July, 2022 | BioEnergy Consult

Water Saving Tips for Schools and Colleges

By Salman Zafar | July 6, 2022 - 7:33 pm |July 6, 2022 Education, Energy Efficiency, Green

Like all large organizations, schools and colleges need to examine their environmental impact. In addition to energy usage and waste management, water use is another critical area of environmental health for schools and colleges.

With regards to the climate crisis, children and young adults are amongst the loudest voices. Many grassroots campaigns have resulted in the successful lobbying of institutions to change damaging practices. These include divesting from fossil fuel companies and halting research that supports the oil and gas industry. Here are some of our best water saving tips in an educational setting:

For an essay writer, the climate crisis is a subject rich in content. Opening up the debate around school or college policy to students is an excellent way to generate ideas. They’ll outnumber those suggested in this article by 10-to-1. Make sure to tap the young minds at your disposal.

When it comes to your institution’s infrastructure, there are many different kinds of alterations and fixes. Retrofitting aspects of the building’s plumbing is a far easier task than a complete overhaul. These fixes use both high- and low-tech solutions.

Some of the most effective technological fixes are incredibly simple. One of many ingenious toilet water saving tips is the flush bag, a plastic bag that absorbs water. The bag goes into the toilet cistern, which’s the sizable boxy bit at the back of a toilet. When the toilet is flushed, the bag expands and takes up space that would have previously been occupied by water. This space displacement will save roughly one-liter of water per flush, other size bags can reduce more space, but it is a matter of balancing function and environmental favor.

Flush bags illustrate a pertinent point; when dealing with large numbers of individuals, incremental changes add up to a large percentage. If you can save 1,000 liters of water per day, the reduction becomes significant over an academic year. Little and often should be the water-saving motto of your school.

Other excellent marginal gains devices include sensor-activated taps; to prevent accidental (or intentional) tap-running. The tap flow rate in the US is generally very high. Adaptors exist, which will reduce the flow rate and thus save gallons of water. Another thing to note is that our existing infrastructure has always put human needs first; there is a lot of slack in the system.

‘The system’ leads us to the next tip. Think for the future when planning your school’s re-development. Ideas to make a school carbon neutral, or even carbon positive, must include water usage, not just energy usage. Water does not miraculously flow. Some sort of connection to the energy grid is essential.

Schools and colleges can look for renewable energy providers who service their area. Swapping energy providers may be simple, or there could be legal obstacles; it depends on the type of school or college.

For those with a hefty endowment, taking energy generation in-house is one option. Generating a self-reliant water source is hard and not on the list of priorities for most institutions. Who has a natural spring sitting on the grounds these days? However, in the years to come, water desalination plants could become much more affordable and offer locally available water to the area, not just the institution.

One place that needs water saving tips is California. The state has suffered dramatic and devastating wildfires evermore frequently in recent years, making news the world over. In areas that are prone to wildfires like this, water is of deep concern. They’re running out. Schools, colleges, and the entire state have to reduce their demand. Reducing this demand will only become more critical, familiar, and necessary in the coming years.

Schools and universities can lead the way on this front. They’re able to set their own rules and develop sound practices in their students while they’re at it. Education is just as important as technological fixes; ensuring water doesn’t get wasted is as much about bringing together the team as it is stuffing bags in toilets.

Embodied carbon is the amount of carbon it took for an object to be made or to function. Embodied water is not just the fact that you’re 90% h2o; it’s the amount of freshwater affected or used to create a material or maintenance of services.

It is easy to think about embodied water in food; wheat grown in the USA contains approximately 849 cubic meters of water per tonne. Understanding metrics such as these can help with long term planning. If your institution provides food, a thorough audit of your water use could suggest ways to alter the kitchen and the menu to reduce water consumption.

Saving water in schools and colleges is literally and metaphorically plugging a leaky pipe. The task is never really over as it is so complex and prone to faults and issues. That said, every institution can save water tomorrow if they implement some of the fixes covered in this article.

