Alpha Biofuels - Offering a Clean Solution to Growth in Singapore

Singapore –- the East Asian city-state –- is known worldwide as a leader in urban cleanliness and environmental stewardship. Visitors to Singapore discover a bustling multicultural metropolis where towering skyscrapers soar above charming British colonial architectural, and where an abundance of tourist sites, glamorous shopping centers, and food courts buzz with activity seven days a week. As one of the world’s most densely populated metropolitan areas, both the government and citizens of Singapore are proud of the nation’s leadership in urban efficiency, quality of life, and environmentalism.

“We may be a densely populated city, but we’re dedicated to continue improving Singapore, so that our people live comfortably and pleasantly,” said Prime Minister Lee Hsien Loog, as Singapore recently welcomed 15,000 experts from around the world for Singapore International Water Week, a summit on cities, water, and the environment.

Among those attending, Singapore natives Allan Lim and Jack Ling are “green” entrepreneurs. In 2004, Lim and Ling, friends who share a passion for outdoor adventures and a concern about the impact of society’s growing carbon footprint, began discussing ways to educate and empower communities about the benefits of clean energy.

Guided by a vision of deriving clean energy from waste, Lim and Ling started Alpha Biofuels, inspired by a 2007 study indicating that as much as 20,000 tons of waste cooking oil was disposed annually into Singapore’s municipal sewage system. Alpha Biofuels set out to provide a solution: to convert Singapore’s waste cooking oil into a clean burning biofuel. With support from government and private sources, Alpha Biofuels eventually developed the Alpha Biodiesel Micro Refinery, a compact and easy-to-operate refinery for converting a variety of waste oils into biodiesel.

To fuel their reactors, Alpha Biofuels began providing containers for the collection of used fryer oil to restaurants and commercial food service establishments. They discovered that fryer oil was limited in supply and costly to acquire; however, collecting oil from grease interceptors servicing Singapore’s food courts and restaurants could enable them to accomplish their goal.

Thermaco’s Trapzilla Supercapacity Grease Interceptor has played a key role in Alpha Biofuel’s success.

“As a producer of biodiesel fuel in Singapore, we have been familiar with the Trapzilla TZ-600 grease trap since 2008,” says Allan Lim. “The Trapzilla TZ-600 grease trap has several features that are unique –- small footprint, odorless, ease of pumping, and no need for flushing the unit with water after pumping. However, the Trapzilla feature that is most important for Alpha Biofuels is its unique ability to retain oil and grease in a form that serves as a raw material for our company's biofuel production.”

So far, neither Singapore's Public Utilities Bureau’s grease trap nor other traditionally designed grease traps in use there have been able to provide waste grease clean enough and low enough in water content to serve as a raw material for Alpha Biofuel’s production of biofuel. “Oil collected from Trapzilla is highly usable for recycling into biodiesel and related other products,” Lim points out. “This feature has allowed us to use oil collected from the Trapzilla for the production of biofuel in Singapore at several key sites.”


Oil collected from Trapzilla is converted to biofuel at the Alpha Biofuels Micro Refinery located at Marina Bay Financial Center, and this biofuel actually powers the construction cranes for the one billion dollar project.

“Since a grease trap is a necessity in food outlets, not only in Singapore but around the world, the increased use of the Trapzilla TZ grease traps hold potential for food-service facilities to achieve energy sustainability without additional cost,” says Lim.

In the meantime, Alpha Biofuel's stated mission –– “to inspire communities about the potential for clean energy alternatives” – is also helping to fulfill the goal of Prime Minister Lee Hsien Loog to make Singapore “one of the jewels of the Tropics.”

Owen George 
Owen George is a contributing author for Thermaco, Inc. and the founder of Owen George Global Strategies, Inc. 

