For the responsible care of the environment at the ethanol factory, tells us the ecologist Ivan Milkov:
Every day I do a visual observation of the factory to find out how the workflow goes and especially to monitor the wastewater treatment plant effluent. Furthermore, the communication with technological staff, which is responsible for tracking the production processes directly, is of utmost importance to me. I observe what the indicators of incoming and outgoing water are.
Two years ago the law for department “Environment” has changed, implementing a biding document, named “IPPC permit” - integrated prevention of environmental pollution, in order to operate the factory, the database we provide to the ministry is compared to the best available techniques that are known in the EU. If the installation doesn’t cover the requirements of those techniques, it is recommended to make an investment program, which would bring the values to normal state. In Essentica, fortunately, we did not need to make such an investment program, because the technology and equipment at the factory meet the highest European environmental standards for safety health and work.
Can you tell us more about the purification plant? (WWTP)
The purification plant was built in 2011. It takes all of the industrial waste water during the manufacturing process of 120,000 liters ethyl alcohol. The purified water is barred in water intake second category. Each water body, depending on the category, has specific norms and criteria to meet. The WWTP at Essentica comes from one of the leading companies for machines and equipment for industrial wastewater purification. The company is Dutch, Paques, it’s the technology and the know-how which this company provides are on exclusively high level. For instance – all or 99% of the purification plants I have seen are from the so-called “open type”, while at our factory all waters enter collective vessels, SBR made of stainless steel and are closed. On one hand there are no odors, and on the other hand the building area for purification plant is minimized, and the vessels are vertical not grounded.
Is the WWTP obligated for regular checks and inspections by the government authorities?
Since the entry of the IPPC permit, they have checked us twice. Such verification is between 3 and 5 days, while the whole times there are inspectors. Both times the controls showed no discrepancies in any of the environmental indicators - water, air, waste, storage of ethyl alcohol and chemicals within the production site. This proves that the company's management, staff, senior management and all employees are involved in the prevention of environmental pollution.
Where else can problems related to the environment occur?
Main pollutant in this field of work are wastewaters from the very distillation when distilled alcohol has two streams - one stream is alcohol, the spirt and the other is called shlempa, which is alcohol-free mush. The raw material for DDGS production is called shlempa and is a byproduct from the production of ethyl alcohol obtained by distillation of fermented cereal brashka. The shlempa’s transportation is trough closed stationary pipelines, thereby ensuring hygienic conditions and maintenance of environmental standards within the factory by eliminating the possibility of spills the environmental and working area.
The DDGS production process is essentially a combination of processes of concentration and drying the dry substances found in shlempa out. Due to its high content of protein and fiber, the alcohol-free shlempa is exclusively interesting subject for livestock. As liquid substance it takes a very large volume and creates many difficulties for transportation and logistics, so in order to become a commercial product with easy communication, simple logistics it is necessary to be concentrated and dried. The revised shlempa to end-product as DDGS has moisture content of about 10-13%, accounting for easy storage, transportation and introducing it into final food mixes, protein-rich animal feed. DDGS can be used in certain cases for direct consumption and in other cases as a feed additive. The product is a commodity, both in Europe and the US, which also has a significant interest. It is well recognized and well accepted by farmers.
The DDGS production has three main technological steps - decanting, vacuum evaporation and drying. The shlempa (alcohol-free mash) coming from the distillation system is about 8% dry matter, the remaining amount is water. First step in the further processing of shlempa is settling it into a decanter centrifuge. At the output we obtain two products - a dense fraction ("cake") with a concentration of dry matter around 33% and a liquid fraction ("decantate") with a concentration of dry matter about 4%. The decantate is fed for concentration in a vacuum evaporator section. At the output we obtain a concentrate ("syrup") with about 32% dry matter and condensate. Then we mix the syrup coming from the vacuum evaporation section and the cake by decantation. The mixture is fed into a dryer for drying to moisture content no higher than 10%. The product thus obtained, known as DDGS is stable over time and suitable for storage and transport. The only one by-product of its production is condensate after vacuum evaporation plant. The technology requires the condensate to be further treated at the internal factory circulating water treatment step.