An Introduction to Biomass Energy

By Salman Zafar | July 5, 2022 - 7:25 pm |November 2, 2023 Biomass Energy, Renewable Energy, Science

16 Comments

Biomass is the material derived from plants that use sunlight to grow which include plant and animal material such as wood from forests, material left over from agricultural and forestry processes, and organic industrial, human and animal wastes.

Biomass energy (or bioenergy) is a type of renewable energy generated from biological (such as, anaerobic digestion) or thermal conversion (for example, combustion) of biomass resources.

Biomass comes from a variety of sources which include:

Wood from natural forests and woodlands
Forestry plantations
Forestry residues
Agricultural residues such as straw, stover, cane trash and green agricultural wastes
Agro-industrial wastes, such as sugarcane bagasse and rice husk
Animal wastes
Industrial wastes, such as black liquor from paper manufacturing
Sewage
Municipal solid wastes (MSW)
Food processing wastes

In nature, if biomass is left lying around on the ground it will break down over a long period of time, releasing carbon dioxide and its store of energy slowly. By burning biomass its store of energy is released quickly and often in a useful way. So converting biomass into useful energy imitates the natural processes but at a faster rate.

Biomass can be transformed into clean energy and/or fuels by a variety of technologies, ranging from conventional combustion process to advanced biofuels technology. Besides recovery of substantial energy, these technologies can lead to a substantial reduction in the overall biomass waste quantities requiring final disposal, which can be better managed for safe disposal in a controlled manner while meeting the pollution control standards.

Biomass conversion systems reduces greenhouse gas emissions in two ways. Heat and electrical energy is generated which reduces the dependence on power plants based on fossil fuels. The greenhouse gas emissions are significantly reduced by preventing methane emissions from decaying biomass.

Moreover, biomass energy plants are highly efficient in harnessing the untapped sources of energy from biomass resources and helpful in development of rural areas.

Recommended Reading: How bioenergy can help in reaching net zero targets

Is it Safe to Drink RO Water?

By Salman Zafar | July 4, 2022 - 11:15 pm |January 21, 2023 Health, Home Improvements

How is RO Water Harmful to Health?

Reverse osmosis removes a lot of impurities from water. Unfortunately, this includes a large percentage (90-99%) of beneficial minerals like calcium and magnesium. Based on several studies conducted by the WHO, demineralized/low mineral water is harmful to health. And according to WHO reports, the effects of drinking demineralized RO water start to show very quickly.

In several weeks or a few months, people who drink demineralized water may notice symptoms that suggest acute magnesium or calcium deficiency. Other complaints like cardiovascular disorders, muscle cramps, tiredness, and weakness also surface. Intake of low mineral water has also been associated with a higher risk of fracture in children, pregnancy disorders, and certain neurodegenerative diseases.

Demineralized water causes malnutrition and leaches away existing minerals in the body (meaning that minerals gotten from food the person eats will be urinated away).

Even when used for cooking, RO water leaches away important minerals from food.

Is RO Water Still a Good Option?

Although RO systems produce demineralized water, they still have some benefits. Reverse osmosis systems are one of the most effective filters available. If you choose to ditch RO filters, you may have to deal with contaminants like lead, arsenic, chlorine, bacteria, and high amounts of total dissolved solids (TDS) that come with tap water. Compared to demineralized water, these contaminants could lead to a longer list of health problems.

Reverse osmosis filters are a lifesaver in places with poor water quality. They make the water potable and prevent the spread of waterborne diseases.

Also, with a well-balanced diet, you’ll barely feel any effects of demineralized water. You can supplement some of the minerals missing from your drinking water with food. Ordinarily, water shouldn’t be your primary source of nutrients, so altering your diet to include more minerals and vitamins should sustain you.

But if you’re still worried about the demineralized water affecting your health, there are ways to go around it.

Some reverse osmosis filters have a remineralization stage where healthy minerals are added back into the water. Of course, the water will not contain the same amounts of minerals as regular water, but it’s better than having no minerals in the water at all. With some more minerals in your water, the adverse effects of RO water will reduce considerably.

Best Reverse Osmosis Filters

We listed mostly under sink filters since they are a more common type of RO filter. But if you prefer a RO filter with zero installation requirements, you can find at least 5 countertop RO filters that are just as effective.

