 2012 at ECCO’s tannery in the Netherlands. A large percentage of the waste is piped directly into the wastewater plant to be converted into biogas. This biogas digester provides a source of renewable fuel and also helps to dispose of waste materials by converting waste from both the leather-making processes, and the wastewater treatment plant, into biogas. All excess organic material from the hides is also converted into biogas.

This project enables ECCO Tannery to reduce waste and to substitute virtually all of its consumption of non-renewable natural gas with renewable biogas. The aim is to use more than 40% of the total tannery waste and replace up to 60% of the total natural gas consumption with biogas.

Methods for Hydrogen Sulphide Removal from Biogas

The major contaminant in biogas is H2S which is both poisonous and corrosive, and causes significant damage to piping, equipment and instrumentation. The concentration of various components of biogas has an impact on its ultimate end use. While boilers can withstand concentrations of H2S up to 1000 ppm, and relatively low pressures, internal combustion engines operate best when H2S is maintained below 100 ppm. The commonly used methods for hydrogen sulphide removal from biogas are internal to the anaerobic digestion process – air/oxygen dosing to digester biogas and iron chloride dosing to digester slurry.

Biological Desulphurization

Biological desulphurization of biogas can be performed by using micro-organisms. Most of the sulphide oxidising micro-organisms belong to the family of Thiobacillus. For the microbiological oxidation of sulphide it is essential to add stoichiometric amounts of oxygen to the biogas. Depending on the concentration of hydrogen sulphide this corresponds to 2 to 6 % air in biogas.

The simplest method of desulphurization is the addition of oxygen or air directly into the digester or in a storage tank serving at the same time as gas holder. Thiobacilli are ubiquitous and thus systems do not require inoculation. They grow on the surface of the digestate, which offers the necessary micro-aerophilic surface and at the same time the necessary nutrients. They form yellow clusters of sulphur. Depending on the temperature, the reaction time, the amount and place of the air added the hydrogen sulphide concentration can be reduced by 95 % to less than 50 ppm.

Measures of safety have to be taken to avoid overdosing of air in case of pump failures. Biogas in air is explosive in the range of 6 to 12 %, depending on the methane content). In steel digesters without rust protection there is a small risk of corrosion at the gas/liquid interface.

Iron Chloride Dosing

Iron chloride can be fed directly to the digester slurry or to the feed substrate in a pre-storage tank. Iron chloride then reacts with produced hydrogen sulphide and form iron sulphide salt (particles). This method is extremely effective in reducing high hydrogen sulphide levels but less effective in attaining a low and stable level of hydrogen sulphide in the range of vehicle fuel demands.

In this respect the method with iron chloride dosing to digester slurry can only be regarded as a partial removal process in order to avoid corrosion in the rest of the upgrading process equipment. The method need to be complemented with a final removal down to about 10 ppm.

The investment cost for such a removal process is limited since the only investment needed is a storage tank for iron chloride solution and a dosing pump. On the other hand the operational cost will be high due to the prime cost for iron chloride.

Biomass Cogeneration Systems

Biomass fuels are typically used most efficiently and beneficially when generating both power and heat through biomass cogeneration systems (also known as combined heat and power or CHP system). Biomass conversion technologies transform a variety of wastes into heat, electricity and biofuels by employing a host of strategies. Conversion routes are generally thermochemical or biochemical, but may also include chemical and physical.

The simplest way is to burn the biomass in a furnace, exploiting the heat generated to produce steam in a boiler, which is then used to drive a steam turbine. Advanced biomass conversion technologies include biomass integrated gasification combined cycle (BIGCC) systems, cofiring (with coal or gas), pyrolysis and second generation biofuels.

Biomass Cogeneration Systems

A typical biomass cogeneration (or biomass cogen) system provides:

  • Distributed generation of electrical and/or mechanical power.
  • Waste-heat recovery for heating, cooling, or process applications.
  • Seamless system integration for a variety of technologies, thermal applications, and fuel types into existing building infrastructure.

Biomass cogeneration systems consist of a number of individual components—prime mover (heat engine), generator, heat recovery, and electrical interconnection—configured into an integrated whole. The type of equipment that drives the overall system (i.e., the prime mover) typically identifies the CHP unit.

Prime Movers

Prime movers for biomass cogeneration units include reciprocating engines, combustion or gas turbines, steam turbines, microturbines, and fuel cells. These prime movers are capable of burning a variety of fuels, including natural gas, coal, oil, and alternative fuels to produce shaft power or mechanical energy.

