Thermaco Grease Traps Blog
Alpha Biofuels - Offering a Clean Solution to Growth in 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
“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.
“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
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 is a contributing author for Thermaco, Inc. and the founder of Owen George Global Strategies, Inc.
Labels: Alpha Biofuels, bio-diesel, biodiesel, biofuel, grease recycling, Micro Refinery, Micro-Refinery, Singapore, Singapore International Water Week, Supercapacity, Trapzilla
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
B. Opt for a Separator that Minimizes
Emulsification Losses from Soapy Flows
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.
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.
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.
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
third party evaluation report:
note this is a large report pdf and will likely take a brief while to download.
Labels: Commercial Dishwasher, Commercial Dishwasher attached to Grease Trap, Detergents, Grease Interceptor, grease removal, reducing emulsions, thermal inversion, Trapzilla
Understanding Kitchen Ware Washing: Detergents and Scrapping Practices
Better Practices in the Modern Era
We are thankful to live in the 21st 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
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.
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.
Links for additional reading:
Food Service Establishment Warewashing Scrapping and
History and Innovations:
Labels: BOD, detergent emulsions, Detergents, emulsions, FOG, grease separator, Kitchen Ware Washing, reducing emulsions