We also tried to include filters with the remineralization feature since they are a better variety.

1. Home Master Artesian

Home Master is an under sink system with the remineralization feature. The filter adds beneficial minerals into the water at two different stages before finally dispensing it. It has easy-to-change filter cartridges and doesn’t come with a bulky filter housing. The system is also designed to reduce wastewater considerably.

2. iSpring RCC7AK

This filter is highly rated for its remineralization abilities. It works in 6 stages, with alkaline remineralization being the last stage. The alkaline filter needs to be changed twice a year, but the RO membrane can last up to 3 years before needing a change.

3. APEC Essence ROES-PH75

APEC essence also has a remineralization feature. It has a 6 stage filtration process, the last stage being an alkaline calcium filter which makes the water taste like bottled water. The filter is suitable for small cabinets. Its installation process is also simple and can be done without a plumber.

Reverse osmosis water may be deficient in a few minerals, but it’s still good to drink with the right precautions. If you have contaminants in your water, you should consider getting one. All that matters is that you take the necessary precautions to ensure that you don’t lack the nutrients you need to stay healthy.

5 Benefits of Biodegradable Packaging for Businesses

By Emily Folk | July 4, 2022 - 7:21 pm |January 18, 2024 Business, Environment, Green, Recycling

13 Comments

Consumers want companies to reflect their values. They’re far more likely to purchase from a business with an identity, whether it manifests in charitable efforts or eco-friendly practices. As a greater number of people show interest in green living, biodegradable packaging presents an opportunity for growth.

That said, the virtues of eco-friendly packaging extend beyond an improved public image. While business owners enjoy the superficial advantages of this transition, they often find it’s only a fraction of what the shift entails. Through switching to biodegradable plastics, they see considerable changes elsewhere.

In this article, we’ll detail five of those changes, exploring the subject to lend business owners a better understanding of biodegradable packaging within their operation. As we touch on the benefits, it’ll become clear that eco-friendly materials aren’t only better for the environment, but better for a company’s bottom line.

1. Free of Toxins & Allergens

Biodegradable packaging options are still somewhat limited, but most of the available materials are non-toxic and allergy-free. This is an essential consideration to consumers who care about the products they’re purchasing and the composition of their packaging. If either is potentially harmful, it hurts a business.

As often as businesses must send packages, forms, and other important information through the mail, packaging with the planet in mind and protecting your items is key. For example, your may need to send you important documents through the mail. Getting your mail in safe, low-waste packaging can protect your health from harmful chemicals, aid the planet, and provide their clients with all they need to know.

An informed consumer will almost invariably choose products packaged with bioplastic over traditional alternatives, aware of the implications of their purchase. Considering the negative health effects of phthalates — a common chemical in plastic packaging — business owners should be aware of the implications as well.

2. Require Fewer Resources

Biodegradable packaging has the potential to reduce water usage, solid waste, electricity and emissions. This is beneficial for the environment, of course, but it also lowers expenses associated with the packaging process. Over time, the accumulated savings prove well worth the cost of the transition.

If a company were to replace their standard packaging materials with bioplastic, they would enjoy weight savings on par with regular plastic. Research shows plastic packaging enables weight savings of over 78 percent compared to alternative materials, a notable statistic for business owners looking to convert.

3. Lower Production Costs

Most biodegradable materials follow the three basic R’s of sustainability.

A business can reduce them, using fewer resources to create thinner and tougher materials which do the same job.
A business can reuse them, taking advantage of materials with special coating which improves their durability.
A business can recycle them, diverting refuse from landfills as they minimize the costs of new materials.

A business owner who invests in biodegradable packaging can cut costs by a significant margin, using fewer resources, reusing their inventory and purchasing inexpensive recycled materials. In doing so, they’ll see reduced packaging expenses over time, and more freely allocate their money elsewhere.

Reusing packaging is proving to be not only environmentally friendly, but an excellent marketing advantage. From Pinterest to Instagram, users are finding a way to re-purpose packaging. Business owners who are vocal in encouraging their customers to prioritize environmentally friendly choices can earn more goodwill and local business as a result. ToolTally is a good example of a blog that focuses on helping DIYers reuse products, and is growing an organic following as a result.