Suggestions for Reducing Detergent/Lipid Emulsions:

A.  Keep Soapy flows from Contacting Downstream Fats and Oils (Lipids)

A commercial dishwasher’s output is hot, soapy water and is ALWAYS running richer than needed in terms of detergent chemicals. Why?  Because it is a far lesser evil to send unused detergent (high in BOD) with sanitizers (chlorides) and water softening agents (a variety of mineral grabbing stuff so as to leave no spots on the washed ware) THAN to have a potential sanitary hazard imposed on the community’s dining customers, i.e. dirty dishes.  Sending a commercial dishwasher’s output through the kitchen’s drainage plumbing emulsifies any and all fats or oils in its route, including the retained grease and oils in a conventional downstream grease separator.  Notice the wording “conventional”.  Anytime a warm (usually no longer hot by that time) soapy flow enters a conventional (think traditional inlet and outlet configuration), it rises “lava lamp” style and displaces the cold water already in the separator.  As the cold water layer falls, it tugs on the underside of the trapped grease mat, adding some gentle mixing action.  Gentle mixing action is not normally a problem with just warm water alone, but as described above, it is the un-utilized detergent that craves to be with the lipids and just like when they play a slow number at a wedding party, the gentle mixing makes it easy for the bachelor detergent molecules to get dance partners with those wallflower lipid molecules.  Once they have that first dance, they are inseparable.  They are also soluble, too, and after that first dance, they not only leave the dance floor, they also leave the entire party out through the grease separator’s outlet exit (pipe).

B.  Opt for a Separator that Minimizes Emulsification Losses from Soapy Flows

This is the concept of designing to eliminate lava lamping or more correctly, thermal inversion.  Thermaco’s Trapzilla is quite small compared to a traditional concrete grease interceptor so how does it separate, retain what it has separated and somehow meet local sewer district discharge criteria?  Two points:  First, It has a unique horizontal baffle that precludes thermal inversion.  The warm water is not allowed to get up into the already trapped grease area, thus no detergents are getting up there either.  Second, the flows coming out of food service establishments are already stratified in the case of high flow discharges (pot sinks) or are readily separable low flow events where the separator easily separates the free-floating fats/oils.  In other words, the last thing out of a pot sink is what was floating on its surface.  As the floatables ride down to the sink drain, because they are the last to leave, they effectively just saunter slowly down the pipes because there is no longer head pressure prompting them to move briskly.   Sink spray down at the pre-rinse sink is a low flow event and begins to separate into stratified layers as it moves through the piping.  Thus, it is not hard to separate those free-floating fat/oil globules from slow moving flows like the end of a sink run or a spray down activity. 

Do we recommend Trapzilla units for food processing plants where the third shift walks around with high-pressure spray hoses?  NO!  That type of 100% physical (sheared) fat/water emulsion is very difficult to separate by any kind of separator short of storing over time in large vertical tanks or slowing running through a centrifugal separator. 

Does the Trapzilla separate as well as a 1000 gallon separator? Not quite, but almost.  We recently conducted a study at a doughnut operation of a Trapzilla versus the site’s prior 1000 gallon separator (see study report link at end of post).  The 1000 gallon was 9.7 mg/l FOG average over two months and the 95 gallon TZ-600 was 23.2 mg/l averaged over the next four months.  It is a pick your poison kind of decision and this is why pretreatment coordinators are increasingly having to walk away from a comfortable one size fits all approach as they balance community needs, collection system needs, WWTP treatment and other parameters going forward.  

Pumping contractors tell us the grease pumped out of Trapzilla® units at sites with commercial dishwashers is brown and they are initially surprised as they are not accustomed to seeing brown grease at those sites.  Obviously, the unspent detergents are not getting to the already trapped grease, a testament to no thermal inversion occurring.

Bill Batten

Doughnut/bakery third party evaluation report: 

Please note this is a large report pdf and will likely take a brief while to download.

http://thermaco.com/catalog/documents/EEC-Trapzilla-Evaluation-Report.pdf

Understanding Kitchen Ware Washing: Detergents and Scrapping Practices

Better Practices in the Modern Era

We are thankful to live in the 21^st century and to not worry about dying from a restaurant dining experience.  I once worked with a man whose 20 year-old brother died in 1940 of food poisoning from a restaurant with poor sanitation.  As recently as the late 1940s, hot water heaters were not reliable and ware-washing detergents were caustic based.  If the water was not hot, the detergent was not effective.  Today’s modern restaurant has plenty of hot water, highly efficient detergents and those detergents also contain sanitizers and water softening agents to ensure complete sanitation and cleaning takes place. 

