A global exporter of diversified food and beverage products, Sabormex, is capitalising on the benefits of its high-efficiency waste water treatment plant by installing a GWE complete biogas reuse system to replace fossil fuels with green energy.
The GWE technology involved in the latest installation by Sabormex in Mexico is represented in Australia and New Zealand by CST Wastewater Solutions, whose Managing Director, Michael Bambridge, says such green energy/ environmental anaerobic digestion technology is applicable to a host of Australasian industries, including particularly food, beverage and agro industry applications.
Founded in 1964 in the city of Puebla, Sabormex (“Mexican flavour”) is behind a large number of well-established Mexican brands including Clemente Jacques (sauces and dressings), La Sierra (canned foods) or Tazza, Garat and Familiar (coffee). These brands are exported to more than 20 countries bringing the authentic Mexican flavor to different corners of the world.
Such diversified production results in very fast and significant changes in the composition and flows of the company’s waste water, which, before treatment, often contains high concentrations of fat, oil and grease and generally high levels of total suspended solids and COD.
In order to deal with the variable characteristics of the waste water, GWE engineered and installed a robust ANUBIX-B anaerobic reactor designed for 24 tons of COD per day. This reactor, operating since 2011, has shown consistently very high removals and stable performances.
This plant has been built by GWE’s long-standing partner ICR Ambiental from Mexico. ICR specialises in the engineering and construction of projects for water and waste water treatment, solids digestion and power generation. ICR has partnered with GWE in many projects over the years by engineering and building waste water treatment plants in Latin America.
All the suspended solids and fats sent to the waste water treatment plant are first separated in a Dissolved Air Flotation installation which generates up to 100m3 of primary sludge every day. In order to digest this primary sludge, which is very rich in organics, GWE has installed an ANAMIX-T reactor.
This is a thermophilic continuous stirred-tank reactor which achieves high removals of pollutants even while fed with a difficult stream containing high concentrations of fat and solids. Up to 10 tons of COD per day are fed to this ANAMIX-T, with the system achieving high removal efficiencies of more than 80%.
Startup of this reactor took only a few weeks, thanks to a special seed sludge collected from another GWE ANAMIX-T which had been operating in Belgium for several years. An innovative method of preserving the activity of bacteria developed by GWE means this seed sludge can be shipped overseas in regular containers.
Following on from the success of the waste water plant, Sabormex has subsequently ordered from GWE a complete biogas reuse system in order to burn the biogas generated by the two anaerobic reactors. This will generate 6,000 Nm3/day of biogas, allowing savings equivalent to up to 8,000 kg fuel oil/day.
This plant is also equipped with GWE’s state-of-the art emergency ground flare with temperature-controlled combustion, which is in line with the stringent emission regulations.
Left: View of the concrete ANAMIX-T reactor at the final stages of construction. Centre and Right: Pictures of how the thermophilic seed sludge has been stored inside a 40’ container for shipment from Belgium to Mexico.
Following on from the success of the waste water plant, Sabormex has subsequently ordered from GWE a complete biogas reuse system in order to burn the biogas generated by the two anaerobic reactors.
This will generate 6,000 Nm3/day of biogas, allowing savings equivalent to up to 8,000 kg fuel oil/day. This plant is also equipped with GWE’s state-of-the art emergency ground flare with temperature-controlled combustion, which is in line with the stringent emission regulations.
The quantity of biogas to be produced by Sabormex is equivalent to about 2,650 tons of the fossil fuel equivalent per year, worth more than $US2 million in the first year and well over $A20 million in its first decade.
Bambridge says anaerobic digestion facilities are recognised by the United Nations Development programme as one of the most useful decentralised sources of energy supply, as they are less capital-intensive than large power plants.
Anaerobic biogas plants – including installations at Australia’s Bluetongue Brewery in NSW and Golden circle in Northgate, Queensland – are among more than 300 GWE anaerobic waste water plants globally, which clean the water to high discharge standards while producing biogas (methane, CH4) that can be used to generate green electricity for sale to the local grid or to fuel boilers and other factory plant fuel consumers.
Many of the plants utilising the biogas in this way achieve payback of plant costs in two years – or even a year in some cases – as they permanently reduce the amount of fossil fuel used and generate permanent environmental gains and financial savings.