4. Reduced Footprint

A business owner has financial goals they have to meet, but they have environmental goals as well. Every professional in an upper-management position has a responsibility to ensure their company meets high standards of environmental compliance, and biodegradable packaging can help — outside a legal context.

To reinforce an earlier point, 70 percent of consumers between the ages of 15 and 20 want to buy goods from companies committed to sustainability, and biodegradable plastics affect the appeal of businesses which would otherwise see less attention. To reduce emissions and increase interest, change is necessary.

5. Convenient Disposal

Recyclable, compostable and biodegradable packaging simplifies disposal for the consumer. It affords them more options in discarding these materials, and companies should always seek to make their products convenient, from start to finish. Biodegradable materials exemplify this mindset.

For example, consumers who prefer to compost their refuse won’t have to make exceptions for packaging. They can add biodegradable packaging to their compost in much the same way they would with any other compost-friendly material, contributing to the product’s value beyond its primary utility.

Looking Toward the Future

When reviewing the benefits listed above, business owners should feel confident in their decision to adopt biodegradable packaging. More than superficial benefits, they’ll enjoy reduced costs and carbon emissions while increasing consumer convenience and reducing plastic pollution. The advantages are clear.

Looking toward the future, it’s safe to speculate more companies will transition toward eco-friendly practices. With this in mind, taking action now is the best option, and though biodegradable packaging is a small step, it’s an important one.

Infographic created by Chicago Tag & Label, a custom label printing company

11 Ideas for Easier Recycling at Home

By Salman Zafar | July 3, 2022 - 7:19 pm |July 22, 2023 Green, Recycling, Waste Management

17 Comments

Going green isn’t just meant for Earth Day. Going green is a way of life. However, Earth Day is a day we pause and commemorate, acknowledge and support environmental programs and Earth-saving strategies. It is also a great day to commit or recommit to employ earth-friendly practices in your life, at home and in the office. There are countless things you can do to “go green.” Most of these things are ease to incorporate into your life. Recycling is one of the easiest ways to go green. Recycling is the process of obtaining or retaining waste and converting it into usable, new materials. Some things that can be used to recycle are:

Aluminum
Steel
Paper
Plastic

Recycling is actually a great way to conserve raw resources and save energy. Recycling at least one ton of paper can save 7,000 gallons of water and 17 trees, according to the Environmental Protection Agency. Hiring a skip would help recycle that amount of paper and you can click here for ideas for ideas on the size of the skip you could employ.

As you see, recycling is an effective and simple way to help the environment. It is something the entire family can do too. Before recycling, call your local waste management services. Determine how to you need to sort and pack items for recycling. In addition, you want to know what day or days the waste management services collects recycling. Check with them to find out where you safely dispose of light bulbs, hazardous materials and batteries. These cannot be recycled or put in the trash.

Your local waste management recycling service has different rules about how items must be sorted, cleaned and packaged. Metal, cardboard, plastics, aluminum, glass and paper can be recycled.

It can be tricky to recycle plastics because some can break down easier than other plastics. The number located on the plastic item will determine if it can be recycled. It will also determine if the plastic can be picked up for recycling.

Source: Fix.com

Although plastics are trickier to sort and recycle, it’s important to dispose of them properly. One important factor to establishing a recycling a program at work, school or home is to create a system that works for everyone. Here are a few ways to recycle at home:

Source: DIY Swank

Recycling is about convenience, convenience, and more convenience! When incorporating a successful program about which you can read in the essay about recycling, make bins easily accessible. They should be in an area that is easily visible and used like the utility room or kitchen where they can be seen and used

Source: Better Homes and Gardens

Now, if you need a simple recycling system everyone can follow (even kids), use caster and baskets. These are easy to access and use. They slide out of site when not in use.

Source: Family Handyman

Use space by going vertical. You can hook bins on walls to utilize space. It will be easy to sort and store.

Source: Sweet Haute

Another way to make a successful recycling program is to make it fun. Use stylish bins and trash cans to recycle items.