Key Components

A biomass-fueled cogeneration facility is an integrated power system comprised of three major components:

  • Biomass receiving and feedstock preparation.
  • Energy conversion – Conversion of the biomass into steam for direct combustion systems or into biogas for the gasification systems.
  • Power and heat production – Conversion of the steam or syngas or biogas into electric power and process steam or hot water

Feedstock for Biomass Cogeneration Plants

The lowest cost forms of biomass for cogeneration plants are residues. Residues are the organic byproducts of food, fiber, and forest production, such as sawdust, rice husks, wheat straw, corn stalks, and sugarcane bagasse. Forest residues and wood wastes represent a large potential resource for energy production and include forest residues, forest thinnings, and primary mill residues.

combined-heat-and-power

Energy crops are perennial grasses and trees grown through traditional agricultural practices that are produced primarily to be used as feedstocks for energy generation, e.g. hybrid poplars, hybrid willows, and switchgrass. Animal manure can be digested anaerobically to produce biogas in large agricultural farms and dairies.

To turn a biomass resource into productive heat and/or electricity requires a number of steps and considerations, most notably evaluating the availability of suitable biomass resources; determining the economics of collection, storage, and transportation; and evaluating available technology options for converting biomass into useful heat or electricity.

Biogas-to-Biomethane Conversion Technologies

biogas-biomethaneRaw biogas contains approximately 30-45% of CO2, and some H2S and other compounds that have to be removed prior to utilization as natural gas, CNG or LNG replacement. Removing these components can be performed by several biogas upgrading techniques. Each process has its own advantages and disadvantages, depending on the biogas origin, composition and geographical orientation of the plant. The biogas-to-biomethane conversion technologies taken into account are pressurized water scrubbing (PWS), catalytic absorption/amine wash (CA), pressure swing absorption (PSA), highly selective membrane separation (MS) and cryogenic liquefaction (CL) which are the most common used biogas cleanup techniques.

The Table below shows a comparison of performance for these techniques at 8 bar (grid) injection.

Table:  Comparison of performance for various upgrading techniques (result at 8 bar) (Robert Lems, 2010) , (Lems R., 2012)

  PWS CA PSA MS CL Unit
Produced gas quality*2 98 99 97-99 99 99.5 CH4%
Methane slip 1 0.1-0.2 1-3 0.3-0.5 0.5 %
Electrical use 0.23-0.25 0.15-0.18 0.25 0.21-0.24 0.35 kWh/Nm3 feed
Thermal energy use 0,82-1.3 kWth/Nm3 prod.
Reliability / up time 96 94 94 98 94 %
Turn down ratio 50-100 50-100 85-100 0-100 75-100 %
CAPEX Medium Medium Medium Low High  
Operation cost Low Medium Medium Low High  
Foot print Large Large Medium Small Large  
Maintenance needed Medium Medium+ Medium+ Low High  
Ease of operation Medium Medium+ Medium Easy Complex  
Consumables &

waste streams

AC*3/Water AC*3/amines AC*3/ absorbents AC*3/None AC*3/None  
References Many Many Medium Medium Very few  

*2 If no oxygen of nitrogen is present in the raw biogas

*3 Activated carbon (AC) consumption is depending on the presence of certain pollutants (trace components) within the raw biogas.

From the above Table, it can be concluded that the differences between technologies with respect to performance seem to be relatively small. However, some “soft factors” can have a significant impact on technology selection. For example, water scrubber technology is a broadly applied technology. The requirement for clean process water, to make up for discharge and condensation, could be a challenging constraint for remote locations.

Moreover, PWS systems are prone to biological contamination (resulting in clogged packing media and foaming), especially when operated at elevated temperatures. Without additional preventative measures this will result in an increase of operational issues and downtime.

Amine scrubbers are a good choice when surplus heat is available for the regeneration of the washing liquid. The transport and discharge of this washing liquid could however be a burden, as well as the added complexity of operation. With respect to cryogenic Liquefaction (CL) one may conclude that, this technology has a questionable track-record, is highly complex, hard to operate, and should therefore not be selected for small-medium scale applications.

Both PSA and MS provide a “dry” system, both technologies operate without the requirement for a solvent/washing liquid, which significantly simplifies operation and maintenance. Distinctive factor between these technologies is that the membrane based system operates in a continuous mode, while the PSA technology is based on columns filled with absorption materials which operate in a rotating/non-continuous mode.

Moreover, the membrane based system has a more favourable methane slip, energy consumption and turndown ratio. The biggest advantage over PSA however, is that membrane systems do not require any transport of absorbents, its ease of operation and superior up-time.

Main disadvantage of membrane systems are that they are sensitive to pollution by organic compounds, which can decrease efficiency. However, by applying a proper pre-treatment (generally based on activated carbon and condensation) in which these compounds are eliminated, this disadvantage can be relatively easy nullified.