Today we have better sanitation practices and the plates are always clean, but how about what is being sent down the drain?  Does it pose a problem for the community’s sewer collection system?  Can the constituents be treated at the community’s wastewater treatment plant? 

Understanding Dishwashing Practices

To fully understand how a dishwasher cleans dishes, we first must look how the dishwashing process takes place in a full service restaurant or institutional kitchen like a hospital.  The glass, silver and plate ware are brought from the serving area and dropped off at the dishwashing area.  The plates, silver ware and glass ware piles up and then the dishwashing area employee eventually walks over to the assembled dirty wares and begins scrapping the food, paper napkins, other spent items into the garbage can. He/she then takes the scrapped plate and rinses the remaining small debris off the plate in the pre-rinse sink.  The procedure just outlined is the best management practice procedure for a site without a food disposal.  Some sites send the food solids/debris down the drain via a food disposal.  There are also waste compaction and removal machines available for large institutional kitchens.  Please see links at end for more information about scrapping systems for institutional kitchens.

Hot Water, Detergents, and Emulsions

Okay, so we have discussed the scrapping and pre-rinse steps leading up to loading the ware to be washed into the dishwasher.  What about fats, oils and grease going into the dishwasher?  What happens to the FOG inside the dishwasher? The dishwasher has hot water and that makes emulsions meaning the grease separator needs a long retention time to separate the grease after it goes through the dishwasher, yes?

No, hot water by itself does not create emulsions or interfere wit the separation of fats or oils from water.  Heating the water actually accelerates separation of physical emulsions.  This is why many rendering companies put their grease trap pumpings in tall tanks and heat to high temperatures so as to accelerate the separation and stratification.  They often afterwards use centrifuge-type separators to finish off the process.

But  . . . . hot water AND detergents together do cause permanent chemical emulsions that cannot be separated.  Period.  What may be still influencing our thinking is what was the case sixty years ago, back when caustic detergents requiring hot water were standard fare. Back then in the age of high pH/high phosphate containing detergents, if one wanted, a detergent/fat emulsion could be separated with acidification (no one did this, but they could have if they made the effort).  Today, advanced chemistry allows detergents to be highly biodegradable, safe for handling and to clean with an efficiency not dreamt in the 1950s.

These wondrous detergents create emulsions that can only be separated by changing the aqueous dielectric and nobody wants those dielectric chemicals in their influent.  So what happens to the detergent/fat emulsions?  They stay intact all the way to primary treatment where the biology jumps on usually the detergent end, thus letting the lipid end loose for later digestion.  Some of the floating scum on primary treatment tanks is likely the released lipids. 

Summary

Today’s advanced detergents, efficient water heating systems and modern dishwashing systems provide the utmost in food service establishment sanitation and dining public safety.  Dishware scrapping is a critical practice affecting pretreatment BOD and FOG loading.  Hot water by itself does not create emulsions, rather fluid heating serves to help separate physical emulsions.  Hot water, unspent detergent and lipids DO create detergent fat/oil emulsions.  Modern detergents are highly effective at emulsifying lipids (animal fats and vegetable oils) and the emulsions created usually stay intact all the way to the treatment plant where the detergent ending is likely to be digested before the lipid ending.

Bill Batten


Links for additional reading:

Food Service Establishment Warewashing Scrapping and Disposal Systems:

http://www.insinkerator.com/en-us/Foodservice-Equipment/Pulper-Systems/Pages/Default.aspx

http://www.salvajor.com/troughCollector.aspx

Detergent Chemistry:  History and Innovations:

http://en.wikipedia.org/wiki/Detergent

http://www.livestrong.com/article/153387-what-ingredients-are-in-detergent/

http://www.jrhessco.com/nonionic-surfactants/

http://www.google.com/patents/US6660711