Source: Sweet Haute

Another way to make a successful recycling program is to make it fun. Use stylish bins and trash cans to recycle items.

You may not have time to personally decorate trash cans by spray painting them. How about using printable labels. These labels can go generic bins to help separate recyclables.

Source: Lil Blue Boo

Batteries are not to be recycled. They cannot be put into a trash can for non-recycling either. Instead, they should be properly thrown away at a collection center or a participating auto part store. The same thing should be done with light bulbs.

Make a special area of your home or office to use as a personal sorting center. This is where you can sort and clean recyclables. You may want to look at some personal recycling centers to get an understand of what you need.

Source: I Should Be Mopping the Floor

Many people do not have an area they can keep bulky recycling or trash in the home or office. If this is the case for you, create a dedicated spot in the garage or other area. It won’t take long before your family or co-workers are pitching in to recycle.

Recycling is full of great ideas to help the environment. Find the ones you like. Used them in your successful recycling program.

Useful Resources

https://diygarden.co.uk/garden-shredders/best-garden-shredders

Environmental Benefits of Polyurethane

By Salman Zafar | July 2, 2022 - 7:14 pm |August 27, 2022 Environment, Green, Recycling

2 Comments

Stated by urethane manufacturers, today’s manufacturing community is becoming increasingly mindful of environmental impacts that arise during industrial processes. Industrial recycling, waste to energy systems, and emissions improvements are just part of a wide-ranging effort to minimize the impact of manufacturing on the environment.

Plastics have become a lightning rod for environmental commentators, as pictures go viral of various waste being found in far-flung areas of our planet.

Something that is not discussed in these discourses is the wide variety of plastics currently available, and how not all plastics degrade in the same fashion. Polyurethane has been unduly spotlighted in these negative conversations.

With limited resources available to the public on the matter, there is plenty of misinformation which we hope to clarify in this article.

Plastic Waste & A Start to Policy Changes

There have been some extremely shocking photos and stories that have come out in recent years with regard to plastic waste. Photos of all sizes of plastic waste being found in rivers, oceans, and forests have been circulated millions of times.

Some cities and countries have started enacting policy changes in a reactionary fashion after seeing the widespread outpouring of anger on social media.

Most plastics that have been illustrated in these campaigns are thermoplastics, which amount to well over 95% of all plastic found during ocean studies. Polyurethanes, however, account for less than 2% of all waste detected during ocean surveys.

Damaging Thermoplastics

In thermoplastics, no molecular bonds are holding the individual strands of polymer together. It’s held together by weak ionic forces, called Van Der Waal forces.

Think of these bonds as a ball of yarn, essentially being held together by the tangled ends of molecular chains. Simply put, the plastic will break down until the last thing left is individual strands. These are the “micro-plastics” which are commonly talked about in the news.

Finer than a human hair, sometimes even microscopic, this is the smallest the material will degrade to. Individual atoms will not separate from the polymer strand and will continue to linger in the environment for decades.

Eco-Friendly Polyurethane

If you aren’t familiar with cast polyurethane it is considered a thermoset plastic. Do not confuse these with the thermoplastic we just discussed.

Polyurethane differs in that once the polymer has been reacted, the individual strands change on an atomic level and crosslink between each other. At these crosslinks, a new molecule is formed, entirely changing the properties of the material.

This molecular cross-linking is what makes polyurethane much more resilient in heavy-duty applications. Once the material has reached the end of its life, it can not be melted down and reformed.

Don’t think of this as a disadvantage since polyurethane materials will generally last longer than any thermoplastic equivalent. This minimizes the amount of polyurethane entering the waste stream right at the initial source.

Recycling Polyurethanes

There are multiple avenues that can be pursued when it comes to the recycling of polyurethane. Parts may be chemically reacted to turn back into their prepolymer state, however, the cost involved in this process can be quite steep.

When polyurethane breaks down in the environment, it will not break down into its individual polymer strands. Instead, individual bonds are broken down between molecules, releasing individual molecules into the environment.

These molecules are almost exclusively inert compounds that will not react or accumulate toxicity in natural environments.

Microbial degradation has become increasingly prevalent, especially in the area of fungi. Scientists have been able to find microorganisms that are well-suited for breaking downcast urethane products ecologically.