Based on membrane technology, DMT Environmental Technology, developed the Carborex ®MS. A cost-effective plug and play, containerized (and therefore), easy to build in remote locations) biogas upgrading system. The Carborex ®MS membrane system has relatively little mechanical moving components (compared to other upgrading technologies) and therefore, ensures stability of biomethane production, and consequently, the viability of the biogas plant operation.

Moreover, its design for ease of operation and robustness makes this technological platform perfectly suitable for operation at locations with limited experience and expertise on handling of biogas plants.

Impression of a membrane system; Carborex ®MS – by courtesy of DMT

Impression of a membrane system; Carborex ®MS – by courtesy of DMT

Conclusions

Capture of biogas through application of closed ponds or AD’s is not only a necessity for mitigation of greenhouse gas emissions, it is also a method of optimizing liquid waste treatment and methane recovery. Billions of cubic meters of biomethane can be produced on a yearly basis, facilitating a significant reduction of fossil fuel dependency.

Moreover, upgrading of raw biogas-to-biomethane (grid, CNG or LNG quality) provides additional utilization routes that have the extra advantage to be independent of existing infrastructure. To sum up, membrane based technology is the best way forward due to its ease of operation, robustness and the high quality of the end-products.

References

  • Lems R., D. E. (2012). Next generation biogas upgrading using high selective gas separation membranes. 17th European Biosolids Organic Resources Conference. Leeds: Aqua Enviro Technology .
  • Robert Lems, E. D. (2010). Making pressurized water scrubbing the ultimate biogas upgrading technology with the DMT TS-PWS® system. Energy from Biomass and Waste UK . London: EBW-UK .

Co-Authors: H. Dekker and E.H.M. Dirkse (DMT Environmental Technology)

Note: This is the final article in the special series on ‘Sustainable Utilization of POME-based Biomethane’ by Langerak et al of DMT Environmental Technology (Holland). The first two articles can be viewed at these links

http://www.bioenergyconsult.com/biomethane-utilization/

http://www.bioenergyconsult.com/pome-biogas/

Everything You Need to Know About Solar and The Urban Heat Island Effect

As cities grow, open spaces, trees and other greenery, and other naturally occurring surfaces diminish, replaced by concrete and asphalt surfaces. When this happens, the heat absorbed by these surfaces has nowhere to go, and so is radiated and reflected into the immediate surrounding areas. This creates an urban heat island.

This leads to an increase in heat in the immediately surrounding areas, making temperatures a few degrees hotter than the actual weather. This causes discomfort to residents of the area and can also incur damage in the form of heat-damaged structures.

There is also a human cost associated with urban heat islands. Heat-related medical emergencies such as heat stroke become more prevalent in such areas as the heat can go up to dangerous levels. The EPA has taken stock of this phenomenon and is now advising cities to take steps to mitigate it. One such way is the use of Los Angeles solar as a means of making cities cooler and more comfortable to live in.

How does solar minimize this effect?

Cool Roof Strategy

A cool roof strategy is a one that seeks to use heat absorbing and/or dissipating roofing materials and technologies. Typical roofs use materials that either reflect or absorb and radiate back heat. Conversely, cool roofs, like solar, can help absorb sun rays and convert them into beneficial energy.

Solar excels at this because of the way the cells are designed and organized to absorb the maximum amount of sunlight. Solar roofs are also designed to trap this heat rather than radiate it back into the environment, something that can help reduce the amount of secondary heat being released into the environment.

Reduced Construction

When solar roofs are implemented, there is usually a reduced need to construct structures that support the traditional electric grid. Such a scenario can play out in several ways. If a new estate is being built with nothing but solar power, there is a possibility that some open spaces can be retained as fallow ground in places where utility implements would have been installed.

While the gains at this level would be marginal, implementation of this strategy across several thousand estates can help move the needle in reducing the urban heat island effect.

Combination Approach

This approach offers the greatest promise of reducing heat in urban settings. By combining the cool roof strategy with other strategies like green roofing, planting more trees and vegetation, cool paving and general smart city growth, a lot of ground can be covered.

Planting more trees and vegetation will go a long way in reducing heat in urban settings.

All these strategies have one thing in common in that they all absorb and dissipate heat in an efficient and sustainable manner. The EPA recommends these measures, among others, to cities grappling with the urban heat island effect or anticipating it as open spaces and greenery levels go down.

Many cities have a high incentive to deal with this issue because of its effect on residents and visitors to the area. If street-level temperatures are unbearable, it is possible that tourists and potential new residents may shy away from the area in favor of other cooler cities.