Polyurethane For the Win

The chemical makeup of polyurethane, combined with the increased lifetime of individual parts, means you can lower your commercial ecological footprint. Polyurethanes are non-toxic to the environment as they break down, and do not contain BPA or other chemicals which can interfere with endocrine systems.

The minimal effects on the environment will make this polymer even more desirable as we become increasingly environmentally conscious.

A Handy Guide to Choose a Good Therapist

By Salman Zafar | July 2, 2022 - 11:15 am |July 2, 2022 Health, Lifestyle

1 Comment

When seeking a therapist, you will come across a long list of professionals, and it will be really difficult to choose a good one. Therapists have a diverse range of qualification, skills and personalities which may or may not suit you. An effective therapy program is typically based on the relationship between therapist and client. So, what makes a good therapist? Let us explore the qualities of a good therapist to help you make the most out of your therapy sessions.

1. Strong communication skills

A good communicator exhibits confidence and assertiveness, and will make a new person feel comfortable during one-to-one session or on the phone or via email. Coupled with social skills, effective communication skills will help in creating a positive therapeutic bonding between the therapist and the client.

A good therapist will discuss issues in an honest, open and inquisitive manner using plain language, and will also ask for your feedback and opinion on those issues.

2. Effective listening and observation skills

A critical trait of a good therapist is to patiently and proactively listen to people. Your therapist should be skilled in deciphering your spoken words and silence, and in observing your body language. Your therapist should also have a good memory in order to remember things you told them earlier, and connect with what you are saying in the present.

An effective counsellor is not bored by conversation or have allow others to contribute to a conversation. They attentively listen to what you say and then reflect back to help you see new perspectives and draw your own conclusions.

3. Trustworthy

Mutual trust is a very important aspect of therapy and confidentiality is the cornerstone. During the sessions, you will be discussing very private and complex issues with your therapist, and policies should be in place to keep all the shared information confidential, both during and after the treatment process. Confidentiality is essential for the client to open up and feel comfortable in a safe environment without the fear of being betrayed.

Like any other relationship, building trust in therapy sessions is a time-taking process that cannot be rushed. A good therapist will operate within ethical limits, will respect your privacy and will never overstep your personal boundaries. In-session flirtation is among the top signs of a bad therapist.

4. Unbiased and non-judgmental

A good therapist is non-confrontational, unbiased and non-judgmental. Therapists demonstrate respect and will talk to you in a manner which tells they believe you. You are treated with empathy and your thoughts and feelings are not judged or made fun of.

The therapist suggests alternative ways of seeing and doing things and respects your outlook, thus acting as a source of support with whom you can share private things without any hesitation.

5. Flexible and optimistic

When it comes to therapeutic treatment, every client is unique and need a tailored approach. A good therapist should be flexible in his approach and discuss a range of possible strategies to try in your unique circumstance.

Positivity is a critical trait of a therapist and you should feel confident that therapy will improve. Besides identifying the causes of stress, the therapist will also explore the things which can make you happy and peaceful.

6. Open to supervision

A good therapist should be willing to talk about clinical issues with a more experienced colleague in order to get the work quality evaluated. Supervision will help in getting new ideas or insights into a particular issue.

In high-risk situations, it is advisable for a good counsellor to avoid working in isolation and let access supervision to let others know they are doing with clients.

Conclusion

The qualities of a therapist play a crucial role in the successful outcome of therapy. Every therapist may not meet each of the above-mentioned criteria, but if you are aware of the traits of a good therapist, you can decide whether you or your loved one is getting the best treatment.

Ethanol Production from Lignocellulosic Biomass

By Salman Zafar | July 1, 2022 - 7:08 pm |July 1, 2022 Biofuels, Biomass Energy, Renewable Energy

12 Comments

Cellulosic ethanol technology is one of the most commonly discussed second-generation biofuel technologies worldwide. Cellulosic biofuels are derived from the cellulose in plants, some of which are being developed specifically as “energy” crops rather than for food production. These include perennial grasses and trees, such as switchgrass and Miscanthus. Crop residues, in the form of stems and leaves, represent another substantial source of cellulosic biomass.

The largest potential feedstock for ethanol is lignocellulosic biomass, which includes materials such as agricultural residues (corn stover, crop straws, husks and bagasse), herbaceous crops (alfalfa, switchgrass), short rotation woody crops, forestry residues, waste paper and other wastes (municipal and industrial).

Bioethanol production from these feedstocks could be an attractive alternative for disposal of these residues. Lignocellulosic biomass feedstocks do not interfere with food security and are important for both rural and urban areas in terms of energy security reason, environmental concern, employment opportunities, agricultural development, foreign exchange saving, socioeconomic issues etc.

Production of Ethanol

The production of ethanol from lignocellulosic biomass can be achieved through two different processing routes. They are:

Biochemical – in which enzymes and other micro-organisms are used to convert cellulose and hemicellulose components of the feedstocks to sugars prior to their fermentation to produce ethanol;
Thermochemical – where pyrolysis/gasification technologies produce a synthesis gas (CO + H₂) from which a wide range of long carbon chain biofuels, such as synthetic diesel or aviation fuel, can be reformed.

Lignocellulosic biomass consists mainly of lignin and the polysaccharides cellulose and hemicellulose. Compared with the production of ethanol from first-generation feedstocks, the use of lignocellulosic biomass is more complicated because the polysaccharides are more stable and the pentose sugars are not readily fermentable by Saccharomyces cerevisiae.

In order to convert lignocellulosic biomass to biofuels the polysaccharides must first be hydrolysed, or broken down, into simple sugars using either acid or enzymes. Several biotechnology-based approaches are being used to overcome such problems, including the development of strains of Saccharomyces cerevisiae that can ferment pentose sugars, the use of alternative yeast species that naturally ferment pentose sugars, and the engineering of enzymes that are able to break down cellulose and hemicellulose into simple sugars.

Ethanol from lignocellulosic biomass is produced mainly via biochemical routes. The three major steps involved are pretreatment, enzymatic hydrolysis, and fermentation. Biomass is pretreated to improve the accessibility of enzymes. After pretreatment, biomass undergoes enzymatic hydrolysis for conversion of polysaccharides into monomer sugars, such as glucose and xylose. Subsequently, sugars are fermented to ethanol by the use of different microorganisms.

Pretreated biomass can directly be converted to ethanol by using the process called simultaneous saccharification and cofermentation (SSCF). Pretreatment is a critical step which enhances the enzymatic hydrolysis of biomass. Basically, it alters the physical and chemical properties of biomass and improves the enzyme access and effectiveness which may also lead to a change in crystallinity and degree of polymerization of cellulose.

The internal surface area and pore volume of pretreated biomass are increased which facilitates substantial improvement in accessibility of enzymes. The process also helps in enhancing the rate and yield of monomeric sugars during enzymatic hydrolysis steps.

Pretreatment of Lignocellulosic Biomass

Pretreatment methods can be broadly classified into four groups – physical, chemical, physio-chemical and biological. Physical pretreatment processes employ the mechanical comminution or irradiation processes to change only the physical characteristics of biomass. The physio-chemical process utilizes steam or steam and gases, like SO₂ and CO₂.

The chemical processes employs acids (H₂SO₄, HCl, organic acids etc) or alkalis (NaOH, Na₂CO₃, Ca(OH)₂, NH₃ etc). The acid treatment typically shows the selectivity towards hydrolyzing the hemicelluloses components, whereas alkalis have better selectivity for the lignin. The fractionation of biomass components after such processes help in improving the enzymes accessibility which is also important to the efficient utilization of enzymes.

Conclusions

The major cost components in bioethanol production from lignocellulosic biomass are the pretreatment and the enzymatic hydrolysis steps. In fact, these two process are someway interrelated too where an efficient pretreatment strategy can save substantial enzyme consumption. Pretreatment step can also affect the cost of other operations such as size reduction prior to pretreatment.

Therefore, optimization of these two important steps, which collectively contributes about 70% of the total processing cost, are the major challenges in the commercialization of bioethanol from 2^nd generation biofuel feedstock.